Original Research

Take-Home Points

• At our institution, LALB has shortened our hospital stay.
• There is a trend towards decreased opioid consumption with LALB.
• With the opioid epidemic we face today, LALB can be one of many options in our toolbox towards a solution.
• As stated in prior publications, the effectiveness of LALB is definitely technique dependent.
• Additional clinical studies are warranted to better determine the efficacy and cost-effectiveness of LALB.

Almost 1 million total knee arthroplasties (TKAs) are performed in the United States each year, and the number continues to grow.^1.2 For patients about to undergo TKA, a significant concern is postoperative pain.³ Fear of postoperative pain is often cited as a reason for delaying surgery.³ Recent literature suggests that patients with poor pain management during the first 48 hours after surgery have a 50% chance of gaining satisfactory long-term pain relief.⁴ In addition, inadequate postoperative pain management can interfere with participation in and progression of physical rehabilitation, prolong hospital stay, and increase patient dissatisfaction.⁵ Poorly controlled pain results in decreased range of motion (ROM), strength, stability, and ambulation thereby prolongs hospital stays, and increases costs and overall dissatisfaction with the procedure.

Post-TKA pain management has received much attention in recent years. A multimodal pain management protocol is now a key component of clinical pathways in TKA. Appropriate postoperative pain control lowers postoperative complications and accelerates recovery.⁶ Pain-caused loss of function makes surgical patients more susceptible to edema, deep vein thrombosis, and pulmonary embolism.⁴ Various oral and intravenous medications are used to lessen the pain response during the perioperative period. In addition, regional or neuraxial anesthesia is often added to blunt the immediate surgical pain response.^7,8 At our institution, TKA traditionally has been performed with femoral nerve catheters (FNCs) for postoperative pain control. Although effective, this method often results in decreased quadriceps musculature function, which delays rehabilitation and increases the fall risk. Recently, there has been a shift toward using local anesthetic infusions about the knee to provide adequate pain relief and restore motor function, which is often sacrificed with use of regional nerve blocks and continuous catheter infusions.⁹

Many institutions have started using a new long-acting local anesthetic in their multimodal pain management pathways: Exparel (Pacira Pharmaceuticals), a liposomal membrane-bound bupivacaine with sustained release of approximately 72 hours. Several studies have verified the safety of this medication.¹⁰ A systemic review of prospective studies revealed that, compared with bupivacaine, long-acting liposomal bupivacaine (LALB) in therapeutic doses had a higher safety margin and a favorable safety profile.¹⁰ However, no study has compared the effectiveness of LALB and FNC in a matched TKA cohort with each patient serving as his or her own control.

We recently reviewed our multimodal pain management protocol for any areas in need of improvement and decided to compare the effects of the indwelling FNC protocol that was in use with the effects of injecting the local anesthetic LALB. We conducted a study to compare the 2 methods with respect to pain control, ROM, ability to ambulate, and hospital length of stay (LOS). We hypothesized that the longer acting local anesthetic would provide comparable post-TKA pain control and post-TKA opioid use but would accelerate post-TKA rehabilitation.

Materials and Methods

This retrospective, longitudinal, repeated- measures study was approved by the Greenville Hospital System Institutional Review Board and conducted at the Steadman Hawkins Clinic of the Carolinas, Greenville Health System.

Interventions

Twenty-three patients underwent separately staged bilateral TKAs between 2010 and 2013. For each TKA, a Genesis II implant (Smith & Nephew) was used, and the surgery was performed with the patient under spinal anesthesia. In each case, FNC was used for pain control after the first TKA, and periarticular injection (PAI) of LALB for pain control after the second TKA.

 

In the first TKAs, FNC-administered ropivacaine 0.2% (2 mg/mL) was maintained at a standard basal rate of 8 mL/h for 48 hours. In the second TKAs, LALB was administered along with bupivacaine/epinephrine. Twenty milliliters of LALB from a single-use vial was diluted in 40 mL of normal (0.9%) saline to obtain a 60-mL solution, and a 25-gauge needle was used to inject this solution into the periarticular soft tissues; another needle was used for PAI of 30 mL of bupivacaine 0.25% with epinephrine.

Continuous passive motion devices were not used. Most patients began therapy on day of surgery. Knee immobilizers were not used in the FNC group.

The same standardized multimodal pain management protocol was used for all TKAs. Non- narcotic medications, including acetaminophen, ketorolac, and celecoxib, were given on a scheduled basis. Tramadol and opioid medications were administered as needed for pain. The attending physician based patient discharge timing on pain control, ability to safely ambulate, and absence of complications.

Outcome Measures

Outcome measures were LOS; extension and flexion at discharge and 3-week follow-up; total ROM (extension plus flexion) at discharge and 3-week follow-up; per-day and total hospital stay morphine -equivalent doses (MEDs); and per-attempt walking distance during gait training.

ROM was measured with a standard goniometer. Flexion was tested with the patient supine and the hip and knee in neutral rotation. The goniometer axis was along the lateral epicondyle of the femur with the proximal arm of the goniometer parallel to the long axis of the femur and pointing at the greater trochanter and with the distal arm parallel to the long axis of the fibula and pointing at the lateral malleolus. The patient was instructed to flex the hip and knee by moving the heel toward the buttock. Expected normal ROM is 135°. The same landmarks were used for extension. The patient was instructed to push the back of the knee toward the plinth/bed, for maximal active extension. The same ROM assessment strategy was used during the hospitalization and at the 3-week follow-up.

Several opioid medications (eg, hydrocodone, oxycodone, tramadol, hydromorphone, morphine) with different dosages were used during hospitalization. Opioid doses were converted to MEDs to permit FNC–LALB comparisons. For each patient, total MEDs were divided by LOS to determine MEDs per day.

Mean per-attempt walking distance was calculated by dividing the total distance walked during hospitalization—the sum of the number of feet walked during each and every attempt, as measured by the treating physical therapist—by the total number of walking attempts.

Data Analysis

A paired-samples t test was used to calculate differences between all outcome measures: LOS; extension and flexion at discharge and 3-month follow-up; per-day and total MEDs; and mean per-attempt walking distance. P < .05 was considered significant. We elected not to adjust our α for a potential familywise error.

Results

Of the 23 patients, 14 were female and 9 were male, and 19 were white and 4 were black. Mean (SD) age was 64.4 (6.4) years for the FNC group and 66.0 (6.0) years for the LALB group. The age difference was not statistically significant.

Statistically significant differences favoring LALB over FNC were found for mean LOS (LALB, 2.3 days; FNC, 2.8 days; P < .01), mean per-attempt walking distance (LALB, 135.9 feet; FNC, 84.2 feet; P < .01), and mean total ROM at 3-week follow-up (LALB, 116.3°; FNC, 107.2°; P = .02). Furthermore, a statistically significant difference was found for mean total MEDs during hospitalization (LALB, 145.47; FNC, 214.30; P = .02) (Table). In addition, there was a nonsignificant trend toward less drug administration.

 

 

Discussion

Poor pain control during the post-TKA period may have a significant impact on recovery rate, standard of living, psychological health, and postoperative complications.¹⁰ Inadequate postoperative pain control increases postoperative morbidity, hinders physiotherapy, increases anxiety, disrupts sleep patterns, and decreases patient satisfaction.⁹ There has been increased interest in PAIs. Local anesthetics are additional sources of pain control at surgical sites. However, the half-life of most local anesthetics is short. Soft-tissue infiltration of LALB into a surgical site extends the duration of active analgesia. Our study found that, compared with patients who received FNC, patients who received LALB had comparable pain control, improved knee ROM, and shorter hospital stays. In addition, the LALB group had no reports of quadriceps weakness or falls, both of which are associated with femoral nerve blocks. The FNC group had no reported falls, either. PAIs have the benefit of avoiding the invasiveness of femoral nerve blocks and possible neuritis.

Many complications are associated with or indirectly related to delayed rehabilitation and immobility during the acute post-TKA period. From prolonged hospitalization to need for manipulation, the consequences of inadequate pain control and decreased function can be numerous and costly for patients and the healthcare system. In the present study, LALB use led to a statistically significant overall decrease in mean LOS (LALB group, 2.3 days; FNC, 2.8 days). With LALB, there was a higher likelihood of discharge the day after surgery; 20% of patients in the LALB group and no patients in the FNC group went home that day.

The implication is that inadequate pain control led to decreased motion and decreased progression during postoperative rehabilitation. Local infiltration resulted in increased total ROM (extension plus flexion) at 3-week follow-up (LALB, 116.3°; FNC, 107.2°). In addition, there was an increase in walking distance per day of hospital stay (LALB, 135.9 feet; FNC, 84.2 feet). Furthermore, patients indicated LALB when asked which anesthetic they preferred. To our knowledge, this is the first study to compare LALB and FNC data in a matched TKA cohort with each patient serving as his or her own control.

Our study had several limitations. First was the retrospective design. Second was the small sample size, which made definitive conclusions difficult. However, the statistically significant differences we noted validated our conclusions. A statistically significant difference favoring LALB over FNC was found for total MEDs during hospitalization, but there was no significant difference in per-day MEDs. A possible reason for this difference is that LALB patients had shorter hospital stays, and therefore received fewer doses overall. Another possible reason is the small sample size; whereas a larger study using our protocol may find a statistically significant difference between LALB and FNC, we found only a trend. In the FNC group, anesthetic infiltration occurred with use of a computerized pump, which was removed on postoperative day 2; most of these patients were discharged home that day or the morning of postoperative day 3. As it is possible that some of these patients could have gone home sooner, our LOS data may have been affected. We do not consider this limitation significant, as one of our discharge criteria was 150 feet of ambulation, and most patients who received FNCs could not ambulate that far until after FNC removal. Furthermore, this study compared LALB only with FNC. It is possible that our improved outcomes could have resulted from the PAIs themselves, irrespective of LALB. In a recent TKA study by Bagsby and colleagues,¹¹ pain was controlled better with the less expensive traditional PAI of ropivacaine, epinephrine, and morphine than with the PAI of liposomal bupivacaine. Last, in our study, the experience of undergoing the first TKA may have increased patients’ confidence going into the second TKA and then helped them make faster progress in rehabilitation. Regardless, the promising results of our study and the firsthand use of LALB at our institution led us to modify our intraoperative pain management protocol for surgeons who perform TKA.

As we continue to use LALB, our study numbers will increase, and we may discover other factors that, though now underpowered, will prove to be statistically significant. Additional clinical studies are needed to better determine the efficacy and cost-effectiveness of LALB and other long-acting local anesthetic formulations. 

Take-Home Points

• At our institution, LALB has shortened our hospital stay.
• There is a trend towards decreased opioid consumption with LALB.
• With the opioid epidemic we face today, LALB can be one of many options in our toolbox towards a solution.
• As stated in prior publications, the effectiveness of LALB is definitely technique dependent.
• Additional clinical studies are warranted to better determine the efficacy and cost-effectiveness of LALB.

Almost 1 million total knee arthroplasties (TKAs) are performed in the United States each year, and the number continues to grow.^1.2 For patients about to undergo TKA, a significant concern is postoperative pain.³ Fear of postoperative pain is often cited as a reason for delaying surgery.³ Recent literature suggests that patients with poor pain management during the first 48 hours after surgery have a 50% chance of gaining satisfactory long-term pain relief.⁴ In addition, inadequate postoperative pain management can interfere with participation in and progression of physical rehabilitation, prolong hospital stay, and increase patient dissatisfaction.⁵ Poorly controlled pain results in decreased range of motion (ROM), strength, stability, and ambulation thereby prolongs hospital stays, and increases costs and overall dissatisfaction with the procedure.

Post-TKA pain management has received much attention in recent years. A multimodal pain management protocol is now a key component of clinical pathways in TKA. Appropriate postoperative pain control lowers postoperative complications and accelerates recovery.⁶ Pain-caused loss of function makes surgical patients more susceptible to edema, deep vein thrombosis, and pulmonary embolism.⁴ Various oral and intravenous medications are used to lessen the pain response during the perioperative period. In addition, regional or neuraxial anesthesia is often added to blunt the immediate surgical pain response.^7,8 At our institution, TKA traditionally has been performed with femoral nerve catheters (FNCs) for postoperative pain control. Although effective, this method often results in decreased quadriceps musculature function, which delays rehabilitation and increases the fall risk. Recently, there has been a shift toward using local anesthetic infusions about the knee to provide adequate pain relief and restore motor function, which is often sacrificed with use of regional nerve blocks and continuous catheter infusions.⁹

Many institutions have started using a new long-acting local anesthetic in their multimodal pain management pathways: Exparel (Pacira Pharmaceuticals), a liposomal membrane-bound bupivacaine with sustained release of approximately 72 hours. Several studies have verified the safety of this medication.¹⁰ A systemic review of prospective studies revealed that, compared with bupivacaine, long-acting liposomal bupivacaine (LALB) in therapeutic doses had a higher safety margin and a favorable safety profile.¹⁰ However, no study has compared the effectiveness of LALB and FNC in a matched TKA cohort with each patient serving as his or her own control.

We recently reviewed our multimodal pain management protocol for any areas in need of improvement and decided to compare the effects of the indwelling FNC protocol that was in use with the effects of injecting the local anesthetic LALB. We conducted a study to compare the 2 methods with respect to pain control, ROM, ability to ambulate, and hospital length of stay (LOS). We hypothesized that the longer acting local anesthetic would provide comparable post-TKA pain control and post-TKA opioid use but would accelerate post-TKA rehabilitation.

Materials and Methods

This retrospective, longitudinal, repeated- measures study was approved by the Greenville Hospital System Institutional Review Board and conducted at the Steadman Hawkins Clinic of the Carolinas, Greenville Health System.

Interventions

Twenty-three patients underwent separately staged bilateral TKAs between 2010 and 2013. For each TKA, a Genesis II implant (Smith & Nephew) was used, and the surgery was performed with the patient under spinal anesthesia. In each case, FNC was used for pain control after the first TKA, and periarticular injection (PAI) of LALB for pain control after the second TKA.

 

In the first TKAs, FNC-administered ropivacaine 0.2% (2 mg/mL) was maintained at a standard basal rate of 8 mL/h for 48 hours. In the second TKAs, LALB was administered along with bupivacaine/epinephrine. Twenty milliliters of LALB from a single-use vial was diluted in 40 mL of normal (0.9%) saline to obtain a 60-mL solution, and a 25-gauge needle was used to inject this solution into the periarticular soft tissues; another needle was used for PAI of 30 mL of bupivacaine 0.25% with epinephrine.

Continuous passive motion devices were not used. Most patients began therapy on day of surgery. Knee immobilizers were not used in the FNC group.

The same standardized multimodal pain management protocol was used for all TKAs. Non- narcotic medications, including acetaminophen, ketorolac, and celecoxib, were given on a scheduled basis. Tramadol and opioid medications were administered as needed for pain. The attending physician based patient discharge timing on pain control, ability to safely ambulate, and absence of complications.

Outcome Measures

Outcome measures were LOS; extension and flexion at discharge and 3-week follow-up; total ROM (extension plus flexion) at discharge and 3-week follow-up; per-day and total hospital stay morphine -equivalent doses (MEDs); and per-attempt walking distance during gait training.

ROM was measured with a standard goniometer. Flexion was tested with the patient supine and the hip and knee in neutral rotation. The goniometer axis was along the lateral epicondyle of the femur with the proximal arm of the goniometer parallel to the long axis of the femur and pointing at the greater trochanter and with the distal arm parallel to the long axis of the fibula and pointing at the lateral malleolus. The patient was instructed to flex the hip and knee by moving the heel toward the buttock. Expected normal ROM is 135°. The same landmarks were used for extension. The patient was instructed to push the back of the knee toward the plinth/bed, for maximal active extension. The same ROM assessment strategy was used during the hospitalization and at the 3-week follow-up.

Several opioid medications (eg, hydrocodone, oxycodone, tramadol, hydromorphone, morphine) with different dosages were used during hospitalization. Opioid doses were converted to MEDs to permit FNC–LALB comparisons. For each patient, total MEDs were divided by LOS to determine MEDs per day.

Mean per-attempt walking distance was calculated by dividing the total distance walked during hospitalization—the sum of the number of feet walked during each and every attempt, as measured by the treating physical therapist—by the total number of walking attempts.

Data Analysis

A paired-samples t test was used to calculate differences between all outcome measures: LOS; extension and flexion at discharge and 3-month follow-up; per-day and total MEDs; and mean per-attempt walking distance. P < .05 was considered significant. We elected not to adjust our α for a potential familywise error.

Results

Of the 23 patients, 14 were female and 9 were male, and 19 were white and 4 were black. Mean (SD) age was 64.4 (6.4) years for the FNC group and 66.0 (6.0) years for the LALB group. The age difference was not statistically significant.

Statistically significant differences favoring LALB over FNC were found for mean LOS (LALB, 2.3 days; FNC, 2.8 days; P < .01), mean per-attempt walking distance (LALB, 135.9 feet; FNC, 84.2 feet; P < .01), and mean total ROM at 3-week follow-up (LALB, 116.3°; FNC, 107.2°; P = .02). Furthermore, a statistically significant difference was found for mean total MEDs during hospitalization (LALB, 145.47; FNC, 214.30; P = .02) (Table). In addition, there was a nonsignificant trend toward less drug administration.

 

 

Discussion

Poor pain control during the post-TKA period may have a significant impact on recovery rate, standard of living, psychological health, and postoperative complications.¹⁰ Inadequate postoperative pain control increases postoperative morbidity, hinders physiotherapy, increases anxiety, disrupts sleep patterns, and decreases patient satisfaction.⁹ There has been increased interest in PAIs. Local anesthetics are additional sources of pain control at surgical sites. However, the half-life of most local anesthetics is short. Soft-tissue infiltration of LALB into a surgical site extends the duration of active analgesia. Our study found that, compared with patients who received FNC, patients who received LALB had comparable pain control, improved knee ROM, and shorter hospital stays. In addition, the LALB group had no reports of quadriceps weakness or falls, both of which are associated with femoral nerve blocks. The FNC group had no reported falls, either. PAIs have the benefit of avoiding the invasiveness of femoral nerve blocks and possible neuritis.

Many complications are associated with or indirectly related to delayed rehabilitation and immobility during the acute post-TKA period. From prolonged hospitalization to need for manipulation, the consequences of inadequate pain control and decreased function can be numerous and costly for patients and the healthcare system. In the present study, LALB use led to a statistically significant overall decrease in mean LOS (LALB group, 2.3 days; FNC, 2.8 days). With LALB, there was a higher likelihood of discharge the day after surgery; 20% of patients in the LALB group and no patients in the FNC group went home that day.

The implication is that inadequate pain control led to decreased motion and decreased progression during postoperative rehabilitation. Local infiltration resulted in increased total ROM (extension plus flexion) at 3-week follow-up (LALB, 116.3°; FNC, 107.2°). In addition, there was an increase in walking distance per day of hospital stay (LALB, 135.9 feet; FNC, 84.2 feet). Furthermore, patients indicated LALB when asked which anesthetic they preferred. To our knowledge, this is the first study to compare LALB and FNC data in a matched TKA cohort with each patient serving as his or her own control.

Our study had several limitations. First was the retrospective design. Second was the small sample size, which made definitive conclusions difficult. However, the statistically significant differences we noted validated our conclusions. A statistically significant difference favoring LALB over FNC was found for total MEDs during hospitalization, but there was no significant difference in per-day MEDs. A possible reason for this difference is that LALB patients had shorter hospital stays, and therefore received fewer doses overall. Another possible reason is the small sample size; whereas a larger study using our protocol may find a statistically significant difference between LALB and FNC, we found only a trend. In the FNC group, anesthetic infiltration occurred with use of a computerized pump, which was removed on postoperative day 2; most of these patients were discharged home that day or the morning of postoperative day 3. As it is possible that some of these patients could have gone home sooner, our LOS data may have been affected. We do not consider this limitation significant, as one of our discharge criteria was 150 feet of ambulation, and most patients who received FNCs could not ambulate that far until after FNC removal. Furthermore, this study compared LALB only with FNC. It is possible that our improved outcomes could have resulted from the PAIs themselves, irrespective of LALB. In a recent TKA study by Bagsby and colleagues,¹¹ pain was controlled better with the less expensive traditional PAI of ropivacaine, epinephrine, and morphine than with the PAI of liposomal bupivacaine. Last, in our study, the experience of undergoing the first TKA may have increased patients’ confidence going into the second TKA and then helped them make faster progress in rehabilitation. Regardless, the promising results of our study and the firsthand use of LALB at our institution led us to modify our intraoperative pain management protocol for surgeons who perform TKA.

As we continue to use LALB, our study numbers will increase, and we may discover other factors that, though now underpowered, will prove to be statistically significant. Additional clinical studies are needed to better determine the efficacy and cost-effectiveness of LALB and other long-acting local anesthetic formulations. 

Take-Home Points

• At our institution, LALB has shortened our hospital stay.
• There is a trend towards decreased opioid consumption with LALB.
• With the opioid epidemic we face today, LALB can be one of many options in our toolbox towards a solution.
• As stated in prior publications, the effectiveness of LALB is definitely technique dependent.
• Additional clinical studies are warranted to better determine the efficacy and cost-effectiveness of LALB.

Almost 1 million total knee arthroplasties (TKAs) are performed in the United States each year, and the number continues to grow.^1.2 For patients about to undergo TKA, a significant concern is postoperative pain.³ Fear of postoperative pain is often cited as a reason for delaying surgery.³ Recent literature suggests that patients with poor pain management during the first 48 hours after surgery have a 50% chance of gaining satisfactory long-term pain relief.⁴ In addition, inadequate postoperative pain management can interfere with participation in and progression of physical rehabilitation, prolong hospital stay, and increase patient dissatisfaction.⁵ Poorly controlled pain results in decreased range of motion (ROM), strength, stability, and ambulation thereby prolongs hospital stays, and increases costs and overall dissatisfaction with the procedure.

Post-TKA pain management has received much attention in recent years. A multimodal pain management protocol is now a key component of clinical pathways in TKA. Appropriate postoperative pain control lowers postoperative complications and accelerates recovery.⁶ Pain-caused loss of function makes surgical patients more susceptible to edema, deep vein thrombosis, and pulmonary embolism.⁴ Various oral and intravenous medications are used to lessen the pain response during the perioperative period. In addition, regional or neuraxial anesthesia is often added to blunt the immediate surgical pain response.^7,8 At our institution, TKA traditionally has been performed with femoral nerve catheters (FNCs) for postoperative pain control. Although effective, this method often results in decreased quadriceps musculature function, which delays rehabilitation and increases the fall risk. Recently, there has been a shift toward using local anesthetic infusions about the knee to provide adequate pain relief and restore motor function, which is often sacrificed with use of regional nerve blocks and continuous catheter infusions.⁹

Many institutions have started using a new long-acting local anesthetic in their multimodal pain management pathways: Exparel (Pacira Pharmaceuticals), a liposomal membrane-bound bupivacaine with sustained release of approximately 72 hours. Several studies have verified the safety of this medication.¹⁰ A systemic review of prospective studies revealed that, compared with bupivacaine, long-acting liposomal bupivacaine (LALB) in therapeutic doses had a higher safety margin and a favorable safety profile.¹⁰ However, no study has compared the effectiveness of LALB and FNC in a matched TKA cohort with each patient serving as his or her own control.

We recently reviewed our multimodal pain management protocol for any areas in need of improvement and decided to compare the effects of the indwelling FNC protocol that was in use with the effects of injecting the local anesthetic LALB. We conducted a study to compare the 2 methods with respect to pain control, ROM, ability to ambulate, and hospital length of stay (LOS). We hypothesized that the longer acting local anesthetic would provide comparable post-TKA pain control and post-TKA opioid use but would accelerate post-TKA rehabilitation.

Materials and Methods

This retrospective, longitudinal, repeated- measures study was approved by the Greenville Hospital System Institutional Review Board and conducted at the Steadman Hawkins Clinic of the Carolinas, Greenville Health System.

Interventions

Twenty-three patients underwent separately staged bilateral TKAs between 2010 and 2013. For each TKA, a Genesis II implant (Smith & Nephew) was used, and the surgery was performed with the patient under spinal anesthesia. In each case, FNC was used for pain control after the first TKA, and periarticular injection (PAI) of LALB for pain control after the second TKA.

 

In the first TKAs, FNC-administered ropivacaine 0.2% (2 mg/mL) was maintained at a standard basal rate of 8 mL/h for 48 hours. In the second TKAs, LALB was administered along with bupivacaine/epinephrine. Twenty milliliters of LALB from a single-use vial was diluted in 40 mL of normal (0.9%) saline to obtain a 60-mL solution, and a 25-gauge needle was used to inject this solution into the periarticular soft tissues; another needle was used for PAI of 30 mL of bupivacaine 0.25% with epinephrine.

Continuous passive motion devices were not used. Most patients began therapy on day of surgery. Knee immobilizers were not used in the FNC group.

The same standardized multimodal pain management protocol was used for all TKAs. Non- narcotic medications, including acetaminophen, ketorolac, and celecoxib, were given on a scheduled basis. Tramadol and opioid medications were administered as needed for pain. The attending physician based patient discharge timing on pain control, ability to safely ambulate, and absence of complications.

Outcome Measures

Outcome measures were LOS; extension and flexion at discharge and 3-week follow-up; total ROM (extension plus flexion) at discharge and 3-week follow-up; per-day and total hospital stay morphine -equivalent doses (MEDs); and per-attempt walking distance during gait training.

ROM was measured with a standard goniometer. Flexion was tested with the patient supine and the hip and knee in neutral rotation. The goniometer axis was along the lateral epicondyle of the femur with the proximal arm of the goniometer parallel to the long axis of the femur and pointing at the greater trochanter and with the distal arm parallel to the long axis of the fibula and pointing at the lateral malleolus. The patient was instructed to flex the hip and knee by moving the heel toward the buttock. Expected normal ROM is 135°. The same landmarks were used for extension. The patient was instructed to push the back of the knee toward the plinth/bed, for maximal active extension. The same ROM assessment strategy was used during the hospitalization and at the 3-week follow-up.

Several opioid medications (eg, hydrocodone, oxycodone, tramadol, hydromorphone, morphine) with different dosages were used during hospitalization. Opioid doses were converted to MEDs to permit FNC–LALB comparisons. For each patient, total MEDs were divided by LOS to determine MEDs per day.

Mean per-attempt walking distance was calculated by dividing the total distance walked during hospitalization—the sum of the number of feet walked during each and every attempt, as measured by the treating physical therapist—by the total number of walking attempts.

Data Analysis

A paired-samples t test was used to calculate differences between all outcome measures: LOS; extension and flexion at discharge and 3-month follow-up; per-day and total MEDs; and mean per-attempt walking distance. P < .05 was considered significant. We elected not to adjust our α for a potential familywise error.

Results

Of the 23 patients, 14 were female and 9 were male, and 19 were white and 4 were black. Mean (SD) age was 64.4 (6.4) years for the FNC group and 66.0 (6.0) years for the LALB group. The age difference was not statistically significant.

Statistically significant differences favoring LALB over FNC were found for mean LOS (LALB, 2.3 days; FNC, 2.8 days; P < .01), mean per-attempt walking distance (LALB, 135.9 feet; FNC, 84.2 feet; P < .01), and mean total ROM at 3-week follow-up (LALB, 116.3°; FNC, 107.2°; P = .02). Furthermore, a statistically significant difference was found for mean total MEDs during hospitalization (LALB, 145.47; FNC, 214.30; P = .02) (Table). In addition, there was a nonsignificant trend toward less drug administration.

 

 

Discussion

Poor pain control during the post-TKA period may have a significant impact on recovery rate, standard of living, psychological health, and postoperative complications.¹⁰ Inadequate postoperative pain control increases postoperative morbidity, hinders physiotherapy, increases anxiety, disrupts sleep patterns, and decreases patient satisfaction.⁹ There has been increased interest in PAIs. Local anesthetics are additional sources of pain control at surgical sites. However, the half-life of most local anesthetics is short. Soft-tissue infiltration of LALB into a surgical site extends the duration of active analgesia. Our study found that, compared with patients who received FNC, patients who received LALB had comparable pain control, improved knee ROM, and shorter hospital stays. In addition, the LALB group had no reports of quadriceps weakness or falls, both of which are associated with femoral nerve blocks. The FNC group had no reported falls, either. PAIs have the benefit of avoiding the invasiveness of femoral nerve blocks and possible neuritis.

Many complications are associated with or indirectly related to delayed rehabilitation and immobility during the acute post-TKA period. From prolonged hospitalization to need for manipulation, the consequences of inadequate pain control and decreased function can be numerous and costly for patients and the healthcare system. In the present study, LALB use led to a statistically significant overall decrease in mean LOS (LALB group, 2.3 days; FNC, 2.8 days). With LALB, there was a higher likelihood of discharge the day after surgery; 20% of patients in the LALB group and no patients in the FNC group went home that day.

The implication is that inadequate pain control led to decreased motion and decreased progression during postoperative rehabilitation. Local infiltration resulted in increased total ROM (extension plus flexion) at 3-week follow-up (LALB, 116.3°; FNC, 107.2°). In addition, there was an increase in walking distance per day of hospital stay (LALB, 135.9 feet; FNC, 84.2 feet). Furthermore, patients indicated LALB when asked which anesthetic they preferred. To our knowledge, this is the first study to compare LALB and FNC data in a matched TKA cohort with each patient serving as his or her own control.

Our study had several limitations. First was the retrospective design. Second was the small sample size, which made definitive conclusions difficult. However, the statistically significant differences we noted validated our conclusions. A statistically significant difference favoring LALB over FNC was found for total MEDs during hospitalization, but there was no significant difference in per-day MEDs. A possible reason for this difference is that LALB patients had shorter hospital stays, and therefore received fewer doses overall. Another possible reason is the small sample size; whereas a larger study using our protocol may find a statistically significant difference between LALB and FNC, we found only a trend. In the FNC group, anesthetic infiltration occurred with use of a computerized pump, which was removed on postoperative day 2; most of these patients were discharged home that day or the morning of postoperative day 3. As it is possible that some of these patients could have gone home sooner, our LOS data may have been affected. We do not consider this limitation significant, as one of our discharge criteria was 150 feet of ambulation, and most patients who received FNCs could not ambulate that far until after FNC removal. Furthermore, this study compared LALB only with FNC. It is possible that our improved outcomes could have resulted from the PAIs themselves, irrespective of LALB. In a recent TKA study by Bagsby and colleagues,¹¹ pain was controlled better with the less expensive traditional PAI of ropivacaine, epinephrine, and morphine than with the PAI of liposomal bupivacaine. Last, in our study, the experience of undergoing the first TKA may have increased patients’ confidence going into the second TKA and then helped them make faster progress in rehabilitation. Regardless, the promising results of our study and the firsthand use of LALB at our institution led us to modify our intraoperative pain management protocol for surgeons who perform TKA.

As we continue to use LALB, our study numbers will increase, and we may discover other factors that, though now underpowered, will prove to be statistically significant. Additional clinical studies are needed to better determine the efficacy and cost-effectiveness of LALB and other long-acting local anesthetic formulations. 

Hospitalists’ performance is routinely evaluated by third-party payers, employers, and patients. As hospitalist programs mature, there is a need to develop processes to identify, internally measure, and report on individual and group performance. We know from Society of Hospital Medicine (SHM) data that a significant amount of hospitalists’ total compensation is at least partially based on performance. Often this is based at least in part on quality data. In 2006, SHM issued a white paper detailing the key elements of a successful performance monitoring and reporting process.^1,2 Recommendations included the identification of meaningful operational and clinical performance metrics, and the ability to monitor and report both group and individual metrics was highlighted as an essential component. There is evidence that comparison of individual provider performance with that of their peers is a necessary element of successful provider dashboards.³ Additionally, regular feedback and a clear, visual presentation of the data are important components of successful provider feedback dashboards.^3-6

Much of the literature regarding provider feedback dashboards has been based in the outpatient setting. The majority of these dashboards focus on the management of chronic illnesses (eg, diabetes and hypertension), rates of preventative care services (eg, colonoscopy or mammogram), or avoidance of unnecessary care (eg, antibiotics for sinusitis).^4,5 Unlike in the outpatient setting, in which 1 provider often provides a majority of the care for a given episode of care, hospitalized patients are often cared for by multiple providers, challenging the appropriate attribution of patient-level metrics to specific providers. Under the standard approach, an entire hospitalization is attributed to 1 physician, generally the attending of record for the hospitalization, which may be the admitting provider or the discharging provider, depending on the approach used by the hospital. However, assigning responsibility for an entire hospitalization to a provider who may have only seen the patient for a small percentage of a hospitalization may jeopardize the validity of metrics. As provider metrics are increasingly being used for compensation, it is important to ensure that the method for attribution correctly identifies the providers caring for patients. To our knowledge there is no gold standard approach for attributing metrics to providers when patients are cared for by multiple providers, and the standard attending of record–based approach may lack face validity in many cases.

We aimed to develop and operationalize a system to more fairly attribute patient-level data to individual providers across a single hospitalization even when multiple providers cared for the patient. We then compared our methodology to the standard approach, in which the attending of record receives full attribution for each metric, to determine the difference on a provider level between the 2 models.

METHODS

Clinical Setting

The Johns Hopkins Hospital is a 1145-bed, tertiary-care hospital. Over the years of this project, the Johns Hopkins Hospitalist Program was an approximately 20-physician group providing care in a variety of settings, including a dedicated hospitalist floor, where this metrics program was initiated. Hospitalists in this setting work Monday through Friday, with 1 hospitalist and a moonlighter covering on the weekends. Admissions are performed by an admitter, and overnight care is provided by a nocturnist. Initially 17 beds, this unit expanded to 24 beds in June 2012. For the purposes of this article, we included all general medicine patients admitted to this floor between July 1, 2010, and June 30, 2014, who were cared for by hospitalists. During this period, all patients were inpatients; no patients were admitted under observation status. All of these patients were cared for by hospitalists without housestaff or advanced practitioners. Since 2014, the metrics program has been expanded to other hospitalist-run services in the hospital, but for simplicity, we have not presented these more recent data.

Individual Provider Metrics

Metrics were chosen to reflect institutional quality and efficiency priorities. Our choice of metrics was restricted to those that (1) plausibly reflect provider performance, at least in part, and (2) could be accessed in electronic form (without any manual chart review). Whenever possible, we chose metrics with objective data. Additionally, because funding for this effort was provided by the hospital, we sought to ensure that enough of the metrics were related to cost to justify ongoing hospital support of the project. SAS 9.2 (SAS Institute Inc, Cary, NC) was used to calculate metric weights. Specific metrics included American College of Chest Physicians (ACCP)–compliant venous thromboembolism (VTE) prophylaxis,⁷ observed-to-expected length of stay (LOS) ratio, percentage of discharges per day, discharges before 3 pm, depth of coding, patient satisfaction, readmissions, communication with the primary care provider, and time to signature for discharge summaries (Table 1).

 

Appropriate prophylaxis for VTE was calculated by using an algorithm embedded within the computerized provider order entry system, which assessed the prescription of ACCP-compliant VTE prophylaxis within 24 hours following admission. This included a risk assessment, and credit was given for no prophylaxis and/or mechanical and/or pharmacologic prophylaxis per the ACCP guidelines.⁷

Observed-to-expected LOS was defined by using the University HealthSystem Consortium (UHC; now Vizient Inc) expected LOS for the given calendar year. This approach incorporates patient diagnoses, demographics, and other administrative variables to define an expected LOS for each patient.

The percent of patients discharged per day was defined from billing data as the percentage of a provider’s evaluation and management charges that were the final charge of a patient’s stay (regardless of whether a discharge day service was coded).

Discharge prior to 3 pm was defined from administrative data as the time a patient was discharged from the electronic medical system.

Depth of coding was defined as the number of coded diagnoses submitted to the Maryland Health Services Cost Review Commission for determining payment and was viewed as an indicator of the thoroughness of provider documentation.

Patient satisfaction was defined at the patient level (for those patients who turned in patient satisfaction surveys) as the pooled value of the 5 provider questions on the hospital’s patient satisfaction survey administered by Press Ganey: “time the physician spent with you,” “did the physician show concern for your questions/worries,” “did the physician keep you informed,” “friendliness/courtesy of the physician,” and “skill of the physician.”⁸

Readmission rates were defined as same-hospital readmissions divided by the total number of patients discharged by a given provider, with exclusions based on the Centers for Medicare and Medicaid Services hospital-wide, all-cause readmission measure.¹ The expected same-hospital readmission rate was defined for each patient as the observed readmission rate in the entire UHC (Vizient) data set for all patients with the same All Patient Refined Diagnosis Related Group and severity of illness, as we have described previously.⁹

Communication with the primary care provider was the only self-reported metric used. It was based on a mandatory prompt on the discharge worksheet in the electronic medical record (EMR). Successful communication with the outpatient provider was defined as verbal or electronic communication by the hospitalist with the outpatient provider. Partial (50%) credit was given for providers who attempted but were unsuccessful in communicating with the outpatient provider, for patients for whom the provider had access to the Johns Hopkins EMR system, and for planned admissions without new or important information to convey. No credit was given for providers who indicated that communication was not indicated, who indicated that a patient and/or family would update the provider, or who indicated that the discharge summary would be sufficient.⁹ Because the discharge worksheet could be initiated at any time during the hospitalization, providers could document communication with the outpatient provider at any point during hospitalization.

Discharge summary turnaround was defined as the average number of days elapsed between the day of discharge and the signing of the discharge summary in the EMR.

Assigning Ownership of Patients to Individual Providers

Using billing data, we assigned ownership of patient care based on the type, timing, and number of charges that occurred during each hospitalization (Figure 1). Eligible charges included all history and physical (codes 99221, 99222, and 99223), subsequent care (codes 99231, 99232, and 99233), and discharge charges (codes 99238 and 99239).

By using a unique identifier assigned for each hospitalization, professional fees submitted by providers were used to identify which provider saw the patient on the admission day, discharge day, as well as subsequent care days. Providers’ productivity, bonus supplements, and policy compliance were determined by using billing data, which encouraged the prompt submittal of charges.

The provider who billed the admission history and physical (codes 99221, 99222, and 99223) within 1 calendar date of the patient’s initial admission was defined as the admitting provider. Patients transferred to the hospitalist service from other services were not assigned an admitting hospitalist. The sole metric assigned to the admitting hospitalist was ACCP-compliant VTE prophylaxis.

The provider who billed the final subsequent care or discharge code (codes 99231, 99232, 99233, 99238, and 99239) within 1 calendar date of discharge was defined as the discharging provider. For hospitalizations characterized by a single provider charge (eg, for patients admitted and discharged on the same day), the provider billing this charge was assigned as both the admitting and discharging physician. Patients upgraded to the intensive care unit (ICU) were not counted as a discharge unless the patient was downgraded and discharged from the hospitalist service. The discharging provider was assigned responsibility for the time of discharge, the percent of patients discharged per day, the discharge summary turnaround time, and hospital readmissions.

Metrics that were assigned to multiple providers for a single hospitalization were termed “provider day–weighted” metrics. The formula for calculating the weight for each provider day–weighted metric was as follows: weight for provider A = [number of daily charges billed by provider A] divided by [LOS +1]. The initial hospital day was counted as day 0. LOS plus 1 was used to recognize that a typical hospitalization will have a charge on the day of admission (day 0) and a charge on the day of discharge such that an LOS of 2 days (eg, a patient admitted on Monday and discharged on Wednesday) will have 3 daily charges. Provider day–weighted metrics included patient satisfaction, communication with the outpatient provider, depth of coding, and observed-to-expected LOS.

Our billing software prevented providers from the same group from billing multiple daily charges, thus ensuring that there were no duplicated charges submitted for a given day.

 

Presenting Results

Providers were only shown data from the day-weighted approach. For ease of visual interpretation, scores for each metric were scaled ordinally from 1 (worst performance) to 9 (best performance; Table 1). Data were displayed in a dashboard format on a password-protected website for each provider to view his or her own data relative to that of the hospitalist peer group. The dashboard was implemented in this format on July 1, 2011. Data were updated quarterly (Figure 2).

Results were displayed in a polyhedral or spider-web graph (Figure 2). Provider and group metrics were scaled according to predefined benchmarks established for each metric and standardized to a scale ranging from 1 to 9. The scale for each metric was set based on examining historical data and group median performance on the metrics to ensure that there was a range of performance (ie, to avoid having most hospitalists scoring a 1 or 9). Scaling thresholds were periodically adjusted as appropriate to maintain good visual discrimination. Higher scores (creating a larger-volume polygon) are desirable even for metrics such as LOS, for which a low value is desirable. Both a spider-web graph and trends over time were available to the provider (Figure 2). These graphs display a comparison of the individual provider scores for each metric to the hospitalist group average for that metric.

Comparison with the Standard (Attending of Record) Method of Attribution

For the purposes of this report, we sought to determine whether there were meaningful differences between our day-weighted approach versus the standard method of attribution, in which the attending of record is assigned responsibility for each metric that would not have been attributed to the discharging attending under both methods. Our goal was to determine where and whether there was a meaningful difference between the 2 methodologies, recognizing that the degree of difference between these 2 methodologies might vary in other institutions and settings. In our hospital, the attending of record is generally the discharging attending. In order to compare the 2 methodologies, we arbitrarily picked 2015 to retrospectively evaluate the differences between these 2 methods of attribution. We did not display or provide data using the standard methodology to providers at any point; this approach was used only for the purposes of this report. Because these metrics are intended to evaluate relative provider performance, we assigned a percentile to each provider for his or her performance on the given metric using our attribution methodology and then, similarly, assigned a percentile to each provider using the standard methodology. This yielded 2 percentile scores for each provider and each metric. We then compared these percentile ranks for providers in 2 ways: (1) we determined how often providers who scored in the top half of the group for a given metric (above the 50th percentile) also scored in the top half of the group for that metric by using the other calculation method, and (2) we calculated the absolute value of the difference in percentiles between the 2 methods to characterize the impact on a provider’s ranking for that metric that might result from switching to the other method. For instance, if a provider scored at the 20th percentile for the group in patient satisfaction with 1 attribution method and scored at the 40th percentile for the group in patient satisfaction using the other method, the absolute change in percentile would be 20 percentile points. But, this provider would still be below the 50th percentile by both methods (concordant bottom half performance). We did not perform this comparison for metrics assigned to the discharging provider (such as discharge summary turnaround time or readmissions) because the attending of record designation is assigned to the discharging provider at our hospital.

RESULTS

The dashboard was successfully operationalized on July 1, 2011, with displays visible to providers as shown in Figure 2. Consistent with the principles of providing effective performance feedback to providers, the display simultaneously showed providers their individual performance as well as the performance of their peers. Providers were able to view their spider-web plot for prior quarters. Not shown are additional views that allowed providers to see quarterly trends in their data versus their peers across several fiscal years. Also available to providers was their ranking relative to their peers for each metric; specific peers were deidentified in the display.

There was notable discordance between provider rankings between the 2 methodologies, as shown in Table 2. Provider performance above or below the median was concordant 56% to 75% of the time (depending on the particular metric), indicating substantial discordance because top-half or bottom-half concordance would be expected to occur by chance 50% of the time. Although the provider percentile differences between the 2 methods tended to be modest for most providers (the median difference between the methods was 13 to 22 percentile points for the various metrics), there were some providers for whom the method of calculation dramatically impacted their rankings. For 5 of the 6 metrics we examined, at least 1 provider had a 50-percentile or greater change in his or her ranking based on the method used. This indicates that at least some providers would have had markedly different scores relative to their peers had we used the alternative methodology (Table 2). In VTE prophylaxis, for example, at least 1 provider had a 94-percentile change in his or her ranking; similarly, a provider had an 88-perentile change in his or her LOS ranking between the 2 methodologies.

 

DISCUSSION

We found that it is possible to assign metrics across 1 hospital stay to multiple providers by using billing data. We also found a meaningful discrepancy in how well providers scored (relative to their peers) based on the method used for attribution. These results imply that hospitals should consider attributing performance metrics based on ascribed ownership from billing data and not just from attending of record status.

As hospitalist programs and providers in general are increasingly being asked to develop dashboards to monitor individual and group performance, correctly attributing care to providers is likely to become increasingly important. Experts agree that principles of effective provider performance dashboards include ranking individual provider performance relative to peers, clearly displaying data in an easily accessible format, and ensuring that data can be credibly attributed to the individual provider.^3,4,6 However, there appears to be no gold standard method for attribution, especially in the inpatient setting. Our results imply that hospitals should consider attributing performance metrics based on ascribed ownership from billing data and not just from attending of record status.

Several limitations of our findings are important to consider. First, our program is a relatively small, academic group with handoffs that typically occur every 1 to 2 weeks and sometimes with additional handoffs on weekends. Different care patterns and settings might impact the utility of our attribution methodology relative to the standard methodology. Additionally, it is important to note that the relative merits of the different methodologies cannot be ascertained from our comparison. We can demonstrate discordance between the attribution methodologies, but we cannot say that 1 method is correct and the other is flawed. Although we believe that our day-weighted approach feels fairer to providers based on group input and feedback, we did not conduct a formal survey to examine providers’ preferences for the standard versus day-weighted approaches. The appropriateness of a particular attribution method needs to be assessed locally and may vary based on the clinical setting. For instance, on a service in which patients are admitted for procedures, it may make more sense to attribute the outcome of the case to the proceduralist even if that provider did not bill for the patient’s care on a daily basis. Finally, the computational requirements of our methodology are not trivial and require linking billing data with administrative patient-level data, which may be challenging to operationalize in some institutions.

These limitations aside, we believe that our attribution methodology has face validity. For example, a provider might be justifiably frustrated if, using the standard methodology, he or she is charged with the LOS of a patient who had been hospitalized for months, particularly if that patient is discharged shortly after the provider assumes care. Our method addresses this type of misattribution. Particularly when individual provider compensation is based on performance on metrics (as is the case at our institution), optimizing provider attribution to particular patients may be important, and face validity may be required for group buy-in.

In summary, we have demonstrated that it is possible to use billing data to assign ownership of patients to multiple providers over 1 hospital stay. This could be applied to other hospitalist programs as well as other healthcare settings in which multiple providers care for patients during 1 healthcare encounter (eg, ICUs).

Disclosure

The authors declare they have no relevant conflicts of interest.

Hospitalists’ performance is routinely evaluated by third-party payers, employers, and patients. As hospitalist programs mature, there is a need to develop processes to identify, internally measure, and report on individual and group performance. We know from Society of Hospital Medicine (SHM) data that a significant amount of hospitalists’ total compensation is at least partially based on performance. Often this is based at least in part on quality data. In 2006, SHM issued a white paper detailing the key elements of a successful performance monitoring and reporting process.^1,2 Recommendations included the identification of meaningful operational and clinical performance metrics, and the ability to monitor and report both group and individual metrics was highlighted as an essential component. There is evidence that comparison of individual provider performance with that of their peers is a necessary element of successful provider dashboards.³ Additionally, regular feedback and a clear, visual presentation of the data are important components of successful provider feedback dashboards.^3-6

Much of the literature regarding provider feedback dashboards has been based in the outpatient setting. The majority of these dashboards focus on the management of chronic illnesses (eg, diabetes and hypertension), rates of preventative care services (eg, colonoscopy or mammogram), or avoidance of unnecessary care (eg, antibiotics for sinusitis).^4,5 Unlike in the outpatient setting, in which 1 provider often provides a majority of the care for a given episode of care, hospitalized patients are often cared for by multiple providers, challenging the appropriate attribution of patient-level metrics to specific providers. Under the standard approach, an entire hospitalization is attributed to 1 physician, generally the attending of record for the hospitalization, which may be the admitting provider or the discharging provider, depending on the approach used by the hospital. However, assigning responsibility for an entire hospitalization to a provider who may have only seen the patient for a small percentage of a hospitalization may jeopardize the validity of metrics. As provider metrics are increasingly being used for compensation, it is important to ensure that the method for attribution correctly identifies the providers caring for patients. To our knowledge there is no gold standard approach for attributing metrics to providers when patients are cared for by multiple providers, and the standard attending of record–based approach may lack face validity in many cases.

We aimed to develop and operationalize a system to more fairly attribute patient-level data to individual providers across a single hospitalization even when multiple providers cared for the patient. We then compared our methodology to the standard approach, in which the attending of record receives full attribution for each metric, to determine the difference on a provider level between the 2 models.

METHODS

Clinical Setting

The Johns Hopkins Hospital is a 1145-bed, tertiary-care hospital. Over the years of this project, the Johns Hopkins Hospitalist Program was an approximately 20-physician group providing care in a variety of settings, including a dedicated hospitalist floor, where this metrics program was initiated. Hospitalists in this setting work Monday through Friday, with 1 hospitalist and a moonlighter covering on the weekends. Admissions are performed by an admitter, and overnight care is provided by a nocturnist. Initially 17 beds, this unit expanded to 24 beds in June 2012. For the purposes of this article, we included all general medicine patients admitted to this floor between July 1, 2010, and June 30, 2014, who were cared for by hospitalists. During this period, all patients were inpatients; no patients were admitted under observation status. All of these patients were cared for by hospitalists without housestaff or advanced practitioners. Since 2014, the metrics program has been expanded to other hospitalist-run services in the hospital, but for simplicity, we have not presented these more recent data.

Individual Provider Metrics

Metrics were chosen to reflect institutional quality and efficiency priorities. Our choice of metrics was restricted to those that (1) plausibly reflect provider performance, at least in part, and (2) could be accessed in electronic form (without any manual chart review). Whenever possible, we chose metrics with objective data. Additionally, because funding for this effort was provided by the hospital, we sought to ensure that enough of the metrics were related to cost to justify ongoing hospital support of the project. SAS 9.2 (SAS Institute Inc, Cary, NC) was used to calculate metric weights. Specific metrics included American College of Chest Physicians (ACCP)–compliant venous thromboembolism (VTE) prophylaxis,⁷ observed-to-expected length of stay (LOS) ratio, percentage of discharges per day, discharges before 3 pm, depth of coding, patient satisfaction, readmissions, communication with the primary care provider, and time to signature for discharge summaries (Table 1).

 

Appropriate prophylaxis for VTE was calculated by using an algorithm embedded within the computerized provider order entry system, which assessed the prescription of ACCP-compliant VTE prophylaxis within 24 hours following admission. This included a risk assessment, and credit was given for no prophylaxis and/or mechanical and/or pharmacologic prophylaxis per the ACCP guidelines.⁷

Observed-to-expected LOS was defined by using the University HealthSystem Consortium (UHC; now Vizient Inc) expected LOS for the given calendar year. This approach incorporates patient diagnoses, demographics, and other administrative variables to define an expected LOS for each patient.

The percent of patients discharged per day was defined from billing data as the percentage of a provider’s evaluation and management charges that were the final charge of a patient’s stay (regardless of whether a discharge day service was coded).

Discharge prior to 3 pm was defined from administrative data as the time a patient was discharged from the electronic medical system.

Depth of coding was defined as the number of coded diagnoses submitted to the Maryland Health Services Cost Review Commission for determining payment and was viewed as an indicator of the thoroughness of provider documentation.

Patient satisfaction was defined at the patient level (for those patients who turned in patient satisfaction surveys) as the pooled value of the 5 provider questions on the hospital’s patient satisfaction survey administered by Press Ganey: “time the physician spent with you,” “did the physician show concern for your questions/worries,” “did the physician keep you informed,” “friendliness/courtesy of the physician,” and “skill of the physician.”⁸

Readmission rates were defined as same-hospital readmissions divided by the total number of patients discharged by a given provider, with exclusions based on the Centers for Medicare and Medicaid Services hospital-wide, all-cause readmission measure.¹ The expected same-hospital readmission rate was defined for each patient as the observed readmission rate in the entire UHC (Vizient) data set for all patients with the same All Patient Refined Diagnosis Related Group and severity of illness, as we have described previously.⁹

Communication with the primary care provider was the only self-reported metric used. It was based on a mandatory prompt on the discharge worksheet in the electronic medical record (EMR). Successful communication with the outpatient provider was defined as verbal or electronic communication by the hospitalist with the outpatient provider. Partial (50%) credit was given for providers who attempted but were unsuccessful in communicating with the outpatient provider, for patients for whom the provider had access to the Johns Hopkins EMR system, and for planned admissions without new or important information to convey. No credit was given for providers who indicated that communication was not indicated, who indicated that a patient and/or family would update the provider, or who indicated that the discharge summary would be sufficient.⁹ Because the discharge worksheet could be initiated at any time during the hospitalization, providers could document communication with the outpatient provider at any point during hospitalization.

Discharge summary turnaround was defined as the average number of days elapsed between the day of discharge and the signing of the discharge summary in the EMR.

Assigning Ownership of Patients to Individual Providers

Using billing data, we assigned ownership of patient care based on the type, timing, and number of charges that occurred during each hospitalization (Figure 1). Eligible charges included all history and physical (codes 99221, 99222, and 99223), subsequent care (codes 99231, 99232, and 99233), and discharge charges (codes 99238 and 99239).

By using a unique identifier assigned for each hospitalization, professional fees submitted by providers were used to identify which provider saw the patient on the admission day, discharge day, as well as subsequent care days. Providers’ productivity, bonus supplements, and policy compliance were determined by using billing data, which encouraged the prompt submittal of charges.

The provider who billed the admission history and physical (codes 99221, 99222, and 99223) within 1 calendar date of the patient’s initial admission was defined as the admitting provider. Patients transferred to the hospitalist service from other services were not assigned an admitting hospitalist. The sole metric assigned to the admitting hospitalist was ACCP-compliant VTE prophylaxis.

The provider who billed the final subsequent care or discharge code (codes 99231, 99232, 99233, 99238, and 99239) within 1 calendar date of discharge was defined as the discharging provider. For hospitalizations characterized by a single provider charge (eg, for patients admitted and discharged on the same day), the provider billing this charge was assigned as both the admitting and discharging physician. Patients upgraded to the intensive care unit (ICU) were not counted as a discharge unless the patient was downgraded and discharged from the hospitalist service. The discharging provider was assigned responsibility for the time of discharge, the percent of patients discharged per day, the discharge summary turnaround time, and hospital readmissions.

Metrics that were assigned to multiple providers for a single hospitalization were termed “provider day–weighted” metrics. The formula for calculating the weight for each provider day–weighted metric was as follows: weight for provider A = [number of daily charges billed by provider A] divided by [LOS +1]. The initial hospital day was counted as day 0. LOS plus 1 was used to recognize that a typical hospitalization will have a charge on the day of admission (day 0) and a charge on the day of discharge such that an LOS of 2 days (eg, a patient admitted on Monday and discharged on Wednesday) will have 3 daily charges. Provider day–weighted metrics included patient satisfaction, communication with the outpatient provider, depth of coding, and observed-to-expected LOS.

Our billing software prevented providers from the same group from billing multiple daily charges, thus ensuring that there were no duplicated charges submitted for a given day.

 

Presenting Results

Providers were only shown data from the day-weighted approach. For ease of visual interpretation, scores for each metric were scaled ordinally from 1 (worst performance) to 9 (best performance; Table 1). Data were displayed in a dashboard format on a password-protected website for each provider to view his or her own data relative to that of the hospitalist peer group. The dashboard was implemented in this format on July 1, 2011. Data were updated quarterly (Figure 2).

Results were displayed in a polyhedral or spider-web graph (Figure 2). Provider and group metrics were scaled according to predefined benchmarks established for each metric and standardized to a scale ranging from 1 to 9. The scale for each metric was set based on examining historical data and group median performance on the metrics to ensure that there was a range of performance (ie, to avoid having most hospitalists scoring a 1 or 9). Scaling thresholds were periodically adjusted as appropriate to maintain good visual discrimination. Higher scores (creating a larger-volume polygon) are desirable even for metrics such as LOS, for which a low value is desirable. Both a spider-web graph and trends over time were available to the provider (Figure 2). These graphs display a comparison of the individual provider scores for each metric to the hospitalist group average for that metric.

Comparison with the Standard (Attending of Record) Method of Attribution

For the purposes of this report, we sought to determine whether there were meaningful differences between our day-weighted approach versus the standard method of attribution, in which the attending of record is assigned responsibility for each metric that would not have been attributed to the discharging attending under both methods. Our goal was to determine where and whether there was a meaningful difference between the 2 methodologies, recognizing that the degree of difference between these 2 methodologies might vary in other institutions and settings. In our hospital, the attending of record is generally the discharging attending. In order to compare the 2 methodologies, we arbitrarily picked 2015 to retrospectively evaluate the differences between these 2 methods of attribution. We did not display or provide data using the standard methodology to providers at any point; this approach was used only for the purposes of this report. Because these metrics are intended to evaluate relative provider performance, we assigned a percentile to each provider for his or her performance on the given metric using our attribution methodology and then, similarly, assigned a percentile to each provider using the standard methodology. This yielded 2 percentile scores for each provider and each metric. We then compared these percentile ranks for providers in 2 ways: (1) we determined how often providers who scored in the top half of the group for a given metric (above the 50th percentile) also scored in the top half of the group for that metric by using the other calculation method, and (2) we calculated the absolute value of the difference in percentiles between the 2 methods to characterize the impact on a provider’s ranking for that metric that might result from switching to the other method. For instance, if a provider scored at the 20th percentile for the group in patient satisfaction with 1 attribution method and scored at the 40th percentile for the group in patient satisfaction using the other method, the absolute change in percentile would be 20 percentile points. But, this provider would still be below the 50th percentile by both methods (concordant bottom half performance). We did not perform this comparison for metrics assigned to the discharging provider (such as discharge summary turnaround time or readmissions) because the attending of record designation is assigned to the discharging provider at our hospital.

RESULTS

The dashboard was successfully operationalized on July 1, 2011, with displays visible to providers as shown in Figure 2. Consistent with the principles of providing effective performance feedback to providers, the display simultaneously showed providers their individual performance as well as the performance of their peers. Providers were able to view their spider-web plot for prior quarters. Not shown are additional views that allowed providers to see quarterly trends in their data versus their peers across several fiscal years. Also available to providers was their ranking relative to their peers for each metric; specific peers were deidentified in the display.

There was notable discordance between provider rankings between the 2 methodologies, as shown in Table 2. Provider performance above or below the median was concordant 56% to 75% of the time (depending on the particular metric), indicating substantial discordance because top-half or bottom-half concordance would be expected to occur by chance 50% of the time. Although the provider percentile differences between the 2 methods tended to be modest for most providers (the median difference between the methods was 13 to 22 percentile points for the various metrics), there were some providers for whom the method of calculation dramatically impacted their rankings. For 5 of the 6 metrics we examined, at least 1 provider had a 50-percentile or greater change in his or her ranking based on the method used. This indicates that at least some providers would have had markedly different scores relative to their peers had we used the alternative methodology (Table 2). In VTE prophylaxis, for example, at least 1 provider had a 94-percentile change in his or her ranking; similarly, a provider had an 88-perentile change in his or her LOS ranking between the 2 methodologies.

 

DISCUSSION

We found that it is possible to assign metrics across 1 hospital stay to multiple providers by using billing data. We also found a meaningful discrepancy in how well providers scored (relative to their peers) based on the method used for attribution. These results imply that hospitals should consider attributing performance metrics based on ascribed ownership from billing data and not just from attending of record status.

As hospitalist programs and providers in general are increasingly being asked to develop dashboards to monitor individual and group performance, correctly attributing care to providers is likely to become increasingly important. Experts agree that principles of effective provider performance dashboards include ranking individual provider performance relative to peers, clearly displaying data in an easily accessible format, and ensuring that data can be credibly attributed to the individual provider.^3,4,6 However, there appears to be no gold standard method for attribution, especially in the inpatient setting. Our results imply that hospitals should consider attributing performance metrics based on ascribed ownership from billing data and not just from attending of record status.

Several limitations of our findings are important to consider. First, our program is a relatively small, academic group with handoffs that typically occur every 1 to 2 weeks and sometimes with additional handoffs on weekends. Different care patterns and settings might impact the utility of our attribution methodology relative to the standard methodology. Additionally, it is important to note that the relative merits of the different methodologies cannot be ascertained from our comparison. We can demonstrate discordance between the attribution methodologies, but we cannot say that 1 method is correct and the other is flawed. Although we believe that our day-weighted approach feels fairer to providers based on group input and feedback, we did not conduct a formal survey to examine providers’ preferences for the standard versus day-weighted approaches. The appropriateness of a particular attribution method needs to be assessed locally and may vary based on the clinical setting. For instance, on a service in which patients are admitted for procedures, it may make more sense to attribute the outcome of the case to the proceduralist even if that provider did not bill for the patient’s care on a daily basis. Finally, the computational requirements of our methodology are not trivial and require linking billing data with administrative patient-level data, which may be challenging to operationalize in some institutions.

These limitations aside, we believe that our attribution methodology has face validity. For example, a provider might be justifiably frustrated if, using the standard methodology, he or she is charged with the LOS of a patient who had been hospitalized for months, particularly if that patient is discharged shortly after the provider assumes care. Our method addresses this type of misattribution. Particularly when individual provider compensation is based on performance on metrics (as is the case at our institution), optimizing provider attribution to particular patients may be important, and face validity may be required for group buy-in.

In summary, we have demonstrated that it is possible to use billing data to assign ownership of patients to multiple providers over 1 hospital stay. This could be applied to other hospitalist programs as well as other healthcare settings in which multiple providers care for patients during 1 healthcare encounter (eg, ICUs).

Disclosure

The authors declare they have no relevant conflicts of interest.

Hospitalists’ performance is routinely evaluated by third-party payers, employers, and patients. As hospitalist programs mature, there is a need to develop processes to identify, internally measure, and report on individual and group performance. We know from Society of Hospital Medicine (SHM) data that a significant amount of hospitalists’ total compensation is at least partially based on performance. Often this is based at least in part on quality data. In 2006, SHM issued a white paper detailing the key elements of a successful performance monitoring and reporting process.^1,2 Recommendations included the identification of meaningful operational and clinical performance metrics, and the ability to monitor and report both group and individual metrics was highlighted as an essential component. There is evidence that comparison of individual provider performance with that of their peers is a necessary element of successful provider dashboards.³ Additionally, regular feedback and a clear, visual presentation of the data are important components of successful provider feedback dashboards.^3-6

Much of the literature regarding provider feedback dashboards has been based in the outpatient setting. The majority of these dashboards focus on the management of chronic illnesses (eg, diabetes and hypertension), rates of preventative care services (eg, colonoscopy or mammogram), or avoidance of unnecessary care (eg, antibiotics for sinusitis).^4,5 Unlike in the outpatient setting, in which 1 provider often provides a majority of the care for a given episode of care, hospitalized patients are often cared for by multiple providers, challenging the appropriate attribution of patient-level metrics to specific providers. Under the standard approach, an entire hospitalization is attributed to 1 physician, generally the attending of record for the hospitalization, which may be the admitting provider or the discharging provider, depending on the approach used by the hospital. However, assigning responsibility for an entire hospitalization to a provider who may have only seen the patient for a small percentage of a hospitalization may jeopardize the validity of metrics. As provider metrics are increasingly being used for compensation, it is important to ensure that the method for attribution correctly identifies the providers caring for patients. To our knowledge there is no gold standard approach for attributing metrics to providers when patients are cared for by multiple providers, and the standard attending of record–based approach may lack face validity in many cases.

We aimed to develop and operationalize a system to more fairly attribute patient-level data to individual providers across a single hospitalization even when multiple providers cared for the patient. We then compared our methodology to the standard approach, in which the attending of record receives full attribution for each metric, to determine the difference on a provider level between the 2 models.

METHODS

Clinical Setting

The Johns Hopkins Hospital is a 1145-bed, tertiary-care hospital. Over the years of this project, the Johns Hopkins Hospitalist Program was an approximately 20-physician group providing care in a variety of settings, including a dedicated hospitalist floor, where this metrics program was initiated. Hospitalists in this setting work Monday through Friday, with 1 hospitalist and a moonlighter covering on the weekends. Admissions are performed by an admitter, and overnight care is provided by a nocturnist. Initially 17 beds, this unit expanded to 24 beds in June 2012. For the purposes of this article, we included all general medicine patients admitted to this floor between July 1, 2010, and June 30, 2014, who were cared for by hospitalists. During this period, all patients were inpatients; no patients were admitted under observation status. All of these patients were cared for by hospitalists without housestaff or advanced practitioners. Since 2014, the metrics program has been expanded to other hospitalist-run services in the hospital, but for simplicity, we have not presented these more recent data.

Individual Provider Metrics

Metrics were chosen to reflect institutional quality and efficiency priorities. Our choice of metrics was restricted to those that (1) plausibly reflect provider performance, at least in part, and (2) could be accessed in electronic form (without any manual chart review). Whenever possible, we chose metrics with objective data. Additionally, because funding for this effort was provided by the hospital, we sought to ensure that enough of the metrics were related to cost to justify ongoing hospital support of the project. SAS 9.2 (SAS Institute Inc, Cary, NC) was used to calculate metric weights. Specific metrics included American College of Chest Physicians (ACCP)–compliant venous thromboembolism (VTE) prophylaxis,⁷ observed-to-expected length of stay (LOS) ratio, percentage of discharges per day, discharges before 3 pm, depth of coding, patient satisfaction, readmissions, communication with the primary care provider, and time to signature for discharge summaries (Table 1).

 

Appropriate prophylaxis for VTE was calculated by using an algorithm embedded within the computerized provider order entry system, which assessed the prescription of ACCP-compliant VTE prophylaxis within 24 hours following admission. This included a risk assessment, and credit was given for no prophylaxis and/or mechanical and/or pharmacologic prophylaxis per the ACCP guidelines.⁷

Observed-to-expected LOS was defined by using the University HealthSystem Consortium (UHC; now Vizient Inc) expected LOS for the given calendar year. This approach incorporates patient diagnoses, demographics, and other administrative variables to define an expected LOS for each patient.

The percent of patients discharged per day was defined from billing data as the percentage of a provider’s evaluation and management charges that were the final charge of a patient’s stay (regardless of whether a discharge day service was coded).

Discharge prior to 3 pm was defined from administrative data as the time a patient was discharged from the electronic medical system.

Depth of coding was defined as the number of coded diagnoses submitted to the Maryland Health Services Cost Review Commission for determining payment and was viewed as an indicator of the thoroughness of provider documentation.

Patient satisfaction was defined at the patient level (for those patients who turned in patient satisfaction surveys) as the pooled value of the 5 provider questions on the hospital’s patient satisfaction survey administered by Press Ganey: “time the physician spent with you,” “did the physician show concern for your questions/worries,” “did the physician keep you informed,” “friendliness/courtesy of the physician,” and “skill of the physician.”⁸

Readmission rates were defined as same-hospital readmissions divided by the total number of patients discharged by a given provider, with exclusions based on the Centers for Medicare and Medicaid Services hospital-wide, all-cause readmission measure.¹ The expected same-hospital readmission rate was defined for each patient as the observed readmission rate in the entire UHC (Vizient) data set for all patients with the same All Patient Refined Diagnosis Related Group and severity of illness, as we have described previously.⁹

Communication with the primary care provider was the only self-reported metric used. It was based on a mandatory prompt on the discharge worksheet in the electronic medical record (EMR). Successful communication with the outpatient provider was defined as verbal or electronic communication by the hospitalist with the outpatient provider. Partial (50%) credit was given for providers who attempted but were unsuccessful in communicating with the outpatient provider, for patients for whom the provider had access to the Johns Hopkins EMR system, and for planned admissions without new or important information to convey. No credit was given for providers who indicated that communication was not indicated, who indicated that a patient and/or family would update the provider, or who indicated that the discharge summary would be sufficient.⁹ Because the discharge worksheet could be initiated at any time during the hospitalization, providers could document communication with the outpatient provider at any point during hospitalization.

Discharge summary turnaround was defined as the average number of days elapsed between the day of discharge and the signing of the discharge summary in the EMR.

Assigning Ownership of Patients to Individual Providers

Using billing data, we assigned ownership of patient care based on the type, timing, and number of charges that occurred during each hospitalization (Figure 1). Eligible charges included all history and physical (codes 99221, 99222, and 99223), subsequent care (codes 99231, 99232, and 99233), and discharge charges (codes 99238 and 99239).

By using a unique identifier assigned for each hospitalization, professional fees submitted by providers were used to identify which provider saw the patient on the admission day, discharge day, as well as subsequent care days. Providers’ productivity, bonus supplements, and policy compliance were determined by using billing data, which encouraged the prompt submittal of charges.

The provider who billed the admission history and physical (codes 99221, 99222, and 99223) within 1 calendar date of the patient’s initial admission was defined as the admitting provider. Patients transferred to the hospitalist service from other services were not assigned an admitting hospitalist. The sole metric assigned to the admitting hospitalist was ACCP-compliant VTE prophylaxis.

The provider who billed the final subsequent care or discharge code (codes 99231, 99232, 99233, 99238, and 99239) within 1 calendar date of discharge was defined as the discharging provider. For hospitalizations characterized by a single provider charge (eg, for patients admitted and discharged on the same day), the provider billing this charge was assigned as both the admitting and discharging physician. Patients upgraded to the intensive care unit (ICU) were not counted as a discharge unless the patient was downgraded and discharged from the hospitalist service. The discharging provider was assigned responsibility for the time of discharge, the percent of patients discharged per day, the discharge summary turnaround time, and hospital readmissions.

Metrics that were assigned to multiple providers for a single hospitalization were termed “provider day–weighted” metrics. The formula for calculating the weight for each provider day–weighted metric was as follows: weight for provider A = [number of daily charges billed by provider A] divided by [LOS +1]. The initial hospital day was counted as day 0. LOS plus 1 was used to recognize that a typical hospitalization will have a charge on the day of admission (day 0) and a charge on the day of discharge such that an LOS of 2 days (eg, a patient admitted on Monday and discharged on Wednesday) will have 3 daily charges. Provider day–weighted metrics included patient satisfaction, communication with the outpatient provider, depth of coding, and observed-to-expected LOS.

Our billing software prevented providers from the same group from billing multiple daily charges, thus ensuring that there were no duplicated charges submitted for a given day.

 

Presenting Results

Providers were only shown data from the day-weighted approach. For ease of visual interpretation, scores for each metric were scaled ordinally from 1 (worst performance) to 9 (best performance; Table 1). Data were displayed in a dashboard format on a password-protected website for each provider to view his or her own data relative to that of the hospitalist peer group. The dashboard was implemented in this format on July 1, 2011. Data were updated quarterly (Figure 2).

Results were displayed in a polyhedral or spider-web graph (Figure 2). Provider and group metrics were scaled according to predefined benchmarks established for each metric and standardized to a scale ranging from 1 to 9. The scale for each metric was set based on examining historical data and group median performance on the metrics to ensure that there was a range of performance (ie, to avoid having most hospitalists scoring a 1 or 9). Scaling thresholds were periodically adjusted as appropriate to maintain good visual discrimination. Higher scores (creating a larger-volume polygon) are desirable even for metrics such as LOS, for which a low value is desirable. Both a spider-web graph and trends over time were available to the provider (Figure 2). These graphs display a comparison of the individual provider scores for each metric to the hospitalist group average for that metric.

Comparison with the Standard (Attending of Record) Method of Attribution

For the purposes of this report, we sought to determine whether there were meaningful differences between our day-weighted approach versus the standard method of attribution, in which the attending of record is assigned responsibility for each metric that would not have been attributed to the discharging attending under both methods. Our goal was to determine where and whether there was a meaningful difference between the 2 methodologies, recognizing that the degree of difference between these 2 methodologies might vary in other institutions and settings. In our hospital, the attending of record is generally the discharging attending. In order to compare the 2 methodologies, we arbitrarily picked 2015 to retrospectively evaluate the differences between these 2 methods of attribution. We did not display or provide data using the standard methodology to providers at any point; this approach was used only for the purposes of this report. Because these metrics are intended to evaluate relative provider performance, we assigned a percentile to each provider for his or her performance on the given metric using our attribution methodology and then, similarly, assigned a percentile to each provider using the standard methodology. This yielded 2 percentile scores for each provider and each metric. We then compared these percentile ranks for providers in 2 ways: (1) we determined how often providers who scored in the top half of the group for a given metric (above the 50th percentile) also scored in the top half of the group for that metric by using the other calculation method, and (2) we calculated the absolute value of the difference in percentiles between the 2 methods to characterize the impact on a provider’s ranking for that metric that might result from switching to the other method. For instance, if a provider scored at the 20th percentile for the group in patient satisfaction with 1 attribution method and scored at the 40th percentile for the group in patient satisfaction using the other method, the absolute change in percentile would be 20 percentile points. But, this provider would still be below the 50th percentile by both methods (concordant bottom half performance). We did not perform this comparison for metrics assigned to the discharging provider (such as discharge summary turnaround time or readmissions) because the attending of record designation is assigned to the discharging provider at our hospital.

RESULTS

The dashboard was successfully operationalized on July 1, 2011, with displays visible to providers as shown in Figure 2. Consistent with the principles of providing effective performance feedback to providers, the display simultaneously showed providers their individual performance as well as the performance of their peers. Providers were able to view their spider-web plot for prior quarters. Not shown are additional views that allowed providers to see quarterly trends in their data versus their peers across several fiscal years. Also available to providers was their ranking relative to their peers for each metric; specific peers were deidentified in the display.

There was notable discordance between provider rankings between the 2 methodologies, as shown in Table 2. Provider performance above or below the median was concordant 56% to 75% of the time (depending on the particular metric), indicating substantial discordance because top-half or bottom-half concordance would be expected to occur by chance 50% of the time. Although the provider percentile differences between the 2 methods tended to be modest for most providers (the median difference between the methods was 13 to 22 percentile points for the various metrics), there were some providers for whom the method of calculation dramatically impacted their rankings. For 5 of the 6 metrics we examined, at least 1 provider had a 50-percentile or greater change in his or her ranking based on the method used. This indicates that at least some providers would have had markedly different scores relative to their peers had we used the alternative methodology (Table 2). In VTE prophylaxis, for example, at least 1 provider had a 94-percentile change in his or her ranking; similarly, a provider had an 88-perentile change in his or her LOS ranking between the 2 methodologies.

 

DISCUSSION

We found that it is possible to assign metrics across 1 hospital stay to multiple providers by using billing data. We also found a meaningful discrepancy in how well providers scored (relative to their peers) based on the method used for attribution. These results imply that hospitals should consider attributing performance metrics based on ascribed ownership from billing data and not just from attending of record status.

As hospitalist programs and providers in general are increasingly being asked to develop dashboards to monitor individual and group performance, correctly attributing care to providers is likely to become increasingly important. Experts agree that principles of effective provider performance dashboards include ranking individual provider performance relative to peers, clearly displaying data in an easily accessible format, and ensuring that data can be credibly attributed to the individual provider.^3,4,6 However, there appears to be no gold standard method for attribution, especially in the inpatient setting. Our results imply that hospitals should consider attributing performance metrics based on ascribed ownership from billing data and not just from attending of record status.

Several limitations of our findings are important to consider. First, our program is a relatively small, academic group with handoffs that typically occur every 1 to 2 weeks and sometimes with additional handoffs on weekends. Different care patterns and settings might impact the utility of our attribution methodology relative to the standard methodology. Additionally, it is important to note that the relative merits of the different methodologies cannot be ascertained from our comparison. We can demonstrate discordance between the attribution methodologies, but we cannot say that 1 method is correct and the other is flawed. Although we believe that our day-weighted approach feels fairer to providers based on group input and feedback, we did not conduct a formal survey to examine providers’ preferences for the standard versus day-weighted approaches. The appropriateness of a particular attribution method needs to be assessed locally and may vary based on the clinical setting. For instance, on a service in which patients are admitted for procedures, it may make more sense to attribute the outcome of the case to the proceduralist even if that provider did not bill for the patient’s care on a daily basis. Finally, the computational requirements of our methodology are not trivial and require linking billing data with administrative patient-level data, which may be challenging to operationalize in some institutions.

These limitations aside, we believe that our attribution methodology has face validity. For example, a provider might be justifiably frustrated if, using the standard methodology, he or she is charged with the LOS of a patient who had been hospitalized for months, particularly if that patient is discharged shortly after the provider assumes care. Our method addresses this type of misattribution. Particularly when individual provider compensation is based on performance on metrics (as is the case at our institution), optimizing provider attribution to particular patients may be important, and face validity may be required for group buy-in.

In summary, we have demonstrated that it is possible to use billing data to assign ownership of patients to multiple providers over 1 hospital stay. This could be applied to other hospitalist programs as well as other healthcare settings in which multiple providers care for patients during 1 healthcare encounter (eg, ICUs).

Disclosure

The authors declare they have no relevant conflicts of interest.

Take-Home Points

• Metastatic disease of the tibia is a rare but significant event in a subset of patients.
• Cancer histologies with historically “acral” spread may not apply to tibial disease.
• Patients with leg pain and any cancer diagnosis should be worked up for tibial metastases.
• Tibial disease is probably a late manifestation, and early detection may indicate late diagnosis of malignancy.
• The ultimate surgical plan for these patients should be a patient-centered multidisciplinary decision making process.

Metastatic dissemination to bones is common in advanced cancer stages and affects the axial and appendicular skeleton.^1-4 The appendicular skeleton bones most often involved are the proximal femur and the proximal humerus.^5,6 The tibia is involved third most often but is comparatively rarely affected.^4-6 Metastatic involvement distal to the knee or elbow is more typical of advanced disease.^1,3 Distal appendicular lesions are called acral metastases, but the term is inconsistently used and may refer to lesions either distal to the knee and elbow or distal to the ankle and wrist. Regardless of terminology, tibia lesions are uncommon and not well described.^1,4,7,8

The tibia is the primary weight-bearing leg bone. Metastatic tibia lesions may cause pain and instability and impair mobility. Although distal skeletal dissemination often presents late in advanced disease in patients with relatively poor prognoses, in some cases early surgical intervention is indicated for pain relief, increased mobility, and improved quality of life.^4,8-10

Materials and Methods

Our Institutional Review Board approved this single-institution retrospective study. We used proprietary research software (Clinical Looking Glass) to identify eligible patients treated between 2000 and 2013. The software was used to search all radiology and pathology reports for the term tibia or any variation (eg, tibial) and metastasis or any variation (eg, metastatic). The software was then used to search by Current Procedural Terminology code for any patients treated with intramedullary nail (IMN) or another tibial fixation method. This list was cross-referenced with the list of patients originally identified to help ensure that all eligible patients were identified. 

Inclusion criteria were known malignancy and imaging or biopsy evidence of a metastatic tibia lesion. Treatment strategies for patients with metastatic disease and patients with multiple myeloma are sometimes considered together because of similar goals and methodologies. We specifically excluded patients with multiple myeloma in order to more accurately characterize the natural history of metastatic disease and the timing of metastatic development and to report on a more homogeneous population. Patients were excluded if their electronic medical records were inadequate in establishing a diagnosis.

Demographic and pathology data were collected directly from the institutional electronic medical records system. Dr. Geller and Dr. Greenbaum used Centricity software (General Electric Healthcare) to review all imaging on medical diagnostic display monitors. If their interpretation differed from that in the radiology report, or if clarification was needed, the study was sent to Dr. Thornhill, the institution’s director of musculoskeletal radiology, for review and interpretation. Investigated radiographic characteristics included location, cortical breakthrough, presence of fracture, and size (if advanced imaging was available). Surgical interventions were recorded from reviews of operative reports and postoperative imaging studies.

Time to metastasis was defined as number of days from diagnosis of malignancy to diagnosis of tibial osseous spread. Date of diagnosis of malignancy was the date that a biopsy or other confirmatory test was performed. In cases in which that date was unavailable, an imaging study consistent with disease or a clinical note documenting the known diagnosis date was used instead. When only month and year (ie, not an exact date) of diagnosis were available, the 15th of the month was used as an estimate. Of the 36 patients, 4 had records insufficient for establishing date of diagnosis. The first date of any imaging study confirming (or suggestive of) a metastatic lesion of the tibia was used as the date of tibial metastasis. 

Many patients had osseous lesions at sites other than the tibiae. These lesions were noted on review of imaging studies, screening examinations, and physicians’ clinical notes. Widespread disease was defined as including both axial and appendicular lesions, and lesions of the tibiae.

Tibia lesion presentation was recorded as either symptomatic or incidental. If the tibiae were imaged for pain, including posttraumatic pain, the presentation was symptomatic. If a lesion was identified on staging examination (eg, bone or positron emission tomography scan), or if the tibiae were imaged for another reason, the presentation was incidental.

Results

Demographics

Thirty-six patients had 43 affected tibiae. Sixteen male patients (44.4% of the total) had 19 (44.2%) of the affected tibiae, and 20 female patients (55.6%) had the other 24 affected tibiae (55.8%). Mean age was 63.5 years for all patients (range, 6-95 years), 68.1 years for males, and 59.8 years for females. Of the 36 patients, 32 (88.9%) were over age 40 years (Table). All patients had radiographic evidence of ≥1 tibia lesion, and 6 (16.7%) also had biopsy-proven metastatic disease of the tibia.

Tumor Characteristics

There were 12 different primary neoplasms (Table). The most common were prostate cancer (7 patients, 19.4%; 10 tibiae, 23.3%), breast cancer (7 patients, 19.4%; 9 tibiae, 20.9%), and lung cancer (7 patients, 19.4%; 7 tibiae, 16.3%). For males, the most common diagnoses were prostate cancer (7 cases, 43.8% of males) and diffuse large B-cell lymphoma and lung cancer (3 cases and 18.8% of males each). For females, the most common diagnoses were breast cancer (7 cases, 35.0% of females) and lung cancer (4 cases, 20.0% of females). 

Most of the lesions were proximal (31 tibiae, 72.1%), followed by diaphyseal (7, 16.3%) and distal (2, 4.7%) (Table). Three tibiae (7.0%) were entirely involved, but 1 of these was more affected at the distal end. One tibia had 2 lesions, 1 proximal and 1 distal.

Time to Metastasis, Other Osseous Disease

Mean time from diagnosis of malignancy to diagnosis of osseous disease of the tibia was 1282 days (range, 0-3708 days) (Table). Of the 36 patients, 32 (88.9%) had other metastatic lesions, 3 (8.3%) had isolated tibia lesions, and 1 (2.8%) had a medical record insufficient for establishing lesion status (isolated or not). Of the 32 patients with known other osseous metastases, 14 (43.8%) had widespread (axial and additional appendicular) disease, and 3 (9.4%) had additional lesions only distal to the identified tibial metastases.

Clinical Presentation

Of the 36 lesions, 18 (50%) were asymptomatic and were found on screening examinations, 17 (47.2%) presented with pain, and 1 (2.8%) had a presentation that could not be determined from the medical record (Table). Of the 17 painful lesions, 3 (17.6%) were found after a trauma brought attention to the site, and the other 14 (82.4%) were atraumatic in origin. 

Of the 10 patients with cortical breakthrough, 8 (80%) had painful lesions, 1 (10%) had a lesion that was found on screening examination, and 1 (10%) had a medical record insufficient for establishing clinical presentation. Of the 8 patients who underwent surgical stabilization, 6 (75%) had painful lesions. Only 1 patient with an asymptomatic tibia lesion underwent surgical intervention (total knee arthroplasty).

Surgical Intervention

Two patients (5.6%) with affected tibiae (4.8%) had pathologic fractures. One fracture (non-small cell lung cancer) was treated with open reduction and internal fixation (periarticular locking plate with cement augmentation), and the other (urothelial cancer) was treated with IMN fixation.

Ten patients (27.8%) with affected tibiae (23.8%) had radiographs that showed cortical breakthrough (Table). Two of the 10 cases were managed nonoperatively, and the patients died before surgical stabilization could be attempted. Of the 8 surgically managed cases, 3 were prophylactically stabilized with IMN (2 of these were augmented with cement, and the third with a screw-plate construct), 2 were treated with periarticular resection and reconstruction (total knee megaprosthesis), 1 was treated with an approach undertaken to address a concomitant distal femoral pathologic fracture, and 1 was treated with total knee arthroplasty undertaken to address lesions at the proximal end of the tibia and the distal end of the femur. 

Discussion

We have described a retrospective descriptive study conducted to characterize tibial metastases, their histologies, and the circumstances surrounding diagnosis and surgical management. In all cases, general findings confirmed advanced metastatic disease. In only 3 cases, the tibia lesion was an isolated metastatic lesion.

Sex predilection of tibial metastases remains controversial. One study found males had up to twice as many hand and foot metastases as women,¹¹ but this contrasts with the relatively equal sex ratio found in other studies^8,10 and in the present study. We found metastatic disease of the tibia was unsurprisingly concentrated in patients over age 40 years, in whom the vast majority of all cancers develop.^12,13 Our study agrees with those that have found most tibia lesions develop in patients in the 6th decade of life on average.^8,10 Mean age was 8.3 years higher in our male patients than in our female patients. 

Tumor Characteristics 

The most common primary neoplasms in our cohort were prostate, breast, and lung cancers, which are among the most common cancers in the United States^12,13 and which have a predilection for osseous spread.^2,6,9,14 Renal cell carcinoma has been reported to spread to distal (or “acral”) skeletal sites,^2-4,9,11,14 but the present study did not identify any patients with this diagnosis. Of our patients with a primary lung cancer for whom a histologic description was available (5/7), all had non-small cell lung cancer. Three patients had a primary malignancy of colorectal cancer, which occasionally metastasizes to the distal skeleton.^3,8,11 We identified 3 patients with diffuse large B-cell lymphoma, a histology not widely reported to metastasize to distal skeletal sites.

Metastatic disease of the tibia is most common at the proximal end of the bone.^1,10,11,14 Other studies^8,10 have found the proximal tibia is affected much more commonly than the tibial diaphysis, and even fewer cases develop at the distal end. Our findings agree with theirs: Proximal lesions outnumber all other lesions combined (Table).

Time to Metastasis

Distal metastases are typical of late-stage metastatic disease,^1,3 but quantification of the time from diagnosis of malignancy to presentation of a tibia lesion is not well defined. In our study, time to metastasis was <100 days for some patients (Table). As osseous involvement, especially acral disease, was considered a late-stage manifestation of malignancy, this result was unexpected and most likely represents undiagnosed and untreated malignancy. Six patients in this group were diagnosed with tibial metastases within 30 days, essentially at the same time the primary neoplasm was diagnosed. These findings suggest that a tibia lesion found at time of patient presentation should raise concern for late-stage undiagnosed metastatic cancer.

Other Osseous Disease

The patients identified in this study had advanced malignancy, and most had widespread bony dissemination. Those with the lowest disease burden had isolated tibia lesions or additional metastases only distal to the tibia lesion in the ipsilateral lower extremity. Most of these patients had undergone surgery or were scheduled for it (Table). Most of the patients with appendicular metastases proximal to the tibia lesion had disease of the femora, the most common long bones affected by osseous metastatic disease.^5,6 In accordance with orthopedic oncology principles, all other osseous disease should be thoroughly identified and staged before any surgical planning for identified tibia lesions. Ipsilateral distal femoral lesions are of particular importance for patients with proximal tibia lesions, as reconstruction with total knee endoprosthesis can potentially provide a functional reconstructive option after resection of both lesions. 

Clinical Presentation

Most of the patients who had cortical breakthrough or required surgical stabilization had painful lesions. Although tibial metastasis is rare, its potential occurrence should raise concerns and be investigated in the patient with tibial pain.

Surgical Intervention

General surgical management of metastatic disease of other long bones has been extensively studied,^6,7,9,14 but there are fewer published recommendations regarding specific treatments for metastatic lesions of the tibia. In 2003, Kelly and colleagues8 described an algorithm based on the anatomical location of the lesion, with either internal fixation or IMN fixation representing the preferred management for lesions in the metaphyseal or diaphyseal regions. For epiphyseal or extensive proximal metaphyseal lesions, modular oncology endoprostheses are described as the procedure of choice. Piccioli and colleagues¹⁰ in 2013 and Beauchamp and Sim¹ in 1988 described a similar operative approach.

It is unknown if the algorithm of Kelly and colleagues⁸ was referenced during clinical decision-making, but it appears operative management mirrored these principles. Deviations from this general approach in the operative management of the patients in the present study included modifications such as the addition of a screw-plate construct to an IMN for better stability.

Surgical management depends largely on the anatomical location within the bone and on remaining bone stock. Generally, extensive proximal disease is managed with total knee endoprosthesis reconstruction, diaphyseal disease with IMN, and distal disease with internal fixation. Construct augmentation, such as the addition of cement or use of additional hardware, is decided case by case on the basis of desired stability and surrounding bone stock.

Study Limitations

Despite being a larger series, this single-institution study had a relatively small sample size, and its patient demographics and primary malignancies may reflect institutional recruitment bias. In addition, the study was limited by its retrospective design and some incomplete medical records. Eleven patients had only a bone or positron emission tomography scan depicting metastatic disease, limiting characterization of these lesions. One patient lacked radiologic images, and characterizations were based on written reports. As multiple physicians were involved in diagnosis and treatment, there were many inconsistencies in clinical decision-making across the group.

Conclusion

Metastasis to the tibia is a rare but significant event in a subset of patients over the course of their treatment and surveillance. Patients may present with pain secondary to either pathologic or impending pathologic fractures, and in such instances surgical intervention is often needed. Despite the historical reports of “acral” histologies, tibia lesions are not indicative of histology, and biopsy should be considered, especially if management will depend on histology. Patients with lower leg pain and known malignancy should be evaluated to rule out tibial metastasis, but screening examinations may be prudent for asymptomatic patients as well. Increased vigilance may be indicated for those with prostate, breast, or lung cancer. These lesions should be surgically managed case by case using fundamental tenets of both orthopedic fracture care and orthopedic oncology. Ideally, patients should be treated by a multidisciplinary team using a patient-centered approach.

Take-Home Points

• Metastatic disease of the tibia is a rare but significant event in a subset of patients.
• Cancer histologies with historically “acral” spread may not apply to tibial disease.
• Patients with leg pain and any cancer diagnosis should be worked up for tibial metastases.
• Tibial disease is probably a late manifestation, and early detection may indicate late diagnosis of malignancy.
• The ultimate surgical plan for these patients should be a patient-centered multidisciplinary decision making process.

Metastatic dissemination to bones is common in advanced cancer stages and affects the axial and appendicular skeleton.^1-4 The appendicular skeleton bones most often involved are the proximal femur and the proximal humerus.^5,6 The tibia is involved third most often but is comparatively rarely affected.^4-6 Metastatic involvement distal to the knee or elbow is more typical of advanced disease.^1,3 Distal appendicular lesions are called acral metastases, but the term is inconsistently used and may refer to lesions either distal to the knee and elbow or distal to the ankle and wrist. Regardless of terminology, tibia lesions are uncommon and not well described.^1,4,7,8

The tibia is the primary weight-bearing leg bone. Metastatic tibia lesions may cause pain and instability and impair mobility. Although distal skeletal dissemination often presents late in advanced disease in patients with relatively poor prognoses, in some cases early surgical intervention is indicated for pain relief, increased mobility, and improved quality of life.^4,8-10

Materials and Methods

Our Institutional Review Board approved this single-institution retrospective study. We used proprietary research software (Clinical Looking Glass) to identify eligible patients treated between 2000 and 2013. The software was used to search all radiology and pathology reports for the term tibia or any variation (eg, tibial) and metastasis or any variation (eg, metastatic). The software was then used to search by Current Procedural Terminology code for any patients treated with intramedullary nail (IMN) or another tibial fixation method. This list was cross-referenced with the list of patients originally identified to help ensure that all eligible patients were identified. 

Inclusion criteria were known malignancy and imaging or biopsy evidence of a metastatic tibia lesion. Treatment strategies for patients with metastatic disease and patients with multiple myeloma are sometimes considered together because of similar goals and methodologies. We specifically excluded patients with multiple myeloma in order to more accurately characterize the natural history of metastatic disease and the timing of metastatic development and to report on a more homogeneous population. Patients were excluded if their electronic medical records were inadequate in establishing a diagnosis.

Demographic and pathology data were collected directly from the institutional electronic medical records system. Dr. Geller and Dr. Greenbaum used Centricity software (General Electric Healthcare) to review all imaging on medical diagnostic display monitors. If their interpretation differed from that in the radiology report, or if clarification was needed, the study was sent to Dr. Thornhill, the institution’s director of musculoskeletal radiology, for review and interpretation. Investigated radiographic characteristics included location, cortical breakthrough, presence of fracture, and size (if advanced imaging was available). Surgical interventions were recorded from reviews of operative reports and postoperative imaging studies.

Time to metastasis was defined as number of days from diagnosis of malignancy to diagnosis of tibial osseous spread. Date of diagnosis of malignancy was the date that a biopsy or other confirmatory test was performed. In cases in which that date was unavailable, an imaging study consistent with disease or a clinical note documenting the known diagnosis date was used instead. When only month and year (ie, not an exact date) of diagnosis were available, the 15th of the month was used as an estimate. Of the 36 patients, 4 had records insufficient for establishing date of diagnosis. The first date of any imaging study confirming (or suggestive of) a metastatic lesion of the tibia was used as the date of tibial metastasis. 

Many patients had osseous lesions at sites other than the tibiae. These lesions were noted on review of imaging studies, screening examinations, and physicians’ clinical notes. Widespread disease was defined as including both axial and appendicular lesions, and lesions of the tibiae.

Tibia lesion presentation was recorded as either symptomatic or incidental. If the tibiae were imaged for pain, including posttraumatic pain, the presentation was symptomatic. If a lesion was identified on staging examination (eg, bone or positron emission tomography scan), or if the tibiae were imaged for another reason, the presentation was incidental.

Results

Demographics

Thirty-six patients had 43 affected tibiae. Sixteen male patients (44.4% of the total) had 19 (44.2%) of the affected tibiae, and 20 female patients (55.6%) had the other 24 affected tibiae (55.8%). Mean age was 63.5 years for all patients (range, 6-95 years), 68.1 years for males, and 59.8 years for females. Of the 36 patients, 32 (88.9%) were over age 40 years (Table). All patients had radiographic evidence of ≥1 tibia lesion, and 6 (16.7%) also had biopsy-proven metastatic disease of the tibia.

Tumor Characteristics

There were 12 different primary neoplasms (Table). The most common were prostate cancer (7 patients, 19.4%; 10 tibiae, 23.3%), breast cancer (7 patients, 19.4%; 9 tibiae, 20.9%), and lung cancer (7 patients, 19.4%; 7 tibiae, 16.3%). For males, the most common diagnoses were prostate cancer (7 cases, 43.8% of males) and diffuse large B-cell lymphoma and lung cancer (3 cases and 18.8% of males each). For females, the most common diagnoses were breast cancer (7 cases, 35.0% of females) and lung cancer (4 cases, 20.0% of females). 

Most of the lesions were proximal (31 tibiae, 72.1%), followed by diaphyseal (7, 16.3%) and distal (2, 4.7%) (Table). Three tibiae (7.0%) were entirely involved, but 1 of these was more affected at the distal end. One tibia had 2 lesions, 1 proximal and 1 distal.

Time to Metastasis, Other Osseous Disease

Mean time from diagnosis of malignancy to diagnosis of osseous disease of the tibia was 1282 days (range, 0-3708 days) (Table). Of the 36 patients, 32 (88.9%) had other metastatic lesions, 3 (8.3%) had isolated tibia lesions, and 1 (2.8%) had a medical record insufficient for establishing lesion status (isolated or not). Of the 32 patients with known other osseous metastases, 14 (43.8%) had widespread (axial and additional appendicular) disease, and 3 (9.4%) had additional lesions only distal to the identified tibial metastases.

Clinical Presentation

Of the 36 lesions, 18 (50%) were asymptomatic and were found on screening examinations, 17 (47.2%) presented with pain, and 1 (2.8%) had a presentation that could not be determined from the medical record (Table). Of the 17 painful lesions, 3 (17.6%) were found after a trauma brought attention to the site, and the other 14 (82.4%) were atraumatic in origin. 

Of the 10 patients with cortical breakthrough, 8 (80%) had painful lesions, 1 (10%) had a lesion that was found on screening examination, and 1 (10%) had a medical record insufficient for establishing clinical presentation. Of the 8 patients who underwent surgical stabilization, 6 (75%) had painful lesions. Only 1 patient with an asymptomatic tibia lesion underwent surgical intervention (total knee arthroplasty).

Surgical Intervention

Two patients (5.6%) with affected tibiae (4.8%) had pathologic fractures. One fracture (non-small cell lung cancer) was treated with open reduction and internal fixation (periarticular locking plate with cement augmentation), and the other (urothelial cancer) was treated with IMN fixation.

Ten patients (27.8%) with affected tibiae (23.8%) had radiographs that showed cortical breakthrough (Table). Two of the 10 cases were managed nonoperatively, and the patients died before surgical stabilization could be attempted. Of the 8 surgically managed cases, 3 were prophylactically stabilized with IMN (2 of these were augmented with cement, and the third with a screw-plate construct), 2 were treated with periarticular resection and reconstruction (total knee megaprosthesis), 1 was treated with an approach undertaken to address a concomitant distal femoral pathologic fracture, and 1 was treated with total knee arthroplasty undertaken to address lesions at the proximal end of the tibia and the distal end of the femur. 

Discussion

We have described a retrospective descriptive study conducted to characterize tibial metastases, their histologies, and the circumstances surrounding diagnosis and surgical management. In all cases, general findings confirmed advanced metastatic disease. In only 3 cases, the tibia lesion was an isolated metastatic lesion.

Sex predilection of tibial metastases remains controversial. One study found males had up to twice as many hand and foot metastases as women,¹¹ but this contrasts with the relatively equal sex ratio found in other studies^8,10 and in the present study. We found metastatic disease of the tibia was unsurprisingly concentrated in patients over age 40 years, in whom the vast majority of all cancers develop.^12,13 Our study agrees with those that have found most tibia lesions develop in patients in the 6th decade of life on average.^8,10 Mean age was 8.3 years higher in our male patients than in our female patients. 

Tumor Characteristics 

The most common primary neoplasms in our cohort were prostate, breast, and lung cancers, which are among the most common cancers in the United States^12,13 and which have a predilection for osseous spread.^2,6,9,14 Renal cell carcinoma has been reported to spread to distal (or “acral”) skeletal sites,^2-4,9,11,14 but the present study did not identify any patients with this diagnosis. Of our patients with a primary lung cancer for whom a histologic description was available (5/7), all had non-small cell lung cancer. Three patients had a primary malignancy of colorectal cancer, which occasionally metastasizes to the distal skeleton.^3,8,11 We identified 3 patients with diffuse large B-cell lymphoma, a histology not widely reported to metastasize to distal skeletal sites.

Metastatic disease of the tibia is most common at the proximal end of the bone.^1,10,11,14 Other studies^8,10 have found the proximal tibia is affected much more commonly than the tibial diaphysis, and even fewer cases develop at the distal end. Our findings agree with theirs: Proximal lesions outnumber all other lesions combined (Table).

Time to Metastasis

Distal metastases are typical of late-stage metastatic disease,^1,3 but quantification of the time from diagnosis of malignancy to presentation of a tibia lesion is not well defined. In our study, time to metastasis was <100 days for some patients (Table). As osseous involvement, especially acral disease, was considered a late-stage manifestation of malignancy, this result was unexpected and most likely represents undiagnosed and untreated malignancy. Six patients in this group were diagnosed with tibial metastases within 30 days, essentially at the same time the primary neoplasm was diagnosed. These findings suggest that a tibia lesion found at time of patient presentation should raise concern for late-stage undiagnosed metastatic cancer.

Other Osseous Disease

The patients identified in this study had advanced malignancy, and most had widespread bony dissemination. Those with the lowest disease burden had isolated tibia lesions or additional metastases only distal to the tibia lesion in the ipsilateral lower extremity. Most of these patients had undergone surgery or were scheduled for it (Table). Most of the patients with appendicular metastases proximal to the tibia lesion had disease of the femora, the most common long bones affected by osseous metastatic disease.^5,6 In accordance with orthopedic oncology principles, all other osseous disease should be thoroughly identified and staged before any surgical planning for identified tibia lesions. Ipsilateral distal femoral lesions are of particular importance for patients with proximal tibia lesions, as reconstruction with total knee endoprosthesis can potentially provide a functional reconstructive option after resection of both lesions. 

Clinical Presentation

Most of the patients who had cortical breakthrough or required surgical stabilization had painful lesions. Although tibial metastasis is rare, its potential occurrence should raise concerns and be investigated in the patient with tibial pain.

Surgical Intervention

General surgical management of metastatic disease of other long bones has been extensively studied,^6,7,9,14 but there are fewer published recommendations regarding specific treatments for metastatic lesions of the tibia. In 2003, Kelly and colleagues8 described an algorithm based on the anatomical location of the lesion, with either internal fixation or IMN fixation representing the preferred management for lesions in the metaphyseal or diaphyseal regions. For epiphyseal or extensive proximal metaphyseal lesions, modular oncology endoprostheses are described as the procedure of choice. Piccioli and colleagues¹⁰ in 2013 and Beauchamp and Sim¹ in 1988 described a similar operative approach.

It is unknown if the algorithm of Kelly and colleagues⁸ was referenced during clinical decision-making, but it appears operative management mirrored these principles. Deviations from this general approach in the operative management of the patients in the present study included modifications such as the addition of a screw-plate construct to an IMN for better stability.

Surgical management depends largely on the anatomical location within the bone and on remaining bone stock. Generally, extensive proximal disease is managed with total knee endoprosthesis reconstruction, diaphyseal disease with IMN, and distal disease with internal fixation. Construct augmentation, such as the addition of cement or use of additional hardware, is decided case by case on the basis of desired stability and surrounding bone stock.

Study Limitations

Despite being a larger series, this single-institution study had a relatively small sample size, and its patient demographics and primary malignancies may reflect institutional recruitment bias. In addition, the study was limited by its retrospective design and some incomplete medical records. Eleven patients had only a bone or positron emission tomography scan depicting metastatic disease, limiting characterization of these lesions. One patient lacked radiologic images, and characterizations were based on written reports. As multiple physicians were involved in diagnosis and treatment, there were many inconsistencies in clinical decision-making across the group.

Conclusion

Metastasis to the tibia is a rare but significant event in a subset of patients over the course of their treatment and surveillance. Patients may present with pain secondary to either pathologic or impending pathologic fractures, and in such instances surgical intervention is often needed. Despite the historical reports of “acral” histologies, tibia lesions are not indicative of histology, and biopsy should be considered, especially if management will depend on histology. Patients with lower leg pain and known malignancy should be evaluated to rule out tibial metastasis, but screening examinations may be prudent for asymptomatic patients as well. Increased vigilance may be indicated for those with prostate, breast, or lung cancer. These lesions should be surgically managed case by case using fundamental tenets of both orthopedic fracture care and orthopedic oncology. Ideally, patients should be treated by a multidisciplinary team using a patient-centered approach.

Take-Home Points

• Metastatic disease of the tibia is a rare but significant event in a subset of patients.
• Cancer histologies with historically “acral” spread may not apply to tibial disease.
• Patients with leg pain and any cancer diagnosis should be worked up for tibial metastases.
• Tibial disease is probably a late manifestation, and early detection may indicate late diagnosis of malignancy.
• The ultimate surgical plan for these patients should be a patient-centered multidisciplinary decision making process.

Metastatic dissemination to bones is common in advanced cancer stages and affects the axial and appendicular skeleton.^1-4 The appendicular skeleton bones most often involved are the proximal femur and the proximal humerus.^5,6 The tibia is involved third most often but is comparatively rarely affected.^4-6 Metastatic involvement distal to the knee or elbow is more typical of advanced disease.^1,3 Distal appendicular lesions are called acral metastases, but the term is inconsistently used and may refer to lesions either distal to the knee and elbow or distal to the ankle and wrist. Regardless of terminology, tibia lesions are uncommon and not well described.^1,4,7,8

The tibia is the primary weight-bearing leg bone. Metastatic tibia lesions may cause pain and instability and impair mobility. Although distal skeletal dissemination often presents late in advanced disease in patients with relatively poor prognoses, in some cases early surgical intervention is indicated for pain relief, increased mobility, and improved quality of life.^4,8-10

Materials and Methods

Our Institutional Review Board approved this single-institution retrospective study. We used proprietary research software (Clinical Looking Glass) to identify eligible patients treated between 2000 and 2013. The software was used to search all radiology and pathology reports for the term tibia or any variation (eg, tibial) and metastasis or any variation (eg, metastatic). The software was then used to search by Current Procedural Terminology code for any patients treated with intramedullary nail (IMN) or another tibial fixation method. This list was cross-referenced with the list of patients originally identified to help ensure that all eligible patients were identified. 

Inclusion criteria were known malignancy and imaging or biopsy evidence of a metastatic tibia lesion. Treatment strategies for patients with metastatic disease and patients with multiple myeloma are sometimes considered together because of similar goals and methodologies. We specifically excluded patients with multiple myeloma in order to more accurately characterize the natural history of metastatic disease and the timing of metastatic development and to report on a more homogeneous population. Patients were excluded if their electronic medical records were inadequate in establishing a diagnosis.

Demographic and pathology data were collected directly from the institutional electronic medical records system. Dr. Geller and Dr. Greenbaum used Centricity software (General Electric Healthcare) to review all imaging on medical diagnostic display monitors. If their interpretation differed from that in the radiology report, or if clarification was needed, the study was sent to Dr. Thornhill, the institution’s director of musculoskeletal radiology, for review and interpretation. Investigated radiographic characteristics included location, cortical breakthrough, presence of fracture, and size (if advanced imaging was available). Surgical interventions were recorded from reviews of operative reports and postoperative imaging studies.

Time to metastasis was defined as number of days from diagnosis of malignancy to diagnosis of tibial osseous spread. Date of diagnosis of malignancy was the date that a biopsy or other confirmatory test was performed. In cases in which that date was unavailable, an imaging study consistent with disease or a clinical note documenting the known diagnosis date was used instead. When only month and year (ie, not an exact date) of diagnosis were available, the 15th of the month was used as an estimate. Of the 36 patients, 4 had records insufficient for establishing date of diagnosis. The first date of any imaging study confirming (or suggestive of) a metastatic lesion of the tibia was used as the date of tibial metastasis. 

Many patients had osseous lesions at sites other than the tibiae. These lesions were noted on review of imaging studies, screening examinations, and physicians’ clinical notes. Widespread disease was defined as including both axial and appendicular lesions, and lesions of the tibiae.

Tibia lesion presentation was recorded as either symptomatic or incidental. If the tibiae were imaged for pain, including posttraumatic pain, the presentation was symptomatic. If a lesion was identified on staging examination (eg, bone or positron emission tomography scan), or if the tibiae were imaged for another reason, the presentation was incidental.

Results

Demographics

Thirty-six patients had 43 affected tibiae. Sixteen male patients (44.4% of the total) had 19 (44.2%) of the affected tibiae, and 20 female patients (55.6%) had the other 24 affected tibiae (55.8%). Mean age was 63.5 years for all patients (range, 6-95 years), 68.1 years for males, and 59.8 years for females. Of the 36 patients, 32 (88.9%) were over age 40 years (Table). All patients had radiographic evidence of ≥1 tibia lesion, and 6 (16.7%) also had biopsy-proven metastatic disease of the tibia.

Tumor Characteristics

There were 12 different primary neoplasms (Table). The most common were prostate cancer (7 patients, 19.4%; 10 tibiae, 23.3%), breast cancer (7 patients, 19.4%; 9 tibiae, 20.9%), and lung cancer (7 patients, 19.4%; 7 tibiae, 16.3%). For males, the most common diagnoses were prostate cancer (7 cases, 43.8% of males) and diffuse large B-cell lymphoma and lung cancer (3 cases and 18.8% of males each). For females, the most common diagnoses were breast cancer (7 cases, 35.0% of females) and lung cancer (4 cases, 20.0% of females). 

Most of the lesions were proximal (31 tibiae, 72.1%), followed by diaphyseal (7, 16.3%) and distal (2, 4.7%) (Table). Three tibiae (7.0%) were entirely involved, but 1 of these was more affected at the distal end. One tibia had 2 lesions, 1 proximal and 1 distal.

Time to Metastasis, Other Osseous Disease

Mean time from diagnosis of malignancy to diagnosis of osseous disease of the tibia was 1282 days (range, 0-3708 days) (Table). Of the 36 patients, 32 (88.9%) had other metastatic lesions, 3 (8.3%) had isolated tibia lesions, and 1 (2.8%) had a medical record insufficient for establishing lesion status (isolated or not). Of the 32 patients with known other osseous metastases, 14 (43.8%) had widespread (axial and additional appendicular) disease, and 3 (9.4%) had additional lesions only distal to the identified tibial metastases.

Clinical Presentation

Of the 36 lesions, 18 (50%) were asymptomatic and were found on screening examinations, 17 (47.2%) presented with pain, and 1 (2.8%) had a presentation that could not be determined from the medical record (Table). Of the 17 painful lesions, 3 (17.6%) were found after a trauma brought attention to the site, and the other 14 (82.4%) were atraumatic in origin. 

Of the 10 patients with cortical breakthrough, 8 (80%) had painful lesions, 1 (10%) had a lesion that was found on screening examination, and 1 (10%) had a medical record insufficient for establishing clinical presentation. Of the 8 patients who underwent surgical stabilization, 6 (75%) had painful lesions. Only 1 patient with an asymptomatic tibia lesion underwent surgical intervention (total knee arthroplasty).

Surgical Intervention

Two patients (5.6%) with affected tibiae (4.8%) had pathologic fractures. One fracture (non-small cell lung cancer) was treated with open reduction and internal fixation (periarticular locking plate with cement augmentation), and the other (urothelial cancer) was treated with IMN fixation.

Ten patients (27.8%) with affected tibiae (23.8%) had radiographs that showed cortical breakthrough (Table). Two of the 10 cases were managed nonoperatively, and the patients died before surgical stabilization could be attempted. Of the 8 surgically managed cases, 3 were prophylactically stabilized with IMN (2 of these were augmented with cement, and the third with a screw-plate construct), 2 were treated with periarticular resection and reconstruction (total knee megaprosthesis), 1 was treated with an approach undertaken to address a concomitant distal femoral pathologic fracture, and 1 was treated with total knee arthroplasty undertaken to address lesions at the proximal end of the tibia and the distal end of the femur. 

Discussion

We have described a retrospective descriptive study conducted to characterize tibial metastases, their histologies, and the circumstances surrounding diagnosis and surgical management. In all cases, general findings confirmed advanced metastatic disease. In only 3 cases, the tibia lesion was an isolated metastatic lesion.

Sex predilection of tibial metastases remains controversial. One study found males had up to twice as many hand and foot metastases as women,¹¹ but this contrasts with the relatively equal sex ratio found in other studies^8,10 and in the present study. We found metastatic disease of the tibia was unsurprisingly concentrated in patients over age 40 years, in whom the vast majority of all cancers develop.^12,13 Our study agrees with those that have found most tibia lesions develop in patients in the 6th decade of life on average.^8,10 Mean age was 8.3 years higher in our male patients than in our female patients. 

Tumor Characteristics 

The most common primary neoplasms in our cohort were prostate, breast, and lung cancers, which are among the most common cancers in the United States^12,13 and which have a predilection for osseous spread.^2,6,9,14 Renal cell carcinoma has been reported to spread to distal (or “acral”) skeletal sites,^2-4,9,11,14 but the present study did not identify any patients with this diagnosis. Of our patients with a primary lung cancer for whom a histologic description was available (5/7), all had non-small cell lung cancer. Three patients had a primary malignancy of colorectal cancer, which occasionally metastasizes to the distal skeleton.^3,8,11 We identified 3 patients with diffuse large B-cell lymphoma, a histology not widely reported to metastasize to distal skeletal sites.

Metastatic disease of the tibia is most common at the proximal end of the bone.^1,10,11,14 Other studies^8,10 have found the proximal tibia is affected much more commonly than the tibial diaphysis, and even fewer cases develop at the distal end. Our findings agree with theirs: Proximal lesions outnumber all other lesions combined (Table).

Time to Metastasis

Distal metastases are typical of late-stage metastatic disease,^1,3 but quantification of the time from diagnosis of malignancy to presentation of a tibia lesion is not well defined. In our study, time to metastasis was <100 days for some patients (Table). As osseous involvement, especially acral disease, was considered a late-stage manifestation of malignancy, this result was unexpected and most likely represents undiagnosed and untreated malignancy. Six patients in this group were diagnosed with tibial metastases within 30 days, essentially at the same time the primary neoplasm was diagnosed. These findings suggest that a tibia lesion found at time of patient presentation should raise concern for late-stage undiagnosed metastatic cancer.

Other Osseous Disease

The patients identified in this study had advanced malignancy, and most had widespread bony dissemination. Those with the lowest disease burden had isolated tibia lesions or additional metastases only distal to the tibia lesion in the ipsilateral lower extremity. Most of these patients had undergone surgery or were scheduled for it (Table). Most of the patients with appendicular metastases proximal to the tibia lesion had disease of the femora, the most common long bones affected by osseous metastatic disease.^5,6 In accordance with orthopedic oncology principles, all other osseous disease should be thoroughly identified and staged before any surgical planning for identified tibia lesions. Ipsilateral distal femoral lesions are of particular importance for patients with proximal tibia lesions, as reconstruction with total knee endoprosthesis can potentially provide a functional reconstructive option after resection of both lesions. 

Clinical Presentation

Most of the patients who had cortical breakthrough or required surgical stabilization had painful lesions. Although tibial metastasis is rare, its potential occurrence should raise concerns and be investigated in the patient with tibial pain.

Surgical Intervention

General surgical management of metastatic disease of other long bones has been extensively studied,^6,7,9,14 but there are fewer published recommendations regarding specific treatments for metastatic lesions of the tibia. In 2003, Kelly and colleagues8 described an algorithm based on the anatomical location of the lesion, with either internal fixation or IMN fixation representing the preferred management for lesions in the metaphyseal or diaphyseal regions. For epiphyseal or extensive proximal metaphyseal lesions, modular oncology endoprostheses are described as the procedure of choice. Piccioli and colleagues¹⁰ in 2013 and Beauchamp and Sim¹ in 1988 described a similar operative approach.

It is unknown if the algorithm of Kelly and colleagues⁸ was referenced during clinical decision-making, but it appears operative management mirrored these principles. Deviations from this general approach in the operative management of the patients in the present study included modifications such as the addition of a screw-plate construct to an IMN for better stability.

Surgical management depends largely on the anatomical location within the bone and on remaining bone stock. Generally, extensive proximal disease is managed with total knee endoprosthesis reconstruction, diaphyseal disease with IMN, and distal disease with internal fixation. Construct augmentation, such as the addition of cement or use of additional hardware, is decided case by case on the basis of desired stability and surrounding bone stock.

Study Limitations

Despite being a larger series, this single-institution study had a relatively small sample size, and its patient demographics and primary malignancies may reflect institutional recruitment bias. In addition, the study was limited by its retrospective design and some incomplete medical records. Eleven patients had only a bone or positron emission tomography scan depicting metastatic disease, limiting characterization of these lesions. One patient lacked radiologic images, and characterizations were based on written reports. As multiple physicians were involved in diagnosis and treatment, there were many inconsistencies in clinical decision-making across the group.

Conclusion

Metastasis to the tibia is a rare but significant event in a subset of patients over the course of their treatment and surveillance. Patients may present with pain secondary to either pathologic or impending pathologic fractures, and in such instances surgical intervention is often needed. Despite the historical reports of “acral” histologies, tibia lesions are not indicative of histology, and biopsy should be considered, especially if management will depend on histology. Patients with lower leg pain and known malignancy should be evaluated to rule out tibial metastasis, but screening examinations may be prudent for asymptomatic patients as well. Increased vigilance may be indicated for those with prostate, breast, or lung cancer. These lesions should be surgically managed case by case using fundamental tenets of both orthopedic fracture care and orthopedic oncology. Ideally, patients should be treated by a multidisciplinary team using a patient-centered approach.

Lumbar spinal stenosis (LSS) is a common debilitating issue in older patients. Open laminectomies traditionally are the standard treatment for LSS; however, minimally invasive surgery (MIS) has recently become a popular option to facilitate recovery and improve efficiency of care regarding spine procedures.

Guiot and colleagues described the technique for an MIS decompressive lumbar laminectomy procedure.¹ The surgery may represent an important strategy to improve the efficiency of care for patients with severe LSS. Several authors have reported clinical benefits with the MIS lumbar laminectomy, leading to a significant improvement in the Oswetry Disability Index (ODI) 25 in the degenerative stenosis group in cases of LSS.^2-5 In a recent reviewof 13 studies Wong and colleagues concluded that the MIS laminectomy was efficacious in terms of symptomatic relief and patient satisfaction for patients with LSS.⁶ Further, Rosen and colleaguesfound a significant improvement in the ODI scores and in the Short Form-36 body pain and physical functions scores in patients aged ≥ 75 years.⁷

Perioperative measures, including blood loss and narcotic consumption, have been shown to significantly decrease with MIS surgery compared with open decompression.^8,9 Decreased narcotic use is of particular interest for the geriatric population because it is expected to allow those patients to remain more physically active and mentally agile.¹⁰

Also, long-term success is important when assessing the efficacy of new MIS procedures. Oertel and colleagues found that 85% of patients reported long-term success after unilateral laminotomy of bilateral decompression (ULBD).¹¹ These results indicate that a MIS laminectomy is effective in older patients with LSS and neurogenic claudication.

Although there are numerous MIS approaches to alleviating LSS, more research is needed to determine whether it is superior to the open laminectomy.^9,12,13 Skovrliand and colleagues reviewed publications comparing ULBD and open laminectomies and determined that currently insufficient evidence exists to define which technique leads to more positive outcomes.¹⁴ Thus, the purpose of this study is 2-fold. First, this study adds to the current research by comparing estimated blood loss and length of stay (LOS) for microscopic MIS laminectomy vs traditional laminectomy. Second, this study aims to address the difference in health care costs between the 2 types of surgery in the VHA.

The U.S. health care system is facing several challenges and in particular pressure for cost reduction.¹⁵ VA hospitals are not exempt from those challenges, and their operating budgets are influenced by political and economic factors.¹⁶ Because of those challenges, cost-effectiveness is gaining importance.⁷ Future decisions for procedure coverage and reimbursement rates are likely to consider ratios like the cost to quality-adjusted life-years (QALY). Improving this ratio requires a reduction of cost and/or an improvement in outcome.

Minimally invasive spine surgery (MISS) may lower the cost of spine procedures. Wang and colleagues reported that minimally invasive posterior lumbar interbody fusion (PLIF) led to shorter stay and lower blood loss compared with traditional PLIF.¹⁷ These improvements led to about $8,000 in savings for a single-level PLIF.¹⁷

Lumbar degenerative disease is a frequently encountered condition, and lumbar laminectomy is one of the most frequently performed spine procedures at VA hospitals. Consequently, MISS may be an important strategy for the VA to face systematic challenges. At the Southern Arizona VA Health Care System (SAVAHCS) in Tucson, the authors converted lumbar laminectomies from traditional open surgery to a MIS procedure using a tubular retractor system and a paramedian approach. To the authors’ knowledge, no studies have evaluated outcomes and cost efficiency of MIS surgery at the VA. The results of such a study may be instrumental in choosing which surgery is appropriate in a patient-centered health care model.

Material and Methods

Fifty veterans with severe lumbar stenosis and neurogenic claudication underwent a 1- or 2-level laminectomy at SAVAHCS (Table). A traditional laminectomy was performed for all patients until conversion to the MIS procedure, then all subsequent patients underwent the microlaminectomy. There was 1 female patient in each group. The preoperative magnetic resonance imaging (MRI) of the patients showed severe spinal canal stenosis defined radiographically by the absence of cerebrospinal fluid signal at the affected level on MRI (Figures 1A and 2A) and clinically by the presence of neurogenic claudication.

Procedure

The open laminectomies were performed in a traditional midline approach with removal of the spinous process along with the lamina bilaterally to provide spinal canal decompression (Figure 2). 

The MISS laminectomies were performed through a small unilateral paramedian incision created 1.5 cm from the midline.¹ A tubular retractor system was used, and the laminectomy was performed under microscope magnification. A laminotomy initially was completed ipsilateral to the side of the incision until the ligamentum flavum and the lateral recess of the spinal canal were identified. The tube was then aimed medially so that the base of the spinous process was identified and

resected. The ligamentum flavum was dissected from the undersurface of the contralateral lamina. The contralateral lamina then was resected using a high-speed drill. Finally, the ligamentum flavum was resected, and the dura was exposed. The cranial-caudal extent of the resection was confirmed using fluoroscopy. The technique allowed for significant canal expansion (Figures 1A, B, C, and D).

 

The patients were given the choice of going home or being admitted. Overall admission costs were determined by the VA hospital following described models.¹⁸ The LOS in rehabilitation were determined from the records of the SAVAHCS rehabilitation center.

Results

There was not a significant difference in age between the 2 groups; mean age was 69.7 ± 9.8 years for the traditional laminectomy group and 64.4 ± 8.3 years for the MIS group. Operating room time was just over 2 hours on average in both groups. Blood loss was estimated and reported by the surgeon and the anesthesiologist, based on values from the surgical suction system. Patients in the MIS group lost on average 46 cc ± 70 cc compared with 135 cc ± 78 cc in the traditional group. The average number of operated levels was higher in the traditional group (1.7 ± 0.5) compared with the MIS group (1.4 ± 0.5), but this difference did not reach significance (P > .05).

Length of Stay and Cost

The LOS was lower for the MIS group, and 76% chose to be discharged from the recovery room. After a traditional laminectomy, the average patient’s stay was 3 days in the hospital and 5 days in the rehabilitation center. The average MIS group patient stayed < 1 day in the hospital. There were no readmissions within 30 days and no severe morbidity (including no new neurologic deficits or death) in the MIS cohort.

Only 1 MIS patient needed transfer to the rehabilitation center. The estimated cost of care (hospital and rehabilitation) for the traditional group was $10,846 compared with $1,961 for the MIS group.

Discussion

In the authors’ experience, the use of MISS microlaminectomy for the treatment of LSS seems to have led to shorter hospital stays and faster recoveries. Some of the possible reasons for faster patient mobilization included a reduction in postoperative pain and the absence of a wound drain. Larger dissections with a traditional laminectomy often lead to the placement of a wound drain, which requires an inpatient stay until the wound output reaches a certain threshold. The absence of a drain and the reduction in pain with the MISS approach allowed the providers to focus on early ambulation and discharge planning. The microlaminectomy technique allowed for a proper surgical decompression with less tissue dissection than is required for a traditional laminectomy. Previous studies have shown that the microlaminectomy technique provides significant symptomatic relief.^5-7,17

In most cases, the microlaminectomy can be performed on an outpatient basis. The improvement in bed availability is particularly important as surgical procedures may be delayed when hospitals operate at full capacity. Redesigning a procedure typically requiring hospital admission into an outpatient procedure improves availability, allowing for better patient access to health care.¹⁹

Other authors have studied opportunities to transform inpatient neurosurgical care into outpatient procedures. For instance, Purzner and colleagues presented a large series of successful outpatient neurosurgical cases, including craniotomies, cervical fusions, and lumbar microdiscectomies.²⁰ The MISS techniques offer a critical option to facilitate postoperative recovery and improve efficiency of care in regards to spine procedures.^5,17

Cost-Effectiveness Within the VHA

The VA has been described as one of the best health care systems in the U.S.⁹ The arguments in favor of the VA system include its integrated computerized system and its resistance to health care cost inflation over the years.²¹ The $186.5 billion 2018 fiscal year VA budget is surpassed only by the total DoD budget, and it is expected to rise substantially in the near future.²²

Redesigning a procedure typically requiring hospital admission into an outpatient procedure improves bed availability and reduces cost.¹⁹ The authors have demonstrated that a minimally invasive unilateral paramedian approach for the treatment of lumbar stenosis leads to shorter hospital stay, improved bed availability, and lower cost while allowing for a proper surgical decompression. These clinical results are in accord with previous MIS surgery studies.^5,17 The improvement in bed availability is particularly important within the VA system. Elective surgeries occasionally are delayed or cancelled because hospitals operate at full capacity. However, the authors’ outpatient microlaminectomy patients avoid delays or cancellations.

Given that both laminectomy procedures use similar operating room resources (time and material), the lower LOS associated with the microlaminectomy translates in cost saving. At SAVAHCS, acute care hospitalization is estimated at $3,000 per day when accounting for various costs, including nursing, pharmacy, ancillary services, and maintenance. The MIS procedure costs about $9,000 less than the open surgery. Over a 2-year period with 37 MIS patients, SAVAHCS saved about $300,000.

Patient Satisfaction

Patient satisfaction was assessed 1 day after the lumbar microdecompression outpatient surgery. Patients were asked to rate their overall surgical experience on a scale of 1 (worst) to 10 (best). All 24 patients who were contacted following outpatient lumbar microdecompression surgery rated the experience 10. These results indicate that patients do not expect or desire an admission following lumbar surgery, and they may recover comfortably at home. Studies are needed to compare outpatient and inpatient satisfaction ratings.

Conclusion

In this small sample, lumbar microlaminectomy significantly reduced LOS, successfully decompressed the spinal canal, and achieved symptomatic relief. Also, the procedure is associated with a lower blood loss than a traditional laminectomy and may reduce the rate of perioperative morbidity over time. In addition to faster recovery, the reduction in LOS can improve access to care by increasing the availability to inpatient admission.

Lumbar spinal stenosis (LSS) is a common debilitating issue in older patients. Open laminectomies traditionally are the standard treatment for LSS; however, minimally invasive surgery (MIS) has recently become a popular option to facilitate recovery and improve efficiency of care regarding spine procedures.

Guiot and colleagues described the technique for an MIS decompressive lumbar laminectomy procedure.¹ The surgery may represent an important strategy to improve the efficiency of care for patients with severe LSS. Several authors have reported clinical benefits with the MIS lumbar laminectomy, leading to a significant improvement in the Oswetry Disability Index (ODI) 25 in the degenerative stenosis group in cases of LSS.^2-5 In a recent reviewof 13 studies Wong and colleagues concluded that the MIS laminectomy was efficacious in terms of symptomatic relief and patient satisfaction for patients with LSS.⁶ Further, Rosen and colleaguesfound a significant improvement in the ODI scores and in the Short Form-36 body pain and physical functions scores in patients aged ≥ 75 years.⁷

Perioperative measures, including blood loss and narcotic consumption, have been shown to significantly decrease with MIS surgery compared with open decompression.^8,9 Decreased narcotic use is of particular interest for the geriatric population because it is expected to allow those patients to remain more physically active and mentally agile.¹⁰

Also, long-term success is important when assessing the efficacy of new MIS procedures. Oertel and colleagues found that 85% of patients reported long-term success after unilateral laminotomy of bilateral decompression (ULBD).¹¹ These results indicate that a MIS laminectomy is effective in older patients with LSS and neurogenic claudication.

Although there are numerous MIS approaches to alleviating LSS, more research is needed to determine whether it is superior to the open laminectomy.^9,12,13 Skovrliand and colleagues reviewed publications comparing ULBD and open laminectomies and determined that currently insufficient evidence exists to define which technique leads to more positive outcomes.¹⁴ Thus, the purpose of this study is 2-fold. First, this study adds to the current research by comparing estimated blood loss and length of stay (LOS) for microscopic MIS laminectomy vs traditional laminectomy. Second, this study aims to address the difference in health care costs between the 2 types of surgery in the VHA.

The U.S. health care system is facing several challenges and in particular pressure for cost reduction.¹⁵ VA hospitals are not exempt from those challenges, and their operating budgets are influenced by political and economic factors.¹⁶ Because of those challenges, cost-effectiveness is gaining importance.⁷ Future decisions for procedure coverage and reimbursement rates are likely to consider ratios like the cost to quality-adjusted life-years (QALY). Improving this ratio requires a reduction of cost and/or an improvement in outcome.

Minimally invasive spine surgery (MISS) may lower the cost of spine procedures. Wang and colleagues reported that minimally invasive posterior lumbar interbody fusion (PLIF) led to shorter stay and lower blood loss compared with traditional PLIF.¹⁷ These improvements led to about $8,000 in savings for a single-level PLIF.¹⁷

Lumbar degenerative disease is a frequently encountered condition, and lumbar laminectomy is one of the most frequently performed spine procedures at VA hospitals. Consequently, MISS may be an important strategy for the VA to face systematic challenges. At the Southern Arizona VA Health Care System (SAVAHCS) in Tucson, the authors converted lumbar laminectomies from traditional open surgery to a MIS procedure using a tubular retractor system and a paramedian approach. To the authors’ knowledge, no studies have evaluated outcomes and cost efficiency of MIS surgery at the VA. The results of such a study may be instrumental in choosing which surgery is appropriate in a patient-centered health care model.

Material and Methods

Fifty veterans with severe lumbar stenosis and neurogenic claudication underwent a 1- or 2-level laminectomy at SAVAHCS (Table). A traditional laminectomy was performed for all patients until conversion to the MIS procedure, then all subsequent patients underwent the microlaminectomy. There was 1 female patient in each group. The preoperative magnetic resonance imaging (MRI) of the patients showed severe spinal canal stenosis defined radiographically by the absence of cerebrospinal fluid signal at the affected level on MRI (Figures 1A and 2A) and clinically by the presence of neurogenic claudication.

Procedure

The open laminectomies were performed in a traditional midline approach with removal of the spinous process along with the lamina bilaterally to provide spinal canal decompression (Figure 2). 

The MISS laminectomies were performed through a small unilateral paramedian incision created 1.5 cm from the midline.¹ A tubular retractor system was used, and the laminectomy was performed under microscope magnification. A laminotomy initially was completed ipsilateral to the side of the incision until the ligamentum flavum and the lateral recess of the spinal canal were identified. The tube was then aimed medially so that the base of the spinous process was identified and

resected. The ligamentum flavum was dissected from the undersurface of the contralateral lamina. The contralateral lamina then was resected using a high-speed drill. Finally, the ligamentum flavum was resected, and the dura was exposed. The cranial-caudal extent of the resection was confirmed using fluoroscopy. The technique allowed for significant canal expansion (Figures 1A, B, C, and D).

 

The patients were given the choice of going home or being admitted. Overall admission costs were determined by the VA hospital following described models.¹⁸ The LOS in rehabilitation were determined from the records of the SAVAHCS rehabilitation center.

Results

There was not a significant difference in age between the 2 groups; mean age was 69.7 ± 9.8 years for the traditional laminectomy group and 64.4 ± 8.3 years for the MIS group. Operating room time was just over 2 hours on average in both groups. Blood loss was estimated and reported by the surgeon and the anesthesiologist, based on values from the surgical suction system. Patients in the MIS group lost on average 46 cc ± 70 cc compared with 135 cc ± 78 cc in the traditional group. The average number of operated levels was higher in the traditional group (1.7 ± 0.5) compared with the MIS group (1.4 ± 0.5), but this difference did not reach significance (P > .05).

Length of Stay and Cost

The LOS was lower for the MIS group, and 76% chose to be discharged from the recovery room. After a traditional laminectomy, the average patient’s stay was 3 days in the hospital and 5 days in the rehabilitation center. The average MIS group patient stayed < 1 day in the hospital. There were no readmissions within 30 days and no severe morbidity (including no new neurologic deficits or death) in the MIS cohort.

Only 1 MIS patient needed transfer to the rehabilitation center. The estimated cost of care (hospital and rehabilitation) for the traditional group was $10,846 compared with $1,961 for the MIS group.

Discussion

In the authors’ experience, the use of MISS microlaminectomy for the treatment of LSS seems to have led to shorter hospital stays and faster recoveries. Some of the possible reasons for faster patient mobilization included a reduction in postoperative pain and the absence of a wound drain. Larger dissections with a traditional laminectomy often lead to the placement of a wound drain, which requires an inpatient stay until the wound output reaches a certain threshold. The absence of a drain and the reduction in pain with the MISS approach allowed the providers to focus on early ambulation and discharge planning. The microlaminectomy technique allowed for a proper surgical decompression with less tissue dissection than is required for a traditional laminectomy. Previous studies have shown that the microlaminectomy technique provides significant symptomatic relief.^5-7,17

In most cases, the microlaminectomy can be performed on an outpatient basis. The improvement in bed availability is particularly important as surgical procedures may be delayed when hospitals operate at full capacity. Redesigning a procedure typically requiring hospital admission into an outpatient procedure improves availability, allowing for better patient access to health care.¹⁹

Other authors have studied opportunities to transform inpatient neurosurgical care into outpatient procedures. For instance, Purzner and colleagues presented a large series of successful outpatient neurosurgical cases, including craniotomies, cervical fusions, and lumbar microdiscectomies.²⁰ The MISS techniques offer a critical option to facilitate postoperative recovery and improve efficiency of care in regards to spine procedures.^5,17

Cost-Effectiveness Within the VHA

The VA has been described as one of the best health care systems in the U.S.⁹ The arguments in favor of the VA system include its integrated computerized system and its resistance to health care cost inflation over the years.²¹ The $186.5 billion 2018 fiscal year VA budget is surpassed only by the total DoD budget, and it is expected to rise substantially in the near future.²²

Redesigning a procedure typically requiring hospital admission into an outpatient procedure improves bed availability and reduces cost.¹⁹ The authors have demonstrated that a minimally invasive unilateral paramedian approach for the treatment of lumbar stenosis leads to shorter hospital stay, improved bed availability, and lower cost while allowing for a proper surgical decompression. These clinical results are in accord with previous MIS surgery studies.^5,17 The improvement in bed availability is particularly important within the VA system. Elective surgeries occasionally are delayed or cancelled because hospitals operate at full capacity. However, the authors’ outpatient microlaminectomy patients avoid delays or cancellations.

Given that both laminectomy procedures use similar operating room resources (time and material), the lower LOS associated with the microlaminectomy translates in cost saving. At SAVAHCS, acute care hospitalization is estimated at $3,000 per day when accounting for various costs, including nursing, pharmacy, ancillary services, and maintenance. The MIS procedure costs about $9,000 less than the open surgery. Over a 2-year period with 37 MIS patients, SAVAHCS saved about $300,000.

Patient Satisfaction

Patient satisfaction was assessed 1 day after the lumbar microdecompression outpatient surgery. Patients were asked to rate their overall surgical experience on a scale of 1 (worst) to 10 (best). All 24 patients who were contacted following outpatient lumbar microdecompression surgery rated the experience 10. These results indicate that patients do not expect or desire an admission following lumbar surgery, and they may recover comfortably at home. Studies are needed to compare outpatient and inpatient satisfaction ratings.

Conclusion

In this small sample, lumbar microlaminectomy significantly reduced LOS, successfully decompressed the spinal canal, and achieved symptomatic relief. Also, the procedure is associated with a lower blood loss than a traditional laminectomy and may reduce the rate of perioperative morbidity over time. In addition to faster recovery, the reduction in LOS can improve access to care by increasing the availability to inpatient admission.

Lumbar spinal stenosis (LSS) is a common debilitating issue in older patients. Open laminectomies traditionally are the standard treatment for LSS; however, minimally invasive surgery (MIS) has recently become a popular option to facilitate recovery and improve efficiency of care regarding spine procedures.

Guiot and colleagues described the technique for an MIS decompressive lumbar laminectomy procedure.¹ The surgery may represent an important strategy to improve the efficiency of care for patients with severe LSS. Several authors have reported clinical benefits with the MIS lumbar laminectomy, leading to a significant improvement in the Oswetry Disability Index (ODI) 25 in the degenerative stenosis group in cases of LSS.^2-5 In a recent reviewof 13 studies Wong and colleagues concluded that the MIS laminectomy was efficacious in terms of symptomatic relief and patient satisfaction for patients with LSS.⁶ Further, Rosen and colleaguesfound a significant improvement in the ODI scores and in the Short Form-36 body pain and physical functions scores in patients aged ≥ 75 years.⁷

Perioperative measures, including blood loss and narcotic consumption, have been shown to significantly decrease with MIS surgery compared with open decompression.^8,9 Decreased narcotic use is of particular interest for the geriatric population because it is expected to allow those patients to remain more physically active and mentally agile.¹⁰

Also, long-term success is important when assessing the efficacy of new MIS procedures. Oertel and colleagues found that 85% of patients reported long-term success after unilateral laminotomy of bilateral decompression (ULBD).¹¹ These results indicate that a MIS laminectomy is effective in older patients with LSS and neurogenic claudication.

Although there are numerous MIS approaches to alleviating LSS, more research is needed to determine whether it is superior to the open laminectomy.^9,12,13 Skovrliand and colleagues reviewed publications comparing ULBD and open laminectomies and determined that currently insufficient evidence exists to define which technique leads to more positive outcomes.¹⁴ Thus, the purpose of this study is 2-fold. First, this study adds to the current research by comparing estimated blood loss and length of stay (LOS) for microscopic MIS laminectomy vs traditional laminectomy. Second, this study aims to address the difference in health care costs between the 2 types of surgery in the VHA.

The U.S. health care system is facing several challenges and in particular pressure for cost reduction.¹⁵ VA hospitals are not exempt from those challenges, and their operating budgets are influenced by political and economic factors.¹⁶ Because of those challenges, cost-effectiveness is gaining importance.⁷ Future decisions for procedure coverage and reimbursement rates are likely to consider ratios like the cost to quality-adjusted life-years (QALY). Improving this ratio requires a reduction of cost and/or an improvement in outcome.

Minimally invasive spine surgery (MISS) may lower the cost of spine procedures. Wang and colleagues reported that minimally invasive posterior lumbar interbody fusion (PLIF) led to shorter stay and lower blood loss compared with traditional PLIF.¹⁷ These improvements led to about $8,000 in savings for a single-level PLIF.¹⁷

Lumbar degenerative disease is a frequently encountered condition, and lumbar laminectomy is one of the most frequently performed spine procedures at VA hospitals. Consequently, MISS may be an important strategy for the VA to face systematic challenges. At the Southern Arizona VA Health Care System (SAVAHCS) in Tucson, the authors converted lumbar laminectomies from traditional open surgery to a MIS procedure using a tubular retractor system and a paramedian approach. To the authors’ knowledge, no studies have evaluated outcomes and cost efficiency of MIS surgery at the VA. The results of such a study may be instrumental in choosing which surgery is appropriate in a patient-centered health care model.

Material and Methods

Fifty veterans with severe lumbar stenosis and neurogenic claudication underwent a 1- or 2-level laminectomy at SAVAHCS (Table). A traditional laminectomy was performed for all patients until conversion to the MIS procedure, then all subsequent patients underwent the microlaminectomy. There was 1 female patient in each group. The preoperative magnetic resonance imaging (MRI) of the patients showed severe spinal canal stenosis defined radiographically by the absence of cerebrospinal fluid signal at the affected level on MRI (Figures 1A and 2A) and clinically by the presence of neurogenic claudication.

Procedure

The open laminectomies were performed in a traditional midline approach with removal of the spinous process along with the lamina bilaterally to provide spinal canal decompression (Figure 2). 

The MISS laminectomies were performed through a small unilateral paramedian incision created 1.5 cm from the midline.¹ A tubular retractor system was used, and the laminectomy was performed under microscope magnification. A laminotomy initially was completed ipsilateral to the side of the incision until the ligamentum flavum and the lateral recess of the spinal canal were identified. The tube was then aimed medially so that the base of the spinous process was identified and

resected. The ligamentum flavum was dissected from the undersurface of the contralateral lamina. The contralateral lamina then was resected using a high-speed drill. Finally, the ligamentum flavum was resected, and the dura was exposed. The cranial-caudal extent of the resection was confirmed using fluoroscopy. The technique allowed for significant canal expansion (Figures 1A, B, C, and D).

 

The patients were given the choice of going home or being admitted. Overall admission costs were determined by the VA hospital following described models.¹⁸ The LOS in rehabilitation were determined from the records of the SAVAHCS rehabilitation center.

Results

There was not a significant difference in age between the 2 groups; mean age was 69.7 ± 9.8 years for the traditional laminectomy group and 64.4 ± 8.3 years for the MIS group. Operating room time was just over 2 hours on average in both groups. Blood loss was estimated and reported by the surgeon and the anesthesiologist, based on values from the surgical suction system. Patients in the MIS group lost on average 46 cc ± 70 cc compared with 135 cc ± 78 cc in the traditional group. The average number of operated levels was higher in the traditional group (1.7 ± 0.5) compared with the MIS group (1.4 ± 0.5), but this difference did not reach significance (P > .05).

Length of Stay and Cost

The LOS was lower for the MIS group, and 76% chose to be discharged from the recovery room. After a traditional laminectomy, the average patient’s stay was 3 days in the hospital and 5 days in the rehabilitation center. The average MIS group patient stayed < 1 day in the hospital. There were no readmissions within 30 days and no severe morbidity (including no new neurologic deficits or death) in the MIS cohort.

Only 1 MIS patient needed transfer to the rehabilitation center. The estimated cost of care (hospital and rehabilitation) for the traditional group was $10,846 compared with $1,961 for the MIS group.

Discussion

In the authors’ experience, the use of MISS microlaminectomy for the treatment of LSS seems to have led to shorter hospital stays and faster recoveries. Some of the possible reasons for faster patient mobilization included a reduction in postoperative pain and the absence of a wound drain. Larger dissections with a traditional laminectomy often lead to the placement of a wound drain, which requires an inpatient stay until the wound output reaches a certain threshold. The absence of a drain and the reduction in pain with the MISS approach allowed the providers to focus on early ambulation and discharge planning. The microlaminectomy technique allowed for a proper surgical decompression with less tissue dissection than is required for a traditional laminectomy. Previous studies have shown that the microlaminectomy technique provides significant symptomatic relief.^5-7,17

In most cases, the microlaminectomy can be performed on an outpatient basis. The improvement in bed availability is particularly important as surgical procedures may be delayed when hospitals operate at full capacity. Redesigning a procedure typically requiring hospital admission into an outpatient procedure improves availability, allowing for better patient access to health care.¹⁹

Other authors have studied opportunities to transform inpatient neurosurgical care into outpatient procedures. For instance, Purzner and colleagues presented a large series of successful outpatient neurosurgical cases, including craniotomies, cervical fusions, and lumbar microdiscectomies.²⁰ The MISS techniques offer a critical option to facilitate postoperative recovery and improve efficiency of care in regards to spine procedures.^5,17

Cost-Effectiveness Within the VHA

The VA has been described as one of the best health care systems in the U.S.⁹ The arguments in favor of the VA system include its integrated computerized system and its resistance to health care cost inflation over the years.²¹ The $186.5 billion 2018 fiscal year VA budget is surpassed only by the total DoD budget, and it is expected to rise substantially in the near future.²²

Redesigning a procedure typically requiring hospital admission into an outpatient procedure improves bed availability and reduces cost.¹⁹ The authors have demonstrated that a minimally invasive unilateral paramedian approach for the treatment of lumbar stenosis leads to shorter hospital stay, improved bed availability, and lower cost while allowing for a proper surgical decompression. These clinical results are in accord with previous MIS surgery studies.^5,17 The improvement in bed availability is particularly important within the VA system. Elective surgeries occasionally are delayed or cancelled because hospitals operate at full capacity. However, the authors’ outpatient microlaminectomy patients avoid delays or cancellations.

Given that both laminectomy procedures use similar operating room resources (time and material), the lower LOS associated with the microlaminectomy translates in cost saving. At SAVAHCS, acute care hospitalization is estimated at $3,000 per day when accounting for various costs, including nursing, pharmacy, ancillary services, and maintenance. The MIS procedure costs about $9,000 less than the open surgery. Over a 2-year period with 37 MIS patients, SAVAHCS saved about $300,000.

Patient Satisfaction

Patient satisfaction was assessed 1 day after the lumbar microdecompression outpatient surgery. Patients were asked to rate their overall surgical experience on a scale of 1 (worst) to 10 (best). All 24 patients who were contacted following outpatient lumbar microdecompression surgery rated the experience 10. These results indicate that patients do not expect or desire an admission following lumbar surgery, and they may recover comfortably at home. Studies are needed to compare outpatient and inpatient satisfaction ratings.

Conclusion

In this small sample, lumbar microlaminectomy significantly reduced LOS, successfully decompressed the spinal canal, and achieved symptomatic relief. Also, the procedure is associated with a lower blood loss than a traditional laminectomy and may reduce the rate of perioperative morbidity over time. In addition to faster recovery, the reduction in LOS can improve access to care by increasing the availability to inpatient admission.

Take-Home Points

• The incidence of geriatric hip fractures is rising nationally.
• Costs associated with hip fracture care have risen significantly.
• CMN and SHS are effective for stable, intertrochanteric hip fractures.
• Current trends show increased utilization of CMN compared to SHS for stable introchanteric hip fractures.
• Surgeon awareness of implant cost is a critical factor in delivering cost-effective, evidence-based surgical care.

The continuing increase in the population of patients older than 65 years in the United States is well known. For orthopedic surgeons, this trend highlights the importance of effective geriatric fracture care, particularly hip fracture care. Hip fractures in the elderly are expected to increase 50% by 2025 and to number 500,000 by 2040.¹ The growing burden of hip fracture cases is accompanied by increasing costs of care. In 2012, 88% of the healthcare dollars spent on these patients were for direct fracture care, a significant increase from 60% in 2009.² Although fewer than 1 in 5 fractures in the elderly are hip fractures, these injuries account for 72% of the total cost of geriatric fracture care, more than the total cost of all other osteoporosis-related injuries combined.¹ Currently, the direct cost of hip fracture care ranges from $8358 to $32,195 and is expected, in total, to reach $25 billion by 2025.^2,3

About 50% of geriatric hip fractures are extracapsular intertrochanteric or pertrochanteric.⁴ Several studies have compared sliding hip screws (SHSs) with cephalomedullary nails (CMNs) in the effective management of stable intertrochanteric fractures.^5-11 Although these implants have shown an increased risk for peri-implant fracture and subsequent reoperation, markers such as mortality, medical complications, and restoration of prefracture function have all been equivocal relative to SHSs.¹² Ultimately, one implant cannot be definitively recommended over the other for management of stable intertrochanteric hip fractures.^13,14 Nevertheless, the current trend increasingly favors CMNs over SHSs.^4,15 Most orthopedic surgeons are unaware of or underestimate the cost difference between these implants—a fact even more pronounced for newer implants.^4,16 Considering the ever growing cost burden of hip fractures in the United States, orthopedists must consider not only the efficacy of care but the cost of delivery.

We conducted a study to determine the effect that surgeon knowledge of implant cost had on rates of use of SHSs and CMNs in the management of stable intertrochanteric hip fractures. 

Patients and Methods

On May 1, 2012, all 9 attending orthopedic surgeons in a private practice group serving a suburban level II trauma center met to discuss implant prices and implant-related costs for the $850 Versafix SHS, the $1950 short Gamma3 nail (SGN), and the $2900 long Gamma3 nail (LGN), all manufactured by Stryker. All surgeons denied previous knowledge of the costs of these implants. During the discussion, no particular implant was recommended for management of any specific type of fracture. Surgeons were not directly instructed to consider implant cost in subsequent hip fracture surgeries and were not informed of our upcoming study of implant utilization.

After obtaining Institutional Review Board approval, we performed a retrospective chart and radiologic review of all hip fractures (Current Procedural Terminology [CPT] code 27244 or 27245) managed with fixation at our institution between May 1, 2011 and April 30, 2013. Two hundred six patients were identified (Figure 1).

Patients with complicated fractures, defined as ipsilateral femoral head, femoral neck, subtrochanteric, femoral shaft, or distal femur fractures, were excluded. In addition, patients who underwent ipsilateral stemmed total knee arthroplasty were excluded to prevent discrimination against LGN use. All 185 uncomplicated fractures were classified using available radiographs and computed tomography scans and the Orthopaedic Trauma Association (OTA) nomenclature for intertrochanteric hip fractures (Figure 2).¹⁷

Patients with unstable fracture patterns, defined as region 31 type A2.2, type A2.3, and all A3 types,¹⁴ were excluded. One hundred fifty-five patients with uncomplicated stable intertrochanteric hip fractures remained. After review of admission, physical therapy, and anesthesia records, patients who were nonambulators before surgery and patients with an American Society of Anesthesiologists (ASA) score of ≥4 were excluded. These exclusion criteria were used to eliminate cases in which the operative surgeon may have changed implant use secondary to lack of baseline ambulation or medical comorbidities. The eligible patient set was divided into 2 groups: patients treated before the educational meeting and after the educational meeting.

 

One year later, surgeons were again shown their respective hip fracture radiographs, with patient identifying data removed. They were asked to reclassify their respective cases using the OTA system and then indicate the implant they would use for operative fixation in each of their cases.

Patient age, sex, injury side, fracture types, and utilization rates of the SHS, SGN, and LGN implants were compared between the groups. For each eligible patient, implant cost and other financial data were obtained from the hospital’s finance department. Statistical analyses were performed with SPSS (Statistical Package for the Social Sciences) Version 20 for Macintosh. Independent 2-sample t test was used for parametric comparisons, and Fisher exact test was used for nonparametric comparisons.

Results

One hundred nineteen patients met the inclusion criteria: preoperative ambulation, uncomplicated stable intertrochanteric hip fracture managed with SHS or CMN fixation between May 1, 2011 and April 30, 2013, and ASA score of ≤3. Table 1 summarizes the population data of our study sample. Percentage of female patients was higher (P = .066) in the before-discussion group (78.9%) than in the after-discussion group (64.6%). Mean patient age was slightly higher (P = .808) in the after group (85.19 years) than in the before group (84.80 years). A majority (56.3%) of injuries were on the left side in the before group—a notable difference (P = .083) compared with the after group (45.8%). None of these differences was statistically significant.

The injuries most commonly treated in the before (35.2%) and after (39.6%) groups were 31-A2.1 fractures (P = .700), and the injuries least commonly treated in the before (16.9%) and after (14.6%) groups were 31-A1.3 fractures (P = .803). Table 2 summarizes the overall cohort’s implant use rates. Although percentage of use was fairly similar for SGN (36.1%), SHS (33.6%), and LGN (30.3%), these relationships changed in the before–after comparisons. Whereas 38.0% of uncomplicated stable intertrochanteric hip fractures were managed with SHS fixation during the calendar year before the meeting, only 27.1% of similar injuries were managed with the same fixation during the year after the meeting (P = .240). SGN was the implant least commonly used (29.6%) in the before group; by contrast, SGN use was 45.8% (P = .082) in the after group.

Examination of implant use per fracture classification revealed an interesting change. In the before group, SHS was the implant most commonly used for 31-A1.1 fractures (7/16, 43.8%), 31-A1.2 fractures (8/18, 44.4%), and 31-A2.1 fractures (10/25, 40.0%), and LGN was used in 66.7% (8/12) of 31-A1.3 fractures. By contrast, in the after group, SHS was most commonly used only for 31-A1.2 fractures (7/12, 58.3%), SGN was used in 90% (9/10) of 31-A1.1 fractures, and LGN was used in 42.1% (8/19) of 31-A2.1 fractures. In addition, 85.7% (6/7) of 31-A1.3 fractures were managed with a version of the Gamma nail.

 

Reclassification resulted in more A2.1 fractures (42.0% vs 37.0%) and fewer A1.3 fractures (10.1% vs 16.0%). About the same numbers of fractures were classified A1.1 (21.0% vs 21.8%) and A1.2 (26.9% vs 25.2%). SHS was favored for A1.1 fractures (92.0%) and A1.2 fractures (65.6%). SGN was favored for A1.3 fractures (75.0%). Gamma nails of both sizes were favored for A2.1 fractures (88.0%).

Discussion

Comparisons of SHS/plate and CMN constructs in the management of stable intertrochanteric hip fractures have long been discussed in the orthopedic literature. The major concern with CMNs (vs SHSs) is a statistically significantly higher rate of revision surgery, most often for peri-implant fracture. Rates of previous revision surgery for peri- implant fracture have ranged from 2.4% to 6% for CMNs and from 0.6% to 4% for SHSs.^5-7,9 In a Cochrane review of 22 studies (3749 patients), Parker and Handoll¹² compared CMN and SHS outcomes in 23 categories and found a statistically significant difference only in postoperative fracture rate. However, in a meta-analysis of studies conducted between 2000 and 2005, Bhandari and colleagues⁸ found no statistically significant difference in risk of femoral shaft fracture between CMNs (0.6%) and SHSs (0.1%). In addition, Utrilla and colleagues¹⁰ reported no postoperative fractures with use of Gamma3 CMNs. These recent studies may indicate that newer CMN designs can reduce the incidence of postoperative peri-implant fracture.^8,10 Other outcome measures, such as 1-year mortality, functional outcome, and medical complication rate, have shown no statistically significant differences between the 2 implants.^10-12 Ultimately, the current recommendation for fixation of stable intertrochanteric hip fractures is either SHS or CMN.^13,14

Of our study patients, 78.9% (before group) and 64.6% (after group) were female, and 49.3% (before group) and 47.9% (after group) were between 80 and 89 years of age. Similarly, a review of hip fracture Medicare claims made between 1999 and 2002 revealed that >75% of the patients were females and 48% to 49% were octogenarians.^4,18 However, our rates of different fracture types differed from those of Adams and colleagues.⁵ In a 1-year single-institution study, they found that, for both CMNs and SHSs, the most common stable intertrochanteric fractures were 31-A1.1 fractures; in our study’s before and after groups, more than one-third of injuries were 31-A2.1 fractures. Least common were 31-A1.3 fractures, both in the study by Adams and colleagues⁵ and in our before (16.9%) and after (14.6%) groups. Although our fracture rates differ from those of previous studies, all 4 classification categories fall under the umbrella of stable intertrochanteric hip fracture, which is the sole focus of this study.¹⁴ 

We hypothesized that cost would be a significant driver of implant choice in the management of these injuries. Given that SHS costs $1186.91 less than SGN and $1625.88 less than LGN at our institution, we expected that the before- discussion group’s overall SHS use rate of 38.0% would increase after discussion. Instead, SGN became the favored implant, with use in almost half of all fractures in the after group. Although the change in overall implant use rate was notable, these findings were not statistically significant. Examination of individual fracture patterns revealed 2 areas of interest. First, SHS was assumed to be the implant of choice in the management of the relatively simple 31-A1.1 fractures. Although this assumption was verified in the before group (SHS use in 43.8% of fractures), SGN was used in almost every case (90%) in the after group. However, when surgeons were asked 1 year later to recommend an implant for A1.1 fractures, 92% suggested SHS. The more cost-effective SHS construct may be the most amenable for use in these injury types given all intertrochanteric hip fracture patterns, though this has not been studied.

On the other hand, for 31-A2.1 fractures, perhaps the most complicated of the stable patterns, LGN became the implant of choice (42.1%). Despite surgeons’ awareness of the cost differences, management of these fractures shifted in the after group to the most expensive implant, indicative of surgeon concern about eventual loss of reduction with SHS and surgeon comfort with a particular procedure. This trend held when surgeons were asked to reclassify fractures 1 year later, as CMNs were recommended for 88% of 31-A2.1 fractures. Although both SHS and CMN were acceptable in 97% of the fractures included in this study, SGNs or LGNs were preferred for almost every fracture pattern involving the lesser trochanter. All 9 attending surgeons described involvement of the lesser trochanter as an indicator of posteromedial calcar injury. Surgeons became particularly concerned when this fracture pattern occurred in patients with significant osteopenia; SHS fixation, in their opinion, would be poor in the setting of a combination of greater posteromedial instability and poor bone quality. In a level I prospective, randomized trial, Barton and colleagues⁷ found no difference in outcomes between LGN and SHS fixation for 31-A2 proximal femur fractures and recommended SHS implants for the cost savings. In the clinical experience of this group, however, A1.3 and A2.1 fractures were at especially high risk for failure with SHS use, which necessitated greater implant stability through CMN fixation. On the other hand, for simpler fracture patterns, most surgeons suggested SHS implants. In their opinion, SGN and LGN implants offered no additional benefit of stability without evidence of posteromedial injury, even in the setting of osteopenia. For A1.2 fractures, posteromedial involvement was judged on the basis of size of the inferomedial spike or the extent of the inferomedial fracture line. Two surgeons preferred CMN for simple fractures, one because of the increased comfort with the implants and the other because of the minimally invasive surgical technique. Overall, our results indicate that knowledge of implant cost is not a strong enough factor to change surgeon behavior in selecting fixation for uncomplicated stable intertrochanteric hip fractures in previously ambulatory elderly patients. 

The lack of effect could be a consequence of surgeons’ training and comfort with various implants, especially among younger attending surgeons. Most of the attendings in the practice are under age 50 years, which correlates with a preference for CMN fixation.¹⁹ Case loads of >80 intertrochanteric hip fractures per calendar year, as in the after group, also correlates with more CMN use.¹⁹ However, the before group had more intertrochanteric hip fractures, and yet SHS was the implant of choice. Resident physician experience and comfort with various implants may play a role too, as teaching hospitals with resident assistance also correlate with CMN use.¹⁹ However, no major change in resident physician involvement was undertaken during this period. The institution studied is near a major metropolis in the Northeast, a region that has disfavored SHS in recent years.¹⁸ The change from before to after fits an overall trend in changing implant use. Anglen and colleagues¹⁵ found a significant decrease in SHS use, from 97% in 1999 to 33% in 2006, for intertrochanteric fracture fixation. Simultaneously, CMN use increased from 3% to 67%.

This study had several limitations. First, its overall sample size was small, and therefore any data fluctuations may be exaggerated. Furthermore, changes in utilization rates were compared over 2 years, which may not be long enough to show a changing trend in implant selection. Post hoc analysis of the sample size determined a power of 0.76 for an α of 0.05 and an effect size of 0.50. Second, radiologic classification was performed in a retrospective review, not officially by the operative surgeon. Fractures that we considered stable may have been considered unstable by the operative surgeon, influencing implant selection. Third, patients were selected from only one hospital, and orthopedic surgeons from other institutions may be more sensitive to cost considerations, changing implant selection more quickly. Fourth, initial selection of patients by CPT code might not have captured all those who satisfied the inclusion criteria. Fifth, only a single intervention was used, and follow-up meetings certainly could have increased the effectiveness of the intervention. Last, this and other retrospective studies are inherently weaker because of possible bias.

Conclusion

Our study results showed that implant cost is not a significant factor in implant selection for uncomplicated stable intertrochanteric hip fractures in previously ambulatory elderly patients. By itself, knowledge of implant cost may not be a strong enough force to change surgeon behavior or preference secondary to consequences of failure or comfort with particular implants. In an economic climate in which healthcare is scrutinized for both its medical effectiveness and cost-effectiveness, further study of forces that could influence orthopedic surgeons to select a more cost-effective implant is warranted.

Take-Home Points

• The incidence of geriatric hip fractures is rising nationally.
• Costs associated with hip fracture care have risen significantly.
• CMN and SHS are effective for stable, intertrochanteric hip fractures.
• Current trends show increased utilization of CMN compared to SHS for stable introchanteric hip fractures.
• Surgeon awareness of implant cost is a critical factor in delivering cost-effective, evidence-based surgical care.

The continuing increase in the population of patients older than 65 years in the United States is well known. For orthopedic surgeons, this trend highlights the importance of effective geriatric fracture care, particularly hip fracture care. Hip fractures in the elderly are expected to increase 50% by 2025 and to number 500,000 by 2040.¹ The growing burden of hip fracture cases is accompanied by increasing costs of care. In 2012, 88% of the healthcare dollars spent on these patients were for direct fracture care, a significant increase from 60% in 2009.² Although fewer than 1 in 5 fractures in the elderly are hip fractures, these injuries account for 72% of the total cost of geriatric fracture care, more than the total cost of all other osteoporosis-related injuries combined.¹ Currently, the direct cost of hip fracture care ranges from $8358 to $32,195 and is expected, in total, to reach $25 billion by 2025.^2,3

About 50% of geriatric hip fractures are extracapsular intertrochanteric or pertrochanteric.⁴ Several studies have compared sliding hip screws (SHSs) with cephalomedullary nails (CMNs) in the effective management of stable intertrochanteric fractures.^5-11 Although these implants have shown an increased risk for peri-implant fracture and subsequent reoperation, markers such as mortality, medical complications, and restoration of prefracture function have all been equivocal relative to SHSs.¹² Ultimately, one implant cannot be definitively recommended over the other for management of stable intertrochanteric hip fractures.^13,14 Nevertheless, the current trend increasingly favors CMNs over SHSs.^4,15 Most orthopedic surgeons are unaware of or underestimate the cost difference between these implants—a fact even more pronounced for newer implants.^4,16 Considering the ever growing cost burden of hip fractures in the United States, orthopedists must consider not only the efficacy of care but the cost of delivery.

We conducted a study to determine the effect that surgeon knowledge of implant cost had on rates of use of SHSs and CMNs in the management of stable intertrochanteric hip fractures. 

Patients and Methods

On May 1, 2012, all 9 attending orthopedic surgeons in a private practice group serving a suburban level II trauma center met to discuss implant prices and implant-related costs for the $850 Versafix SHS, the $1950 short Gamma3 nail (SGN), and the $2900 long Gamma3 nail (LGN), all manufactured by Stryker. All surgeons denied previous knowledge of the costs of these implants. During the discussion, no particular implant was recommended for management of any specific type of fracture. Surgeons were not directly instructed to consider implant cost in subsequent hip fracture surgeries and were not informed of our upcoming study of implant utilization.

After obtaining Institutional Review Board approval, we performed a retrospective chart and radiologic review of all hip fractures (Current Procedural Terminology [CPT] code 27244 or 27245) managed with fixation at our institution between May 1, 2011 and April 30, 2013. Two hundred six patients were identified (Figure 1).

Patients with complicated fractures, defined as ipsilateral femoral head, femoral neck, subtrochanteric, femoral shaft, or distal femur fractures, were excluded. In addition, patients who underwent ipsilateral stemmed total knee arthroplasty were excluded to prevent discrimination against LGN use. All 185 uncomplicated fractures were classified using available radiographs and computed tomography scans and the Orthopaedic Trauma Association (OTA) nomenclature for intertrochanteric hip fractures (Figure 2).¹⁷

Patients with unstable fracture patterns, defined as region 31 type A2.2, type A2.3, and all A3 types,¹⁴ were excluded. One hundred fifty-five patients with uncomplicated stable intertrochanteric hip fractures remained. After review of admission, physical therapy, and anesthesia records, patients who were nonambulators before surgery and patients with an American Society of Anesthesiologists (ASA) score of ≥4 were excluded. These exclusion criteria were used to eliminate cases in which the operative surgeon may have changed implant use secondary to lack of baseline ambulation or medical comorbidities. The eligible patient set was divided into 2 groups: patients treated before the educational meeting and after the educational meeting.

 

One year later, surgeons were again shown their respective hip fracture radiographs, with patient identifying data removed. They were asked to reclassify their respective cases using the OTA system and then indicate the implant they would use for operative fixation in each of their cases.

Patient age, sex, injury side, fracture types, and utilization rates of the SHS, SGN, and LGN implants were compared between the groups. For each eligible patient, implant cost and other financial data were obtained from the hospital’s finance department. Statistical analyses were performed with SPSS (Statistical Package for the Social Sciences) Version 20 for Macintosh. Independent 2-sample t test was used for parametric comparisons, and Fisher exact test was used for nonparametric comparisons.

Results

One hundred nineteen patients met the inclusion criteria: preoperative ambulation, uncomplicated stable intertrochanteric hip fracture managed with SHS or CMN fixation between May 1, 2011 and April 30, 2013, and ASA score of ≤3. Table 1 summarizes the population data of our study sample. Percentage of female patients was higher (P = .066) in the before-discussion group (78.9%) than in the after-discussion group (64.6%). Mean patient age was slightly higher (P = .808) in the after group (85.19 years) than in the before group (84.80 years). A majority (56.3%) of injuries were on the left side in the before group—a notable difference (P = .083) compared with the after group (45.8%). None of these differences was statistically significant.

The injuries most commonly treated in the before (35.2%) and after (39.6%) groups were 31-A2.1 fractures (P = .700), and the injuries least commonly treated in the before (16.9%) and after (14.6%) groups were 31-A1.3 fractures (P = .803). Table 2 summarizes the overall cohort’s implant use rates. Although percentage of use was fairly similar for SGN (36.1%), SHS (33.6%), and LGN (30.3%), these relationships changed in the before–after comparisons. Whereas 38.0% of uncomplicated stable intertrochanteric hip fractures were managed with SHS fixation during the calendar year before the meeting, only 27.1% of similar injuries were managed with the same fixation during the year after the meeting (P = .240). SGN was the implant least commonly used (29.6%) in the before group; by contrast, SGN use was 45.8% (P = .082) in the after group.

Examination of implant use per fracture classification revealed an interesting change. In the before group, SHS was the implant most commonly used for 31-A1.1 fractures (7/16, 43.8%), 31-A1.2 fractures (8/18, 44.4%), and 31-A2.1 fractures (10/25, 40.0%), and LGN was used in 66.7% (8/12) of 31-A1.3 fractures. By contrast, in the after group, SHS was most commonly used only for 31-A1.2 fractures (7/12, 58.3%), SGN was used in 90% (9/10) of 31-A1.1 fractures, and LGN was used in 42.1% (8/19) of 31-A2.1 fractures. In addition, 85.7% (6/7) of 31-A1.3 fractures were managed with a version of the Gamma nail.

 

Reclassification resulted in more A2.1 fractures (42.0% vs 37.0%) and fewer A1.3 fractures (10.1% vs 16.0%). About the same numbers of fractures were classified A1.1 (21.0% vs 21.8%) and A1.2 (26.9% vs 25.2%). SHS was favored for A1.1 fractures (92.0%) and A1.2 fractures (65.6%). SGN was favored for A1.3 fractures (75.0%). Gamma nails of both sizes were favored for A2.1 fractures (88.0%).

Discussion

Comparisons of SHS/plate and CMN constructs in the management of stable intertrochanteric hip fractures have long been discussed in the orthopedic literature. The major concern with CMNs (vs SHSs) is a statistically significantly higher rate of revision surgery, most often for peri-implant fracture. Rates of previous revision surgery for peri- implant fracture have ranged from 2.4% to 6% for CMNs and from 0.6% to 4% for SHSs.^5-7,9 In a Cochrane review of 22 studies (3749 patients), Parker and Handoll¹² compared CMN and SHS outcomes in 23 categories and found a statistically significant difference only in postoperative fracture rate. However, in a meta-analysis of studies conducted between 2000 and 2005, Bhandari and colleagues⁸ found no statistically significant difference in risk of femoral shaft fracture between CMNs (0.6%) and SHSs (0.1%). In addition, Utrilla and colleagues¹⁰ reported no postoperative fractures with use of Gamma3 CMNs. These recent studies may indicate that newer CMN designs can reduce the incidence of postoperative peri-implant fracture.^8,10 Other outcome measures, such as 1-year mortality, functional outcome, and medical complication rate, have shown no statistically significant differences between the 2 implants.^10-12 Ultimately, the current recommendation for fixation of stable intertrochanteric hip fractures is either SHS or CMN.^13,14

Of our study patients, 78.9% (before group) and 64.6% (after group) were female, and 49.3% (before group) and 47.9% (after group) were between 80 and 89 years of age. Similarly, a review of hip fracture Medicare claims made between 1999 and 2002 revealed that >75% of the patients were females and 48% to 49% were octogenarians.^4,18 However, our rates of different fracture types differed from those of Adams and colleagues.⁵ In a 1-year single-institution study, they found that, for both CMNs and SHSs, the most common stable intertrochanteric fractures were 31-A1.1 fractures; in our study’s before and after groups, more than one-third of injuries were 31-A2.1 fractures. Least common were 31-A1.3 fractures, both in the study by Adams and colleagues⁵ and in our before (16.9%) and after (14.6%) groups. Although our fracture rates differ from those of previous studies, all 4 classification categories fall under the umbrella of stable intertrochanteric hip fracture, which is the sole focus of this study.¹⁴ 

We hypothesized that cost would be a significant driver of implant choice in the management of these injuries. Given that SHS costs $1186.91 less than SGN and $1625.88 less than LGN at our institution, we expected that the before- discussion group’s overall SHS use rate of 38.0% would increase after discussion. Instead, SGN became the favored implant, with use in almost half of all fractures in the after group. Although the change in overall implant use rate was notable, these findings were not statistically significant. Examination of individual fracture patterns revealed 2 areas of interest. First, SHS was assumed to be the implant of choice in the management of the relatively simple 31-A1.1 fractures. Although this assumption was verified in the before group (SHS use in 43.8% of fractures), SGN was used in almost every case (90%) in the after group. However, when surgeons were asked 1 year later to recommend an implant for A1.1 fractures, 92% suggested SHS. The more cost-effective SHS construct may be the most amenable for use in these injury types given all intertrochanteric hip fracture patterns, though this has not been studied.

On the other hand, for 31-A2.1 fractures, perhaps the most complicated of the stable patterns, LGN became the implant of choice (42.1%). Despite surgeons’ awareness of the cost differences, management of these fractures shifted in the after group to the most expensive implant, indicative of surgeon concern about eventual loss of reduction with SHS and surgeon comfort with a particular procedure. This trend held when surgeons were asked to reclassify fractures 1 year later, as CMNs were recommended for 88% of 31-A2.1 fractures. Although both SHS and CMN were acceptable in 97% of the fractures included in this study, SGNs or LGNs were preferred for almost every fracture pattern involving the lesser trochanter. All 9 attending surgeons described involvement of the lesser trochanter as an indicator of posteromedial calcar injury. Surgeons became particularly concerned when this fracture pattern occurred in patients with significant osteopenia; SHS fixation, in their opinion, would be poor in the setting of a combination of greater posteromedial instability and poor bone quality. In a level I prospective, randomized trial, Barton and colleagues⁷ found no difference in outcomes between LGN and SHS fixation for 31-A2 proximal femur fractures and recommended SHS implants for the cost savings. In the clinical experience of this group, however, A1.3 and A2.1 fractures were at especially high risk for failure with SHS use, which necessitated greater implant stability through CMN fixation. On the other hand, for simpler fracture patterns, most surgeons suggested SHS implants. In their opinion, SGN and LGN implants offered no additional benefit of stability without evidence of posteromedial injury, even in the setting of osteopenia. For A1.2 fractures, posteromedial involvement was judged on the basis of size of the inferomedial spike or the extent of the inferomedial fracture line. Two surgeons preferred CMN for simple fractures, one because of the increased comfort with the implants and the other because of the minimally invasive surgical technique. Overall, our results indicate that knowledge of implant cost is not a strong enough factor to change surgeon behavior in selecting fixation for uncomplicated stable intertrochanteric hip fractures in previously ambulatory elderly patients. 

The lack of effect could be a consequence of surgeons’ training and comfort with various implants, especially among younger attending surgeons. Most of the attendings in the practice are under age 50 years, which correlates with a preference for CMN fixation.¹⁹ Case loads of >80 intertrochanteric hip fractures per calendar year, as in the after group, also correlates with more CMN use.¹⁹ However, the before group had more intertrochanteric hip fractures, and yet SHS was the implant of choice. Resident physician experience and comfort with various implants may play a role too, as teaching hospitals with resident assistance also correlate with CMN use.¹⁹ However, no major change in resident physician involvement was undertaken during this period. The institution studied is near a major metropolis in the Northeast, a region that has disfavored SHS in recent years.¹⁸ The change from before to after fits an overall trend in changing implant use. Anglen and colleagues¹⁵ found a significant decrease in SHS use, from 97% in 1999 to 33% in 2006, for intertrochanteric fracture fixation. Simultaneously, CMN use increased from 3% to 67%.

This study had several limitations. First, its overall sample size was small, and therefore any data fluctuations may be exaggerated. Furthermore, changes in utilization rates were compared over 2 years, which may not be long enough to show a changing trend in implant selection. Post hoc analysis of the sample size determined a power of 0.76 for an α of 0.05 and an effect size of 0.50. Second, radiologic classification was performed in a retrospective review, not officially by the operative surgeon. Fractures that we considered stable may have been considered unstable by the operative surgeon, influencing implant selection. Third, patients were selected from only one hospital, and orthopedic surgeons from other institutions may be more sensitive to cost considerations, changing implant selection more quickly. Fourth, initial selection of patients by CPT code might not have captured all those who satisfied the inclusion criteria. Fifth, only a single intervention was used, and follow-up meetings certainly could have increased the effectiveness of the intervention. Last, this and other retrospective studies are inherently weaker because of possible bias.

Conclusion

Our study results showed that implant cost is not a significant factor in implant selection for uncomplicated stable intertrochanteric hip fractures in previously ambulatory elderly patients. By itself, knowledge of implant cost may not be a strong enough force to change surgeon behavior or preference secondary to consequences of failure or comfort with particular implants. In an economic climate in which healthcare is scrutinized for both its medical effectiveness and cost-effectiveness, further study of forces that could influence orthopedic surgeons to select a more cost-effective implant is warranted.

Take-Home Points

• The incidence of geriatric hip fractures is rising nationally.
• Costs associated with hip fracture care have risen significantly.
• CMN and SHS are effective for stable, intertrochanteric hip fractures.
• Current trends show increased utilization of CMN compared to SHS for stable introchanteric hip fractures.
• Surgeon awareness of implant cost is a critical factor in delivering cost-effective, evidence-based surgical care.

The continuing increase in the population of patients older than 65 years in the United States is well known. For orthopedic surgeons, this trend highlights the importance of effective geriatric fracture care, particularly hip fracture care. Hip fractures in the elderly are expected to increase 50% by 2025 and to number 500,000 by 2040.¹ The growing burden of hip fracture cases is accompanied by increasing costs of care. In 2012, 88% of the healthcare dollars spent on these patients were for direct fracture care, a significant increase from 60% in 2009.² Although fewer than 1 in 5 fractures in the elderly are hip fractures, these injuries account for 72% of the total cost of geriatric fracture care, more than the total cost of all other osteoporosis-related injuries combined.¹ Currently, the direct cost of hip fracture care ranges from $8358 to $32,195 and is expected, in total, to reach $25 billion by 2025.^2,3

About 50% of geriatric hip fractures are extracapsular intertrochanteric or pertrochanteric.⁴ Several studies have compared sliding hip screws (SHSs) with cephalomedullary nails (CMNs) in the effective management of stable intertrochanteric fractures.^5-11 Although these implants have shown an increased risk for peri-implant fracture and subsequent reoperation, markers such as mortality, medical complications, and restoration of prefracture function have all been equivocal relative to SHSs.¹² Ultimately, one implant cannot be definitively recommended over the other for management of stable intertrochanteric hip fractures.^13,14 Nevertheless, the current trend increasingly favors CMNs over SHSs.^4,15 Most orthopedic surgeons are unaware of or underestimate the cost difference between these implants—a fact even more pronounced for newer implants.^4,16 Considering the ever growing cost burden of hip fractures in the United States, orthopedists must consider not only the efficacy of care but the cost of delivery.

We conducted a study to determine the effect that surgeon knowledge of implant cost had on rates of use of SHSs and CMNs in the management of stable intertrochanteric hip fractures. 

Patients and Methods

On May 1, 2012, all 9 attending orthopedic surgeons in a private practice group serving a suburban level II trauma center met to discuss implant prices and implant-related costs for the $850 Versafix SHS, the $1950 short Gamma3 nail (SGN), and the $2900 long Gamma3 nail (LGN), all manufactured by Stryker. All surgeons denied previous knowledge of the costs of these implants. During the discussion, no particular implant was recommended for management of any specific type of fracture. Surgeons were not directly instructed to consider implant cost in subsequent hip fracture surgeries and were not informed of our upcoming study of implant utilization.

After obtaining Institutional Review Board approval, we performed a retrospective chart and radiologic review of all hip fractures (Current Procedural Terminology [CPT] code 27244 or 27245) managed with fixation at our institution between May 1, 2011 and April 30, 2013. Two hundred six patients were identified (Figure 1).

Patients with complicated fractures, defined as ipsilateral femoral head, femoral neck, subtrochanteric, femoral shaft, or distal femur fractures, were excluded. In addition, patients who underwent ipsilateral stemmed total knee arthroplasty were excluded to prevent discrimination against LGN use. All 185 uncomplicated fractures were classified using available radiographs and computed tomography scans and the Orthopaedic Trauma Association (OTA) nomenclature for intertrochanteric hip fractures (Figure 2).¹⁷

Patients with unstable fracture patterns, defined as region 31 type A2.2, type A2.3, and all A3 types,¹⁴ were excluded. One hundred fifty-five patients with uncomplicated stable intertrochanteric hip fractures remained. After review of admission, physical therapy, and anesthesia records, patients who were nonambulators before surgery and patients with an American Society of Anesthesiologists (ASA) score of ≥4 were excluded. These exclusion criteria were used to eliminate cases in which the operative surgeon may have changed implant use secondary to lack of baseline ambulation or medical comorbidities. The eligible patient set was divided into 2 groups: patients treated before the educational meeting and after the educational meeting.

 

One year later, surgeons were again shown their respective hip fracture radiographs, with patient identifying data removed. They were asked to reclassify their respective cases using the OTA system and then indicate the implant they would use for operative fixation in each of their cases.

Patient age, sex, injury side, fracture types, and utilization rates of the SHS, SGN, and LGN implants were compared between the groups. For each eligible patient, implant cost and other financial data were obtained from the hospital’s finance department. Statistical analyses were performed with SPSS (Statistical Package for the Social Sciences) Version 20 for Macintosh. Independent 2-sample t test was used for parametric comparisons, and Fisher exact test was used for nonparametric comparisons.

Results

One hundred nineteen patients met the inclusion criteria: preoperative ambulation, uncomplicated stable intertrochanteric hip fracture managed with SHS or CMN fixation between May 1, 2011 and April 30, 2013, and ASA score of ≤3. Table 1 summarizes the population data of our study sample. Percentage of female patients was higher (P = .066) in the before-discussion group (78.9%) than in the after-discussion group (64.6%). Mean patient age was slightly higher (P = .808) in the after group (85.19 years) than in the before group (84.80 years). A majority (56.3%) of injuries were on the left side in the before group—a notable difference (P = .083) compared with the after group (45.8%). None of these differences was statistically significant.

The injuries most commonly treated in the before (35.2%) and after (39.6%) groups were 31-A2.1 fractures (P = .700), and the injuries least commonly treated in the before (16.9%) and after (14.6%) groups were 31-A1.3 fractures (P = .803). Table 2 summarizes the overall cohort’s implant use rates. Although percentage of use was fairly similar for SGN (36.1%), SHS (33.6%), and LGN (30.3%), these relationships changed in the before–after comparisons. Whereas 38.0% of uncomplicated stable intertrochanteric hip fractures were managed with SHS fixation during the calendar year before the meeting, only 27.1% of similar injuries were managed with the same fixation during the year after the meeting (P = .240). SGN was the implant least commonly used (29.6%) in the before group; by contrast, SGN use was 45.8% (P = .082) in the after group.

Examination of implant use per fracture classification revealed an interesting change. In the before group, SHS was the implant most commonly used for 31-A1.1 fractures (7/16, 43.8%), 31-A1.2 fractures (8/18, 44.4%), and 31-A2.1 fractures (10/25, 40.0%), and LGN was used in 66.7% (8/12) of 31-A1.3 fractures. By contrast, in the after group, SHS was most commonly used only for 31-A1.2 fractures (7/12, 58.3%), SGN was used in 90% (9/10) of 31-A1.1 fractures, and LGN was used in 42.1% (8/19) of 31-A2.1 fractures. In addition, 85.7% (6/7) of 31-A1.3 fractures were managed with a version of the Gamma nail.

 

Reclassification resulted in more A2.1 fractures (42.0% vs 37.0%) and fewer A1.3 fractures (10.1% vs 16.0%). About the same numbers of fractures were classified A1.1 (21.0% vs 21.8%) and A1.2 (26.9% vs 25.2%). SHS was favored for A1.1 fractures (92.0%) and A1.2 fractures (65.6%). SGN was favored for A1.3 fractures (75.0%). Gamma nails of both sizes were favored for A2.1 fractures (88.0%).

Discussion

Comparisons of SHS/plate and CMN constructs in the management of stable intertrochanteric hip fractures have long been discussed in the orthopedic literature. The major concern with CMNs (vs SHSs) is a statistically significantly higher rate of revision surgery, most often for peri-implant fracture. Rates of previous revision surgery for peri- implant fracture have ranged from 2.4% to 6% for CMNs and from 0.6% to 4% for SHSs.^5-7,9 In a Cochrane review of 22 studies (3749 patients), Parker and Handoll¹² compared CMN and SHS outcomes in 23 categories and found a statistically significant difference only in postoperative fracture rate. However, in a meta-analysis of studies conducted between 2000 and 2005, Bhandari and colleagues⁸ found no statistically significant difference in risk of femoral shaft fracture between CMNs (0.6%) and SHSs (0.1%). In addition, Utrilla and colleagues¹⁰ reported no postoperative fractures with use of Gamma3 CMNs. These recent studies may indicate that newer CMN designs can reduce the incidence of postoperative peri-implant fracture.^8,10 Other outcome measures, such as 1-year mortality, functional outcome, and medical complication rate, have shown no statistically significant differences between the 2 implants.^10-12 Ultimately, the current recommendation for fixation of stable intertrochanteric hip fractures is either SHS or CMN.^13,14

Of our study patients, 78.9% (before group) and 64.6% (after group) were female, and 49.3% (before group) and 47.9% (after group) were between 80 and 89 years of age. Similarly, a review of hip fracture Medicare claims made between 1999 and 2002 revealed that >75% of the patients were females and 48% to 49% were octogenarians.^4,18 However, our rates of different fracture types differed from those of Adams and colleagues.⁵ In a 1-year single-institution study, they found that, for both CMNs and SHSs, the most common stable intertrochanteric fractures were 31-A1.1 fractures; in our study’s before and after groups, more than one-third of injuries were 31-A2.1 fractures. Least common were 31-A1.3 fractures, both in the study by Adams and colleagues⁵ and in our before (16.9%) and after (14.6%) groups. Although our fracture rates differ from those of previous studies, all 4 classification categories fall under the umbrella of stable intertrochanteric hip fracture, which is the sole focus of this study.¹⁴ 

We hypothesized that cost would be a significant driver of implant choice in the management of these injuries. Given that SHS costs $1186.91 less than SGN and $1625.88 less than LGN at our institution, we expected that the before- discussion group’s overall SHS use rate of 38.0% would increase after discussion. Instead, SGN became the favored implant, with use in almost half of all fractures in the after group. Although the change in overall implant use rate was notable, these findings were not statistically significant. Examination of individual fracture patterns revealed 2 areas of interest. First, SHS was assumed to be the implant of choice in the management of the relatively simple 31-A1.1 fractures. Although this assumption was verified in the before group (SHS use in 43.8% of fractures), SGN was used in almost every case (90%) in the after group. However, when surgeons were asked 1 year later to recommend an implant for A1.1 fractures, 92% suggested SHS. The more cost-effective SHS construct may be the most amenable for use in these injury types given all intertrochanteric hip fracture patterns, though this has not been studied.

On the other hand, for 31-A2.1 fractures, perhaps the most complicated of the stable patterns, LGN became the implant of choice (42.1%). Despite surgeons’ awareness of the cost differences, management of these fractures shifted in the after group to the most expensive implant, indicative of surgeon concern about eventual loss of reduction with SHS and surgeon comfort with a particular procedure. This trend held when surgeons were asked to reclassify fractures 1 year later, as CMNs were recommended for 88% of 31-A2.1 fractures. Although both SHS and CMN were acceptable in 97% of the fractures included in this study, SGNs or LGNs were preferred for almost every fracture pattern involving the lesser trochanter. All 9 attending surgeons described involvement of the lesser trochanter as an indicator of posteromedial calcar injury. Surgeons became particularly concerned when this fracture pattern occurred in patients with significant osteopenia; SHS fixation, in their opinion, would be poor in the setting of a combination of greater posteromedial instability and poor bone quality. In a level I prospective, randomized trial, Barton and colleagues⁷ found no difference in outcomes between LGN and SHS fixation for 31-A2 proximal femur fractures and recommended SHS implants for the cost savings. In the clinical experience of this group, however, A1.3 and A2.1 fractures were at especially high risk for failure with SHS use, which necessitated greater implant stability through CMN fixation. On the other hand, for simpler fracture patterns, most surgeons suggested SHS implants. In their opinion, SGN and LGN implants offered no additional benefit of stability without evidence of posteromedial injury, even in the setting of osteopenia. For A1.2 fractures, posteromedial involvement was judged on the basis of size of the inferomedial spike or the extent of the inferomedial fracture line. Two surgeons preferred CMN for simple fractures, one because of the increased comfort with the implants and the other because of the minimally invasive surgical technique. Overall, our results indicate that knowledge of implant cost is not a strong enough factor to change surgeon behavior in selecting fixation for uncomplicated stable intertrochanteric hip fractures in previously ambulatory elderly patients. 

The lack of effect could be a consequence of surgeons’ training and comfort with various implants, especially among younger attending surgeons. Most of the attendings in the practice are under age 50 years, which correlates with a preference for CMN fixation.¹⁹ Case loads of >80 intertrochanteric hip fractures per calendar year, as in the after group, also correlates with more CMN use.¹⁹ However, the before group had more intertrochanteric hip fractures, and yet SHS was the implant of choice. Resident physician experience and comfort with various implants may play a role too, as teaching hospitals with resident assistance also correlate with CMN use.¹⁹ However, no major change in resident physician involvement was undertaken during this period. The institution studied is near a major metropolis in the Northeast, a region that has disfavored SHS in recent years.¹⁸ The change from before to after fits an overall trend in changing implant use. Anglen and colleagues¹⁵ found a significant decrease in SHS use, from 97% in 1999 to 33% in 2006, for intertrochanteric fracture fixation. Simultaneously, CMN use increased from 3% to 67%.

This study had several limitations. First, its overall sample size was small, and therefore any data fluctuations may be exaggerated. Furthermore, changes in utilization rates were compared over 2 years, which may not be long enough to show a changing trend in implant selection. Post hoc analysis of the sample size determined a power of 0.76 for an α of 0.05 and an effect size of 0.50. Second, radiologic classification was performed in a retrospective review, not officially by the operative surgeon. Fractures that we considered stable may have been considered unstable by the operative surgeon, influencing implant selection. Third, patients were selected from only one hospital, and orthopedic surgeons from other institutions may be more sensitive to cost considerations, changing implant selection more quickly. Fourth, initial selection of patients by CPT code might not have captured all those who satisfied the inclusion criteria. Fifth, only a single intervention was used, and follow-up meetings certainly could have increased the effectiveness of the intervention. Last, this and other retrospective studies are inherently weaker because of possible bias.

Conclusion

Our study results showed that implant cost is not a significant factor in implant selection for uncomplicated stable intertrochanteric hip fractures in previously ambulatory elderly patients. By itself, knowledge of implant cost may not be a strong enough force to change surgeon behavior or preference secondary to consequences of failure or comfort with particular implants. In an economic climate in which healthcare is scrutinized for both its medical effectiveness and cost-effectiveness, further study of forces that could influence orthopedic surgeons to select a more cost-effective implant is warranted.

Lichen planus (LP) is a chronic inflammatory dermatosis of unknown origin that involves the skin and mucous membranes, and lichenoid drug eruption (LDE) is an uncommon cutaneous adverse reaction to a medication.¹ The manifestations resemble each other clinically, and sometimes it is difficult to differentiate between them on histology. The pathogenesis still is not well characterized, especially the key initiating event that leads to the development of LP or LDE postimmunization. There have been reports of LP or LDEs after certain vaccines, especially the hepatitis B and influenza vaccines.^2-4 Both vaccines are routinely administered in the United States; more than 100 million individuals have received the hepatitis B vaccine in the United States since it became available in 1982,⁵ and the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention (CDC) recommends that all individuals 6 months or older receive an influenza vaccine every year.⁶ Currently, influenza vaccine coverage among adults 18 years or older reaches approximately 40% annually in the United States.⁶

Although certain viral infections (eg, hepatitis C virus) seem to play a role in the development of LP,^7,8 the link between LP and hepatitis B vaccination is less well recognized. Reports of LP and LDE after vaccination have been largely limited to case reports and case series.^2-4,9,10 Therefore, we aimed to characterize and review cases of LP and LDE following vaccination by analyzing the Vaccine Adverse Event Reporting System (VAERS) database.

Methods

The VAERS is a national vaccine safety surveillance database maintained jointly by the CDC and the US Food and Drug Administration to analyze adverse events (AEs) following immunizations. Serious AEs and deaths recorded in the VAERS were followed up periodically by VAERS staff. Information on vaccine-associated LP or LDE was retrieved from the VAERS database using the CDC WONDER online interface (http://wonder.cdc.gov/vaers.html). To examine if LP or LDE after vaccination occurred more frequently in patients with certain demographic risk factors, all reported cases of LP and LDE associated with vaccines administered from July 1990 to November 2014 were identified in the symptoms section of the VAERS system using the search terms lichen planus, oral lichen planus, and lichenoid drug eruption. Characteristics such as age, gender, time to onset, type of vaccine, method of diagnosis, and clinical outcome were collected.

The statistical package for social sciences (SPSS version 22) was utilized for the descriptive analysis. Fisher exact and χ² tests were used to evaluate statistical significance. A 2-sided P value of <.05 was considered statistically significant.

Results

There were 434,943 reported AEs following vaccination in the VAERS database from July 1990 to November 2014; among them, 33 cases involved LP or LDE. Of these vaccine-associated AEs, LP was diagnosed in 23 (69.7%) cases, while LDE and oral LP were diagnosed in 6 (18.2%) and 4 (12.1%) cases, respectively. Females represented slightly more than half (57.6% [19/33]) of the total cases. The median age of onset was 47 years. Approximately two-thirds of the identified cases were confirmed on skin biopsy and histology, while the rest were diagnosed either by a dermatologist or a primary care physician. The time to onset of symptoms ranged from 1 to 297 days after vaccination, with a median time of 14 days.

Patients with LP or LDE were significantly older compared to the reported AEs overall (P<.001); the median age of onset was 47 years for LP or LDE compared to 24 years for all reported AEs. Table 1 shows the various vaccines associated with LP or LDE. The hepatitis B, influenza, and herpes zoster vaccines were the 3 most common types of vaccines associated with these conditions. The hepatitis B vaccine accounted for 24.2% (8/33) of the reported events, followed by influenza (18.2% [6/33]) and herpes zoster (15.2% [5/33]) vaccines. In addition, there were 3 cases of cutaneous reaction after receiving the combination hepatitis A and hepatitis B vaccine. Table 2 presents details of the reported events associated with hepatitis B, influenza, herpes zoster, combination hepatitis A and hepatitis B, and hepatitis A vaccination.

Of 8 AEs associated with hepatitis B vaccination, 1 AE resulted in permanent disability and required hospitalization. Of 5 cases of AEs associated with herpes zoster vaccination, 1 AE resulted in permanent disability.

 

Comment

The estimated prevalence of LP ranges from 0.22% to 5% worldwide,^11-15 with an incidence of 0.032% to 0.037%.¹⁶ Although rare, LP and LDE can occur from certain medications or vaccines. Cases of LP have been reported after hepatitis B and influenza vaccinations. The first case of LP following hepatitis B vaccination was described by Ciaccio and Rebora¹⁷ in 1990. Since then, a total of 50 similar cases have been reported worldwide.² There also have been reports of LP following influenza, tetanus-diphtheria-pertussis, measles-mumps-rubella, and inactivated polio vaccines.^3,4,9,10 Table 3 summarizes cases of LP following various vaccinations.

The key initiating event of the pathogenesis for both LP and LDE is not completely understood. Both conditions share similar immunologic mechanisms of persistently activated CD8 autocytotoxic T lymphocytes against epidermal cells.¹⁸ These cells can induce apoptosis of basal epidermal keratinocytes and generate various cytokines (eg, IFN-γ, IL-5) to enhance expression of class II MHC molecules and antigen presentation to CD4 T cells.^19-22 It is conceivable that one of the initiating factors may be related to components in vaccines.

Hepatitis B, influenza, and herpes zoster vaccines were the 3 most common vaccines implicated in postimmunization LP or LDEs in our study. The excipients of these vaccines were compared based on the product inserts to identify any common components. It was found that all 3 vaccines contain either yeast protein or egg protein with various forms of phosphate buffers, while the hepatitis A and herpes zoster vaccines share Medical Research Council cell strain 5 (human diploid) cells as well as other cellular components.²³ Sato et al⁴ suggested that specific vaccine components, such as the vaccine itself or egg proteins, could have contributed to the development of LP following vaccination. It has been postulated that the protein S fraction of hepatitis B surface antigen plays a crucial role in the pathogenesis of both LP and LDE after hepatitis B vaccination.^2,24 It is likely that protein S shares common epitopes on keratinocytes that are recognized by the immune system, thus activating cytotoxic T lymphocytes and inducing apoptosis.^2,24

In this study, the median time to onset of vaccine-related LP was 14 days, which is consistent with a case series by Sato et al,⁴ suggesting that adverse reactions mainly occurred within 2 weeks after influenza vaccination. Onset of symptoms within 2 weeks of vaccination would therefore be a crucial clue for diagnosing possible vaccine-related LP or LDE. On the other hand, at least 4 patients in our study had onset of LP and LDE more than 1 month after vaccination; 2 of 4 cases even reported symptom onset at 175 and 297 days after hepatitis B vaccination, which were much longer than the 120 days reported by Tarakji et al.² It is not known if these cases constitute true vaccine-associated LP or LDE or if unmeasured confounding factors such as concurrent medications or comorbidities may have contributed to the development of these AEs.

It also is interesting to note that LP and LDE affected mainly middle-aged women. An increased risk of autoimmunity in female adults partly explains this observation.²⁵ Some vaccines, such as herpes zoster and influenza vaccines, generally are recommended for older adults who also are more likely to have multiple comorbidities or take multiple medications/supplements, which can potentially skew the prevalence of AEs toward an older age group. It should be noted, however, that LP and LDE were relatively uncommon AEs following vaccination in the current study. In this study, LP and LDE consisted of only 0.01% (N=42,230) of all AEs after hepatitis B vaccination, while the more common AEs such as pyrexia, nonspecific rashes, nonspecific gastrointestinal symptoms, and headache contributed to approximately 66.5% of all reported events.

One of the strengths of our study is that up to two-thirds of cases were confirmed histologically and all patients were seen and followed up by dermatologists or physicians. The VAERS is an easily accessible, up-to-date, and live reporting system that collects all AEs associated with vaccines in the United States. Important clinical and laboratory information usually is available in the database; however, the main limitation is that this study can only demonstrate a possible association but not a causal relationship between vaccination and LP or LDE. There can be various sources of biases such as underreporting, overreporting, or inaccurate reporting.^26,27 Pertinent clinical information (eg, new medications, new dental fillings/implants) that could potentially misrepresent the actual relationship between vaccination and development of AEs also was not available in the VAERS database. A cohort study with long-term follow-up or a large-scale case-control study would be useful in evaluating such associations.

Conclusion

Lichen planus and LDE can occur, albeit rarely, after vaccination, especially following hepatitis B vaccination. When middle-aged adults present to the clinic with LP or LDE, it is important to inquire about recent vaccination history in addition to a detailed medication history.

Lichen planus (LP) is a chronic inflammatory dermatosis of unknown origin that involves the skin and mucous membranes, and lichenoid drug eruption (LDE) is an uncommon cutaneous adverse reaction to a medication.¹ The manifestations resemble each other clinically, and sometimes it is difficult to differentiate between them on histology. The pathogenesis still is not well characterized, especially the key initiating event that leads to the development of LP or LDE postimmunization. There have been reports of LP or LDEs after certain vaccines, especially the hepatitis B and influenza vaccines.^2-4 Both vaccines are routinely administered in the United States; more than 100 million individuals have received the hepatitis B vaccine in the United States since it became available in 1982,⁵ and the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention (CDC) recommends that all individuals 6 months or older receive an influenza vaccine every year.⁶ Currently, influenza vaccine coverage among adults 18 years or older reaches approximately 40% annually in the United States.⁶

Although certain viral infections (eg, hepatitis C virus) seem to play a role in the development of LP,^7,8 the link between LP and hepatitis B vaccination is less well recognized. Reports of LP and LDE after vaccination have been largely limited to case reports and case series.^2-4,9,10 Therefore, we aimed to characterize and review cases of LP and LDE following vaccination by analyzing the Vaccine Adverse Event Reporting System (VAERS) database.

Methods

The VAERS is a national vaccine safety surveillance database maintained jointly by the CDC and the US Food and Drug Administration to analyze adverse events (AEs) following immunizations. Serious AEs and deaths recorded in the VAERS were followed up periodically by VAERS staff. Information on vaccine-associated LP or LDE was retrieved from the VAERS database using the CDC WONDER online interface (http://wonder.cdc.gov/vaers.html). To examine if LP or LDE after vaccination occurred more frequently in patients with certain demographic risk factors, all reported cases of LP and LDE associated with vaccines administered from July 1990 to November 2014 were identified in the symptoms section of the VAERS system using the search terms lichen planus, oral lichen planus, and lichenoid drug eruption. Characteristics such as age, gender, time to onset, type of vaccine, method of diagnosis, and clinical outcome were collected.

The statistical package for social sciences (SPSS version 22) was utilized for the descriptive analysis. Fisher exact and χ² tests were used to evaluate statistical significance. A 2-sided P value of <.05 was considered statistically significant.

Results

There were 434,943 reported AEs following vaccination in the VAERS database from July 1990 to November 2014; among them, 33 cases involved LP or LDE. Of these vaccine-associated AEs, LP was diagnosed in 23 (69.7%) cases, while LDE and oral LP were diagnosed in 6 (18.2%) and 4 (12.1%) cases, respectively. Females represented slightly more than half (57.6% [19/33]) of the total cases. The median age of onset was 47 years. Approximately two-thirds of the identified cases were confirmed on skin biopsy and histology, while the rest were diagnosed either by a dermatologist or a primary care physician. The time to onset of symptoms ranged from 1 to 297 days after vaccination, with a median time of 14 days.

Patients with LP or LDE were significantly older compared to the reported AEs overall (P<.001); the median age of onset was 47 years for LP or LDE compared to 24 years for all reported AEs. Table 1 shows the various vaccines associated with LP or LDE. The hepatitis B, influenza, and herpes zoster vaccines were the 3 most common types of vaccines associated with these conditions. The hepatitis B vaccine accounted for 24.2% (8/33) of the reported events, followed by influenza (18.2% [6/33]) and herpes zoster (15.2% [5/33]) vaccines. In addition, there were 3 cases of cutaneous reaction after receiving the combination hepatitis A and hepatitis B vaccine. Table 2 presents details of the reported events associated with hepatitis B, influenza, herpes zoster, combination hepatitis A and hepatitis B, and hepatitis A vaccination.

Of 8 AEs associated with hepatitis B vaccination, 1 AE resulted in permanent disability and required hospitalization. Of 5 cases of AEs associated with herpes zoster vaccination, 1 AE resulted in permanent disability.

 

Comment

The estimated prevalence of LP ranges from 0.22% to 5% worldwide,^11-15 with an incidence of 0.032% to 0.037%.¹⁶ Although rare, LP and LDE can occur from certain medications or vaccines. Cases of LP have been reported after hepatitis B and influenza vaccinations. The first case of LP following hepatitis B vaccination was described by Ciaccio and Rebora¹⁷ in 1990. Since then, a total of 50 similar cases have been reported worldwide.² There also have been reports of LP following influenza, tetanus-diphtheria-pertussis, measles-mumps-rubella, and inactivated polio vaccines.^3,4,9,10 Table 3 summarizes cases of LP following various vaccinations.

The key initiating event of the pathogenesis for both LP and LDE is not completely understood. Both conditions share similar immunologic mechanisms of persistently activated CD8 autocytotoxic T lymphocytes against epidermal cells.¹⁸ These cells can induce apoptosis of basal epidermal keratinocytes and generate various cytokines (eg, IFN-γ, IL-5) to enhance expression of class II MHC molecules and antigen presentation to CD4 T cells.^19-22 It is conceivable that one of the initiating factors may be related to components in vaccines.

Hepatitis B, influenza, and herpes zoster vaccines were the 3 most common vaccines implicated in postimmunization LP or LDEs in our study. The excipients of these vaccines were compared based on the product inserts to identify any common components. It was found that all 3 vaccines contain either yeast protein or egg protein with various forms of phosphate buffers, while the hepatitis A and herpes zoster vaccines share Medical Research Council cell strain 5 (human diploid) cells as well as other cellular components.²³ Sato et al⁴ suggested that specific vaccine components, such as the vaccine itself or egg proteins, could have contributed to the development of LP following vaccination. It has been postulated that the protein S fraction of hepatitis B surface antigen plays a crucial role in the pathogenesis of both LP and LDE after hepatitis B vaccination.^2,24 It is likely that protein S shares common epitopes on keratinocytes that are recognized by the immune system, thus activating cytotoxic T lymphocytes and inducing apoptosis.^2,24

In this study, the median time to onset of vaccine-related LP was 14 days, which is consistent with a case series by Sato et al,⁴ suggesting that adverse reactions mainly occurred within 2 weeks after influenza vaccination. Onset of symptoms within 2 weeks of vaccination would therefore be a crucial clue for diagnosing possible vaccine-related LP or LDE. On the other hand, at least 4 patients in our study had onset of LP and LDE more than 1 month after vaccination; 2 of 4 cases even reported symptom onset at 175 and 297 days after hepatitis B vaccination, which were much longer than the 120 days reported by Tarakji et al.² It is not known if these cases constitute true vaccine-associated LP or LDE or if unmeasured confounding factors such as concurrent medications or comorbidities may have contributed to the development of these AEs.

It also is interesting to note that LP and LDE affected mainly middle-aged women. An increased risk of autoimmunity in female adults partly explains this observation.²⁵ Some vaccines, such as herpes zoster and influenza vaccines, generally are recommended for older adults who also are more likely to have multiple comorbidities or take multiple medications/supplements, which can potentially skew the prevalence of AEs toward an older age group. It should be noted, however, that LP and LDE were relatively uncommon AEs following vaccination in the current study. In this study, LP and LDE consisted of only 0.01% (N=42,230) of all AEs after hepatitis B vaccination, while the more common AEs such as pyrexia, nonspecific rashes, nonspecific gastrointestinal symptoms, and headache contributed to approximately 66.5% of all reported events.

One of the strengths of our study is that up to two-thirds of cases were confirmed histologically and all patients were seen and followed up by dermatologists or physicians. The VAERS is an easily accessible, up-to-date, and live reporting system that collects all AEs associated with vaccines in the United States. Important clinical and laboratory information usually is available in the database; however, the main limitation is that this study can only demonstrate a possible association but not a causal relationship between vaccination and LP or LDE. There can be various sources of biases such as underreporting, overreporting, or inaccurate reporting.^26,27 Pertinent clinical information (eg, new medications, new dental fillings/implants) that could potentially misrepresent the actual relationship between vaccination and development of AEs also was not available in the VAERS database. A cohort study with long-term follow-up or a large-scale case-control study would be useful in evaluating such associations.

Conclusion

Lichen planus and LDE can occur, albeit rarely, after vaccination, especially following hepatitis B vaccination. When middle-aged adults present to the clinic with LP or LDE, it is important to inquire about recent vaccination history in addition to a detailed medication history.

Lichen planus (LP) is a chronic inflammatory dermatosis of unknown origin that involves the skin and mucous membranes, and lichenoid drug eruption (LDE) is an uncommon cutaneous adverse reaction to a medication.¹ The manifestations resemble each other clinically, and sometimes it is difficult to differentiate between them on histology. The pathogenesis still is not well characterized, especially the key initiating event that leads to the development of LP or LDE postimmunization. There have been reports of LP or LDEs after certain vaccines, especially the hepatitis B and influenza vaccines.^2-4 Both vaccines are routinely administered in the United States; more than 100 million individuals have received the hepatitis B vaccine in the United States since it became available in 1982,⁵ and the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention (CDC) recommends that all individuals 6 months or older receive an influenza vaccine every year.⁶ Currently, influenza vaccine coverage among adults 18 years or older reaches approximately 40% annually in the United States.⁶

Although certain viral infections (eg, hepatitis C virus) seem to play a role in the development of LP,^7,8 the link between LP and hepatitis B vaccination is less well recognized. Reports of LP and LDE after vaccination have been largely limited to case reports and case series.^2-4,9,10 Therefore, we aimed to characterize and review cases of LP and LDE following vaccination by analyzing the Vaccine Adverse Event Reporting System (VAERS) database.

Methods

The VAERS is a national vaccine safety surveillance database maintained jointly by the CDC and the US Food and Drug Administration to analyze adverse events (AEs) following immunizations. Serious AEs and deaths recorded in the VAERS were followed up periodically by VAERS staff. Information on vaccine-associated LP or LDE was retrieved from the VAERS database using the CDC WONDER online interface (http://wonder.cdc.gov/vaers.html). To examine if LP or LDE after vaccination occurred more frequently in patients with certain demographic risk factors, all reported cases of LP and LDE associated with vaccines administered from July 1990 to November 2014 were identified in the symptoms section of the VAERS system using the search terms lichen planus, oral lichen planus, and lichenoid drug eruption. Characteristics such as age, gender, time to onset, type of vaccine, method of diagnosis, and clinical outcome were collected.

The statistical package for social sciences (SPSS version 22) was utilized for the descriptive analysis. Fisher exact and χ² tests were used to evaluate statistical significance. A 2-sided P value of <.05 was considered statistically significant.

Results

There were 434,943 reported AEs following vaccination in the VAERS database from July 1990 to November 2014; among them, 33 cases involved LP or LDE. Of these vaccine-associated AEs, LP was diagnosed in 23 (69.7%) cases, while LDE and oral LP were diagnosed in 6 (18.2%) and 4 (12.1%) cases, respectively. Females represented slightly more than half (57.6% [19/33]) of the total cases. The median age of onset was 47 years. Approximately two-thirds of the identified cases were confirmed on skin biopsy and histology, while the rest were diagnosed either by a dermatologist or a primary care physician. The time to onset of symptoms ranged from 1 to 297 days after vaccination, with a median time of 14 days.

Patients with LP or LDE were significantly older compared to the reported AEs overall (P<.001); the median age of onset was 47 years for LP or LDE compared to 24 years for all reported AEs. Table 1 shows the various vaccines associated with LP or LDE. The hepatitis B, influenza, and herpes zoster vaccines were the 3 most common types of vaccines associated with these conditions. The hepatitis B vaccine accounted for 24.2% (8/33) of the reported events, followed by influenza (18.2% [6/33]) and herpes zoster (15.2% [5/33]) vaccines. In addition, there were 3 cases of cutaneous reaction after receiving the combination hepatitis A and hepatitis B vaccine. Table 2 presents details of the reported events associated with hepatitis B, influenza, herpes zoster, combination hepatitis A and hepatitis B, and hepatitis A vaccination.

Of 8 AEs associated with hepatitis B vaccination, 1 AE resulted in permanent disability and required hospitalization. Of 5 cases of AEs associated with herpes zoster vaccination, 1 AE resulted in permanent disability.

 

Comment

The estimated prevalence of LP ranges from 0.22% to 5% worldwide,^11-15 with an incidence of 0.032% to 0.037%.¹⁶ Although rare, LP and LDE can occur from certain medications or vaccines. Cases of LP have been reported after hepatitis B and influenza vaccinations. The first case of LP following hepatitis B vaccination was described by Ciaccio and Rebora¹⁷ in 1990. Since then, a total of 50 similar cases have been reported worldwide.² There also have been reports of LP following influenza, tetanus-diphtheria-pertussis, measles-mumps-rubella, and inactivated polio vaccines.^3,4,9,10 Table 3 summarizes cases of LP following various vaccinations.

The key initiating event of the pathogenesis for both LP and LDE is not completely understood. Both conditions share similar immunologic mechanisms of persistently activated CD8 autocytotoxic T lymphocytes against epidermal cells.¹⁸ These cells can induce apoptosis of basal epidermal keratinocytes and generate various cytokines (eg, IFN-γ, IL-5) to enhance expression of class II MHC molecules and antigen presentation to CD4 T cells.^19-22 It is conceivable that one of the initiating factors may be related to components in vaccines.

Hepatitis B, influenza, and herpes zoster vaccines were the 3 most common vaccines implicated in postimmunization LP or LDEs in our study. The excipients of these vaccines were compared based on the product inserts to identify any common components. It was found that all 3 vaccines contain either yeast protein or egg protein with various forms of phosphate buffers, while the hepatitis A and herpes zoster vaccines share Medical Research Council cell strain 5 (human diploid) cells as well as other cellular components.²³ Sato et al⁴ suggested that specific vaccine components, such as the vaccine itself or egg proteins, could have contributed to the development of LP following vaccination. It has been postulated that the protein S fraction of hepatitis B surface antigen plays a crucial role in the pathogenesis of both LP and LDE after hepatitis B vaccination.^2,24 It is likely that protein S shares common epitopes on keratinocytes that are recognized by the immune system, thus activating cytotoxic T lymphocytes and inducing apoptosis.^2,24

In this study, the median time to onset of vaccine-related LP was 14 days, which is consistent with a case series by Sato et al,⁴ suggesting that adverse reactions mainly occurred within 2 weeks after influenza vaccination. Onset of symptoms within 2 weeks of vaccination would therefore be a crucial clue for diagnosing possible vaccine-related LP or LDE. On the other hand, at least 4 patients in our study had onset of LP and LDE more than 1 month after vaccination; 2 of 4 cases even reported symptom onset at 175 and 297 days after hepatitis B vaccination, which were much longer than the 120 days reported by Tarakji et al.² It is not known if these cases constitute true vaccine-associated LP or LDE or if unmeasured confounding factors such as concurrent medications or comorbidities may have contributed to the development of these AEs.

It also is interesting to note that LP and LDE affected mainly middle-aged women. An increased risk of autoimmunity in female adults partly explains this observation.²⁵ Some vaccines, such as herpes zoster and influenza vaccines, generally are recommended for older adults who also are more likely to have multiple comorbidities or take multiple medications/supplements, which can potentially skew the prevalence of AEs toward an older age group. It should be noted, however, that LP and LDE were relatively uncommon AEs following vaccination in the current study. In this study, LP and LDE consisted of only 0.01% (N=42,230) of all AEs after hepatitis B vaccination, while the more common AEs such as pyrexia, nonspecific rashes, nonspecific gastrointestinal symptoms, and headache contributed to approximately 66.5% of all reported events.

One of the strengths of our study is that up to two-thirds of cases were confirmed histologically and all patients were seen and followed up by dermatologists or physicians. The VAERS is an easily accessible, up-to-date, and live reporting system that collects all AEs associated with vaccines in the United States. Important clinical and laboratory information usually is available in the database; however, the main limitation is that this study can only demonstrate a possible association but not a causal relationship between vaccination and LP or LDE. There can be various sources of biases such as underreporting, overreporting, or inaccurate reporting.^26,27 Pertinent clinical information (eg, new medications, new dental fillings/implants) that could potentially misrepresent the actual relationship between vaccination and development of AEs also was not available in the VAERS database. A cohort study with long-term follow-up or a large-scale case-control study would be useful in evaluating such associations.

Conclusion

Lichen planus and LDE can occur, albeit rarely, after vaccination, especially following hepatitis B vaccination. When middle-aged adults present to the clinic with LP or LDE, it is important to inquire about recent vaccination history in addition to a detailed medication history.

Take-Home Points

• Injuries to the medial knee are the most common knee ligament injuries, and often occur in the athletic population.
• Complete posteromedial corner injuries require surgical treatment to restore joint stability and biomechanics.
• Biomechanical evidence has demonstrated an important load-sharing distribution between the sMCL and the POL.
• Valgus instability caused by a medial side injury, can lead to both ACL/posterior cruciate ligament reconstruction graft failure if the medial sided injury is not concurrently repaired or reconstructed.
• Anatomic posteromedial corner reconstruction yields excellent biomechanical and patient-reported outcomes.

Most injuries of the medial structures of the knee are treated conservatively.^1-3 In severe acute injuries and chronic symptomatic instabilities, however, surgical treatment is needed to restore knee stability and to prevent degenerative changes secondary to instability.⁴ Three structures involved in medial stability are the superficial medial collateral ligament (sMCL), which is the primary valgus restraint; the posterior oblique ligament (POL), which is the primary restraint to internal rotation and the secondary valgus restraint; and the semimembranosus.^5,6

Surgical techniques for posteromedial knee reconstruction include direct repair,⁷ repair with augmentation,^8,9 advancement of the tibial insertion of the sMCL,¹⁰ and transfer of the pes anserine tendons.¹¹ In anatomical reconstruction of the posteromedial corner, which has been described before, the sMCL and the POL are reconstructed to reproduce the native motion and stability of the knee.¹² Clinically, repair and reconstruction have similar patient-reported outcomes and medial opening evaluations over the short term.

These approaches require large incisions and extensive dissection of soft tissue on the medial aspect of the knee.⁵ Given these drawbacks, it is reasonable to consider less invasive options. Minimally invasive surgery has the advantages of reduced scarring and blood loss, less disruption of surrounding tissue, faster recovery, and improved aesthetics.⁴

We conducted a study of a minimally invasive technique for reconstructing the posteromedial structures of the knee. We compared medial compartment stability measured on valgus stress radiographs in intact, sectioned, and reconstructed states in cadaveric knees. We hypothesized that a minimally invasive technique using autogenous hamstring graft in the appropriate anatomical location would return valgus stability to its nearly native state.

Materials and Methods

This study was conducted at the Buenos Aires British Hospital in Buenos Aires, Argentina, and at the University of Colorado Hospital in Aurora. Ten fresh-frozen cadaveric knees with no evidence of ligamentous injuries, osteoarthritis, or previous surgery were used. Mean donor age was 69.4 years (range, 45-87 years). Each specimen was maintained at room temperature for 24 hours before use. The femur was sectioned 20 cm proximal to the knee joint. The tibia was sectioned 12.5 cm distal to the knee joint.

Identification and Sectioning of Posteromedial Structures

Anatomical insertion sites of the sMCL, the deep MCL (dMCL), and the POL were identified on the tibia through an oblique 3-cm incision on the posteromedial aspect of the knee (Figures 1A-1C). A valgus stress radiograph with medial compartment gap measurement was obtained for each of the 10 knees before sectioning the medial stabilizing structures.

After intact-state evaluation, each knee’s sMCL, dMCL, and POL were sectioned at their tibial insertion. Valgus stress radiograph was repeated and medial compartment gap was remeasured for comparison of the sectioned state with the intact and reconstructed states.

Anatomical Reconstruction With Mini-Invasive Technique

After sectioning of medial stabilizing structures, minimally invasive reconstruction was performed through 2 small incisions on the medial aspect of each of the 10 knees, as follows. First, the semitendinosus tendon was identified through the oblique incision that had been used for sectioning. Then, an open-ended tendon stripper was placed around the circumference of the semitendinosus and was passed proximomedially, transecting the tendon at its musculotendinous junction. While the tendon stripper was being passed, care was taken to maintain the nearby tibial insertion of the sartorius fascia (Figures 1D-1F).

The proximal end of the semitendinosus tendon (~5 cm proximal to incision) was then cleared of all muscular and fatty soft-tissue remnants and whipstitched with No. 2 Vycril suture (Figure 2). Then, the medial epicondyle was visualized and identified under radiographic guidance. A 1-cm incision was made 10 mm posterior and 2 mm proximal to the epicondyle (midpoint of femoral attachment of sMCL and POL).¹² A 1.8-mm Kirschner wire was inserted into the femur at this location. A blunt awl was used for deep (under sartorius fascia) passage of the semitendinosus tendon, from distal to proximal, and the tendon was looped over the top of the wire and brought through the incision.

With the semitendinosus tendon looped around the wire, isometricity was tested by pulling the suture within the tendon and moving the knee through a full range of motion. The isometric point was confirmed by tendon migration of <2 mm.¹³ Migration was measured by marking the graft 2 mm from its insertion; the graft was then pulled to ensure correct isometric point position. An 18-mm cannulated spiked screw and washer (Arthrex) were then passed over the wire and partially secured to the femur—the attachment point for the proximal sMCL portion of the semitendinosus graft. The semitendinosus tendon was then secured beneath the spiked washer with the knee in 20° of flexion with neutral rotation, recreating the sMCL.

Posteriorly, the distal insertion site of the POL was identified at the posteromedial aspect of the tibia through the oblique incision previously described. A 7-mm tunnel was drilled starting posteromedial (10 mm under tibial articular surface) and exiting just distal and medial to the Gerdy tubercle.

The graft was passed subcutaneously and below the sartorius fascia from posterior to anterior and was secured with a 7-mm × 23-mm cannulated titanium screw. Fixation was performed at full extension with neutral rotation (Figures 3A-3C, 4). 

After final fixation, the medial knee was openly dissected to assess the inverted-V ligament reconstruction for anatomical placement and avoidance of crucial structures.

Stability Testing

Per International Knee Documentation Committee guidelines for stressing the medial compartment,¹⁴ valgus stress radiographs were obtained for all specimens at 0° and 20° of flexion in intact, sectioned, and reconstructed states.

For all radiographs, performed by Dr. Chahla, a 10-N valgus force (measured by dynamometer) was applied to an intramedullary rod placed in the femur while the tibia was firmly attached to a specially designed base¹⁵ (Figures 5A-5C). A situation of 1 df was recreated to allow only varus/valgus motion during testing. 

 

The medial gap formed by the femoral condyle and its corresponding tibial plateau (at site of maximal separation) was tested in all 3 state conditions (intact, sectioned, reconstructed). Distances were digitally measured with a picture archiving and communication system viewer (Imagecast; IDX Systems Corporation). Medial gap was measured by taking the shortest distance between the subchondral bone surface of the most distal aspect of the medial femoral condyle and the corresponding medial tibial plateau. Three independent examiners took all the measurements; each examiner was blinded to the others’ measurements.

Statistics

Paired Student t tests were used to compare the 3 conditions, and the Shapiro-Wilk test was used to check for a normally distributed population. Statistical significance was set at P < .05. Statistical analyses were performed with GraphPad software.

Results

In all 10 specimens, the sMCL, the dMCL, and the POL were successfully identified and sectioned through a medial oblique incision over the distal insertion of the structures.

During all valgus testing states, there was no loss of graft fixation, and there was no gross graft slippage. In addition, all grafts remained in continuity with no evidence of failure, and there were no failures or breakages of the proximal or distal screw.

After posteromedial sectioning, mean medial gap was statistically significantly larger (P = .0002) at full extension (11 mm vs 3.3 mm) and at 20° of flexion (12.6 mm vs 3.8 mm). There was no statistically significant difference between the value of the intact state and the value after minimally invasive reconstruction at 0° (P = .56) or 20° (P = .102) of flexion.

Each knee had a notable endpoint in valgus stress noted on clinical examination after reconstruction. All individual results are listed in the Table. Interobserver reliability for the measurements was almost perfect¹⁶ (κ = 0.86).

Discussion

In this article, we describe a minimally invasive technique for anatomical posteromedial reconstruction of the knee in a cadaveric model. This technique restores the knee’s native valgus stability without causing extensive damage to the surrounding soft tissues and thereby potentially prevents scar formation and reduces blood loss.

Superficial MCL injury, one of the most common knee ligament injuries, is often associated with POL injury.⁷ Although most sMCL injuries are treated nonoperatively, with good results,³ surgical treatment is needed for severe (grade III) instabilities, symptomatic chronic instabilities, and knee dislocations.^12,17 Most posteromedial reconstruction techniques require an extensive approach that causes damage to surrounding soft tissue,^6,7,9,10 which in turn may compromise healing and positive patient outcomes. Surgical techniques include direct repair with sutures or anchors,¹⁸ capsular procedures,¹⁹ augmentations,⁹ internal bracing,⁶ and complete reconstruction of the posteromedial corner.²⁰

LaPrade and Wijdicks¹² have previously described anatomical reconstruction of the posteromedial corner. In their technique, a split semitendinosus autograft is used to reconstruct the sMCL and the POL separately, using 4 implants and reproducing each ligament’s anatomical attachment site. In this proposed technique, the distal attachment of the semitendinosus insertion is left intact, and uses 1 attachment point on the distal femur and 1 on the proximal tibia, allowing use of only 2 implants. In addition, it is performed with a minimally invasive approach, reduces cost, limits surgical exposure, and with experience may shorten operative time. To reduce the graft failure rate, the technique of LaPrade and Wijdicks¹² positions the sMCL tibial attachment as posterior as possible, which can be performed with this minimally invasive approach as well.

To reduce the graft failure rate, the technique of LaPrade and Wijdicks¹² positions the sMCL as posterior as possible. Despite the potential for increased graft stress with an anterior position, as in our modified technique, our group of 10 knees had no graft fixation failures in isolated valgus stress testing in either extension or flexion. Our minimally invasive posteromedial knee reconstruction significantly improved knee stability over the sectioned state as well as medial compartment gapping with valgus stress. There was no significant difference in medial compartment gapping between the intact and reconstructed states.

Our technique was built on open procedures (described by Kim and colleagues¹³) that carefully identify the isometric point of the graft. In addition, it adopted the modification (proposed by Lind and colleagues²¹) in which a fixation point is added at the distal insertion of the POL instead of being sutured to the direct arm of the semitendinosus tendon.

Furthermore, our technique, despite being similar to those described by Dong and colleagues²² and Borden and colleagues,²³  has the advantages of minimally invasive surgery and reduced disruption of soft tissues. Dong and colleagues²² reported on 64 patients with a mean follow-up of 34 months; patients’ medial opening measurements were significantly decreased at follow-up and fell within the normal range. 

The present study had several limitations. First, the age of our specimens was higher than the mean age of patients with knee ligament injury, potentially leading to firmer or more fibrotic tendons less susceptible to elongation. Second, we did not evaluate the knees’ rotational stability, and anterior cruciate ligaments (ACLs) were intact. As most posteromedial injuries co-occur with ACL injuries, a more realistic situation would have been reproduced by assessing rotational stability while performing both ACL reconstruction and the proposed posteromedial reconstruction. Third, static specimen measurements do not reflect the dynamic function of the posteromedial corner. Prospective clinical studies are needed to assess the true effectiveness of the posteromedial corner in the clinical scenario.

Knowledge of the anatomy of the medial aspect of the knee is vital to reconstruction of the medial side of the knee. Our results suggest that a minimally invasive technique can restore valgus stability without the need for extensive dissection and disruption of surrounding soft tissues. More research is needed to determine the results of this technique in vivo.

Take-Home Points

• Injuries to the medial knee are the most common knee ligament injuries, and often occur in the athletic population.
• Complete posteromedial corner injuries require surgical treatment to restore joint stability and biomechanics.
• Biomechanical evidence has demonstrated an important load-sharing distribution between the sMCL and the POL.
• Valgus instability caused by a medial side injury, can lead to both ACL/posterior cruciate ligament reconstruction graft failure if the medial sided injury is not concurrently repaired or reconstructed.
• Anatomic posteromedial corner reconstruction yields excellent biomechanical and patient-reported outcomes.

Most injuries of the medial structures of the knee are treated conservatively.^1-3 In severe acute injuries and chronic symptomatic instabilities, however, surgical treatment is needed to restore knee stability and to prevent degenerative changes secondary to instability.⁴ Three structures involved in medial stability are the superficial medial collateral ligament (sMCL), which is the primary valgus restraint; the posterior oblique ligament (POL), which is the primary restraint to internal rotation and the secondary valgus restraint; and the semimembranosus.^5,6

Surgical techniques for posteromedial knee reconstruction include direct repair,⁷ repair with augmentation,^8,9 advancement of the tibial insertion of the sMCL,¹⁰ and transfer of the pes anserine tendons.¹¹ In anatomical reconstruction of the posteromedial corner, which has been described before, the sMCL and the POL are reconstructed to reproduce the native motion and stability of the knee.¹² Clinically, repair and reconstruction have similar patient-reported outcomes and medial opening evaluations over the short term.

These approaches require large incisions and extensive dissection of soft tissue on the medial aspect of the knee.⁵ Given these drawbacks, it is reasonable to consider less invasive options. Minimally invasive surgery has the advantages of reduced scarring and blood loss, less disruption of surrounding tissue, faster recovery, and improved aesthetics.⁴

We conducted a study of a minimally invasive technique for reconstructing the posteromedial structures of the knee. We compared medial compartment stability measured on valgus stress radiographs in intact, sectioned, and reconstructed states in cadaveric knees. We hypothesized that a minimally invasive technique using autogenous hamstring graft in the appropriate anatomical location would return valgus stability to its nearly native state.

Materials and Methods

This study was conducted at the Buenos Aires British Hospital in Buenos Aires, Argentina, and at the University of Colorado Hospital in Aurora. Ten fresh-frozen cadaveric knees with no evidence of ligamentous injuries, osteoarthritis, or previous surgery were used. Mean donor age was 69.4 years (range, 45-87 years). Each specimen was maintained at room temperature for 24 hours before use. The femur was sectioned 20 cm proximal to the knee joint. The tibia was sectioned 12.5 cm distal to the knee joint.

Identification and Sectioning of Posteromedial Structures

Anatomical insertion sites of the sMCL, the deep MCL (dMCL), and the POL were identified on the tibia through an oblique 3-cm incision on the posteromedial aspect of the knee (Figures 1A-1C). A valgus stress radiograph with medial compartment gap measurement was obtained for each of the 10 knees before sectioning the medial stabilizing structures.

After intact-state evaluation, each knee’s sMCL, dMCL, and POL were sectioned at their tibial insertion. Valgus stress radiograph was repeated and medial compartment gap was remeasured for comparison of the sectioned state with the intact and reconstructed states.

Anatomical Reconstruction With Mini-Invasive Technique

After sectioning of medial stabilizing structures, minimally invasive reconstruction was performed through 2 small incisions on the medial aspect of each of the 10 knees, as follows. First, the semitendinosus tendon was identified through the oblique incision that had been used for sectioning. Then, an open-ended tendon stripper was placed around the circumference of the semitendinosus and was passed proximomedially, transecting the tendon at its musculotendinous junction. While the tendon stripper was being passed, care was taken to maintain the nearby tibial insertion of the sartorius fascia (Figures 1D-1F).

The proximal end of the semitendinosus tendon (~5 cm proximal to incision) was then cleared of all muscular and fatty soft-tissue remnants and whipstitched with No. 2 Vycril suture (Figure 2). Then, the medial epicondyle was visualized and identified under radiographic guidance. A 1-cm incision was made 10 mm posterior and 2 mm proximal to the epicondyle (midpoint of femoral attachment of sMCL and POL).¹² A 1.8-mm Kirschner wire was inserted into the femur at this location. A blunt awl was used for deep (under sartorius fascia) passage of the semitendinosus tendon, from distal to proximal, and the tendon was looped over the top of the wire and brought through the incision.

With the semitendinosus tendon looped around the wire, isometricity was tested by pulling the suture within the tendon and moving the knee through a full range of motion. The isometric point was confirmed by tendon migration of <2 mm.¹³ Migration was measured by marking the graft 2 mm from its insertion; the graft was then pulled to ensure correct isometric point position. An 18-mm cannulated spiked screw and washer (Arthrex) were then passed over the wire and partially secured to the femur—the attachment point for the proximal sMCL portion of the semitendinosus graft. The semitendinosus tendon was then secured beneath the spiked washer with the knee in 20° of flexion with neutral rotation, recreating the sMCL.

Posteriorly, the distal insertion site of the POL was identified at the posteromedial aspect of the tibia through the oblique incision previously described. A 7-mm tunnel was drilled starting posteromedial (10 mm under tibial articular surface) and exiting just distal and medial to the Gerdy tubercle.

The graft was passed subcutaneously and below the sartorius fascia from posterior to anterior and was secured with a 7-mm × 23-mm cannulated titanium screw. Fixation was performed at full extension with neutral rotation (Figures 3A-3C, 4). 

After final fixation, the medial knee was openly dissected to assess the inverted-V ligament reconstruction for anatomical placement and avoidance of crucial structures.

Stability Testing

Per International Knee Documentation Committee guidelines for stressing the medial compartment,¹⁴ valgus stress radiographs were obtained for all specimens at 0° and 20° of flexion in intact, sectioned, and reconstructed states.

For all radiographs, performed by Dr. Chahla, a 10-N valgus force (measured by dynamometer) was applied to an intramedullary rod placed in the femur while the tibia was firmly attached to a specially designed base¹⁵ (Figures 5A-5C). A situation of 1 df was recreated to allow only varus/valgus motion during testing. 

 

The medial gap formed by the femoral condyle and its corresponding tibial plateau (at site of maximal separation) was tested in all 3 state conditions (intact, sectioned, reconstructed). Distances were digitally measured with a picture archiving and communication system viewer (Imagecast; IDX Systems Corporation). Medial gap was measured by taking the shortest distance between the subchondral bone surface of the most distal aspect of the medial femoral condyle and the corresponding medial tibial plateau. Three independent examiners took all the measurements; each examiner was blinded to the others’ measurements.

Statistics

Paired Student t tests were used to compare the 3 conditions, and the Shapiro-Wilk test was used to check for a normally distributed population. Statistical significance was set at P < .05. Statistical analyses were performed with GraphPad software.

Results

In all 10 specimens, the sMCL, the dMCL, and the POL were successfully identified and sectioned through a medial oblique incision over the distal insertion of the structures.

During all valgus testing states, there was no loss of graft fixation, and there was no gross graft slippage. In addition, all grafts remained in continuity with no evidence of failure, and there were no failures or breakages of the proximal or distal screw.

After posteromedial sectioning, mean medial gap was statistically significantly larger (P = .0002) at full extension (11 mm vs 3.3 mm) and at 20° of flexion (12.6 mm vs 3.8 mm). There was no statistically significant difference between the value of the intact state and the value after minimally invasive reconstruction at 0° (P = .56) or 20° (P = .102) of flexion.

Each knee had a notable endpoint in valgus stress noted on clinical examination after reconstruction. All individual results are listed in the Table. Interobserver reliability for the measurements was almost perfect¹⁶ (κ = 0.86).

Discussion

In this article, we describe a minimally invasive technique for anatomical posteromedial reconstruction of the knee in a cadaveric model. This technique restores the knee’s native valgus stability without causing extensive damage to the surrounding soft tissues and thereby potentially prevents scar formation and reduces blood loss.

Superficial MCL injury, one of the most common knee ligament injuries, is often associated with POL injury.⁷ Although most sMCL injuries are treated nonoperatively, with good results,³ surgical treatment is needed for severe (grade III) instabilities, symptomatic chronic instabilities, and knee dislocations.^12,17 Most posteromedial reconstruction techniques require an extensive approach that causes damage to surrounding soft tissue,^6,7,9,10 which in turn may compromise healing and positive patient outcomes. Surgical techniques include direct repair with sutures or anchors,¹⁸ capsular procedures,¹⁹ augmentations,⁹ internal bracing,⁶ and complete reconstruction of the posteromedial corner.²⁰

LaPrade and Wijdicks¹² have previously described anatomical reconstruction of the posteromedial corner. In their technique, a split semitendinosus autograft is used to reconstruct the sMCL and the POL separately, using 4 implants and reproducing each ligament’s anatomical attachment site. In this proposed technique, the distal attachment of the semitendinosus insertion is left intact, and uses 1 attachment point on the distal femur and 1 on the proximal tibia, allowing use of only 2 implants. In addition, it is performed with a minimally invasive approach, reduces cost, limits surgical exposure, and with experience may shorten operative time. To reduce the graft failure rate, the technique of LaPrade and Wijdicks¹² positions the sMCL tibial attachment as posterior as possible, which can be performed with this minimally invasive approach as well.

To reduce the graft failure rate, the technique of LaPrade and Wijdicks¹² positions the sMCL as posterior as possible. Despite the potential for increased graft stress with an anterior position, as in our modified technique, our group of 10 knees had no graft fixation failures in isolated valgus stress testing in either extension or flexion. Our minimally invasive posteromedial knee reconstruction significantly improved knee stability over the sectioned state as well as medial compartment gapping with valgus stress. There was no significant difference in medial compartment gapping between the intact and reconstructed states.

Our technique was built on open procedures (described by Kim and colleagues¹³) that carefully identify the isometric point of the graft. In addition, it adopted the modification (proposed by Lind and colleagues²¹) in which a fixation point is added at the distal insertion of the POL instead of being sutured to the direct arm of the semitendinosus tendon.

Furthermore, our technique, despite being similar to those described by Dong and colleagues²² and Borden and colleagues,²³  has the advantages of minimally invasive surgery and reduced disruption of soft tissues. Dong and colleagues²² reported on 64 patients with a mean follow-up of 34 months; patients’ medial opening measurements were significantly decreased at follow-up and fell within the normal range. 

The present study had several limitations. First, the age of our specimens was higher than the mean age of patients with knee ligament injury, potentially leading to firmer or more fibrotic tendons less susceptible to elongation. Second, we did not evaluate the knees’ rotational stability, and anterior cruciate ligaments (ACLs) were intact. As most posteromedial injuries co-occur with ACL injuries, a more realistic situation would have been reproduced by assessing rotational stability while performing both ACL reconstruction and the proposed posteromedial reconstruction. Third, static specimen measurements do not reflect the dynamic function of the posteromedial corner. Prospective clinical studies are needed to assess the true effectiveness of the posteromedial corner in the clinical scenario.

Knowledge of the anatomy of the medial aspect of the knee is vital to reconstruction of the medial side of the knee. Our results suggest that a minimally invasive technique can restore valgus stability without the need for extensive dissection and disruption of surrounding soft tissues. More research is needed to determine the results of this technique in vivo.

Take-Home Points

• Injuries to the medial knee are the most common knee ligament injuries, and often occur in the athletic population.
• Complete posteromedial corner injuries require surgical treatment to restore joint stability and biomechanics.
• Biomechanical evidence has demonstrated an important load-sharing distribution between the sMCL and the POL.
• Valgus instability caused by a medial side injury, can lead to both ACL/posterior cruciate ligament reconstruction graft failure if the medial sided injury is not concurrently repaired or reconstructed.
• Anatomic posteromedial corner reconstruction yields excellent biomechanical and patient-reported outcomes.

Most injuries of the medial structures of the knee are treated conservatively.^1-3 In severe acute injuries and chronic symptomatic instabilities, however, surgical treatment is needed to restore knee stability and to prevent degenerative changes secondary to instability.⁴ Three structures involved in medial stability are the superficial medial collateral ligament (sMCL), which is the primary valgus restraint; the posterior oblique ligament (POL), which is the primary restraint to internal rotation and the secondary valgus restraint; and the semimembranosus.^5,6

Surgical techniques for posteromedial knee reconstruction include direct repair,⁷ repair with augmentation,^8,9 advancement of the tibial insertion of the sMCL,¹⁰ and transfer of the pes anserine tendons.¹¹ In anatomical reconstruction of the posteromedial corner, which has been described before, the sMCL and the POL are reconstructed to reproduce the native motion and stability of the knee.¹² Clinically, repair and reconstruction have similar patient-reported outcomes and medial opening evaluations over the short term.

These approaches require large incisions and extensive dissection of soft tissue on the medial aspect of the knee.⁵ Given these drawbacks, it is reasonable to consider less invasive options. Minimally invasive surgery has the advantages of reduced scarring and blood loss, less disruption of surrounding tissue, faster recovery, and improved aesthetics.⁴

We conducted a study of a minimally invasive technique for reconstructing the posteromedial structures of the knee. We compared medial compartment stability measured on valgus stress radiographs in intact, sectioned, and reconstructed states in cadaveric knees. We hypothesized that a minimally invasive technique using autogenous hamstring graft in the appropriate anatomical location would return valgus stability to its nearly native state.

Materials and Methods

This study was conducted at the Buenos Aires British Hospital in Buenos Aires, Argentina, and at the University of Colorado Hospital in Aurora. Ten fresh-frozen cadaveric knees with no evidence of ligamentous injuries, osteoarthritis, or previous surgery were used. Mean donor age was 69.4 years (range, 45-87 years). Each specimen was maintained at room temperature for 24 hours before use. The femur was sectioned 20 cm proximal to the knee joint. The tibia was sectioned 12.5 cm distal to the knee joint.

Identification and Sectioning of Posteromedial Structures

Anatomical insertion sites of the sMCL, the deep MCL (dMCL), and the POL were identified on the tibia through an oblique 3-cm incision on the posteromedial aspect of the knee (Figures 1A-1C). A valgus stress radiograph with medial compartment gap measurement was obtained for each of the 10 knees before sectioning the medial stabilizing structures.

After intact-state evaluation, each knee’s sMCL, dMCL, and POL were sectioned at their tibial insertion. Valgus stress radiograph was repeated and medial compartment gap was remeasured for comparison of the sectioned state with the intact and reconstructed states.

Anatomical Reconstruction With Mini-Invasive Technique

After sectioning of medial stabilizing structures, minimally invasive reconstruction was performed through 2 small incisions on the medial aspect of each of the 10 knees, as follows. First, the semitendinosus tendon was identified through the oblique incision that had been used for sectioning. Then, an open-ended tendon stripper was placed around the circumference of the semitendinosus and was passed proximomedially, transecting the tendon at its musculotendinous junction. While the tendon stripper was being passed, care was taken to maintain the nearby tibial insertion of the sartorius fascia (Figures 1D-1F).

The proximal end of the semitendinosus tendon (~5 cm proximal to incision) was then cleared of all muscular and fatty soft-tissue remnants and whipstitched with No. 2 Vycril suture (Figure 2). Then, the medial epicondyle was visualized and identified under radiographic guidance. A 1-cm incision was made 10 mm posterior and 2 mm proximal to the epicondyle (midpoint of femoral attachment of sMCL and POL).¹² A 1.8-mm Kirschner wire was inserted into the femur at this location. A blunt awl was used for deep (under sartorius fascia) passage of the semitendinosus tendon, from distal to proximal, and the tendon was looped over the top of the wire and brought through the incision.

With the semitendinosus tendon looped around the wire, isometricity was tested by pulling the suture within the tendon and moving the knee through a full range of motion. The isometric point was confirmed by tendon migration of <2 mm.¹³ Migration was measured by marking the graft 2 mm from its insertion; the graft was then pulled to ensure correct isometric point position. An 18-mm cannulated spiked screw and washer (Arthrex) were then passed over the wire and partially secured to the femur—the attachment point for the proximal sMCL portion of the semitendinosus graft. The semitendinosus tendon was then secured beneath the spiked washer with the knee in 20° of flexion with neutral rotation, recreating the sMCL.

Posteriorly, the distal insertion site of the POL was identified at the posteromedial aspect of the tibia through the oblique incision previously described. A 7-mm tunnel was drilled starting posteromedial (10 mm under tibial articular surface) and exiting just distal and medial to the Gerdy tubercle.

The graft was passed subcutaneously and below the sartorius fascia from posterior to anterior and was secured with a 7-mm × 23-mm cannulated titanium screw. Fixation was performed at full extension with neutral rotation (Figures 3A-3C, 4). 

After final fixation, the medial knee was openly dissected to assess the inverted-V ligament reconstruction for anatomical placement and avoidance of crucial structures.

Stability Testing

Per International Knee Documentation Committee guidelines for stressing the medial compartment,¹⁴ valgus stress radiographs were obtained for all specimens at 0° and 20° of flexion in intact, sectioned, and reconstructed states.

For all radiographs, performed by Dr. Chahla, a 10-N valgus force (measured by dynamometer) was applied to an intramedullary rod placed in the femur while the tibia was firmly attached to a specially designed base¹⁵ (Figures 5A-5C). A situation of 1 df was recreated to allow only varus/valgus motion during testing. 

 

The medial gap formed by the femoral condyle and its corresponding tibial plateau (at site of maximal separation) was tested in all 3 state conditions (intact, sectioned, reconstructed). Distances were digitally measured with a picture archiving and communication system viewer (Imagecast; IDX Systems Corporation). Medial gap was measured by taking the shortest distance between the subchondral bone surface of the most distal aspect of the medial femoral condyle and the corresponding medial tibial plateau. Three independent examiners took all the measurements; each examiner was blinded to the others’ measurements.

Statistics

Paired Student t tests were used to compare the 3 conditions, and the Shapiro-Wilk test was used to check for a normally distributed population. Statistical significance was set at P < .05. Statistical analyses were performed with GraphPad software.

Results

In all 10 specimens, the sMCL, the dMCL, and the POL were successfully identified and sectioned through a medial oblique incision over the distal insertion of the structures.

During all valgus testing states, there was no loss of graft fixation, and there was no gross graft slippage. In addition, all grafts remained in continuity with no evidence of failure, and there were no failures or breakages of the proximal or distal screw.

After posteromedial sectioning, mean medial gap was statistically significantly larger (P = .0002) at full extension (11 mm vs 3.3 mm) and at 20° of flexion (12.6 mm vs 3.8 mm). There was no statistically significant difference between the value of the intact state and the value after minimally invasive reconstruction at 0° (P = .56) or 20° (P = .102) of flexion.

Each knee had a notable endpoint in valgus stress noted on clinical examination after reconstruction. All individual results are listed in the Table. Interobserver reliability for the measurements was almost perfect¹⁶ (κ = 0.86).

Discussion

In this article, we describe a minimally invasive technique for anatomical posteromedial reconstruction of the knee in a cadaveric model. This technique restores the knee’s native valgus stability without causing extensive damage to the surrounding soft tissues and thereby potentially prevents scar formation and reduces blood loss.

Superficial MCL injury, one of the most common knee ligament injuries, is often associated with POL injury.⁷ Although most sMCL injuries are treated nonoperatively, with good results,³ surgical treatment is needed for severe (grade III) instabilities, symptomatic chronic instabilities, and knee dislocations.^12,17 Most posteromedial reconstruction techniques require an extensive approach that causes damage to surrounding soft tissue,^6,7,9,10 which in turn may compromise healing and positive patient outcomes. Surgical techniques include direct repair with sutures or anchors,¹⁸ capsular procedures,¹⁹ augmentations,⁹ internal bracing,⁶ and complete reconstruction of the posteromedial corner.²⁰

LaPrade and Wijdicks¹² have previously described anatomical reconstruction of the posteromedial corner. In their technique, a split semitendinosus autograft is used to reconstruct the sMCL and the POL separately, using 4 implants and reproducing each ligament’s anatomical attachment site. In this proposed technique, the distal attachment of the semitendinosus insertion is left intact, and uses 1 attachment point on the distal femur and 1 on the proximal tibia, allowing use of only 2 implants. In addition, it is performed with a minimally invasive approach, reduces cost, limits surgical exposure, and with experience may shorten operative time. To reduce the graft failure rate, the technique of LaPrade and Wijdicks¹² positions the sMCL tibial attachment as posterior as possible, which can be performed with this minimally invasive approach as well.

To reduce the graft failure rate, the technique of LaPrade and Wijdicks¹² positions the sMCL as posterior as possible. Despite the potential for increased graft stress with an anterior position, as in our modified technique, our group of 10 knees had no graft fixation failures in isolated valgus stress testing in either extension or flexion. Our minimally invasive posteromedial knee reconstruction significantly improved knee stability over the sectioned state as well as medial compartment gapping with valgus stress. There was no significant difference in medial compartment gapping between the intact and reconstructed states.

Our technique was built on open procedures (described by Kim and colleagues¹³) that carefully identify the isometric point of the graft. In addition, it adopted the modification (proposed by Lind and colleagues²¹) in which a fixation point is added at the distal insertion of the POL instead of being sutured to the direct arm of the semitendinosus tendon.

Furthermore, our technique, despite being similar to those described by Dong and colleagues²² and Borden and colleagues,²³  has the advantages of minimally invasive surgery and reduced disruption of soft tissues. Dong and colleagues²² reported on 64 patients with a mean follow-up of 34 months; patients’ medial opening measurements were significantly decreased at follow-up and fell within the normal range. 

The present study had several limitations. First, the age of our specimens was higher than the mean age of patients with knee ligament injury, potentially leading to firmer or more fibrotic tendons less susceptible to elongation. Second, we did not evaluate the knees’ rotational stability, and anterior cruciate ligaments (ACLs) were intact. As most posteromedial injuries co-occur with ACL injuries, a more realistic situation would have been reproduced by assessing rotational stability while performing both ACL reconstruction and the proposed posteromedial reconstruction. Third, static specimen measurements do not reflect the dynamic function of the posteromedial corner. Prospective clinical studies are needed to assess the true effectiveness of the posteromedial corner in the clinical scenario.

Knowledge of the anatomy of the medial aspect of the knee is vital to reconstruction of the medial side of the knee. Our results suggest that a minimally invasive technique can restore valgus stability without the need for extensive dissection and disruption of surrounding soft tissues. More research is needed to determine the results of this technique in vivo.

Take-Home Points

• There is a 41% rate of AVN or PTOA after operatively managed talus fracture.
• Surgical timing does not affect development of AVN or PTOA.
• Open fractures are associated with development of AVN and PTOA.
• Quality of reduction is likely more important than timing of reduction.
• Urgent surgical treatment is necessary for threatened soft tissue or neurovascular compromise.

Talus fractures are rare injuries that present a significant treatment dilemma.^1-12 These fractures represent <1% of all fractures⁴ and are second only to calcaneus fractures in fractures of the hindfoot. Talus fractures with associated dislocations are even rarer and may provide treating surgeons with a significant surgical quandary.^6,13-16

Talus fractures historically have been characterized by their anatomical location: head, neck, or body. Two systems are commonly used to classify talus fractures: Hawkins and AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association). The first, developed by Hawkins⁷ and modified by Canale and Kelly² and Vallier and colleagues,¹ identifies 4 basic fracture types with associated dislocations. The other system, published in 1996¹⁷ and republished in 2007,¹⁸ uses the combined methods of AO and OTA to systematically describe talus fractures. Although these classification systems accurately describe talus fractures with associated dislocation, both have difficulty predicting clinical outcomes.^1,19,20

Talus fractures commonly result in avascular necrosis (AVN) of the talus and posttraumatic osteoarthritis (PTOA) of the tibiotalar and subtalar joints.^{3,8,9,12,14-16} Hawkins⁷ initially described subchondral lucency as indicating revascularization of the talus after injury. AVN and PTOA rates traditionally have been thought to be related to a blood supply disruption, given the prognostic value of the Hawkins sign.^1,7,12,21 New methods, including a dual-incision approach and expedited transfer to foot and ankle surgeons or orthopedic traumatologists, have improved reduction quality^21-24 but not patient outcomes.^{3,5,8,9,12,14}

Recently, time from injury to surgical intervention has been a topic of much discussion, and there have been studies on the specific effects of timing with respect to outcome.^1,15,16 Vallier and colleagues,¹ who wanted to identify injury characteristics predictive of osteonecrosis, found that delaying reduction and surgical fixation did not increase the risk of AVN. Another study found that urgent reduction of fracture-dislocation with delayed open reduction and internal fixation (ORIF) using a dual approach may improve clinical outcomes.²¹

In this vein, we conducted a study to evaluate the effect of time to surgical reduction of talus fractures and talus fracture-dislocations on the development of AVN and PTOA. We hypothesized that time to surgical reduction of talus fracture-dislocation as classified with the AO/OTA system would have no effect of the development of AVN/PTOA.

Methods

After this study received Institutional Review Board approval, we retrospectively reviewed the records on talus fractures surgically managed at a level I trauma center during the 10-year period 2003 to 2013. Of the 119 potential cases identified using Current Procedural Terminology code 28445 (ORIF of talus), 13 were excluded (12 for inaccurate coding or missing documentation, 1 for being a pediatric case), leaving 106 for analysis. Using the Hawkins and AO/OTA systems, 3 independent reviewers classified the injuries on plain radiographs.

Injury dates and times were obtained from the medical records. Operating room start times were also obtained. Surgical timing was defined as time from injury to operating room start. For cases without an injury time, time of presentation to emergency department was used.

Open fracture-dislocations were managed with intravenous antibiotics, urgent surgical irrigation, débridement, and immediate fixation or temporizing external fixation after reduction. All fractures were definitively managed with standard ORIF with an anteromedial, anterolateral, or dual approach and mini-fragment implants. After fixation, weight-bearing typically was restricted for 6 to 12 weeks.

Follow-up radiographs were evaluated. Presence or absence of Hawkins sign⁷ was noted on radiographs at 6 or 8 weeks, and all follow-up radiographs were evaluated for AVN as defined by increased radiographic density within the talar dome or collapse of the articular surface. All radiographs were evaluated for PTOA as defined by loss of joint space within the tibiotalar, subtalar, or talonavicular joint on follow-up radiographs.

Clinical outcomes were analyzed for development of AVN, PTOA, or secondary corrective surgery or arthrodesis. Continuous variables were evaluated with the t test, and the χ² test was used to compare distributions of categorical variables. The Wilcoxon rank sum test was used to compare non-normally distributed variables. Significance was set at P < .05.

 

 

Results

Classification Analysis (Table 1)

We identified 106 surgically managed talus fractures. Five (4.7%) were lateral process and talar head fractures (AO/OTA 81-A). Seventy-six (71.7%) were talar neck fractures (81-B), which included 13 (12%) 81-B1 fractures, 31 (29%) 81-B2 fractures, and 32 (30%) 81-B3 fractures. Twenty-five (23.6%) were talar body fractures (81-C). AO/OTA 81-B3 fractures were identified and separately analyzed and compared with talus fractures of all other classes. AO/OTA 81-B talar neck fractures were classified with the Hawkins system7 as well: 13 (12%) were Hawkins 1 fractures, 31 (29%) Hawkins 2 fractures, 25 (24%) Hawkins 3 fractures, and 7 (7%) Hawkins 4 fractures.

Subject Analysis (Table 2)

Of the 106 patients, 69 were female and 37 male. Mean age was 37.7 years (range, 18-78 years). Mean body mass index (BMI) was 29.45 kg/m². Of the 106 cases, 52 were managed by board- certified orthopedic trauma surgeons, 32 by board- certified foot and ankle surgeons, and 22 by orthopedic surgeons with other specialty training.

The mechanisms of injury were motor vehicle accident (70/106; 66%), fall from height (25; 24%), misstep (4), sports related (2), object falling on ankle (2), and not reported (3). 

Of the 106 patients, 45 (42%) had isolated talus injuries, 35 had concomitant ipsilateral lower extremity injuries, 25 had concomitant contralateral lower extremity injuries, and 1 had a concomitant upper extremity injury. 

Smoking status was everyday (14 patients), past (10), never (34), and unreported (48). Five patients reported a history of alcohol abuse, and 4 patients reported illicit drug use. Two had a history of atrial fibrillation, 9 had hypertension, 3 had hyperlipidemia, 3 had renal disease, 3 had heart disease, 4 had diabetes, 3 had lung disease, and 1 had a history of lung cancer.

Overall Analysis of AVN/PTOA (Table 3)

Of the 106 patients, 43 (41%) developed AVN/PTOA, and 63 (59%) did not, while fifty-four (51%) of the 106 patients who developed AVN/PTOA had polytrauma, and 52 (49%) of those who did not develop AVN/PTOA had polytrauma (P = .79). There was no significant difference in mean age (38.74 years for AVN/PTOA, 36.21 years for no AVN/PTOA; P = .20) or BMI (28.99 kg/m² for AVN/PTOA, 29.15 kg/m2 for no AVN/PTOA; P = .45). Direct comparison of proportions of polytrauma to development of AVN/PTOA revealed no significant difference. Direct comparison of the proportions of open injuries to development of AVN/PTOA revealed a significant difference. Fifteen (35%) of the 43 patients who developed AVN/PTOA had open injuries, and 10 (16%) of the 63 who did not develop AVN/PTOA had open injuries (P = .03). There was no significant difference in follow-up between patients who developed AVN/PTOA and those who did not (P = .26).

Analysis of AVN/PTOA in 81-B3 Fracture-Dislocations (Table 4)

Of the 32 patients with AO/OTA 81-B3 (Hawkins 3 or 4) fractures, 16 (50%) developed AVN/PTOA, and 16 did not. There was no significant difference in mean age (41.05 years for AVN/PTOA, 37.40 years for no AVN/PTOA; P = .29), BMI (28.86 kg/m² for AVN/PTOA, 27.94 kg/m2 for no AVN/PTOA; P = .38), or surgical timing (19.09 hours for AVN/PTOA, 16.65 hours for no AVN/PTOA; P = .29) for development of AVN/PTOA. Direct comparison of the proportions of polytrauma and open injuries to development of AVN/PTOA in patients with 81-B3 fracture- dislocations revealed no significant difference. Nine of the 16 patients (56%) who developed AVN/PTOA had polytrauma, and 11 of the 16 (69%) who did not develop AVN/PTOA had polytrauma (P = .465). Although open injury was found to predict AVN/PTOA overall, this was not true for talus fracture-dislocations alone. Five of the 10 patients who developed AVN/PTOA had open injuries, and 5 of the 10 who did not develop AVN/PTOA had open injuries (P = 1.0). There was a significant difference in follow-up time between these groups. Patients who had 81-B3 fracture-dislocations and developed AVN/PTOA were followed for a mean of 120.4 weeks, and those who did not develop AVN/PTOA were followed for a mean of 40.33 weeks (P = .001).

 

 

Analysis of AVN/PTOA in All Other Talus Fractures (Table 5)

Of the 74 patients with talus fractures without dislocations, 27 (36.5%) developed AVN/PTOA during the follow-up period, and 47 (63.5%) did not. There was no significant difference in mean age (37.37 years for AVN/PTOA, 35.78 years for no AVN/PTOA; P = .33), BMI (29.07 kg/m² for AVN/PTOA, 29.57 kg/m² for no AVN/PTOA; P = .39), or surgical timing (164.8 hours for AVN/PTOA, 105.41 for no AVN/PTOA; P = .14). Direct comparison of the proportions of polytrauma to development of AVN/PTOA in patients with talus fractures without dislocations revealed no significant difference. Fourteen of the 27 patients who developed AVN/PTOA had polytrauma, and 23 of the 47 who did not develop AVN/PTOA had polytrauma (P = .18). Direct comparison of the proportions of open injuries to development of AVN/PTOA in patients with talus fractures without dislocations revealed a significant difference (P = .009). There was a significant difference in follow-up time between these groups. Patients who had talus fractures without dislocations and developed AVN/PTOA were followed for a mean of 154.3 weeks, and those who did not develop AVN/PTOA were followed for a mean of 216 weeks (P = .02).

Discussion

Our results showed that time from talus fracture-dislocation to surgical reduction had no effect on development of AVN/PTOA. The findings in this largest series to date agree with earlier findings^1,8,15,16,24 and add to the volume of literature suggesting that time to surgical reduction of talus fractures and talus fracture-dislocations does not markedly affect outcome.

Talus fractures continue to present a significant treatment dilemma. Despite recent improvements in surgical techniques and overall management of these injuries, rates of AVN and PTOA have not significantly decreased.^1,16,23 At most treating facilities, talus fracture-dislocations are considered surgical emergencies/urgencies, and every effort is made to reduce and surgically address these injuries as soon as possible.^1,13

In this study, rates of AVN/PTOA were 41% (all talus fractures) and 50% (displaced talar neck fractures), and the difference was not significant (Table 3). These rates are higher but consistent with previously reported rates (range, 14%-49%).^{1,2,7-9,12,14,24} There was no difference in surgical timing for development of AVN/PTOA. We analyzed the cases of all patients who had talus fractures and developed AVN/PTOA (43/106). Within this group, there were no significant differences in surgical timing, age, sex, polytrauma, or BMI between patients who developed AVN/PTOA and those who did not. Compared with patients who did not develop AVN/PTOA, those who developed AVN/PTOA were significantly more likely to have open injuries. This finding, consistent with those in other reports^9,12,13 (Table 3), indicates outcome is more likely related to injury severity and not necessarily injury class.

We retrospectively analyzed talus fractures and talus fracture-dislocations to determine if urgent surgical management affects outcomes. Current practice at our institution is to routinely reduce and surgically address these fractures urgently, often during the middle of the night, when orthopedic resources are reduced. Our study found a significant difference in surgical timing for patients with talus fracture-dislocations and patients with talus fractures without dislocations (Table 2). Given our findings, urgent surgical reduction and fixation are not indicated to preserve the talus blood supply and prevent AVN/PTOA, though we still recommend urgent surgical management in the setting of an open wound, skin necrosis, or soft-tissue/neurovascular compromise. 

This study had several limitations, primarily related to its retrospective nature. Surgical timing was defined as time from injury, as noted in the medical record, to operating room start. In some instances, time of injury was not noted in the medical record, and time of presentation to emergency room was used instead. Thus, surgical timing for these patients may have been longer than identified. In addition, given the rare injury pattern and the retrospective design, this study was susceptible to type II error and may have been underpowered to detect whether time to surgical reduction predicted complications. Also, the study did not address functional outcome as measured by validated outcome scores. Outcome measures were obtained in many but not all cases, making functional outcome measurement difficult. Similarly, the quality of the anatomical reductions was not assessed, potentially affecting complication rates. Postoperative reduction assessment, possibly performed with computed tomography, is an avenue of further study.

 

Strengths of this study include its large sample size (this was one of the largest studies of talus fractures), long follow-up (mean, 150 weeks), and novel use of AO/OTA classification.

We postulate that development of AVN/PTOA is not necessarily related to the urgency or timing of surgical reduction and fixation and is more likely related to injury severity. This idea is supported by the finding that development of AVN/PTOA was significantly correlated to open injuries in all talus fractures, including talus fracture-dislocations and isolated talus fractures.

Conclusion 

Talus fracture-dislocations are devastating injuries with high rates of complications. In this study, open talus fractures, and fractures with associated tibiotalar or subtalar dislocations, had higher complication rates. Given the evidence presented, we recommend basing surgical timing on injury severity, not necessarily for AVN/PTOA prevention. Specifically, in the absence of an open wound, skin necrosis, or soft-tissue/neurovascular compromise, talus fracture-dislocations can be surgically reduced and stabilized when optimal resources are available.

Take-Home Points

• There is a 41% rate of AVN or PTOA after operatively managed talus fracture.
• Surgical timing does not affect development of AVN or PTOA.
• Open fractures are associated with development of AVN and PTOA.
• Quality of reduction is likely more important than timing of reduction.
• Urgent surgical treatment is necessary for threatened soft tissue or neurovascular compromise.

Talus fractures are rare injuries that present a significant treatment dilemma.^1-12 These fractures represent <1% of all fractures⁴ and are second only to calcaneus fractures in fractures of the hindfoot. Talus fractures with associated dislocations are even rarer and may provide treating surgeons with a significant surgical quandary.^6,13-16

Talus fractures historically have been characterized by their anatomical location: head, neck, or body. Two systems are commonly used to classify talus fractures: Hawkins and AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association). The first, developed by Hawkins⁷ and modified by Canale and Kelly² and Vallier and colleagues,¹ identifies 4 basic fracture types with associated dislocations. The other system, published in 1996¹⁷ and republished in 2007,¹⁸ uses the combined methods of AO and OTA to systematically describe talus fractures. Although these classification systems accurately describe talus fractures with associated dislocation, both have difficulty predicting clinical outcomes.^1,19,20

Talus fractures commonly result in avascular necrosis (AVN) of the talus and posttraumatic osteoarthritis (PTOA) of the tibiotalar and subtalar joints.^{3,8,9,12,14-16} Hawkins⁷ initially described subchondral lucency as indicating revascularization of the talus after injury. AVN and PTOA rates traditionally have been thought to be related to a blood supply disruption, given the prognostic value of the Hawkins sign.^1,7,12,21 New methods, including a dual-incision approach and expedited transfer to foot and ankle surgeons or orthopedic traumatologists, have improved reduction quality^21-24 but not patient outcomes.^{3,5,8,9,12,14}

Recently, time from injury to surgical intervention has been a topic of much discussion, and there have been studies on the specific effects of timing with respect to outcome.^1,15,16 Vallier and colleagues,¹ who wanted to identify injury characteristics predictive of osteonecrosis, found that delaying reduction and surgical fixation did not increase the risk of AVN. Another study found that urgent reduction of fracture-dislocation with delayed open reduction and internal fixation (ORIF) using a dual approach may improve clinical outcomes.²¹

In this vein, we conducted a study to evaluate the effect of time to surgical reduction of talus fractures and talus fracture-dislocations on the development of AVN and PTOA. We hypothesized that time to surgical reduction of talus fracture-dislocation as classified with the AO/OTA system would have no effect of the development of AVN/PTOA.

Methods

After this study received Institutional Review Board approval, we retrospectively reviewed the records on talus fractures surgically managed at a level I trauma center during the 10-year period 2003 to 2013. Of the 119 potential cases identified using Current Procedural Terminology code 28445 (ORIF of talus), 13 were excluded (12 for inaccurate coding or missing documentation, 1 for being a pediatric case), leaving 106 for analysis. Using the Hawkins and AO/OTA systems, 3 independent reviewers classified the injuries on plain radiographs.

Injury dates and times were obtained from the medical records. Operating room start times were also obtained. Surgical timing was defined as time from injury to operating room start. For cases without an injury time, time of presentation to emergency department was used.

Open fracture-dislocations were managed with intravenous antibiotics, urgent surgical irrigation, débridement, and immediate fixation or temporizing external fixation after reduction. All fractures were definitively managed with standard ORIF with an anteromedial, anterolateral, or dual approach and mini-fragment implants. After fixation, weight-bearing typically was restricted for 6 to 12 weeks.

Follow-up radiographs were evaluated. Presence or absence of Hawkins sign⁷ was noted on radiographs at 6 or 8 weeks, and all follow-up radiographs were evaluated for AVN as defined by increased radiographic density within the talar dome or collapse of the articular surface. All radiographs were evaluated for PTOA as defined by loss of joint space within the tibiotalar, subtalar, or talonavicular joint on follow-up radiographs.

Clinical outcomes were analyzed for development of AVN, PTOA, or secondary corrective surgery or arthrodesis. Continuous variables were evaluated with the t test, and the χ² test was used to compare distributions of categorical variables. The Wilcoxon rank sum test was used to compare non-normally distributed variables. Significance was set at P < .05.

 

 

Results

Classification Analysis (Table 1)

We identified 106 surgically managed talus fractures. Five (4.7%) were lateral process and talar head fractures (AO/OTA 81-A). Seventy-six (71.7%) were talar neck fractures (81-B), which included 13 (12%) 81-B1 fractures, 31 (29%) 81-B2 fractures, and 32 (30%) 81-B3 fractures. Twenty-five (23.6%) were talar body fractures (81-C). AO/OTA 81-B3 fractures were identified and separately analyzed and compared with talus fractures of all other classes. AO/OTA 81-B talar neck fractures were classified with the Hawkins system7 as well: 13 (12%) were Hawkins 1 fractures, 31 (29%) Hawkins 2 fractures, 25 (24%) Hawkins 3 fractures, and 7 (7%) Hawkins 4 fractures.

Subject Analysis (Table 2)

Of the 106 patients, 69 were female and 37 male. Mean age was 37.7 years (range, 18-78 years). Mean body mass index (BMI) was 29.45 kg/m². Of the 106 cases, 52 were managed by board- certified orthopedic trauma surgeons, 32 by board- certified foot and ankle surgeons, and 22 by orthopedic surgeons with other specialty training.

The mechanisms of injury were motor vehicle accident (70/106; 66%), fall from height (25; 24%), misstep (4), sports related (2), object falling on ankle (2), and not reported (3). 

Of the 106 patients, 45 (42%) had isolated talus injuries, 35 had concomitant ipsilateral lower extremity injuries, 25 had concomitant contralateral lower extremity injuries, and 1 had a concomitant upper extremity injury. 

Smoking status was everyday (14 patients), past (10), never (34), and unreported (48). Five patients reported a history of alcohol abuse, and 4 patients reported illicit drug use. Two had a history of atrial fibrillation, 9 had hypertension, 3 had hyperlipidemia, 3 had renal disease, 3 had heart disease, 4 had diabetes, 3 had lung disease, and 1 had a history of lung cancer.

Overall Analysis of AVN/PTOA (Table 3)

Of the 106 patients, 43 (41%) developed AVN/PTOA, and 63 (59%) did not, while fifty-four (51%) of the 106 patients who developed AVN/PTOA had polytrauma, and 52 (49%) of those who did not develop AVN/PTOA had polytrauma (P = .79). There was no significant difference in mean age (38.74 years for AVN/PTOA, 36.21 years for no AVN/PTOA; P = .20) or BMI (28.99 kg/m² for AVN/PTOA, 29.15 kg/m2 for no AVN/PTOA; P = .45). Direct comparison of proportions of polytrauma to development of AVN/PTOA revealed no significant difference. Direct comparison of the proportions of open injuries to development of AVN/PTOA revealed a significant difference. Fifteen (35%) of the 43 patients who developed AVN/PTOA had open injuries, and 10 (16%) of the 63 who did not develop AVN/PTOA had open injuries (P = .03). There was no significant difference in follow-up between patients who developed AVN/PTOA and those who did not (P = .26).

Analysis of AVN/PTOA in 81-B3 Fracture-Dislocations (Table 4)

Of the 32 patients with AO/OTA 81-B3 (Hawkins 3 or 4) fractures, 16 (50%) developed AVN/PTOA, and 16 did not. There was no significant difference in mean age (41.05 years for AVN/PTOA, 37.40 years for no AVN/PTOA; P = .29), BMI (28.86 kg/m² for AVN/PTOA, 27.94 kg/m2 for no AVN/PTOA; P = .38), or surgical timing (19.09 hours for AVN/PTOA, 16.65 hours for no AVN/PTOA; P = .29) for development of AVN/PTOA. Direct comparison of the proportions of polytrauma and open injuries to development of AVN/PTOA in patients with 81-B3 fracture- dislocations revealed no significant difference. Nine of the 16 patients (56%) who developed AVN/PTOA had polytrauma, and 11 of the 16 (69%) who did not develop AVN/PTOA had polytrauma (P = .465). Although open injury was found to predict AVN/PTOA overall, this was not true for talus fracture-dislocations alone. Five of the 10 patients who developed AVN/PTOA had open injuries, and 5 of the 10 who did not develop AVN/PTOA had open injuries (P = 1.0). There was a significant difference in follow-up time between these groups. Patients who had 81-B3 fracture-dislocations and developed AVN/PTOA were followed for a mean of 120.4 weeks, and those who did not develop AVN/PTOA were followed for a mean of 40.33 weeks (P = .001).

 

 

Analysis of AVN/PTOA in All Other Talus Fractures (Table 5)

Of the 74 patients with talus fractures without dislocations, 27 (36.5%) developed AVN/PTOA during the follow-up period, and 47 (63.5%) did not. There was no significant difference in mean age (37.37 years for AVN/PTOA, 35.78 years for no AVN/PTOA; P = .33), BMI (29.07 kg/m² for AVN/PTOA, 29.57 kg/m² for no AVN/PTOA; P = .39), or surgical timing (164.8 hours for AVN/PTOA, 105.41 for no AVN/PTOA; P = .14). Direct comparison of the proportions of polytrauma to development of AVN/PTOA in patients with talus fractures without dislocations revealed no significant difference. Fourteen of the 27 patients who developed AVN/PTOA had polytrauma, and 23 of the 47 who did not develop AVN/PTOA had polytrauma (P = .18). Direct comparison of the proportions of open injuries to development of AVN/PTOA in patients with talus fractures without dislocations revealed a significant difference (P = .009). There was a significant difference in follow-up time between these groups. Patients who had talus fractures without dislocations and developed AVN/PTOA were followed for a mean of 154.3 weeks, and those who did not develop AVN/PTOA were followed for a mean of 216 weeks (P = .02).

Discussion

Our results showed that time from talus fracture-dislocation to surgical reduction had no effect on development of AVN/PTOA. The findings in this largest series to date agree with earlier findings^1,8,15,16,24 and add to the volume of literature suggesting that time to surgical reduction of talus fractures and talus fracture-dislocations does not markedly affect outcome.

Talus fractures continue to present a significant treatment dilemma. Despite recent improvements in surgical techniques and overall management of these injuries, rates of AVN and PTOA have not significantly decreased.^1,16,23 At most treating facilities, talus fracture-dislocations are considered surgical emergencies/urgencies, and every effort is made to reduce and surgically address these injuries as soon as possible.^1,13

In this study, rates of AVN/PTOA were 41% (all talus fractures) and 50% (displaced talar neck fractures), and the difference was not significant (Table 3). These rates are higher but consistent with previously reported rates (range, 14%-49%).^{1,2,7-9,12,14,24} There was no difference in surgical timing for development of AVN/PTOA. We analyzed the cases of all patients who had talus fractures and developed AVN/PTOA (43/106). Within this group, there were no significant differences in surgical timing, age, sex, polytrauma, or BMI between patients who developed AVN/PTOA and those who did not. Compared with patients who did not develop AVN/PTOA, those who developed AVN/PTOA were significantly more likely to have open injuries. This finding, consistent with those in other reports^9,12,13 (Table 3), indicates outcome is more likely related to injury severity and not necessarily injury class.

We retrospectively analyzed talus fractures and talus fracture-dislocations to determine if urgent surgical management affects outcomes. Current practice at our institution is to routinely reduce and surgically address these fractures urgently, often during the middle of the night, when orthopedic resources are reduced. Our study found a significant difference in surgical timing for patients with talus fracture-dislocations and patients with talus fractures without dislocations (Table 2). Given our findings, urgent surgical reduction and fixation are not indicated to preserve the talus blood supply and prevent AVN/PTOA, though we still recommend urgent surgical management in the setting of an open wound, skin necrosis, or soft-tissue/neurovascular compromise. 

This study had several limitations, primarily related to its retrospective nature. Surgical timing was defined as time from injury, as noted in the medical record, to operating room start. In some instances, time of injury was not noted in the medical record, and time of presentation to emergency room was used instead. Thus, surgical timing for these patients may have been longer than identified. In addition, given the rare injury pattern and the retrospective design, this study was susceptible to type II error and may have been underpowered to detect whether time to surgical reduction predicted complications. Also, the study did not address functional outcome as measured by validated outcome scores. Outcome measures were obtained in many but not all cases, making functional outcome measurement difficult. Similarly, the quality of the anatomical reductions was not assessed, potentially affecting complication rates. Postoperative reduction assessment, possibly performed with computed tomography, is an avenue of further study.

 

Strengths of this study include its large sample size (this was one of the largest studies of talus fractures), long follow-up (mean, 150 weeks), and novel use of AO/OTA classification.

We postulate that development of AVN/PTOA is not necessarily related to the urgency or timing of surgical reduction and fixation and is more likely related to injury severity. This idea is supported by the finding that development of AVN/PTOA was significantly correlated to open injuries in all talus fractures, including talus fracture-dislocations and isolated talus fractures.

Conclusion 

Talus fracture-dislocations are devastating injuries with high rates of complications. In this study, open talus fractures, and fractures with associated tibiotalar or subtalar dislocations, had higher complication rates. Given the evidence presented, we recommend basing surgical timing on injury severity, not necessarily for AVN/PTOA prevention. Specifically, in the absence of an open wound, skin necrosis, or soft-tissue/neurovascular compromise, talus fracture-dislocations can be surgically reduced and stabilized when optimal resources are available.

Take-Home Points

• There is a 41% rate of AVN or PTOA after operatively managed talus fracture.
• Surgical timing does not affect development of AVN or PTOA.
• Open fractures are associated with development of AVN and PTOA.
• Quality of reduction is likely more important than timing of reduction.
• Urgent surgical treatment is necessary for threatened soft tissue or neurovascular compromise.

Talus fractures are rare injuries that present a significant treatment dilemma.^1-12 These fractures represent <1% of all fractures⁴ and are second only to calcaneus fractures in fractures of the hindfoot. Talus fractures with associated dislocations are even rarer and may provide treating surgeons with a significant surgical quandary.^6,13-16

Talus fractures historically have been characterized by their anatomical location: head, neck, or body. Two systems are commonly used to classify talus fractures: Hawkins and AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association). The first, developed by Hawkins⁷ and modified by Canale and Kelly² and Vallier and colleagues,¹ identifies 4 basic fracture types with associated dislocations. The other system, published in 1996¹⁷ and republished in 2007,¹⁸ uses the combined methods of AO and OTA to systematically describe talus fractures. Although these classification systems accurately describe talus fractures with associated dislocation, both have difficulty predicting clinical outcomes.^1,19,20

Talus fractures commonly result in avascular necrosis (AVN) of the talus and posttraumatic osteoarthritis (PTOA) of the tibiotalar and subtalar joints.^{3,8,9,12,14-16} Hawkins⁷ initially described subchondral lucency as indicating revascularization of the talus after injury. AVN and PTOA rates traditionally have been thought to be related to a blood supply disruption, given the prognostic value of the Hawkins sign.^1,7,12,21 New methods, including a dual-incision approach and expedited transfer to foot and ankle surgeons or orthopedic traumatologists, have improved reduction quality^21-24 but not patient outcomes.^{3,5,8,9,12,14}

Recently, time from injury to surgical intervention has been a topic of much discussion, and there have been studies on the specific effects of timing with respect to outcome.^1,15,16 Vallier and colleagues,¹ who wanted to identify injury characteristics predictive of osteonecrosis, found that delaying reduction and surgical fixation did not increase the risk of AVN. Another study found that urgent reduction of fracture-dislocation with delayed open reduction and internal fixation (ORIF) using a dual approach may improve clinical outcomes.²¹

In this vein, we conducted a study to evaluate the effect of time to surgical reduction of talus fractures and talus fracture-dislocations on the development of AVN and PTOA. We hypothesized that time to surgical reduction of talus fracture-dislocation as classified with the AO/OTA system would have no effect of the development of AVN/PTOA.

Methods

After this study received Institutional Review Board approval, we retrospectively reviewed the records on talus fractures surgically managed at a level I trauma center during the 10-year period 2003 to 2013. Of the 119 potential cases identified using Current Procedural Terminology code 28445 (ORIF of talus), 13 were excluded (12 for inaccurate coding or missing documentation, 1 for being a pediatric case), leaving 106 for analysis. Using the Hawkins and AO/OTA systems, 3 independent reviewers classified the injuries on plain radiographs.

Injury dates and times were obtained from the medical records. Operating room start times were also obtained. Surgical timing was defined as time from injury to operating room start. For cases without an injury time, time of presentation to emergency department was used.

Open fracture-dislocations were managed with intravenous antibiotics, urgent surgical irrigation, débridement, and immediate fixation or temporizing external fixation after reduction. All fractures were definitively managed with standard ORIF with an anteromedial, anterolateral, or dual approach and mini-fragment implants. After fixation, weight-bearing typically was restricted for 6 to 12 weeks.

Follow-up radiographs were evaluated. Presence or absence of Hawkins sign⁷ was noted on radiographs at 6 or 8 weeks, and all follow-up radiographs were evaluated for AVN as defined by increased radiographic density within the talar dome or collapse of the articular surface. All radiographs were evaluated for PTOA as defined by loss of joint space within the tibiotalar, subtalar, or talonavicular joint on follow-up radiographs.

Clinical outcomes were analyzed for development of AVN, PTOA, or secondary corrective surgery or arthrodesis. Continuous variables were evaluated with the t test, and the χ² test was used to compare distributions of categorical variables. The Wilcoxon rank sum test was used to compare non-normally distributed variables. Significance was set at P < .05.

 

 

Results

Classification Analysis (Table 1)

We identified 106 surgically managed talus fractures. Five (4.7%) were lateral process and talar head fractures (AO/OTA 81-A). Seventy-six (71.7%) were talar neck fractures (81-B), which included 13 (12%) 81-B1 fractures, 31 (29%) 81-B2 fractures, and 32 (30%) 81-B3 fractures. Twenty-five (23.6%) were talar body fractures (81-C). AO/OTA 81-B3 fractures were identified and separately analyzed and compared with talus fractures of all other classes. AO/OTA 81-B talar neck fractures were classified with the Hawkins system7 as well: 13 (12%) were Hawkins 1 fractures, 31 (29%) Hawkins 2 fractures, 25 (24%) Hawkins 3 fractures, and 7 (7%) Hawkins 4 fractures.

Subject Analysis (Table 2)

Of the 106 patients, 69 were female and 37 male. Mean age was 37.7 years (range, 18-78 years). Mean body mass index (BMI) was 29.45 kg/m². Of the 106 cases, 52 were managed by board- certified orthopedic trauma surgeons, 32 by board- certified foot and ankle surgeons, and 22 by orthopedic surgeons with other specialty training.

The mechanisms of injury were motor vehicle accident (70/106; 66%), fall from height (25; 24%), misstep (4), sports related (2), object falling on ankle (2), and not reported (3). 

Of the 106 patients, 45 (42%) had isolated talus injuries, 35 had concomitant ipsilateral lower extremity injuries, 25 had concomitant contralateral lower extremity injuries, and 1 had a concomitant upper extremity injury. 

Smoking status was everyday (14 patients), past (10), never (34), and unreported (48). Five patients reported a history of alcohol abuse, and 4 patients reported illicit drug use. Two had a history of atrial fibrillation, 9 had hypertension, 3 had hyperlipidemia, 3 had renal disease, 3 had heart disease, 4 had diabetes, 3 had lung disease, and 1 had a history of lung cancer.

Overall Analysis of AVN/PTOA (Table 3)

Of the 106 patients, 43 (41%) developed AVN/PTOA, and 63 (59%) did not, while fifty-four (51%) of the 106 patients who developed AVN/PTOA had polytrauma, and 52 (49%) of those who did not develop AVN/PTOA had polytrauma (P = .79). There was no significant difference in mean age (38.74 years for AVN/PTOA, 36.21 years for no AVN/PTOA; P = .20) or BMI (28.99 kg/m² for AVN/PTOA, 29.15 kg/m2 for no AVN/PTOA; P = .45). Direct comparison of proportions of polytrauma to development of AVN/PTOA revealed no significant difference. Direct comparison of the proportions of open injuries to development of AVN/PTOA revealed a significant difference. Fifteen (35%) of the 43 patients who developed AVN/PTOA had open injuries, and 10 (16%) of the 63 who did not develop AVN/PTOA had open injuries (P = .03). There was no significant difference in follow-up between patients who developed AVN/PTOA and those who did not (P = .26).

Analysis of AVN/PTOA in 81-B3 Fracture-Dislocations (Table 4)

Of the 32 patients with AO/OTA 81-B3 (Hawkins 3 or 4) fractures, 16 (50%) developed AVN/PTOA, and 16 did not. There was no significant difference in mean age (41.05 years for AVN/PTOA, 37.40 years for no AVN/PTOA; P = .29), BMI (28.86 kg/m² for AVN/PTOA, 27.94 kg/m2 for no AVN/PTOA; P = .38), or surgical timing (19.09 hours for AVN/PTOA, 16.65 hours for no AVN/PTOA; P = .29) for development of AVN/PTOA. Direct comparison of the proportions of polytrauma and open injuries to development of AVN/PTOA in patients with 81-B3 fracture- dislocations revealed no significant difference. Nine of the 16 patients (56%) who developed AVN/PTOA had polytrauma, and 11 of the 16 (69%) who did not develop AVN/PTOA had polytrauma (P = .465). Although open injury was found to predict AVN/PTOA overall, this was not true for talus fracture-dislocations alone. Five of the 10 patients who developed AVN/PTOA had open injuries, and 5 of the 10 who did not develop AVN/PTOA had open injuries (P = 1.0). There was a significant difference in follow-up time between these groups. Patients who had 81-B3 fracture-dislocations and developed AVN/PTOA were followed for a mean of 120.4 weeks, and those who did not develop AVN/PTOA were followed for a mean of 40.33 weeks (P = .001).

 

 

Analysis of AVN/PTOA in All Other Talus Fractures (Table 5)

Of the 74 patients with talus fractures without dislocations, 27 (36.5%) developed AVN/PTOA during the follow-up period, and 47 (63.5%) did not. There was no significant difference in mean age (37.37 years for AVN/PTOA, 35.78 years for no AVN/PTOA; P = .33), BMI (29.07 kg/m² for AVN/PTOA, 29.57 kg/m² for no AVN/PTOA; P = .39), or surgical timing (164.8 hours for AVN/PTOA, 105.41 for no AVN/PTOA; P = .14). Direct comparison of the proportions of polytrauma to development of AVN/PTOA in patients with talus fractures without dislocations revealed no significant difference. Fourteen of the 27 patients who developed AVN/PTOA had polytrauma, and 23 of the 47 who did not develop AVN/PTOA had polytrauma (P = .18). Direct comparison of the proportions of open injuries to development of AVN/PTOA in patients with talus fractures without dislocations revealed a significant difference (P = .009). There was a significant difference in follow-up time between these groups. Patients who had talus fractures without dislocations and developed AVN/PTOA were followed for a mean of 154.3 weeks, and those who did not develop AVN/PTOA were followed for a mean of 216 weeks (P = .02).

Discussion

Our results showed that time from talus fracture-dislocation to surgical reduction had no effect on development of AVN/PTOA. The findings in this largest series to date agree with earlier findings^1,8,15,16,24 and add to the volume of literature suggesting that time to surgical reduction of talus fractures and talus fracture-dislocations does not markedly affect outcome.

Talus fractures continue to present a significant treatment dilemma. Despite recent improvements in surgical techniques and overall management of these injuries, rates of AVN and PTOA have not significantly decreased.^1,16,23 At most treating facilities, talus fracture-dislocations are considered surgical emergencies/urgencies, and every effort is made to reduce and surgically address these injuries as soon as possible.^1,13

In this study, rates of AVN/PTOA were 41% (all talus fractures) and 50% (displaced talar neck fractures), and the difference was not significant (Table 3). These rates are higher but consistent with previously reported rates (range, 14%-49%).^{1,2,7-9,12,14,24} There was no difference in surgical timing for development of AVN/PTOA. We analyzed the cases of all patients who had talus fractures and developed AVN/PTOA (43/106). Within this group, there were no significant differences in surgical timing, age, sex, polytrauma, or BMI between patients who developed AVN/PTOA and those who did not. Compared with patients who did not develop AVN/PTOA, those who developed AVN/PTOA were significantly more likely to have open injuries. This finding, consistent with those in other reports^9,12,13 (Table 3), indicates outcome is more likely related to injury severity and not necessarily injury class.

We retrospectively analyzed talus fractures and talus fracture-dislocations to determine if urgent surgical management affects outcomes. Current practice at our institution is to routinely reduce and surgically address these fractures urgently, often during the middle of the night, when orthopedic resources are reduced. Our study found a significant difference in surgical timing for patients with talus fracture-dislocations and patients with talus fractures without dislocations (Table 2). Given our findings, urgent surgical reduction and fixation are not indicated to preserve the talus blood supply and prevent AVN/PTOA, though we still recommend urgent surgical management in the setting of an open wound, skin necrosis, or soft-tissue/neurovascular compromise. 

This study had several limitations, primarily related to its retrospective nature. Surgical timing was defined as time from injury, as noted in the medical record, to operating room start. In some instances, time of injury was not noted in the medical record, and time of presentation to emergency room was used instead. Thus, surgical timing for these patients may have been longer than identified. In addition, given the rare injury pattern and the retrospective design, this study was susceptible to type II error and may have been underpowered to detect whether time to surgical reduction predicted complications. Also, the study did not address functional outcome as measured by validated outcome scores. Outcome measures were obtained in many but not all cases, making functional outcome measurement difficult. Similarly, the quality of the anatomical reductions was not assessed, potentially affecting complication rates. Postoperative reduction assessment, possibly performed with computed tomography, is an avenue of further study.

 

Strengths of this study include its large sample size (this was one of the largest studies of talus fractures), long follow-up (mean, 150 weeks), and novel use of AO/OTA classification.

We postulate that development of AVN/PTOA is not necessarily related to the urgency or timing of surgical reduction and fixation and is more likely related to injury severity. This idea is supported by the finding that development of AVN/PTOA was significantly correlated to open injuries in all talus fractures, including talus fracture-dislocations and isolated talus fractures.

Conclusion 

Talus fracture-dislocations are devastating injuries with high rates of complications. In this study, open talus fractures, and fractures with associated tibiotalar or subtalar dislocations, had higher complication rates. Given the evidence presented, we recommend basing surgical timing on injury severity, not necessarily for AVN/PTOA prevention. Specifically, in the absence of an open wound, skin necrosis, or soft-tissue/neurovascular compromise, talus fracture-dislocations can be surgically reduced and stabilized when optimal resources are available.

Take-Home Points

• Cellular healing response differs between bony and soft tissue biceps tenodesis.
• Bony tenodesis incites an inflammatory healing response.
• Bony tenodesis healing occurs at the tendon-bone interface.
• Intrasseous bony fixation leads to tendon degeneration within the bone.
• Tendon-to-tendon tenodesis may result in regenerative tendon healing.

The long head of the biceps tendon (LHBT) is a well-established pain generator of the anterior shoulder^1,2 and may be surgically addressed in refractory cases.³ According to a recent study of 44,932 cases, biceps tenodesis rates increased 80% over just 3 years (2008-2011).⁴ Nevertheless, optimal tenodesis location and technique remain controversial. Proximal and distal tenodesis, including numerous soft-tissue and bony techniques, have been described.^5-7 Several studies have focused on the biomechanical strength of various fixation modalities.^8-14 These data highlight the ongoing evolution of our understanding of biceps-labrum complex (BLC) disease.

Over the years, tenodesis location has proved to be an important factor in outcomes.^3,15-20 Several recent studies have elucidated the role of the extra-articular LHBT and the limited capabilities of diagnostic arthroscopy.^15-17,20,21 Taylor and colleagues¹⁷ defined the bicipital tunnel as the extra-articular segment of LHBT and its fibro-osseous enclosure. The tunnel extends from the articular margin through the subpectoral region and can be divided into 3 zones: Zone 1 goes from the articular margin to the inferior margin of the subscapularis, zone 2 goes from the inferior margin of the subscapularis to the proximal margin of the pectoralis major tendon, and zone 3 is the subpectoral region. Zone 2 is often referred to as “no man’s land” for its relative invisibility from arthroscopy above and open exposure below.^17,21 Notably, a recent study reported a 47% prevalence of hidden tunnel lesions in patients with chronic BLC disease symptoms.¹⁸ Other studies have shown that standard proximal tenodesis methods often fail to address LHBT pathology in this area, leading to residual symptoms.^9,22 It is evident that tenodesis location and technique play important roles in patient outcomes. Sanders and colleagues¹⁶ found that the revision rate was significantly higher among patients who underwent biceps tenodesis without release of the bicipital tunnel sheath than among patients who underwent tenodesis with the release. Dr. O’Brien developed an alternative option: soft-tissue tenodesis with transfer of the LHBT to the conjoint tendon within the subdeltoid space.^23,24 This technique addresses intra-articular and extra-articular tunnel disease while mitigating the complications associated with bony tenodesis. Early and midterm studies have shown this to be an effective intervention for chronically symptomatic BLC disease.^25,26

Despite the abundance of literature on tenodesis techniques, no one has histologically evaluated the location-dependent healing and inflammatory responses. We conducted a study to determine the impact of tenodesis location on healing and inflammation in a rat model. We hypothesized that, compared with tendon-to-bone techniques, soft-tissue tenodesis would minimize inflammatory response and optimize healing.

Methods 

The study was approved by the Institutional Animal Care and Use Committee at the Hospital for Special Surgery. 

Animals

Biceps tenodesis was performed at 1 of 3 locations in 36 thirteen-week-old Sprague-Dawley rats (Charles River Laboratories). All rats were prepared for surgery by an experienced veterinary technician. Sedation was induced with isoflurane gas through a nose cone. 

Surgical Procedure

Animals were randomly assigned to 3 different tenodesis groups: tendon-to-bone in the bicipital groove (metaphyseal, M); tendon-to-bone in the subpectoral region (diaphyseal, D); and soft tissue-to-soft tissue transfer to the conjoint tendon (T). A standard deltopectoral approach was used to expose the biceps tendon. The tendon was tagged with a 5-0 polypropylene suture and tenotomized at the level of the bicipital groove (zone 1). All wounds were irrigated and closed with 4-0 nylon suture.

For animals undergoing tendon-to-bone metaphyseal tenodesis, a 0.045-mm Kirschner wire was used to drill bicortically into the intertubercular sulcus. Wire positioning distal to the physeal plate was confirmed with fluoroscopy. A locking stitch of 5-0 polypropylene suture was run along the free edge of the tendon. The tendon was then passed through the bone tunnel in an anterior-to-posterior direction, and the limbs of the suture were tied around the lateral cortex. 

The process was repeated for animals undergoing diaphyseal tenodesis; only the tenodesis location was different. The inferior border of the pectoralis major was identified, and a bicortical tunnel was made in the center of the diaphyseal bone. The tendon was then prepared and tenodesed to bone using the method already described.

In soft-tissue tenodesis, the conjoint tendon was identified and carefully dissected from surrounding tissues. The LHBT was then tenodesed to the attached conjoint tendon with interrupted simple stitches of 5-0 polypropylene suture.

The animals were allowed to bear weight on the operative limb immediately after surgery and without immobilization.

Specimen Harvest and Preparation

Four animals from each group were sacrificed at 6, 12, and 24 weeks. Harvested specimens were fixed in 10% neutral-buffered formalin solution. Bony specimens consisted of the upper half of the humerus and the tenodesed biceps tendon, and soft-tissue specimens consisted of the tenodesed LHBT-conjoint tendon complex. Bony specimens were decalcified in 10% ethylenediaminetetraacetic acid. All specimens were paraffin-embedded and sectioned at 7 microns.

Analysis of Cellularity

Sections were stained with hematoxylin-eosin. Overall cellularity at the tenodesis interface was quantified by averaging the nuclei count within 3 separate standardized ×20 magnification high power fields. Only nucleated cells were included in the cell count. Immunohistochemical staining with tenomodulin (Santa Cruz Laboratories, sc-49324) was performed to characterize the cell population at the interface. Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with the anti-tenomodulin goat monoclonal antibody diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with methyl green. Specimens treated with tenomodulin were evaluated for presence or absence of a positive reaction at the tenodesis interface. 

Analysis of Inflammation

Inflammation at the interface was evaluated with the CD68 macrophage marker (ABcam, ab31630). Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with anti-CD68 mouse monoclonal antibodies diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with neutral red. Inflammation was quantified by averaging the number of reactive cells within 3 separate standardized ×20 magnification high power fields.

Statistical Analysis

Descriptive statistics were calculated for cell and macrophage counts for each group at every time point. Two-way analysis of variance was used to compare the cell and macrophage counts between groups at each time point as well as the count differences within each group between time points. P values were Bonferroni-corrected to account for the multiple comparisons between groups. P < .05 was used to signify statistical significance.

Results

All 36 animals survived to their designated harvest time without complications. Twelve specimens were successfully harvested at 6 weeks and another 12 at 24 weeks. At 12 weeks, tenodesis failure occurred in 1 animal in group D, leaving 11 specimens for analysis.

Cellularity

At the 6-week harvest, 1 group T specimen was sectioned incorrectly and discarded, leaving 3 specimens for evaluation. Descriptive statistics for each group and each time point are listed in Table 1A. There were no significant differences in mean cellularity between the bony tenodesis groups at any time point (P = 1.000) (Table 1B).

At 6 weeks, both group M (P = .012) and group D (P = .021) showed significantly more cellularity than group T (Figure 1). The same was true for group M (P = .002) and group D (P = .001) at the 12-week harvest. There were no significant differences in cellularity between the 3 groups at 24 weeks. 

Within-group analysis revealed a trend of increasing cellularity at 12 weeks followed by a decrease at 24 weeks in all 3 groups (Table 2).

Group M showed a significant overall decrease in cellularity from 6 to 24 weeks (P = .035) and from 12 to 24 weeks (P = .004). The overall decrease in cell count from 6 to 24 weeks was not significant in group D (P = .124), whereas the decrease from 12 to 24 weeks was significant (P = .005). There were no significant differences in cellularity for group T between any of the time points.

Inflammatory Response 

During specimen processing, 1 group D specimen was severely degraded after pronase treatment, leaving 3 specimens for evaluation. Descriptive statistics for each group are listed in Table 3A.

At 6 weeks, mean CD68 cell count was significantly higher in group M than in group D (P = .011) and group T (P < .001) (Table 3B). Likewise, CD68 count was significantly higher in group D than in group T (P < .001). There were no differences in CD68 counts between the 2 bony tenodesis groups at 12 weeks (P = .486) or 24 weeks (P = .315). Both bony tenodesis groups, however, had persistently higher CD68 counts at 12 weeks when compared with group T (group M, P = .002; group D, P < .001). In these specimens, an inflammatory milieu characterized by a large accumulation of lymphocytes and giant cells was noted at the bone-tendon interface.

In comparison, inflammatory cells were scant at the tendon-tendon interface in group T specimens (Figure 2). There were no differences in CD68 reaction between the 3 tenodesis groups at 24 weeks. In all cases of tendon-to-bone tenodesis, no recognizable formed tendon was seen within the bone tunnel. Rather, all tendon-to-bone tenodeses were characterized by dense connective tissue at the bone surface, surrounded by an accumulation of macrophages.

Within-group analysis revealed a significant decrease in CD68 cells from 6 to 12 weeks and overall from 6 to 24 weeks in group M (Table 4). There was no significant change in CD68 cell counts between any time points within group D (P = 1.000) and between 6 and 12 weeks in group T (P = 1.000). Interestingly, the CD68 counts in group T showed an overall increase from 6 to 24 weeks (P = .019). The increase was even more significant from 12 to 24 weeks (P = .004).

Tissue-Specific Staining

At 6 weeks, antigen retrieval resulted in severe degradation of 2 group M specimens, 2 group D specimens, and 1 group T specimen. The most notable tenomodulin reaction occurred in group T at the 6- and 12-week harvests, with the 6-week group having the most robust reaction. There was scant reaction in this group at 24 weeks.

One group D specimen showed a positive reaction at 24 weeks. No reaction occurred in the remaining bony specimens across all time points (Figure 3).

Discussion

In this study, the healing response differed between bony and soft-tissue tenodesis techniques in a rat model. Tendon-to-bone tenodesis, both diaphyseal and metaphyseal, appeared to incite an inflammatory degenerative response, whereas tendon-to-tendon healing occurred in a more quiescent and perhaps even regenerative manner.

The early inflammatory response that occurred in the bony tenodesis groups is not unlike what occurs in fracture healing.²⁷ The reaction was even more robust at 12 weeks, signifying an ongoing inflammatory process. In this context, tendon degeneration may plausibly explain the consistent absence of mature tendon within the tunnels at all 3 time points. Some tendon degeneration may be explained by the vascular damage that occurred during surgery, but this damage was a constant factor in all 3 study groups. Interestingly, group M showed the highest early CD68 counts, consistent with this being the more biologically active region of bone.²⁸

Group T had significantly lower cell and macrophage counts throughout the study period, possibly indicating improved healing—an observation supported by a study in which the impact of macrophage depletion on bone-tendon interface healing was evaluated.²⁹ The authors found that, in suppressing macrophage activity, the morphologic and biomechanical properties at the healing interface were significantly improved.²⁹ These findings are consistent with Dr. O’Brien’s anecdotal experience with patients who previously underwent the biceps transfer; on second-look arthroscopy, there was complete seamless integration of tendon and conjoint tendon (Figure 4). 

 

Studies have found that the inflammatory process is closely associated with pain, and pain syndromes such as fibromyalgia.^30,31 Persistent inflammation, as seen in our bony tenodesis group, could explain the recalcitrant anterior shoulder pain that often occurs in patients after bony tenodesis of the LHBT.^2,6,19,32 

Studies have also suggested that osteoclasts at the bone-tendon interface—osteoclasts share a cell lineage with macrophages—may contribute to bone loss and tunnel widening.^33,34 Osteoclasts are expected at the bone tunnel, as fracture healing occurs at the bone-tendon interface. These osteoclasts could have contributed to the strong CD68 reaction in our bony tenodesis groups. However, CD68 historically has been described as the classic macrophage marker.³⁵ We specifically selected CD68 for this reason: Macrophages are the primary inflammatory cells involved in early healing and are key to the inflammatory process.³⁶

Results of the tenomodulin analysis suggested 2 different healing processes are occurring in the bony and tendon groups. Tenomodulin is a known tenocyte marker for developing and mature tendon in both rats and humans.^37,38 In our study, only group T had a positive tenomodulin reaction. Notably, the reaction occurred only at 6 and 12 weeks. This finding may indicate that a regenerative healing pattern becomes quiescent by 24 weeks. Indeed, it has been suggested that tenomodulin is a key regulator of tenocyte proliferation and tendon maturation.³⁹

The complete absence of tenomodulin reaction in our bony tenodesis groups in the setting of significant inflammation further supports our theory of tendon degeneration within the tunnel. One potential explanation for this finding may be that as the tendon heals to the surface of the bone, the intra-osseous tendon is no longer load-bearing and is resorbed by the body through an inflammatory response. This finding differs from those in previous studies, which have described viable tendon within the bone tunnel at all time points up to 26 weeks.⁴⁰ More recently, it has been suggested that callus formation at the external cortical tendon-bone interface is critical for healing and mechanical strength.^41,42 In addition, recent studies have found a predominantly fibroblastic healing process at the midtunnel, potentially leading to the formation of loose fibrovascular tissue at the tendon-bone interface.⁴³ These data, in concert with ours, call into question the rationale for performing intra-osseous tenodesis through bone tunnels.

Our study results, if confirmed in humans, will have significant clinical implications. If a similar effect can be confirmed in the human shoulder, one could argue that soft-tissue tenodesis may result in decreased postoperative shoulder pain. In addition, if tendon degeneration does occur within the intramedullary tunnel, surface fixation may be the better, safer alternative. Although older studies reported suboptimal strength with this type of fixation,^8,44 more recent studies have found surface fixation strength equivalent to screw fixation strength.^45,46 Such a shift in the treatment paradigm would obviate the need for violation of the humeral cortex, eliminating potential stress risers associated with screw fixation,⁴⁷ and effectively eliminating the risk of iatrogenic fracture.^48,49 It would be interesting to investigate what occurs histologically at the bone-tendon interface in surface fixation (ie, suture anchors). Would the inflammatory response at the surface be similar to the inflammatory intramedullary healing, or would it be similar to the quieter tendon-tendon healing? Answers to such questions have the potential to streamline the treatment algorithm for patients who require tenodesis.

Study Limitations

Our study had several limitations. First, as this was a basic science study using a rat model, its conclusions can only be extrapolated to humans. Second, given the nonspecific nature of the cellular analysis, we cannot draw any definitive conclusions about the cell population at the bone-tendon interface. For example, although tenomodulin is expressed by tenocytes, it is not an established specific marker for tenocytes and may be expressed by other fibroblastic cells. Still, our results provide insight into the local microenvironment and identify important differences between the tenodesis methods. Similarly, the complete absence of tendon within the bone tunnels suggests that an analysis of osteoclastic activity at the tenodesis interface may have been a valuable addition to the study. This finding, however, was unexpected, and we did not have the foresight to include it in our methods. A third limitation is that our fixation method essentially uses the suspension tenodesis method. This fixation method differs from the common fixation techniques used in the clinical setting. Testing of other fixation constructs would require a larger animal model. Furthermore, in suspension- type constructs, micromotion within the bone tunnel may independently elicit an inflammatory response. Inert suture was used in our fixation in order to reduce the risk of an iatrogenic inflammatory response. Last, it would have been valuable to perform a biomechanical analysis of the strength of each tenodesis construct. This was explored with our institution’s biomechanics team, but specimen size precluded successful analysis.

Conclusion

Our results indicated that, compared with tendon-to-tendon fixation, tendon-to-bone tenodesis produces a significantly greater inflammatory response at the tenodesis interface. An inflammatory milieu in the absence of tendon within the bony tunnel suggests intraosseous tendon degeneration. Tendon-to-tendon tenodesis, on the other hand, seems to limit the inflammatory response. In addition, a robust tenomodulin reaction in the early phases of tendon-to-tendon healing suggests regenerative healing. Our results showed a fundamental difference in the healing response between the 2 tenodesis methods. Further study is needed to evaluate the validity and applicability of our findings to the human patient population. Most important, our results underscore the need for more study to elucidate optimal tenodesis location and encourage orthopedic surgeons to reexamine current clinical practice patterns.

Take-Home Points

• Cellular healing response differs between bony and soft tissue biceps tenodesis.
• Bony tenodesis incites an inflammatory healing response.
• Bony tenodesis healing occurs at the tendon-bone interface.
• Intrasseous bony fixation leads to tendon degeneration within the bone.
• Tendon-to-tendon tenodesis may result in regenerative tendon healing.

The long head of the biceps tendon (LHBT) is a well-established pain generator of the anterior shoulder^1,2 and may be surgically addressed in refractory cases.³ According to a recent study of 44,932 cases, biceps tenodesis rates increased 80% over just 3 years (2008-2011).⁴ Nevertheless, optimal tenodesis location and technique remain controversial. Proximal and distal tenodesis, including numerous soft-tissue and bony techniques, have been described.^5-7 Several studies have focused on the biomechanical strength of various fixation modalities.^8-14 These data highlight the ongoing evolution of our understanding of biceps-labrum complex (BLC) disease.

Over the years, tenodesis location has proved to be an important factor in outcomes.^3,15-20 Several recent studies have elucidated the role of the extra-articular LHBT and the limited capabilities of diagnostic arthroscopy.^15-17,20,21 Taylor and colleagues¹⁷ defined the bicipital tunnel as the extra-articular segment of LHBT and its fibro-osseous enclosure. The tunnel extends from the articular margin through the subpectoral region and can be divided into 3 zones: Zone 1 goes from the articular margin to the inferior margin of the subscapularis, zone 2 goes from the inferior margin of the subscapularis to the proximal margin of the pectoralis major tendon, and zone 3 is the subpectoral region. Zone 2 is often referred to as “no man’s land” for its relative invisibility from arthroscopy above and open exposure below.^17,21 Notably, a recent study reported a 47% prevalence of hidden tunnel lesions in patients with chronic BLC disease symptoms.¹⁸ Other studies have shown that standard proximal tenodesis methods often fail to address LHBT pathology in this area, leading to residual symptoms.^9,22 It is evident that tenodesis location and technique play important roles in patient outcomes. Sanders and colleagues¹⁶ found that the revision rate was significantly higher among patients who underwent biceps tenodesis without release of the bicipital tunnel sheath than among patients who underwent tenodesis with the release. Dr. O’Brien developed an alternative option: soft-tissue tenodesis with transfer of the LHBT to the conjoint tendon within the subdeltoid space.^23,24 This technique addresses intra-articular and extra-articular tunnel disease while mitigating the complications associated with bony tenodesis. Early and midterm studies have shown this to be an effective intervention for chronically symptomatic BLC disease.^25,26

Despite the abundance of literature on tenodesis techniques, no one has histologically evaluated the location-dependent healing and inflammatory responses. We conducted a study to determine the impact of tenodesis location on healing and inflammation in a rat model. We hypothesized that, compared with tendon-to-bone techniques, soft-tissue tenodesis would minimize inflammatory response and optimize healing.

Methods 

The study was approved by the Institutional Animal Care and Use Committee at the Hospital for Special Surgery. 

Animals

Biceps tenodesis was performed at 1 of 3 locations in 36 thirteen-week-old Sprague-Dawley rats (Charles River Laboratories). All rats were prepared for surgery by an experienced veterinary technician. Sedation was induced with isoflurane gas through a nose cone. 

Surgical Procedure

Animals were randomly assigned to 3 different tenodesis groups: tendon-to-bone in the bicipital groove (metaphyseal, M); tendon-to-bone in the subpectoral region (diaphyseal, D); and soft tissue-to-soft tissue transfer to the conjoint tendon (T). A standard deltopectoral approach was used to expose the biceps tendon. The tendon was tagged with a 5-0 polypropylene suture and tenotomized at the level of the bicipital groove (zone 1). All wounds were irrigated and closed with 4-0 nylon suture.

For animals undergoing tendon-to-bone metaphyseal tenodesis, a 0.045-mm Kirschner wire was used to drill bicortically into the intertubercular sulcus. Wire positioning distal to the physeal plate was confirmed with fluoroscopy. A locking stitch of 5-0 polypropylene suture was run along the free edge of the tendon. The tendon was then passed through the bone tunnel in an anterior-to-posterior direction, and the limbs of the suture were tied around the lateral cortex. 

The process was repeated for animals undergoing diaphyseal tenodesis; only the tenodesis location was different. The inferior border of the pectoralis major was identified, and a bicortical tunnel was made in the center of the diaphyseal bone. The tendon was then prepared and tenodesed to bone using the method already described.

In soft-tissue tenodesis, the conjoint tendon was identified and carefully dissected from surrounding tissues. The LHBT was then tenodesed to the attached conjoint tendon with interrupted simple stitches of 5-0 polypropylene suture.

The animals were allowed to bear weight on the operative limb immediately after surgery and without immobilization.

Specimen Harvest and Preparation

Four animals from each group were sacrificed at 6, 12, and 24 weeks. Harvested specimens were fixed in 10% neutral-buffered formalin solution. Bony specimens consisted of the upper half of the humerus and the tenodesed biceps tendon, and soft-tissue specimens consisted of the tenodesed LHBT-conjoint tendon complex. Bony specimens were decalcified in 10% ethylenediaminetetraacetic acid. All specimens were paraffin-embedded and sectioned at 7 microns.

Analysis of Cellularity

Sections were stained with hematoxylin-eosin. Overall cellularity at the tenodesis interface was quantified by averaging the nuclei count within 3 separate standardized ×20 magnification high power fields. Only nucleated cells were included in the cell count. Immunohistochemical staining with tenomodulin (Santa Cruz Laboratories, sc-49324) was performed to characterize the cell population at the interface. Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with the anti-tenomodulin goat monoclonal antibody diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with methyl green. Specimens treated with tenomodulin were evaluated for presence or absence of a positive reaction at the tenodesis interface. 

Analysis of Inflammation

Inflammation at the interface was evaluated with the CD68 macrophage marker (ABcam, ab31630). Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with anti-CD68 mouse monoclonal antibodies diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with neutral red. Inflammation was quantified by averaging the number of reactive cells within 3 separate standardized ×20 magnification high power fields.

Statistical Analysis

Descriptive statistics were calculated for cell and macrophage counts for each group at every time point. Two-way analysis of variance was used to compare the cell and macrophage counts between groups at each time point as well as the count differences within each group between time points. P values were Bonferroni-corrected to account for the multiple comparisons between groups. P < .05 was used to signify statistical significance.

Results

All 36 animals survived to their designated harvest time without complications. Twelve specimens were successfully harvested at 6 weeks and another 12 at 24 weeks. At 12 weeks, tenodesis failure occurred in 1 animal in group D, leaving 11 specimens for analysis.

Cellularity

At the 6-week harvest, 1 group T specimen was sectioned incorrectly and discarded, leaving 3 specimens for evaluation. Descriptive statistics for each group and each time point are listed in Table 1A. There were no significant differences in mean cellularity between the bony tenodesis groups at any time point (P = 1.000) (Table 1B).

At 6 weeks, both group M (P = .012) and group D (P = .021) showed significantly more cellularity than group T (Figure 1). The same was true for group M (P = .002) and group D (P = .001) at the 12-week harvest. There were no significant differences in cellularity between the 3 groups at 24 weeks. 

Within-group analysis revealed a trend of increasing cellularity at 12 weeks followed by a decrease at 24 weeks in all 3 groups (Table 2).

Group M showed a significant overall decrease in cellularity from 6 to 24 weeks (P = .035) and from 12 to 24 weeks (P = .004). The overall decrease in cell count from 6 to 24 weeks was not significant in group D (P = .124), whereas the decrease from 12 to 24 weeks was significant (P = .005). There were no significant differences in cellularity for group T between any of the time points.

Inflammatory Response 

During specimen processing, 1 group D specimen was severely degraded after pronase treatment, leaving 3 specimens for evaluation. Descriptive statistics for each group are listed in Table 3A.

At 6 weeks, mean CD68 cell count was significantly higher in group M than in group D (P = .011) and group T (P < .001) (Table 3B). Likewise, CD68 count was significantly higher in group D than in group T (P < .001). There were no differences in CD68 counts between the 2 bony tenodesis groups at 12 weeks (P = .486) or 24 weeks (P = .315). Both bony tenodesis groups, however, had persistently higher CD68 counts at 12 weeks when compared with group T (group M, P = .002; group D, P < .001). In these specimens, an inflammatory milieu characterized by a large accumulation of lymphocytes and giant cells was noted at the bone-tendon interface.

In comparison, inflammatory cells were scant at the tendon-tendon interface in group T specimens (Figure 2). There were no differences in CD68 reaction between the 3 tenodesis groups at 24 weeks. In all cases of tendon-to-bone tenodesis, no recognizable formed tendon was seen within the bone tunnel. Rather, all tendon-to-bone tenodeses were characterized by dense connective tissue at the bone surface, surrounded by an accumulation of macrophages.

Within-group analysis revealed a significant decrease in CD68 cells from 6 to 12 weeks and overall from 6 to 24 weeks in group M (Table 4). There was no significant change in CD68 cell counts between any time points within group D (P = 1.000) and between 6 and 12 weeks in group T (P = 1.000). Interestingly, the CD68 counts in group T showed an overall increase from 6 to 24 weeks (P = .019). The increase was even more significant from 12 to 24 weeks (P = .004).

Tissue-Specific Staining

At 6 weeks, antigen retrieval resulted in severe degradation of 2 group M specimens, 2 group D specimens, and 1 group T specimen. The most notable tenomodulin reaction occurred in group T at the 6- and 12-week harvests, with the 6-week group having the most robust reaction. There was scant reaction in this group at 24 weeks.

One group D specimen showed a positive reaction at 24 weeks. No reaction occurred in the remaining bony specimens across all time points (Figure 3).

Discussion

In this study, the healing response differed between bony and soft-tissue tenodesis techniques in a rat model. Tendon-to-bone tenodesis, both diaphyseal and metaphyseal, appeared to incite an inflammatory degenerative response, whereas tendon-to-tendon healing occurred in a more quiescent and perhaps even regenerative manner.

The early inflammatory response that occurred in the bony tenodesis groups is not unlike what occurs in fracture healing.²⁷ The reaction was even more robust at 12 weeks, signifying an ongoing inflammatory process. In this context, tendon degeneration may plausibly explain the consistent absence of mature tendon within the tunnels at all 3 time points. Some tendon degeneration may be explained by the vascular damage that occurred during surgery, but this damage was a constant factor in all 3 study groups. Interestingly, group M showed the highest early CD68 counts, consistent with this being the more biologically active region of bone.²⁸

Group T had significantly lower cell and macrophage counts throughout the study period, possibly indicating improved healing—an observation supported by a study in which the impact of macrophage depletion on bone-tendon interface healing was evaluated.²⁹ The authors found that, in suppressing macrophage activity, the morphologic and biomechanical properties at the healing interface were significantly improved.²⁹ These findings are consistent with Dr. O’Brien’s anecdotal experience with patients who previously underwent the biceps transfer; on second-look arthroscopy, there was complete seamless integration of tendon and conjoint tendon (Figure 4). 

 

Studies have found that the inflammatory process is closely associated with pain, and pain syndromes such as fibromyalgia.^30,31 Persistent inflammation, as seen in our bony tenodesis group, could explain the recalcitrant anterior shoulder pain that often occurs in patients after bony tenodesis of the LHBT.^2,6,19,32 

Studies have also suggested that osteoclasts at the bone-tendon interface—osteoclasts share a cell lineage with macrophages—may contribute to bone loss and tunnel widening.^33,34 Osteoclasts are expected at the bone tunnel, as fracture healing occurs at the bone-tendon interface. These osteoclasts could have contributed to the strong CD68 reaction in our bony tenodesis groups. However, CD68 historically has been described as the classic macrophage marker.³⁵ We specifically selected CD68 for this reason: Macrophages are the primary inflammatory cells involved in early healing and are key to the inflammatory process.³⁶

Results of the tenomodulin analysis suggested 2 different healing processes are occurring in the bony and tendon groups. Tenomodulin is a known tenocyte marker for developing and mature tendon in both rats and humans.^37,38 In our study, only group T had a positive tenomodulin reaction. Notably, the reaction occurred only at 6 and 12 weeks. This finding may indicate that a regenerative healing pattern becomes quiescent by 24 weeks. Indeed, it has been suggested that tenomodulin is a key regulator of tenocyte proliferation and tendon maturation.³⁹

The complete absence of tenomodulin reaction in our bony tenodesis groups in the setting of significant inflammation further supports our theory of tendon degeneration within the tunnel. One potential explanation for this finding may be that as the tendon heals to the surface of the bone, the intra-osseous tendon is no longer load-bearing and is resorbed by the body through an inflammatory response. This finding differs from those in previous studies, which have described viable tendon within the bone tunnel at all time points up to 26 weeks.⁴⁰ More recently, it has been suggested that callus formation at the external cortical tendon-bone interface is critical for healing and mechanical strength.^41,42 In addition, recent studies have found a predominantly fibroblastic healing process at the midtunnel, potentially leading to the formation of loose fibrovascular tissue at the tendon-bone interface.⁴³ These data, in concert with ours, call into question the rationale for performing intra-osseous tenodesis through bone tunnels.

Our study results, if confirmed in humans, will have significant clinical implications. If a similar effect can be confirmed in the human shoulder, one could argue that soft-tissue tenodesis may result in decreased postoperative shoulder pain. In addition, if tendon degeneration does occur within the intramedullary tunnel, surface fixation may be the better, safer alternative. Although older studies reported suboptimal strength with this type of fixation,^8,44 more recent studies have found surface fixation strength equivalent to screw fixation strength.^45,46 Such a shift in the treatment paradigm would obviate the need for violation of the humeral cortex, eliminating potential stress risers associated with screw fixation,⁴⁷ and effectively eliminating the risk of iatrogenic fracture.^48,49 It would be interesting to investigate what occurs histologically at the bone-tendon interface in surface fixation (ie, suture anchors). Would the inflammatory response at the surface be similar to the inflammatory intramedullary healing, or would it be similar to the quieter tendon-tendon healing? Answers to such questions have the potential to streamline the treatment algorithm for patients who require tenodesis.

Study Limitations

Our study had several limitations. First, as this was a basic science study using a rat model, its conclusions can only be extrapolated to humans. Second, given the nonspecific nature of the cellular analysis, we cannot draw any definitive conclusions about the cell population at the bone-tendon interface. For example, although tenomodulin is expressed by tenocytes, it is not an established specific marker for tenocytes and may be expressed by other fibroblastic cells. Still, our results provide insight into the local microenvironment and identify important differences between the tenodesis methods. Similarly, the complete absence of tendon within the bone tunnels suggests that an analysis of osteoclastic activity at the tenodesis interface may have been a valuable addition to the study. This finding, however, was unexpected, and we did not have the foresight to include it in our methods. A third limitation is that our fixation method essentially uses the suspension tenodesis method. This fixation method differs from the common fixation techniques used in the clinical setting. Testing of other fixation constructs would require a larger animal model. Furthermore, in suspension- type constructs, micromotion within the bone tunnel may independently elicit an inflammatory response. Inert suture was used in our fixation in order to reduce the risk of an iatrogenic inflammatory response. Last, it would have been valuable to perform a biomechanical analysis of the strength of each tenodesis construct. This was explored with our institution’s biomechanics team, but specimen size precluded successful analysis.

Conclusion

Our results indicated that, compared with tendon-to-tendon fixation, tendon-to-bone tenodesis produces a significantly greater inflammatory response at the tenodesis interface. An inflammatory milieu in the absence of tendon within the bony tunnel suggests intraosseous tendon degeneration. Tendon-to-tendon tenodesis, on the other hand, seems to limit the inflammatory response. In addition, a robust tenomodulin reaction in the early phases of tendon-to-tendon healing suggests regenerative healing. Our results showed a fundamental difference in the healing response between the 2 tenodesis methods. Further study is needed to evaluate the validity and applicability of our findings to the human patient population. Most important, our results underscore the need for more study to elucidate optimal tenodesis location and encourage orthopedic surgeons to reexamine current clinical practice patterns.

Take-Home Points

• Cellular healing response differs between bony and soft tissue biceps tenodesis.
• Bony tenodesis incites an inflammatory healing response.
• Bony tenodesis healing occurs at the tendon-bone interface.
• Intrasseous bony fixation leads to tendon degeneration within the bone.
• Tendon-to-tendon tenodesis may result in regenerative tendon healing.

The long head of the biceps tendon (LHBT) is a well-established pain generator of the anterior shoulder^1,2 and may be surgically addressed in refractory cases.³ According to a recent study of 44,932 cases, biceps tenodesis rates increased 80% over just 3 years (2008-2011).⁴ Nevertheless, optimal tenodesis location and technique remain controversial. Proximal and distal tenodesis, including numerous soft-tissue and bony techniques, have been described.^5-7 Several studies have focused on the biomechanical strength of various fixation modalities.^8-14 These data highlight the ongoing evolution of our understanding of biceps-labrum complex (BLC) disease.

Over the years, tenodesis location has proved to be an important factor in outcomes.^3,15-20 Several recent studies have elucidated the role of the extra-articular LHBT and the limited capabilities of diagnostic arthroscopy.^15-17,20,21 Taylor and colleagues¹⁷ defined the bicipital tunnel as the extra-articular segment of LHBT and its fibro-osseous enclosure. The tunnel extends from the articular margin through the subpectoral region and can be divided into 3 zones: Zone 1 goes from the articular margin to the inferior margin of the subscapularis, zone 2 goes from the inferior margin of the subscapularis to the proximal margin of the pectoralis major tendon, and zone 3 is the subpectoral region. Zone 2 is often referred to as “no man’s land” for its relative invisibility from arthroscopy above and open exposure below.^17,21 Notably, a recent study reported a 47% prevalence of hidden tunnel lesions in patients with chronic BLC disease symptoms.¹⁸ Other studies have shown that standard proximal tenodesis methods often fail to address LHBT pathology in this area, leading to residual symptoms.^9,22 It is evident that tenodesis location and technique play important roles in patient outcomes. Sanders and colleagues¹⁶ found that the revision rate was significantly higher among patients who underwent biceps tenodesis without release of the bicipital tunnel sheath than among patients who underwent tenodesis with the release. Dr. O’Brien developed an alternative option: soft-tissue tenodesis with transfer of the LHBT to the conjoint tendon within the subdeltoid space.^23,24 This technique addresses intra-articular and extra-articular tunnel disease while mitigating the complications associated with bony tenodesis. Early and midterm studies have shown this to be an effective intervention for chronically symptomatic BLC disease.^25,26

Despite the abundance of literature on tenodesis techniques, no one has histologically evaluated the location-dependent healing and inflammatory responses. We conducted a study to determine the impact of tenodesis location on healing and inflammation in a rat model. We hypothesized that, compared with tendon-to-bone techniques, soft-tissue tenodesis would minimize inflammatory response and optimize healing.

Methods 

The study was approved by the Institutional Animal Care and Use Committee at the Hospital for Special Surgery. 

Animals

Biceps tenodesis was performed at 1 of 3 locations in 36 thirteen-week-old Sprague-Dawley rats (Charles River Laboratories). All rats were prepared for surgery by an experienced veterinary technician. Sedation was induced with isoflurane gas through a nose cone. 

Surgical Procedure

Animals were randomly assigned to 3 different tenodesis groups: tendon-to-bone in the bicipital groove (metaphyseal, M); tendon-to-bone in the subpectoral region (diaphyseal, D); and soft tissue-to-soft tissue transfer to the conjoint tendon (T). A standard deltopectoral approach was used to expose the biceps tendon. The tendon was tagged with a 5-0 polypropylene suture and tenotomized at the level of the bicipital groove (zone 1). All wounds were irrigated and closed with 4-0 nylon suture.

For animals undergoing tendon-to-bone metaphyseal tenodesis, a 0.045-mm Kirschner wire was used to drill bicortically into the intertubercular sulcus. Wire positioning distal to the physeal plate was confirmed with fluoroscopy. A locking stitch of 5-0 polypropylene suture was run along the free edge of the tendon. The tendon was then passed through the bone tunnel in an anterior-to-posterior direction, and the limbs of the suture were tied around the lateral cortex. 

The process was repeated for animals undergoing diaphyseal tenodesis; only the tenodesis location was different. The inferior border of the pectoralis major was identified, and a bicortical tunnel was made in the center of the diaphyseal bone. The tendon was then prepared and tenodesed to bone using the method already described.

In soft-tissue tenodesis, the conjoint tendon was identified and carefully dissected from surrounding tissues. The LHBT was then tenodesed to the attached conjoint tendon with interrupted simple stitches of 5-0 polypropylene suture.

The animals were allowed to bear weight on the operative limb immediately after surgery and without immobilization.

Specimen Harvest and Preparation

Four animals from each group were sacrificed at 6, 12, and 24 weeks. Harvested specimens were fixed in 10% neutral-buffered formalin solution. Bony specimens consisted of the upper half of the humerus and the tenodesed biceps tendon, and soft-tissue specimens consisted of the tenodesed LHBT-conjoint tendon complex. Bony specimens were decalcified in 10% ethylenediaminetetraacetic acid. All specimens were paraffin-embedded and sectioned at 7 microns.

Analysis of Cellularity

Sections were stained with hematoxylin-eosin. Overall cellularity at the tenodesis interface was quantified by averaging the nuclei count within 3 separate standardized ×20 magnification high power fields. Only nucleated cells were included in the cell count. Immunohistochemical staining with tenomodulin (Santa Cruz Laboratories, sc-49324) was performed to characterize the cell population at the interface. Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with the anti-tenomodulin goat monoclonal antibody diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with methyl green. Specimens treated with tenomodulin were evaluated for presence or absence of a positive reaction at the tenodesis interface. 

Analysis of Inflammation

Inflammation at the interface was evaluated with the CD68 macrophage marker (ABcam, ab31630). Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with anti-CD68 mouse monoclonal antibodies diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with neutral red. Inflammation was quantified by averaging the number of reactive cells within 3 separate standardized ×20 magnification high power fields.

Statistical Analysis

Descriptive statistics were calculated for cell and macrophage counts for each group at every time point. Two-way analysis of variance was used to compare the cell and macrophage counts between groups at each time point as well as the count differences within each group between time points. P values were Bonferroni-corrected to account for the multiple comparisons between groups. P < .05 was used to signify statistical significance.

Results

All 36 animals survived to their designated harvest time without complications. Twelve specimens were successfully harvested at 6 weeks and another 12 at 24 weeks. At 12 weeks, tenodesis failure occurred in 1 animal in group D, leaving 11 specimens for analysis.

Cellularity

At the 6-week harvest, 1 group T specimen was sectioned incorrectly and discarded, leaving 3 specimens for evaluation. Descriptive statistics for each group and each time point are listed in Table 1A. There were no significant differences in mean cellularity between the bony tenodesis groups at any time point (P = 1.000) (Table 1B).

At 6 weeks, both group M (P = .012) and group D (P = .021) showed significantly more cellularity than group T (Figure 1). The same was true for group M (P = .002) and group D (P = .001) at the 12-week harvest. There were no significant differences in cellularity between the 3 groups at 24 weeks. 

Within-group analysis revealed a trend of increasing cellularity at 12 weeks followed by a decrease at 24 weeks in all 3 groups (Table 2).

Group M showed a significant overall decrease in cellularity from 6 to 24 weeks (P = .035) and from 12 to 24 weeks (P = .004). The overall decrease in cell count from 6 to 24 weeks was not significant in group D (P = .124), whereas the decrease from 12 to 24 weeks was significant (P = .005). There were no significant differences in cellularity for group T between any of the time points.

Inflammatory Response 

During specimen processing, 1 group D specimen was severely degraded after pronase treatment, leaving 3 specimens for evaluation. Descriptive statistics for each group are listed in Table 3A.

At 6 weeks, mean CD68 cell count was significantly higher in group M than in group D (P = .011) and group T (P < .001) (Table 3B). Likewise, CD68 count was significantly higher in group D than in group T (P < .001). There were no differences in CD68 counts between the 2 bony tenodesis groups at 12 weeks (P = .486) or 24 weeks (P = .315). Both bony tenodesis groups, however, had persistently higher CD68 counts at 12 weeks when compared with group T (group M, P = .002; group D, P < .001). In these specimens, an inflammatory milieu characterized by a large accumulation of lymphocytes and giant cells was noted at the bone-tendon interface.

In comparison, inflammatory cells were scant at the tendon-tendon interface in group T specimens (Figure 2). There were no differences in CD68 reaction between the 3 tenodesis groups at 24 weeks. In all cases of tendon-to-bone tenodesis, no recognizable formed tendon was seen within the bone tunnel. Rather, all tendon-to-bone tenodeses were characterized by dense connective tissue at the bone surface, surrounded by an accumulation of macrophages.

Within-group analysis revealed a significant decrease in CD68 cells from 6 to 12 weeks and overall from 6 to 24 weeks in group M (Table 4). There was no significant change in CD68 cell counts between any time points within group D (P = 1.000) and between 6 and 12 weeks in group T (P = 1.000). Interestingly, the CD68 counts in group T showed an overall increase from 6 to 24 weeks (P = .019). The increase was even more significant from 12 to 24 weeks (P = .004).

Tissue-Specific Staining

At 6 weeks, antigen retrieval resulted in severe degradation of 2 group M specimens, 2 group D specimens, and 1 group T specimen. The most notable tenomodulin reaction occurred in group T at the 6- and 12-week harvests, with the 6-week group having the most robust reaction. There was scant reaction in this group at 24 weeks.

One group D specimen showed a positive reaction at 24 weeks. No reaction occurred in the remaining bony specimens across all time points (Figure 3).

Discussion

In this study, the healing response differed between bony and soft-tissue tenodesis techniques in a rat model. Tendon-to-bone tenodesis, both diaphyseal and metaphyseal, appeared to incite an inflammatory degenerative response, whereas tendon-to-tendon healing occurred in a more quiescent and perhaps even regenerative manner.

The early inflammatory response that occurred in the bony tenodesis groups is not unlike what occurs in fracture healing.²⁷ The reaction was even more robust at 12 weeks, signifying an ongoing inflammatory process. In this context, tendon degeneration may plausibly explain the consistent absence of mature tendon within the tunnels at all 3 time points. Some tendon degeneration may be explained by the vascular damage that occurred during surgery, but this damage was a constant factor in all 3 study groups. Interestingly, group M showed the highest early CD68 counts, consistent with this being the more biologically active region of bone.²⁸

Group T had significantly lower cell and macrophage counts throughout the study period, possibly indicating improved healing—an observation supported by a study in which the impact of macrophage depletion on bone-tendon interface healing was evaluated.²⁹ The authors found that, in suppressing macrophage activity, the morphologic and biomechanical properties at the healing interface were significantly improved.²⁹ These findings are consistent with Dr. O’Brien’s anecdotal experience with patients who previously underwent the biceps transfer; on second-look arthroscopy, there was complete seamless integration of tendon and conjoint tendon (Figure 4). 

 

Studies have found that the inflammatory process is closely associated with pain, and pain syndromes such as fibromyalgia.^30,31 Persistent inflammation, as seen in our bony tenodesis group, could explain the recalcitrant anterior shoulder pain that often occurs in patients after bony tenodesis of the LHBT.^2,6,19,32 

Studies have also suggested that osteoclasts at the bone-tendon interface—osteoclasts share a cell lineage with macrophages—may contribute to bone loss and tunnel widening.^33,34 Osteoclasts are expected at the bone tunnel, as fracture healing occurs at the bone-tendon interface. These osteoclasts could have contributed to the strong CD68 reaction in our bony tenodesis groups. However, CD68 historically has been described as the classic macrophage marker.³⁵ We specifically selected CD68 for this reason: Macrophages are the primary inflammatory cells involved in early healing and are key to the inflammatory process.³⁶

Results of the tenomodulin analysis suggested 2 different healing processes are occurring in the bony and tendon groups. Tenomodulin is a known tenocyte marker for developing and mature tendon in both rats and humans.^37,38 In our study, only group T had a positive tenomodulin reaction. Notably, the reaction occurred only at 6 and 12 weeks. This finding may indicate that a regenerative healing pattern becomes quiescent by 24 weeks. Indeed, it has been suggested that tenomodulin is a key regulator of tenocyte proliferation and tendon maturation.³⁹

The complete absence of tenomodulin reaction in our bony tenodesis groups in the setting of significant inflammation further supports our theory of tendon degeneration within the tunnel. One potential explanation for this finding may be that as the tendon heals to the surface of the bone, the intra-osseous tendon is no longer load-bearing and is resorbed by the body through an inflammatory response. This finding differs from those in previous studies, which have described viable tendon within the bone tunnel at all time points up to 26 weeks.⁴⁰ More recently, it has been suggested that callus formation at the external cortical tendon-bone interface is critical for healing and mechanical strength.^41,42 In addition, recent studies have found a predominantly fibroblastic healing process at the midtunnel, potentially leading to the formation of loose fibrovascular tissue at the tendon-bone interface.⁴³ These data, in concert with ours, call into question the rationale for performing intra-osseous tenodesis through bone tunnels.

Our study results, if confirmed in humans, will have significant clinical implications. If a similar effect can be confirmed in the human shoulder, one could argue that soft-tissue tenodesis may result in decreased postoperative shoulder pain. In addition, if tendon degeneration does occur within the intramedullary tunnel, surface fixation may be the better, safer alternative. Although older studies reported suboptimal strength with this type of fixation,^8,44 more recent studies have found surface fixation strength equivalent to screw fixation strength.^45,46 Such a shift in the treatment paradigm would obviate the need for violation of the humeral cortex, eliminating potential stress risers associated with screw fixation,⁴⁷ and effectively eliminating the risk of iatrogenic fracture.^48,49 It would be interesting to investigate what occurs histologically at the bone-tendon interface in surface fixation (ie, suture anchors). Would the inflammatory response at the surface be similar to the inflammatory intramedullary healing, or would it be similar to the quieter tendon-tendon healing? Answers to such questions have the potential to streamline the treatment algorithm for patients who require tenodesis.

Study Limitations

Our study had several limitations. First, as this was a basic science study using a rat model, its conclusions can only be extrapolated to humans. Second, given the nonspecific nature of the cellular analysis, we cannot draw any definitive conclusions about the cell population at the bone-tendon interface. For example, although tenomodulin is expressed by tenocytes, it is not an established specific marker for tenocytes and may be expressed by other fibroblastic cells. Still, our results provide insight into the local microenvironment and identify important differences between the tenodesis methods. Similarly, the complete absence of tendon within the bone tunnels suggests that an analysis of osteoclastic activity at the tenodesis interface may have been a valuable addition to the study. This finding, however, was unexpected, and we did not have the foresight to include it in our methods. A third limitation is that our fixation method essentially uses the suspension tenodesis method. This fixation method differs from the common fixation techniques used in the clinical setting. Testing of other fixation constructs would require a larger animal model. Furthermore, in suspension- type constructs, micromotion within the bone tunnel may independently elicit an inflammatory response. Inert suture was used in our fixation in order to reduce the risk of an iatrogenic inflammatory response. Last, it would have been valuable to perform a biomechanical analysis of the strength of each tenodesis construct. This was explored with our institution’s biomechanics team, but specimen size precluded successful analysis.

Conclusion

Our results indicated that, compared with tendon-to-tendon fixation, tendon-to-bone tenodesis produces a significantly greater inflammatory response at the tenodesis interface. An inflammatory milieu in the absence of tendon within the bony tunnel suggests intraosseous tendon degeneration. Tendon-to-tendon tenodesis, on the other hand, seems to limit the inflammatory response. In addition, a robust tenomodulin reaction in the early phases of tendon-to-tendon healing suggests regenerative healing. Our results showed a fundamental difference in the healing response between the 2 tenodesis methods. Further study is needed to evaluate the validity and applicability of our findings to the human patient population. Most important, our results underscore the need for more study to elucidate optimal tenodesis location and encourage orthopedic surgeons to reexamine current clinical practice patterns.

Take-Home Points

• TTO specifics depend on anatomy, radiographic alignment characteristics, and presence of chondral defects.
• Osteotomy and movement of the tibial tubercle can include anteriorization, anteromedialization, proximalization, medialization, or distalization.
• TTO was most commonly performed for isolated patellar instability in the presence of knee pain.
• Young women with prior surgery on the affected knee made up the primary patient population for this procedure.
• While TTO significantly improves knee pain and clinical outcome scores, >1 in 5 patients required reoperation for hardware removal.

Patellofemoral pain and patellofemoral instability are common orthopedic problems. Studies have found that 30% of patients 13 to 19 years old have patellofemoral pain and that 29 in 100,000 patients 10 to 17 years old have patellofemoral instability.^1-3 The reported rate of recurrence after nonoperative management of patellofemoral instability is 33%.⁴ Tibial tubercle osteotomy (TTO), first described by Hauser⁵ in 1938, is an effective treatment option for many patellofemoral disorders.

TTO indications include patellofemoral maltracking or malalignment, patellar instability, patellofemoral arthritis, and focal patellofemoral chondral defects.⁶ With TTO, the goal is to move the tibial tubercle in a direction that will either improve patellar tracking or offload the medial or lateral patellar facet to improve pain and function.^7,8 This action typically involves anterior, medial, lateral, or distal translation of the tibial tubercle, as posteriorization can lead to increased contact forces across the patellofemoral joint, resulting in accelerated patellofemoral wear and increased pain.⁹

We systematically reviewed the TTO literature to identify indications, clinical outcomes, complications, and reoperations. We hypothesized that the overall complication rate and the overall reoperation rate would both be <10%.

Clinical Evaluation of Patellofemoral Pathology

Patients with patellofemoral pain often report anterior knee pain, which typically begins gradually and is often activity related. Several symptoms may be present: pain with prolonged sitting with knees bent; pain on rising from a seated position; pain or crepitus with climbing stairs; and pain during repetitive activity such as running, squatting, or jumping. Location, duration, and onset of symptoms should be elicited. Patellofemoral instability can be described as dislocation events or subluxation events; number of events, mechanisms of injury, and resulting need for reduction should be documented. As age, sex, body mass index, and physical fitness are relevant to risk of recurrence, the physician should ask about general ligamentous laxity, other joint dislocations, and prior surgical intervention. Swelling or mechanical symptoms may indicate patellofemoral joint pathology.^6,10

Physical examination of patients with patellofemoral pathology begins with assessment for overall limb alignment (including resting position of patella and corresponding quadriceps angle [Q-angle]), generalized ligamentous laxity (including hypermobile joints, evaluated with Brighton criteria), overall peri-knee muscle tone and strength, effusion, and gait pattern.

Knee and hip range of motion should be documented. Apprehension (Figure 1) and lack of a firm endpoint on placement of a lateralizing moment on the patella suggest prior dislocation or subluxation. Patella and surrounding anatomy must be palpated for location and severity of tenderness. Finally, patellar tilt, height, mobility, and dynamic tracking, including J-sign, are pertinent to evaluation. The J-sign for patellar tracking is positive when the patella deviates laterally as the knee moves from flexion into extension. Examination of the asymptomatic contralateral side is essential for comparison. Plain radiographs are important first-line imaging. Computed tomography or magnetic resonance imaging can be used to measure tibial tubercle-trochlear groove (TT-TG) distance. TT-TG distance of >15 mm is abnormal, and >20 mm indicates TTO is required. Advanced imaging is additionally valuable in assessing for chondral injury or trochlear dysplasia.^6,10

Common TTO Procedures

TTO specifics depend on anatomy, radiographic alignment characteristics, and presence of chondral defects. Essentially, the patella is translated to offload the affected areas. Osteotomy and movement of the tibial tubercle can include anteriorization, anteromedialization, proximalization, medialization, or distalization.

Lateralization or anterolateralization may be pertinent to revision if an osteotomy direction results in overcorrection of tuberosity position. Anteriorization (Figures 2A-2C) does not have a role in patellofemoral instability, but can unload areas of excessive patellar chondral force concentration at the central or proximal patella by increasing the angle between the patellar and quadriceps tendons and thereby decreasing the joint reaction forces.

Straight medialization (Figures 3A, 3B) offloads lateral patellar chondral injury and may decrease lateral instability.

Distalization (Figures 4A-4C) can correct for patella alta in the setting of patellar instability and allows earlier engagement of the patella in the trochlea to increase osseous restraint to lateral translation.⁶

Anteromedialization (Figure 5) is indicated in patients with a normal proximal and medial patellar chondral surface and a laterally positioned patella leading to alteration of the contact area in the trochlear groove and resulting pain, lateral patellar or trochlear chondral disease, or instability. Osteotomy angle can provide varied medialization through consistent slope and anteriorization. For example, a 60° slope osteotomy provides 9 mm of medialization with 15 mm of anteriorization.⁶ The procedure, similar to the additional TTO operations, begins with a lateral parapatellar incision that is extended distal to the tibial tubercle and anterior over the crest. The soft tissues around the tubercle are released to allow mobilization.

Variable osteotomy jigs allow for different slope cuts for more medialization or anteriorization, based on preoperative findings. The osteotomy cuts are started with a thin oscillating blade (Figure 6) and finished with an osteotome.

The tubercle fragment (Figure 7) is shifted and provisionally fixed with a Kirschner wire before being drilled and fixated with two 4.5-mm countersunk cortical screws (Figures 8, 9A-9B).

Locally harvested corticocancellous bone can help anteriorize the tubercle block. Osteotomy specifics allow for corresponding anatomical translations of the TTO to address the preoperative pathology.

Methods

Search Strategy and Data Collection

We searched the PubMed (Medline) database for all English-language TTO studies published between database inception and April 9, 2015. After PROSPERO registration, and following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we used the algorithm (“tibial” AND “tubercle” AND “osteotomy”) NOT (“total” AND “knee” AND “arthroplasty”) to search the literature. Inclusion criteria included level I-IV studies on TTO indications, operative findings, and outcomes. Exclusion criteria were non-English studies, unpublished studies, level V evidence, letters to the editor, editorials, review articles, basic science articles, technique articles, revision procedures, articles without clinical outcomes, and conference proceeding abstracts. Studies that reported on duplicate populations were included only with the most recent available clinical outcomes. All abstracts were reviewed in duplicate by Dr. Levy and Dr. Rao and assessed with respect to the criteria outlined. Then the same authors performed full-text reviews of eligible studies before including these studies in the systematic review.

They also manually checked the references in study articles to identify additional studies for possible inclusion in the review. A standardized form created by the authors at the start of the review was used to extract data (Table 1).

Assessment of Study Quality

The quality of each TTO study in the review was assessed with a modified Coleman methodology score (MCMS), which ranges from 0 to 100. A study with an MCMS of <55 points is considered a poor-quality study.¹¹

Data Synthesis and Statistical Analysis

Given that most of the included studies were level IV, a formal meta-analysis was not indicated. In this article, we report categorical data as frequencies with percentages and preoperative and postoperative continuous data as means (SDs), with weighted means based on number of patients in each study, where applicable. We used 2-tailed t tests for comparisons made with the free Meta-Analysis Calculator and Grapher (http://www.healthstrategy.com/meta/meta.pl ). Statistical significance was set at P < .05. 

Results

Search Results and Included Studies

Twenty-one studies (976 patients, 1055 knees) were included in the analysis (Figure 10; Table 2).^12-32 These studies were published between 1986 and 2013. There were 18 level IV studies (85.7%), 3 level III studies (14%), and no level I or II studies. Better quality studies had a mean (SD) MCMS of 19.8 (8.2), well under the 55-point cutoff. In the 16 studies that reported sex, women accounted for 69% of the population. Weighted mean (SD) age was 27.68 (10.45) years (range, 12-77 years) (18 studies reporting).   

Only 1 study provided preoperative body mass index (27 kg/m2). There were 55.35% of patients who had prior surgery on the affected knee (6 studies reporting).

Preoperative Data

Preoperative pathologic, radiographic, and clinical scoring data were scarcely reported and nonuniform (Table 2). The most common pathology treated with TTO was isolated patellofemoral instability (746/1055 patients, 70.7%). The other pathologies addressed were isolated patellofemoral osteoarthritis/chondromalacia patellae (143, 13.6%), patellofemoral instability with patella alta (61, 5.8%), patellofemoral instability with patellofemoral osteoarthritis (45, 4.3%), isolated patella baja (41, 3.9%), isolated patella alta (19, 1.8%), and patellofemoral osteoarthritis with patella baja (2, 0.2%). Five hundred fifty-five patients (53%) had a preoperative complaint that included knee pain, and 809 (77%) reported preoperative patellar laxity or instability events. The imaging data reported were Q-angle, Insall-Salvati ratio, Caton-Deschamps index, Blackburne-Peel ratio, Outerbridge osteoarthritis grade, and TT-TG distance. Preoperative clinical scoring data most prominently included a visual analog scale (VAS) score of 70.50 (4 studies reporting), a Lysholm score of 59.19 (5 studies), and a Kujala score of 41.16 (4 studies). Shelbourne-Trumper and Cox-Insall scores were reported in 1 and 2 studies, respectively.

Operative Characteristics

Of the 21 studies, 12 reported only on patients who had TTO performed in isolation; in the other 9 studies, cohorts included patients who underwent concurrent procedures. In the 17 studies (856 patients) that listed numbers of patients who underwent specific concomitant procedures, 715 patients (83.5%) underwent an isolated TTO procedure, and the other 141 (16.5%) underwent either concomitant lateral femoral trochleoplasty, arthroscopic drilling of chondral lesions, patellar shaving chondroplasty, partial meniscectomy or concomitant meniscal repair, intra-articular loose body removal, and/or lateral release with or without medial plication. 

Twenty studies reported specifics on the intraoperative direction of the tibial bone block osteotomy (Table 3). In most cases (50.8%), anteromedial translation (anteromedialization) was performed; anteriorization was performed in 18.7% of cases, medialization in 9.6%, medial and distal translation in 7.2%, a “triple” (anteriorization, medialization, proximalization) in 6%, isolated distalization in 2.8%, and proximalization in 1.6%. The remaining 2.8% of procedure specifics were not identified. 

Postoperative Data

Table 4 lists the overall cohort’s postoperative radiographic, clinical outcome scoring, and complications data. Fifteen studies reported follow-up of >2 years. As with the preoperative data, radiographic and clinical scoring data were relatively nonuniform; some numeric data, however, should be highlighted. Statistical analysis allowed for comparison of preoperative-postoperative VAS, Lysholm, and Kujala scores, each of which was significantly higher after surgery (P < .001). Seven studies reported an overall clinical outcome rating, with the cumulative majority of patients reporting good (37.9%) or excellent (39.2%) results. 

There was a cumulative total of 79 complications (8% of cohort): 17 recurrent patellar dislocations (1.9%), 4 recurrent patellar subluxations (0.4%), 10 wound complications (1.0%), 2 intraoperative complications (0.2%), 14 tibial tubercle fractures (1.3%), 19 proximal tibia fractures (1.8%), 4 cases of anterior knee pain (0.4%), 4 cases of neuropraxia (0.4%), and 5 infections (0.5%). Of note, 219 knees (21%) required reoperation, but 170 (16.3%) of these were for painful hardware removal. Sixteen knees (1.5%) required revision TTO, 1 (0.1%) required subsequent high tibial osteotomy, 2 (0.2%) underwent patellofemoral arthroplasty for advanced arthritic changes, and 5 (0.5%) underwent total knee arthroplasty for advanced arthritic changes.

Studies With TTO Performed in Isolation

Twelve studies reported outcomes of isolated TTO procedures. In the 638 patients who underwent isolated TTO, the pathologies addressed were instability/laxity (429 patients, 67%), patellofemoral osteoarthritis (74, 12%), patella alta with instability (61, 10%), patellofemoral osteoarthritis with instability (31, 5%), patella baja (24, 4%), and patella alta (19, 3%). Pain was a preoperative issue in 289 (45%) of these patients and instability in 472 (74%).

Only 2.8% of patients experienced postoperative patellar dislocation events. Of the 12 studies, 2 reported VAS scores (34-point weighted mean improvement, 65 points before surgery to 31 after surgery), 3 reported Lysholm scores (30-point improvement, from 60 to 90), and 2 reported Kujala scores (21-point improvement, from 46 to 67).

Complication rates for this isolated-TTO pooled cohort of patients were 1.2% for revision TTOs, 0.5% for wound complications, 0.8% for tibial tubercle fractures, and 1.9% for proximal tibia fractures. In total, 16% of patients required hardware removal after surgery. 

Discussion

This study found that TTO improved patient pain and clinical outcome scores despite having a high (16%) rate of reoperation for painful hardware in patients with preoperative pain or instability, or with patellofemoral osteoarthritis or aberrant patellar anatomy. This reoperation rate and the overall complication rate both exceeded our hypothesized 10% cumulative rate. However, <1% of patients required conversion to a definitive end-stage surgery (patellofemoral arthroplasty or total knee arthroplasty) by final follow-up, and the rates of comorbidities (anterior knee pain, wound infection, recurrent patellar subluxation/dislocation, tibial fracture) were relatively low.

Patellofemoral disorders are common in the general population and a frequent primary complaint on presentation to orthopedic offices. Having a thorough understanding of knee joint biomechanics is imperative when trying to determine whether surgery is appropriate for these complaints and how to proceed. Extensor mechanism abnormalities, including high lateral force vectors (or larger TT-TG distances) and excessive patellar tilt, can affect alignment and increase the risk for patellofemoral dislocations, patellofemoral anterior- based knee pains, and chondral lesions. Patella alta, an elevated patella, risks increased contact stresses between the patella and the trochlear groove³³ and decreases the osseous constraints that inhibit dislocation of the patella with physiologic flexion of the joint.³⁴ With TTO, the change in tuberosity position can alter angles in the extensor mechanism and thereby decrease joint reaction forces and patellofemoral contact area forces.^35,36

Although its use began as an option for combating patellar instability events in patients with predisposed patellofemoral kinematics,⁵ TTO has evolved in its therapeutic uses to include offloading patellar and trochlear focal chondral lesions and slowing progression of patellofemoral arthritis. Multiple iterations and modifications of the procedure have involved distal and medial transfer of the tibial tuberosity, medialization alone, concurrent anterior and medial elevation of the tuberosity, and proximal or distal transfers, depending on the pathology being corrected. Although TTO is highly versatile in treating multiple patellofemoral joint pathologies, this study found that its primary indication continues to be patellar instability, with anteromedialization as the most common direction of tubercle transfer in support of the medial structures providing the medial force vector that keeps the patella in place. These medial structures include the medial patellofemoral ligament, the vastus medialis obliquus, the medial patellotibial ligament, and the medial retinaculum. 

Also notable was the relatively high rate of reoperation after TTO. However, >75% of reoperations were performed to remove painful hardware, and the need for reoperation seemed to have no effect on the statistically significant overall preoperative-to-postoperative improvement in VAS, Lysholm, and Kujala scores. Rates of definitive surgery for end-stage patellofemoral changes, including patellofemoral arthroplasty and total knee arthroplasty, were quite low at the weighted mean follow-up of several years after surgery, suggesting a role for TTO in avoiding arthroplasty. Although the infection rate was <1%, the rate of tibial tubercle or proximal tibia fractures was a cumulative 3.1%. Patients should be counseled on this complication risk, as treatment can require cast immobilization and weight-bearing limitations.²⁴

The 69% proportion of women in the overall cohort and the mean (SD) age of 27.68 (10.45) years highlight the primary patient population that undergoes TTO. Compared with men, young women are more likely to have aberrant patellofemoral biomechanics, owing to their native anatomy, including their relatively larger Q-angle and TT-TG distance and thus increased lateral translational force vectors on the patella.³⁷ In addition, more than half of patients who are having TTO underwent previous surgery on the affected knee—an indication that TTO is still not universally considered first-line in addressing patellofemoral pathology.

Limitations of the Analysis

The limitations of this analysis derive from the limitations of the included studies, which were mostly retrospective case series with relatively short follow-up. The low MCMS (<55) of all 21 studies highlights their low quality as well. These studies showed considerable heterogeneity in their reporting of specific preoperative, intraoperative, and postoperative radiographic, physical examination, and clinical outcome scores, which may be indicative of the relatively low rate of use of TTO, a procedure originally described decades ago. These studies also showed ample heterogeneity in the specific radiographic parameters or outcome scales they used to present their data. We were therefore limited in our ability to cohesively summarize and provide cumulative data points from the patients as a unified cohort. There was substantial variety in the procedures performed, surgical techniques used, concomitant pathologies addressed at time of surgery, and diagnoses treated—indicating a performance bias. This additionally precluded any significant meta-analysis within the patient cohort. A higher quality study, a randomized controlled trial, is needed to answer more definitively and completely the questions we left unanswered, including the effect on radiographic parameters, additional clinical outcomes, and patient satisfaction.

Conclusion

TTO is most commonly performed for isolated patellar instability in the presence of knee pain. Other pathologies addressed are patellofemoral osteoarthritis, and patella alta and patella baja with and without associated knee pain. TTO significantly improves knee pain and clinical outcome scores, though 21% of patients (>1 in 5) require reoperation for hardware removal. Young women with prior surgery on the affected knee are the primary patient population.

Take-Home Points

• TTO specifics depend on anatomy, radiographic alignment characteristics, and presence of chondral defects.
• Osteotomy and movement of the tibial tubercle can include anteriorization, anteromedialization, proximalization, medialization, or distalization.
• TTO was most commonly performed for isolated patellar instability in the presence of knee pain.
• Young women with prior surgery on the affected knee made up the primary patient population for this procedure.
• While TTO significantly improves knee pain and clinical outcome scores, >1 in 5 patients required reoperation for hardware removal.

Patellofemoral pain and patellofemoral instability are common orthopedic problems. Studies have found that 30% of patients 13 to 19 years old have patellofemoral pain and that 29 in 100,000 patients 10 to 17 years old have patellofemoral instability.^1-3 The reported rate of recurrence after nonoperative management of patellofemoral instability is 33%.⁴ Tibial tubercle osteotomy (TTO), first described by Hauser⁵ in 1938, is an effective treatment option for many patellofemoral disorders.

TTO indications include patellofemoral maltracking or malalignment, patellar instability, patellofemoral arthritis, and focal patellofemoral chondral defects.⁶ With TTO, the goal is to move the tibial tubercle in a direction that will either improve patellar tracking or offload the medial or lateral patellar facet to improve pain and function.^7,8 This action typically involves anterior, medial, lateral, or distal translation of the tibial tubercle, as posteriorization can lead to increased contact forces across the patellofemoral joint, resulting in accelerated patellofemoral wear and increased pain.⁹

We systematically reviewed the TTO literature to identify indications, clinical outcomes, complications, and reoperations. We hypothesized that the overall complication rate and the overall reoperation rate would both be <10%.

Clinical Evaluation of Patellofemoral Pathology

Patients with patellofemoral pain often report anterior knee pain, which typically begins gradually and is often activity related. Several symptoms may be present: pain with prolonged sitting with knees bent; pain on rising from a seated position; pain or crepitus with climbing stairs; and pain during repetitive activity such as running, squatting, or jumping. Location, duration, and onset of symptoms should be elicited. Patellofemoral instability can be described as dislocation events or subluxation events; number of events, mechanisms of injury, and resulting need for reduction should be documented. As age, sex, body mass index, and physical fitness are relevant to risk of recurrence, the physician should ask about general ligamentous laxity, other joint dislocations, and prior surgical intervention. Swelling or mechanical symptoms may indicate patellofemoral joint pathology.^6,10

Physical examination of patients with patellofemoral pathology begins with assessment for overall limb alignment (including resting position of patella and corresponding quadriceps angle [Q-angle]), generalized ligamentous laxity (including hypermobile joints, evaluated with Brighton criteria), overall peri-knee muscle tone and strength, effusion, and gait pattern.

Knee and hip range of motion should be documented. Apprehension (Figure 1) and lack of a firm endpoint on placement of a lateralizing moment on the patella suggest prior dislocation or subluxation. Patella and surrounding anatomy must be palpated for location and severity of tenderness. Finally, patellar tilt, height, mobility, and dynamic tracking, including J-sign, are pertinent to evaluation. The J-sign for patellar tracking is positive when the patella deviates laterally as the knee moves from flexion into extension. Examination of the asymptomatic contralateral side is essential for comparison. Plain radiographs are important first-line imaging. Computed tomography or magnetic resonance imaging can be used to measure tibial tubercle-trochlear groove (TT-TG) distance. TT-TG distance of >15 mm is abnormal, and >20 mm indicates TTO is required. Advanced imaging is additionally valuable in assessing for chondral injury or trochlear dysplasia.^6,10

Common TTO Procedures

TTO specifics depend on anatomy, radiographic alignment characteristics, and presence of chondral defects. Essentially, the patella is translated to offload the affected areas. Osteotomy and movement of the tibial tubercle can include anteriorization, anteromedialization, proximalization, medialization, or distalization.

Lateralization or anterolateralization may be pertinent to revision if an osteotomy direction results in overcorrection of tuberosity position. Anteriorization (Figures 2A-2C) does not have a role in patellofemoral instability, but can unload areas of excessive patellar chondral force concentration at the central or proximal patella by increasing the angle between the patellar and quadriceps tendons and thereby decreasing the joint reaction forces.

Straight medialization (Figures 3A, 3B) offloads lateral patellar chondral injury and may decrease lateral instability.

Distalization (Figures 4A-4C) can correct for patella alta in the setting of patellar instability and allows earlier engagement of the patella in the trochlea to increase osseous restraint to lateral translation.⁶

Anteromedialization (Figure 5) is indicated in patients with a normal proximal and medial patellar chondral surface and a laterally positioned patella leading to alteration of the contact area in the trochlear groove and resulting pain, lateral patellar or trochlear chondral disease, or instability. Osteotomy angle can provide varied medialization through consistent slope and anteriorization. For example, a 60° slope osteotomy provides 9 mm of medialization with 15 mm of anteriorization.⁶ The procedure, similar to the additional TTO operations, begins with a lateral parapatellar incision that is extended distal to the tibial tubercle and anterior over the crest. The soft tissues around the tubercle are released to allow mobilization.

Variable osteotomy jigs allow for different slope cuts for more medialization or anteriorization, based on preoperative findings. The osteotomy cuts are started with a thin oscillating blade (Figure 6) and finished with an osteotome.

The tubercle fragment (Figure 7) is shifted and provisionally fixed with a Kirschner wire before being drilled and fixated with two 4.5-mm countersunk cortical screws (Figures 8, 9A-9B).

Locally harvested corticocancellous bone can help anteriorize the tubercle block. Osteotomy specifics allow for corresponding anatomical translations of the TTO to address the preoperative pathology.

Methods

Search Strategy and Data Collection

We searched the PubMed (Medline) database for all English-language TTO studies published between database inception and April 9, 2015. After PROSPERO registration, and following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we used the algorithm (“tibial” AND “tubercle” AND “osteotomy”) NOT (“total” AND “knee” AND “arthroplasty”) to search the literature. Inclusion criteria included level I-IV studies on TTO indications, operative findings, and outcomes. Exclusion criteria were non-English studies, unpublished studies, level V evidence, letters to the editor, editorials, review articles, basic science articles, technique articles, revision procedures, articles without clinical outcomes, and conference proceeding abstracts. Studies that reported on duplicate populations were included only with the most recent available clinical outcomes. All abstracts were reviewed in duplicate by Dr. Levy and Dr. Rao and assessed with respect to the criteria outlined. Then the same authors performed full-text reviews of eligible studies before including these studies in the systematic review.

They also manually checked the references in study articles to identify additional studies for possible inclusion in the review. A standardized form created by the authors at the start of the review was used to extract data (Table 1).

Assessment of Study Quality

The quality of each TTO study in the review was assessed with a modified Coleman methodology score (MCMS), which ranges from 0 to 100. A study with an MCMS of <55 points is considered a poor-quality study.¹¹

Data Synthesis and Statistical Analysis

Given that most of the included studies were level IV, a formal meta-analysis was not indicated. In this article, we report categorical data as frequencies with percentages and preoperative and postoperative continuous data as means (SDs), with weighted means based on number of patients in each study, where applicable. We used 2-tailed t tests for comparisons made with the free Meta-Analysis Calculator and Grapher (http://www.healthstrategy.com/meta/meta.pl ). Statistical significance was set at P < .05. 

Results

Search Results and Included Studies

Twenty-one studies (976 patients, 1055 knees) were included in the analysis (Figure 10; Table 2).^12-32 These studies were published between 1986 and 2013. There were 18 level IV studies (85.7%), 3 level III studies (14%), and no level I or II studies. Better quality studies had a mean (SD) MCMS of 19.8 (8.2), well under the 55-point cutoff. In the 16 studies that reported sex, women accounted for 69% of the population. Weighted mean (SD) age was 27.68 (10.45) years (range, 12-77 years) (18 studies reporting).   

Only 1 study provided preoperative body mass index (27 kg/m2). There were 55.35% of patients who had prior surgery on the affected knee (6 studies reporting).

Preoperative Data

Preoperative pathologic, radiographic, and clinical scoring data were scarcely reported and nonuniform (Table 2). The most common pathology treated with TTO was isolated patellofemoral instability (746/1055 patients, 70.7%). The other pathologies addressed were isolated patellofemoral osteoarthritis/chondromalacia patellae (143, 13.6%), patellofemoral instability with patella alta (61, 5.8%), patellofemoral instability with patellofemoral osteoarthritis (45, 4.3%), isolated patella baja (41, 3.9%), isolated patella alta (19, 1.8%), and patellofemoral osteoarthritis with patella baja (2, 0.2%). Five hundred fifty-five patients (53%) had a preoperative complaint that included knee pain, and 809 (77%) reported preoperative patellar laxity or instability events. The imaging data reported were Q-angle, Insall-Salvati ratio, Caton-Deschamps index, Blackburne-Peel ratio, Outerbridge osteoarthritis grade, and TT-TG distance. Preoperative clinical scoring data most prominently included a visual analog scale (VAS) score of 70.50 (4 studies reporting), a Lysholm score of 59.19 (5 studies), and a Kujala score of 41.16 (4 studies). Shelbourne-Trumper and Cox-Insall scores were reported in 1 and 2 studies, respectively.

Operative Characteristics

Of the 21 studies, 12 reported only on patients who had TTO performed in isolation; in the other 9 studies, cohorts included patients who underwent concurrent procedures. In the 17 studies (856 patients) that listed numbers of patients who underwent specific concomitant procedures, 715 patients (83.5%) underwent an isolated TTO procedure, and the other 141 (16.5%) underwent either concomitant lateral femoral trochleoplasty, arthroscopic drilling of chondral lesions, patellar shaving chondroplasty, partial meniscectomy or concomitant meniscal repair, intra-articular loose body removal, and/or lateral release with or without medial plication. 

Twenty studies reported specifics on the intraoperative direction of the tibial bone block osteotomy (Table 3). In most cases (50.8%), anteromedial translation (anteromedialization) was performed; anteriorization was performed in 18.7% of cases, medialization in 9.6%, medial and distal translation in 7.2%, a “triple” (anteriorization, medialization, proximalization) in 6%, isolated distalization in 2.8%, and proximalization in 1.6%. The remaining 2.8% of procedure specifics were not identified. 

Postoperative Data

Table 4 lists the overall cohort’s postoperative radiographic, clinical outcome scoring, and complications data. Fifteen studies reported follow-up of >2 years. As with the preoperative data, radiographic and clinical scoring data were relatively nonuniform; some numeric data, however, should be highlighted. Statistical analysis allowed for comparison of preoperative-postoperative VAS, Lysholm, and Kujala scores, each of which was significantly higher after surgery (P < .001). Seven studies reported an overall clinical outcome rating, with the cumulative majority of patients reporting good (37.9%) or excellent (39.2%) results. 

There was a cumulative total of 79 complications (8% of cohort): 17 recurrent patellar dislocations (1.9%), 4 recurrent patellar subluxations (0.4%), 10 wound complications (1.0%), 2 intraoperative complications (0.2%), 14 tibial tubercle fractures (1.3%), 19 proximal tibia fractures (1.8%), 4 cases of anterior knee pain (0.4%), 4 cases of neuropraxia (0.4%), and 5 infections (0.5%). Of note, 219 knees (21%) required reoperation, but 170 (16.3%) of these were for painful hardware removal. Sixteen knees (1.5%) required revision TTO, 1 (0.1%) required subsequent high tibial osteotomy, 2 (0.2%) underwent patellofemoral arthroplasty for advanced arthritic changes, and 5 (0.5%) underwent total knee arthroplasty for advanced arthritic changes.

Studies With TTO Performed in Isolation

Twelve studies reported outcomes of isolated TTO procedures. In the 638 patients who underwent isolated TTO, the pathologies addressed were instability/laxity (429 patients, 67%), patellofemoral osteoarthritis (74, 12%), patella alta with instability (61, 10%), patellofemoral osteoarthritis with instability (31, 5%), patella baja (24, 4%), and patella alta (19, 3%). Pain was a preoperative issue in 289 (45%) of these patients and instability in 472 (74%).

Only 2.8% of patients experienced postoperative patellar dislocation events. Of the 12 studies, 2 reported VAS scores (34-point weighted mean improvement, 65 points before surgery to 31 after surgery), 3 reported Lysholm scores (30-point improvement, from 60 to 90), and 2 reported Kujala scores (21-point improvement, from 46 to 67).

Complication rates for this isolated-TTO pooled cohort of patients were 1.2% for revision TTOs, 0.5% for wound complications, 0.8% for tibial tubercle fractures, and 1.9% for proximal tibia fractures. In total, 16% of patients required hardware removal after surgery. 

Discussion

This study found that TTO improved patient pain and clinical outcome scores despite having a high (16%) rate of reoperation for painful hardware in patients with preoperative pain or instability, or with patellofemoral osteoarthritis or aberrant patellar anatomy. This reoperation rate and the overall complication rate both exceeded our hypothesized 10% cumulative rate. However, <1% of patients required conversion to a definitive end-stage surgery (patellofemoral arthroplasty or total knee arthroplasty) by final follow-up, and the rates of comorbidities (anterior knee pain, wound infection, recurrent patellar subluxation/dislocation, tibial fracture) were relatively low.

Patellofemoral disorders are common in the general population and a frequent primary complaint on presentation to orthopedic offices. Having a thorough understanding of knee joint biomechanics is imperative when trying to determine whether surgery is appropriate for these complaints and how to proceed. Extensor mechanism abnormalities, including high lateral force vectors (or larger TT-TG distances) and excessive patellar tilt, can affect alignment and increase the risk for patellofemoral dislocations, patellofemoral anterior- based knee pains, and chondral lesions. Patella alta, an elevated patella, risks increased contact stresses between the patella and the trochlear groove³³ and decreases the osseous constraints that inhibit dislocation of the patella with physiologic flexion of the joint.³⁴ With TTO, the change in tuberosity position can alter angles in the extensor mechanism and thereby decrease joint reaction forces and patellofemoral contact area forces.^35,36

Although its use began as an option for combating patellar instability events in patients with predisposed patellofemoral kinematics,⁵ TTO has evolved in its therapeutic uses to include offloading patellar and trochlear focal chondral lesions and slowing progression of patellofemoral arthritis. Multiple iterations and modifications of the procedure have involved distal and medial transfer of the tibial tuberosity, medialization alone, concurrent anterior and medial elevation of the tuberosity, and proximal or distal transfers, depending on the pathology being corrected. Although TTO is highly versatile in treating multiple patellofemoral joint pathologies, this study found that its primary indication continues to be patellar instability, with anteromedialization as the most common direction of tubercle transfer in support of the medial structures providing the medial force vector that keeps the patella in place. These medial structures include the medial patellofemoral ligament, the vastus medialis obliquus, the medial patellotibial ligament, and the medial retinaculum. 

Also notable was the relatively high rate of reoperation after TTO. However, >75% of reoperations were performed to remove painful hardware, and the need for reoperation seemed to have no effect on the statistically significant overall preoperative-to-postoperative improvement in VAS, Lysholm, and Kujala scores. Rates of definitive surgery for end-stage patellofemoral changes, including patellofemoral arthroplasty and total knee arthroplasty, were quite low at the weighted mean follow-up of several years after surgery, suggesting a role for TTO in avoiding arthroplasty. Although the infection rate was <1%, the rate of tibial tubercle or proximal tibia fractures was a cumulative 3.1%. Patients should be counseled on this complication risk, as treatment can require cast immobilization and weight-bearing limitations.²⁴

The 69% proportion of women in the overall cohort and the mean (SD) age of 27.68 (10.45) years highlight the primary patient population that undergoes TTO. Compared with men, young women are more likely to have aberrant patellofemoral biomechanics, owing to their native anatomy, including their relatively larger Q-angle and TT-TG distance and thus increased lateral translational force vectors on the patella.³⁷ In addition, more than half of patients who are having TTO underwent previous surgery on the affected knee—an indication that TTO is still not universally considered first-line in addressing patellofemoral pathology.

Limitations of the Analysis

The limitations of this analysis derive from the limitations of the included studies, which were mostly retrospective case series with relatively short follow-up. The low MCMS (<55) of all 21 studies highlights their low quality as well. These studies showed considerable heterogeneity in their reporting of specific preoperative, intraoperative, and postoperative radiographic, physical examination, and clinical outcome scores, which may be indicative of the relatively low rate of use of TTO, a procedure originally described decades ago. These studies also showed ample heterogeneity in the specific radiographic parameters or outcome scales they used to present their data. We were therefore limited in our ability to cohesively summarize and provide cumulative data points from the patients as a unified cohort. There was substantial variety in the procedures performed, surgical techniques used, concomitant pathologies addressed at time of surgery, and diagnoses treated—indicating a performance bias. This additionally precluded any significant meta-analysis within the patient cohort. A higher quality study, a randomized controlled trial, is needed to answer more definitively and completely the questions we left unanswered, including the effect on radiographic parameters, additional clinical outcomes, and patient satisfaction.

Conclusion

TTO is most commonly performed for isolated patellar instability in the presence of knee pain. Other pathologies addressed are patellofemoral osteoarthritis, and patella alta and patella baja with and without associated knee pain. TTO significantly improves knee pain and clinical outcome scores, though 21% of patients (>1 in 5) require reoperation for hardware removal. Young women with prior surgery on the affected knee are the primary patient population.

Take-Home Points

• TTO specifics depend on anatomy, radiographic alignment characteristics, and presence of chondral defects.
• Osteotomy and movement of the tibial tubercle can include anteriorization, anteromedialization, proximalization, medialization, or distalization.
• TTO was most commonly performed for isolated patellar instability in the presence of knee pain.
• Young women with prior surgery on the affected knee made up the primary patient population for this procedure.
• While TTO significantly improves knee pain and clinical outcome scores, >1 in 5 patients required reoperation for hardware removal.

Patellofemoral pain and patellofemoral instability are common orthopedic problems. Studies have found that 30% of patients 13 to 19 years old have patellofemoral pain and that 29 in 100,000 patients 10 to 17 years old have patellofemoral instability.^1-3 The reported rate of recurrence after nonoperative management of patellofemoral instability is 33%.⁴ Tibial tubercle osteotomy (TTO), first described by Hauser⁵ in 1938, is an effective treatment option for many patellofemoral disorders.

TTO indications include patellofemoral maltracking or malalignment, patellar instability, patellofemoral arthritis, and focal patellofemoral chondral defects.⁶ With TTO, the goal is to move the tibial tubercle in a direction that will either improve patellar tracking or offload the medial or lateral patellar facet to improve pain and function.^7,8 This action typically involves anterior, medial, lateral, or distal translation of the tibial tubercle, as posteriorization can lead to increased contact forces across the patellofemoral joint, resulting in accelerated patellofemoral wear and increased pain.⁹

We systematically reviewed the TTO literature to identify indications, clinical outcomes, complications, and reoperations. We hypothesized that the overall complication rate and the overall reoperation rate would both be <10%.

Clinical Evaluation of Patellofemoral Pathology

Patients with patellofemoral pain often report anterior knee pain, which typically begins gradually and is often activity related. Several symptoms may be present: pain with prolonged sitting with knees bent; pain on rising from a seated position; pain or crepitus with climbing stairs; and pain during repetitive activity such as running, squatting, or jumping. Location, duration, and onset of symptoms should be elicited. Patellofemoral instability can be described as dislocation events or subluxation events; number of events, mechanisms of injury, and resulting need for reduction should be documented. As age, sex, body mass index, and physical fitness are relevant to risk of recurrence, the physician should ask about general ligamentous laxity, other joint dislocations, and prior surgical intervention. Swelling or mechanical symptoms may indicate patellofemoral joint pathology.^6,10

Physical examination of patients with patellofemoral pathology begins with assessment for overall limb alignment (including resting position of patella and corresponding quadriceps angle [Q-angle]), generalized ligamentous laxity (including hypermobile joints, evaluated with Brighton criteria), overall peri-knee muscle tone and strength, effusion, and gait pattern.

Knee and hip range of motion should be documented. Apprehension (Figure 1) and lack of a firm endpoint on placement of a lateralizing moment on the patella suggest prior dislocation or subluxation. Patella and surrounding anatomy must be palpated for location and severity of tenderness. Finally, patellar tilt, height, mobility, and dynamic tracking, including J-sign, are pertinent to evaluation. The J-sign for patellar tracking is positive when the patella deviates laterally as the knee moves from flexion into extension. Examination of the asymptomatic contralateral side is essential for comparison. Plain radiographs are important first-line imaging. Computed tomography or magnetic resonance imaging can be used to measure tibial tubercle-trochlear groove (TT-TG) distance. TT-TG distance of >15 mm is abnormal, and >20 mm indicates TTO is required. Advanced imaging is additionally valuable in assessing for chondral injury or trochlear dysplasia.^6,10

Common TTO Procedures

TTO specifics depend on anatomy, radiographic alignment characteristics, and presence of chondral defects. Essentially, the patella is translated to offload the affected areas. Osteotomy and movement of the tibial tubercle can include anteriorization, anteromedialization, proximalization, medialization, or distalization.

Lateralization or anterolateralization may be pertinent to revision if an osteotomy direction results in overcorrection of tuberosity position. Anteriorization (Figures 2A-2C) does not have a role in patellofemoral instability, but can unload areas of excessive patellar chondral force concentration at the central or proximal patella by increasing the angle between the patellar and quadriceps tendons and thereby decreasing the joint reaction forces.

Straight medialization (Figures 3A, 3B) offloads lateral patellar chondral injury and may decrease lateral instability.

Distalization (Figures 4A-4C) can correct for patella alta in the setting of patellar instability and allows earlier engagement of the patella in the trochlea to increase osseous restraint to lateral translation.⁶

Anteromedialization (Figure 5) is indicated in patients with a normal proximal and medial patellar chondral surface and a laterally positioned patella leading to alteration of the contact area in the trochlear groove and resulting pain, lateral patellar or trochlear chondral disease, or instability. Osteotomy angle can provide varied medialization through consistent slope and anteriorization. For example, a 60° slope osteotomy provides 9 mm of medialization with 15 mm of anteriorization.⁶ The procedure, similar to the additional TTO operations, begins with a lateral parapatellar incision that is extended distal to the tibial tubercle and anterior over the crest. The soft tissues around the tubercle are released to allow mobilization.

Variable osteotomy jigs allow for different slope cuts for more medialization or anteriorization, based on preoperative findings. The osteotomy cuts are started with a thin oscillating blade (Figure 6) and finished with an osteotome.

The tubercle fragment (Figure 7) is shifted and provisionally fixed with a Kirschner wire before being drilled and fixated with two 4.5-mm countersunk cortical screws (Figures 8, 9A-9B).

Locally harvested corticocancellous bone can help anteriorize the tubercle block. Osteotomy specifics allow for corresponding anatomical translations of the TTO to address the preoperative pathology.

Methods

Search Strategy and Data Collection

We searched the PubMed (Medline) database for all English-language TTO studies published between database inception and April 9, 2015. After PROSPERO registration, and following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we used the algorithm (“tibial” AND “tubercle” AND “osteotomy”) NOT (“total” AND “knee” AND “arthroplasty”) to search the literature. Inclusion criteria included level I-IV studies on TTO indications, operative findings, and outcomes. Exclusion criteria were non-English studies, unpublished studies, level V evidence, letters to the editor, editorials, review articles, basic science articles, technique articles, revision procedures, articles without clinical outcomes, and conference proceeding abstracts. Studies that reported on duplicate populations were included only with the most recent available clinical outcomes. All abstracts were reviewed in duplicate by Dr. Levy and Dr. Rao and assessed with respect to the criteria outlined. Then the same authors performed full-text reviews of eligible studies before including these studies in the systematic review.

They also manually checked the references in study articles to identify additional studies for possible inclusion in the review. A standardized form created by the authors at the start of the review was used to extract data (Table 1).

Assessment of Study Quality

The quality of each TTO study in the review was assessed with a modified Coleman methodology score (MCMS), which ranges from 0 to 100. A study with an MCMS of <55 points is considered a poor-quality study.¹¹

Data Synthesis and Statistical Analysis

Given that most of the included studies were level IV, a formal meta-analysis was not indicated. In this article, we report categorical data as frequencies with percentages and preoperative and postoperative continuous data as means (SDs), with weighted means based on number of patients in each study, where applicable. We used 2-tailed t tests for comparisons made with the free Meta-Analysis Calculator and Grapher (http://www.healthstrategy.com/meta/meta.pl ). Statistical significance was set at P < .05. 

Results

Search Results and Included Studies

Twenty-one studies (976 patients, 1055 knees) were included in the analysis (Figure 10; Table 2).^12-32 These studies were published between 1986 and 2013. There were 18 level IV studies (85.7%), 3 level III studies (14%), and no level I or II studies. Better quality studies had a mean (SD) MCMS of 19.8 (8.2), well under the 55-point cutoff. In the 16 studies that reported sex, women accounted for 69% of the population. Weighted mean (SD) age was 27.68 (10.45) years (range, 12-77 years) (18 studies reporting).   

Only 1 study provided preoperative body mass index (27 kg/m2). There were 55.35% of patients who had prior surgery on the affected knee (6 studies reporting).

Preoperative Data

Preoperative pathologic, radiographic, and clinical scoring data were scarcely reported and nonuniform (Table 2). The most common pathology treated with TTO was isolated patellofemoral instability (746/1055 patients, 70.7%). The other pathologies addressed were isolated patellofemoral osteoarthritis/chondromalacia patellae (143, 13.6%), patellofemoral instability with patella alta (61, 5.8%), patellofemoral instability with patellofemoral osteoarthritis (45, 4.3%), isolated patella baja (41, 3.9%), isolated patella alta (19, 1.8%), and patellofemoral osteoarthritis with patella baja (2, 0.2%). Five hundred fifty-five patients (53%) had a preoperative complaint that included knee pain, and 809 (77%) reported preoperative patellar laxity or instability events. The imaging data reported were Q-angle, Insall-Salvati ratio, Caton-Deschamps index, Blackburne-Peel ratio, Outerbridge osteoarthritis grade, and TT-TG distance. Preoperative clinical scoring data most prominently included a visual analog scale (VAS) score of 70.50 (4 studies reporting), a Lysholm score of 59.19 (5 studies), and a Kujala score of 41.16 (4 studies). Shelbourne-Trumper and Cox-Insall scores were reported in 1 and 2 studies, respectively.

Operative Characteristics

Of the 21 studies, 12 reported only on patients who had TTO performed in isolation; in the other 9 studies, cohorts included patients who underwent concurrent procedures. In the 17 studies (856 patients) that listed numbers of patients who underwent specific concomitant procedures, 715 patients (83.5%) underwent an isolated TTO procedure, and the other 141 (16.5%) underwent either concomitant lateral femoral trochleoplasty, arthroscopic drilling of chondral lesions, patellar shaving chondroplasty, partial meniscectomy or concomitant meniscal repair, intra-articular loose body removal, and/or lateral release with or without medial plication. 

Twenty studies reported specifics on the intraoperative direction of the tibial bone block osteotomy (Table 3). In most cases (50.8%), anteromedial translation (anteromedialization) was performed; anteriorization was performed in 18.7% of cases, medialization in 9.6%, medial and distal translation in 7.2%, a “triple” (anteriorization, medialization, proximalization) in 6%, isolated distalization in 2.8%, and proximalization in 1.6%. The remaining 2.8% of procedure specifics were not identified. 

Postoperative Data

Table 4 lists the overall cohort’s postoperative radiographic, clinical outcome scoring, and complications data. Fifteen studies reported follow-up of >2 years. As with the preoperative data, radiographic and clinical scoring data were relatively nonuniform; some numeric data, however, should be highlighted. Statistical analysis allowed for comparison of preoperative-postoperative VAS, Lysholm, and Kujala scores, each of which was significantly higher after surgery (P < .001). Seven studies reported an overall clinical outcome rating, with the cumulative majority of patients reporting good (37.9%) or excellent (39.2%) results. 

There was a cumulative total of 79 complications (8% of cohort): 17 recurrent patellar dislocations (1.9%), 4 recurrent patellar subluxations (0.4%), 10 wound complications (1.0%), 2 intraoperative complications (0.2%), 14 tibial tubercle fractures (1.3%), 19 proximal tibia fractures (1.8%), 4 cases of anterior knee pain (0.4%), 4 cases of neuropraxia (0.4%), and 5 infections (0.5%). Of note, 219 knees (21%) required reoperation, but 170 (16.3%) of these were for painful hardware removal. Sixteen knees (1.5%) required revision TTO, 1 (0.1%) required subsequent high tibial osteotomy, 2 (0.2%) underwent patellofemoral arthroplasty for advanced arthritic changes, and 5 (0.5%) underwent total knee arthroplasty for advanced arthritic changes.

Studies With TTO Performed in Isolation

Twelve studies reported outcomes of isolated TTO procedures. In the 638 patients who underwent isolated TTO, the pathologies addressed were instability/laxity (429 patients, 67%), patellofemoral osteoarthritis (74, 12%), patella alta with instability (61, 10%), patellofemoral osteoarthritis with instability (31, 5%), patella baja (24, 4%), and patella alta (19, 3%). Pain was a preoperative issue in 289 (45%) of these patients and instability in 472 (74%).

Only 2.8% of patients experienced postoperative patellar dislocation events. Of the 12 studies, 2 reported VAS scores (34-point weighted mean improvement, 65 points before surgery to 31 after surgery), 3 reported Lysholm scores (30-point improvement, from 60 to 90), and 2 reported Kujala scores (21-point improvement, from 46 to 67).

Complication rates for this isolated-TTO pooled cohort of patients were 1.2% for revision TTOs, 0.5% for wound complications, 0.8% for tibial tubercle fractures, and 1.9% for proximal tibia fractures. In total, 16% of patients required hardware removal after surgery. 

Discussion

This study found that TTO improved patient pain and clinical outcome scores despite having a high (16%) rate of reoperation for painful hardware in patients with preoperative pain or instability, or with patellofemoral osteoarthritis or aberrant patellar anatomy. This reoperation rate and the overall complication rate both exceeded our hypothesized 10% cumulative rate. However, <1% of patients required conversion to a definitive end-stage surgery (patellofemoral arthroplasty or total knee arthroplasty) by final follow-up, and the rates of comorbidities (anterior knee pain, wound infection, recurrent patellar subluxation/dislocation, tibial fracture) were relatively low.

Patellofemoral disorders are common in the general population and a frequent primary complaint on presentation to orthopedic offices. Having a thorough understanding of knee joint biomechanics is imperative when trying to determine whether surgery is appropriate for these complaints and how to proceed. Extensor mechanism abnormalities, including high lateral force vectors (or larger TT-TG distances) and excessive patellar tilt, can affect alignment and increase the risk for patellofemoral dislocations, patellofemoral anterior- based knee pains, and chondral lesions. Patella alta, an elevated patella, risks increased contact stresses between the patella and the trochlear groove³³ and decreases the osseous constraints that inhibit dislocation of the patella with physiologic flexion of the joint.³⁴ With TTO, the change in tuberosity position can alter angles in the extensor mechanism and thereby decrease joint reaction forces and patellofemoral contact area forces.^35,36

Although its use began as an option for combating patellar instability events in patients with predisposed patellofemoral kinematics,⁵ TTO has evolved in its therapeutic uses to include offloading patellar and trochlear focal chondral lesions and slowing progression of patellofemoral arthritis. Multiple iterations and modifications of the procedure have involved distal and medial transfer of the tibial tuberosity, medialization alone, concurrent anterior and medial elevation of the tuberosity, and proximal or distal transfers, depending on the pathology being corrected. Although TTO is highly versatile in treating multiple patellofemoral joint pathologies, this study found that its primary indication continues to be patellar instability, with anteromedialization as the most common direction of tubercle transfer in support of the medial structures providing the medial force vector that keeps the patella in place. These medial structures include the medial patellofemoral ligament, the vastus medialis obliquus, the medial patellotibial ligament, and the medial retinaculum. 

Also notable was the relatively high rate of reoperation after TTO. However, >75% of reoperations were performed to remove painful hardware, and the need for reoperation seemed to have no effect on the statistically significant overall preoperative-to-postoperative improvement in VAS, Lysholm, and Kujala scores. Rates of definitive surgery for end-stage patellofemoral changes, including patellofemoral arthroplasty and total knee arthroplasty, were quite low at the weighted mean follow-up of several years after surgery, suggesting a role for TTO in avoiding arthroplasty. Although the infection rate was <1%, the rate of tibial tubercle or proximal tibia fractures was a cumulative 3.1%. Patients should be counseled on this complication risk, as treatment can require cast immobilization and weight-bearing limitations.²⁴

The 69% proportion of women in the overall cohort and the mean (SD) age of 27.68 (10.45) years highlight the primary patient population that undergoes TTO. Compared with men, young women are more likely to have aberrant patellofemoral biomechanics, owing to their native anatomy, including their relatively larger Q-angle and TT-TG distance and thus increased lateral translational force vectors on the patella.³⁷ In addition, more than half of patients who are having TTO underwent previous surgery on the affected knee—an indication that TTO is still not universally considered first-line in addressing patellofemoral pathology.

Limitations of the Analysis

The limitations of this analysis derive from the limitations of the included studies, which were mostly retrospective case series with relatively short follow-up. The low MCMS (<55) of all 21 studies highlights their low quality as well. These studies showed considerable heterogeneity in their reporting of specific preoperative, intraoperative, and postoperative radiographic, physical examination, and clinical outcome scores, which may be indicative of the relatively low rate of use of TTO, a procedure originally described decades ago. These studies also showed ample heterogeneity in the specific radiographic parameters or outcome scales they used to present their data. We were therefore limited in our ability to cohesively summarize and provide cumulative data points from the patients as a unified cohort. There was substantial variety in the procedures performed, surgical techniques used, concomitant pathologies addressed at time of surgery, and diagnoses treated—indicating a performance bias. This additionally precluded any significant meta-analysis within the patient cohort. A higher quality study, a randomized controlled trial, is needed to answer more definitively and completely the questions we left unanswered, including the effect on radiographic parameters, additional clinical outcomes, and patient satisfaction.

Conclusion

TTO is most commonly performed for isolated patellar instability in the presence of knee pain. Other pathologies addressed are patellofemoral osteoarthritis, and patella alta and patella baja with and without associated knee pain. TTO significantly improves knee pain and clinical outcome scores, though 21% of patients (>1 in 5) require reoperation for hardware removal. Young women with prior surgery on the affected knee are the primary patient population.