Original Research

Unicompartmental knee arthroplasty (UKA) is considered a less invasive approach for the treatment of unicompartmental knee arthritis when compared with total knee arthroplasty (TKA), with optimal preservation of kinematics.¹ Despite excellent functional outcomes, conversion to TKA may be necessary if the UKA fails, or in patients with progressive knee arthritis. Some studies have found UKA conversion to TKA to be comparable with primary TKA,^2,3 whereas others have found that conversion often requires bone graft, augments, and stemmed components and has increased complications and inferior results compared to primary TKA.^4-7 While some studies report that <10% of UKA conversions to TKA require augments,² others have found that as many as 76% require augments.^4-8

Schwarzkopf and colleagues⁹ recently demonstrated that UKA conversion to TKA is comparable with primary TKA when a conservative tibial resection is performed during the index procedure. However, they reported increased complexity when greater tibial resection was performed and thicker polyethylene inserts were used at the time of the index UKA. The odds ratio of needing an augment or stem during the conversion to TKA was 26.8 (95% confidence interval, 3.71-194) when an aggressive tibial resection was performed during the UKA.⁹ Tibial resection thickness may thus be predictive of anticipated complexity of UKA revision to TKA and may aid in preoperative planning.

Robotic assistance has been shown to enhance the accuracy of bone preparation, implant component alignment, and soft tissue balance in UKA.^10-15 It has yet to be determined whether this improved accuracy translates to improved clinical performance or longevity of the UKA implant. However, the enhanced accuracy of robotic technology may result in more conservative tibial resection when compared to conventional UKA and may be advantageous if conversion to TKA becomes necessary.

The purpose of this study was to compare the distribution of polyethylene insert sizes implanted during conventional and robotic-assisted UKA. We hypothesized that robotic assistance would demonstrate more conservative tibial resection compared to conventional methods of bone preparation.

Methods

We retrospectively compared the distribution of polyethylene insert sizes implanted during consecutive conventional and robotic-assisted UKA procedures. Several manufacturers were queried to provide a listing of the polyethylene insert sizes utilized, ranging from 8 mm to 14 mm. The analysis included 8421 robotic-assisted UKA cases and 27,989 conventional UKA cases. Data were provided by Zimmer Biomet and Smith & Nephew regarding conventional cases, as well as Blue Belt Technologies (now part of Smith & Nephew) and MAKO Surgical (now part of Stryker) regarding robotic-assisted cases. (Dr. Lonner has an ongoing relationship as a consultant with Blue Belt Technologies, whose data was utilized in this study.) Using tibial insert thickness as a surrogate measure of the extent of tibial resection, an insert size of ≥10 mm was defined as aggressive while <10 mm was considered conservative. This cutoff was established based on its corresponding resection level with primary TKA and the anticipated need for augments. Statistical analysis was performed using a Mann-Whitney-Wilcoxon test. Significance was set at P < .05.

Results

Tibial resection thickness was found to be most commonly conservative in nature, with sizes 8-mm and 9-mm polyethylene inserts utilized in the majority of both robotic-assisted and conventional UKA cases. However, statistically more 8-mm and 9-mm polyethylene inserts were used in the robotic group (93.6%) than in the conventional group (84.5%) (P < .0001; Figure). Aggressive tibial resection, requiring tibial inserts ≥10 mm, was performed in 6.4% of robotic-assisted cases and 15.5% of conventional cases.

Discussion

Robotic assistance enhances the accuracy of bone preparation, implant component alignment, and soft tissue balance in UKA.^10-15 It has yet to be determined whether this improved accuracy translates to improved clinical performance or longevity of the UKA implant. However, we demonstrate that the enhanced accuracy of robotic technology results in more conservative tibial resection when compared to conventional techniques with a potential benefit suggested in the literature upon conversion to TKA.

The findings of this study have important implications for patients undergoing conversion of UKA to TKA, potentially optimizing the ease of revision and clinical outcomes. The outcomes of UKA conversion to TKA are often considered inferior to those of primary TKA, compromised by bone loss, need for augmentation, and challenges of restoring the joint line and rotation.^9,16-22 Barrett and Scott¹⁸ reported only 66% of patients had good or excellent results at an average of 4.6 years of follow-up after UKA conversion to TKA. Over 50% required stemmed implants and bone graft or bone cement augmentation to address osseous insufficiency. The authors suggested that the primary determinant of the complexity of the conversion to TKA was the surgical technique used in the index procedure. They concluded that UKA conversion to TKA can be as successful as a primary TKA and primary TKA implants can be used without bone augmentation or stems during the revision procedure if minimal tibial bone is resected at the time of the index UKA.¹⁸ Schwarzkopf and colleagues⁹ supported this conclusion when they found that aggressive tibial resection during UKA resulted in the need for bone graft, stem, wedge, or augment in 70% of cases when converted to TKA. Similarly, Khan and colleagues²³ found that 26% of patients required bone grafting and 26% required some form of augmentation, and Springer and colleagues³ reported that 68% required a graft, augment, or stem.^3,22 Using data from the New Zealand Joint Registry, Pearse and colleagues⁵ reported that revision TKA components were necessary in 28% of patients and concluded that converting a UKA to TKA gives a less reliable result than primary TKA, and with functional results that are not significantly better than a revision from a TKA.

Conservative tibial resection during UKA minimizes the complexity and concerns of bone loss upon conversion to TKA. Schwarzkopf and colleagues⁹ found 96.6% of patients with conservative tibial resection received a primary TKA implant, without augments or stems. Furthermore, patients with a primary TKA implant showed improved tibial survivorship, with revision as an end point, compared with patients who received a TKA implant that required stems and augments or bone graft for support.⁹ Also emphasizing the importance of minimal tibial resection, O’Donnell and colleagues⁸ compared a cohort of patients undergoing conversion of a minimal resection resurfacing onlay-type UKA to TKA with a cohort of patients undergoing primary TKA. They found that 40% of patients required bone grafting for contained defects, 3.6% required metal augments, and 1.8% required stems.⁸ There was no significant difference between the groups in terms of range of motion, functional outcome, or radiologic outcomes. The authors concluded that revision of minimal resection resurfacing implants to TKA is associated with similar results to primary TKA and is superior to revision of UKA with greater bone loss. Prior studies have shown that one of the advantages of robotic-assisted UKA is the accuracy and precision of bone resection. The present study supports this premise by showing that tibial resection is significantly more conservative using robotic-assisted techniques when using tibial component thickness as a surrogate for extent of bone resection. While our study did not address implant durability or the impact of conservative resection on conversion to TKA, studies referenced above suggest that the conservative nature of bone preparation would have a relevant impact on the revision of the implant to TKA.

Our study is a retrospective case series that reports tibial component thickness as a surrogate for volume of tibial resection during UKA. While the implication is that more conservative tibial resection may optimize durability and ease of conversion to TKA, future study will be needed to compare robotic-assisted and conventional cases of UKA upon conversion to TKA in order to ascertain whether the more conventional resections of robotic-assisted UKA in fact lead to revision that is comparable with primary TKA in terms of bone loss at the time of revision, components utilized, the need for bone graft, augments, or stems, and clinical outcomes. Given the method of data collection in this study, we could not control for clinical deformity, selection bias, surgeon experience, or medial vs lateral knee compartments. These potential confounders represent weaknesses of this study.

In conclusion, conversion of UKA to TKA may be associated with significant osseous insufficiency, which may compromise patient outcomes in comparison to primary TKA. Studies have shown that UKA conversion to TKA is comparable to primary TKA when minimal tibial resection is performed during the UKA, and the need for augmentation, grafting or stems is increased with more aggressive tibial resection. This study has shown that when robotic assistance is utilized, tibial resection is more precise, less variable, and more conservative compared to conventional techniques.

Am J Orthop. 2016;45(7):E465-E468. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Unicompartmental knee arthroplasty (UKA) is considered a less invasive approach for the treatment of unicompartmental knee arthritis when compared with total knee arthroplasty (TKA), with optimal preservation of kinematics.¹ Despite excellent functional outcomes, conversion to TKA may be necessary if the UKA fails, or in patients with progressive knee arthritis. Some studies have found UKA conversion to TKA to be comparable with primary TKA,^2,3 whereas others have found that conversion often requires bone graft, augments, and stemmed components and has increased complications and inferior results compared to primary TKA.^4-7 While some studies report that <10% of UKA conversions to TKA require augments,² others have found that as many as 76% require augments.^4-8

Schwarzkopf and colleagues⁹ recently demonstrated that UKA conversion to TKA is comparable with primary TKA when a conservative tibial resection is performed during the index procedure. However, they reported increased complexity when greater tibial resection was performed and thicker polyethylene inserts were used at the time of the index UKA. The odds ratio of needing an augment or stem during the conversion to TKA was 26.8 (95% confidence interval, 3.71-194) when an aggressive tibial resection was performed during the UKA.⁹ Tibial resection thickness may thus be predictive of anticipated complexity of UKA revision to TKA and may aid in preoperative planning.

Robotic assistance has been shown to enhance the accuracy of bone preparation, implant component alignment, and soft tissue balance in UKA.^10-15 It has yet to be determined whether this improved accuracy translates to improved clinical performance or longevity of the UKA implant. However, the enhanced accuracy of robotic technology may result in more conservative tibial resection when compared to conventional UKA and may be advantageous if conversion to TKA becomes necessary.

The purpose of this study was to compare the distribution of polyethylene insert sizes implanted during conventional and robotic-assisted UKA. We hypothesized that robotic assistance would demonstrate more conservative tibial resection compared to conventional methods of bone preparation.

Methods

We retrospectively compared the distribution of polyethylene insert sizes implanted during consecutive conventional and robotic-assisted UKA procedures. Several manufacturers were queried to provide a listing of the polyethylene insert sizes utilized, ranging from 8 mm to 14 mm. The analysis included 8421 robotic-assisted UKA cases and 27,989 conventional UKA cases. Data were provided by Zimmer Biomet and Smith & Nephew regarding conventional cases, as well as Blue Belt Technologies (now part of Smith & Nephew) and MAKO Surgical (now part of Stryker) regarding robotic-assisted cases. (Dr. Lonner has an ongoing relationship as a consultant with Blue Belt Technologies, whose data was utilized in this study.) Using tibial insert thickness as a surrogate measure of the extent of tibial resection, an insert size of ≥10 mm was defined as aggressive while <10 mm was considered conservative. This cutoff was established based on its corresponding resection level with primary TKA and the anticipated need for augments. Statistical analysis was performed using a Mann-Whitney-Wilcoxon test. Significance was set at P < .05.

Results

Tibial resection thickness was found to be most commonly conservative in nature, with sizes 8-mm and 9-mm polyethylene inserts utilized in the majority of both robotic-assisted and conventional UKA cases. However, statistically more 8-mm and 9-mm polyethylene inserts were used in the robotic group (93.6%) than in the conventional group (84.5%) (P < .0001; Figure). Aggressive tibial resection, requiring tibial inserts ≥10 mm, was performed in 6.4% of robotic-assisted cases and 15.5% of conventional cases.

Discussion

Robotic assistance enhances the accuracy of bone preparation, implant component alignment, and soft tissue balance in UKA.^10-15 It has yet to be determined whether this improved accuracy translates to improved clinical performance or longevity of the UKA implant. However, we demonstrate that the enhanced accuracy of robotic technology results in more conservative tibial resection when compared to conventional techniques with a potential benefit suggested in the literature upon conversion to TKA.

The findings of this study have important implications for patients undergoing conversion of UKA to TKA, potentially optimizing the ease of revision and clinical outcomes. The outcomes of UKA conversion to TKA are often considered inferior to those of primary TKA, compromised by bone loss, need for augmentation, and challenges of restoring the joint line and rotation.^9,16-22 Barrett and Scott¹⁸ reported only 66% of patients had good or excellent results at an average of 4.6 years of follow-up after UKA conversion to TKA. Over 50% required stemmed implants and bone graft or bone cement augmentation to address osseous insufficiency. The authors suggested that the primary determinant of the complexity of the conversion to TKA was the surgical technique used in the index procedure. They concluded that UKA conversion to TKA can be as successful as a primary TKA and primary TKA implants can be used without bone augmentation or stems during the revision procedure if minimal tibial bone is resected at the time of the index UKA.¹⁸ Schwarzkopf and colleagues⁹ supported this conclusion when they found that aggressive tibial resection during UKA resulted in the need for bone graft, stem, wedge, or augment in 70% of cases when converted to TKA. Similarly, Khan and colleagues²³ found that 26% of patients required bone grafting and 26% required some form of augmentation, and Springer and colleagues³ reported that 68% required a graft, augment, or stem.^3,22 Using data from the New Zealand Joint Registry, Pearse and colleagues⁵ reported that revision TKA components were necessary in 28% of patients and concluded that converting a UKA to TKA gives a less reliable result than primary TKA, and with functional results that are not significantly better than a revision from a TKA.

Conservative tibial resection during UKA minimizes the complexity and concerns of bone loss upon conversion to TKA. Schwarzkopf and colleagues⁹ found 96.6% of patients with conservative tibial resection received a primary TKA implant, without augments or stems. Furthermore, patients with a primary TKA implant showed improved tibial survivorship, with revision as an end point, compared with patients who received a TKA implant that required stems and augments or bone graft for support.⁹ Also emphasizing the importance of minimal tibial resection, O’Donnell and colleagues⁸ compared a cohort of patients undergoing conversion of a minimal resection resurfacing onlay-type UKA to TKA with a cohort of patients undergoing primary TKA. They found that 40% of patients required bone grafting for contained defects, 3.6% required metal augments, and 1.8% required stems.⁸ There was no significant difference between the groups in terms of range of motion, functional outcome, or radiologic outcomes. The authors concluded that revision of minimal resection resurfacing implants to TKA is associated with similar results to primary TKA and is superior to revision of UKA with greater bone loss. Prior studies have shown that one of the advantages of robotic-assisted UKA is the accuracy and precision of bone resection. The present study supports this premise by showing that tibial resection is significantly more conservative using robotic-assisted techniques when using tibial component thickness as a surrogate for extent of bone resection. While our study did not address implant durability or the impact of conservative resection on conversion to TKA, studies referenced above suggest that the conservative nature of bone preparation would have a relevant impact on the revision of the implant to TKA.

Our study is a retrospective case series that reports tibial component thickness as a surrogate for volume of tibial resection during UKA. While the implication is that more conservative tibial resection may optimize durability and ease of conversion to TKA, future study will be needed to compare robotic-assisted and conventional cases of UKA upon conversion to TKA in order to ascertain whether the more conventional resections of robotic-assisted UKA in fact lead to revision that is comparable with primary TKA in terms of bone loss at the time of revision, components utilized, the need for bone graft, augments, or stems, and clinical outcomes. Given the method of data collection in this study, we could not control for clinical deformity, selection bias, surgeon experience, or medial vs lateral knee compartments. These potential confounders represent weaknesses of this study.

In conclusion, conversion of UKA to TKA may be associated with significant osseous insufficiency, which may compromise patient outcomes in comparison to primary TKA. Studies have shown that UKA conversion to TKA is comparable to primary TKA when minimal tibial resection is performed during the UKA, and the need for augmentation, grafting or stems is increased with more aggressive tibial resection. This study has shown that when robotic assistance is utilized, tibial resection is more precise, less variable, and more conservative compared to conventional techniques.

Am J Orthop. 2016;45(7):E465-E468. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Unicompartmental knee arthroplasty (UKA) is considered a less invasive approach for the treatment of unicompartmental knee arthritis when compared with total knee arthroplasty (TKA), with optimal preservation of kinematics.¹ Despite excellent functional outcomes, conversion to TKA may be necessary if the UKA fails, or in patients with progressive knee arthritis. Some studies have found UKA conversion to TKA to be comparable with primary TKA,^2,3 whereas others have found that conversion often requires bone graft, augments, and stemmed components and has increased complications and inferior results compared to primary TKA.^4-7 While some studies report that <10% of UKA conversions to TKA require augments,² others have found that as many as 76% require augments.^4-8

Schwarzkopf and colleagues⁹ recently demonstrated that UKA conversion to TKA is comparable with primary TKA when a conservative tibial resection is performed during the index procedure. However, they reported increased complexity when greater tibial resection was performed and thicker polyethylene inserts were used at the time of the index UKA. The odds ratio of needing an augment or stem during the conversion to TKA was 26.8 (95% confidence interval, 3.71-194) when an aggressive tibial resection was performed during the UKA.⁹ Tibial resection thickness may thus be predictive of anticipated complexity of UKA revision to TKA and may aid in preoperative planning.

Robotic assistance has been shown to enhance the accuracy of bone preparation, implant component alignment, and soft tissue balance in UKA.^10-15 It has yet to be determined whether this improved accuracy translates to improved clinical performance or longevity of the UKA implant. However, the enhanced accuracy of robotic technology may result in more conservative tibial resection when compared to conventional UKA and may be advantageous if conversion to TKA becomes necessary.

The purpose of this study was to compare the distribution of polyethylene insert sizes implanted during conventional and robotic-assisted UKA. We hypothesized that robotic assistance would demonstrate more conservative tibial resection compared to conventional methods of bone preparation.

Methods

We retrospectively compared the distribution of polyethylene insert sizes implanted during consecutive conventional and robotic-assisted UKA procedures. Several manufacturers were queried to provide a listing of the polyethylene insert sizes utilized, ranging from 8 mm to 14 mm. The analysis included 8421 robotic-assisted UKA cases and 27,989 conventional UKA cases. Data were provided by Zimmer Biomet and Smith & Nephew regarding conventional cases, as well as Blue Belt Technologies (now part of Smith & Nephew) and MAKO Surgical (now part of Stryker) regarding robotic-assisted cases. (Dr. Lonner has an ongoing relationship as a consultant with Blue Belt Technologies, whose data was utilized in this study.) Using tibial insert thickness as a surrogate measure of the extent of tibial resection, an insert size of ≥10 mm was defined as aggressive while <10 mm was considered conservative. This cutoff was established based on its corresponding resection level with primary TKA and the anticipated need for augments. Statistical analysis was performed using a Mann-Whitney-Wilcoxon test. Significance was set at P < .05.

Results

Tibial resection thickness was found to be most commonly conservative in nature, with sizes 8-mm and 9-mm polyethylene inserts utilized in the majority of both robotic-assisted and conventional UKA cases. However, statistically more 8-mm and 9-mm polyethylene inserts were used in the robotic group (93.6%) than in the conventional group (84.5%) (P < .0001; Figure). Aggressive tibial resection, requiring tibial inserts ≥10 mm, was performed in 6.4% of robotic-assisted cases and 15.5% of conventional cases.

Discussion

Robotic assistance enhances the accuracy of bone preparation, implant component alignment, and soft tissue balance in UKA.^10-15 It has yet to be determined whether this improved accuracy translates to improved clinical performance or longevity of the UKA implant. However, we demonstrate that the enhanced accuracy of robotic technology results in more conservative tibial resection when compared to conventional techniques with a potential benefit suggested in the literature upon conversion to TKA.

The findings of this study have important implications for patients undergoing conversion of UKA to TKA, potentially optimizing the ease of revision and clinical outcomes. The outcomes of UKA conversion to TKA are often considered inferior to those of primary TKA, compromised by bone loss, need for augmentation, and challenges of restoring the joint line and rotation.^9,16-22 Barrett and Scott¹⁸ reported only 66% of patients had good or excellent results at an average of 4.6 years of follow-up after UKA conversion to TKA. Over 50% required stemmed implants and bone graft or bone cement augmentation to address osseous insufficiency. The authors suggested that the primary determinant of the complexity of the conversion to TKA was the surgical technique used in the index procedure. They concluded that UKA conversion to TKA can be as successful as a primary TKA and primary TKA implants can be used without bone augmentation or stems during the revision procedure if minimal tibial bone is resected at the time of the index UKA.¹⁸ Schwarzkopf and colleagues⁹ supported this conclusion when they found that aggressive tibial resection during UKA resulted in the need for bone graft, stem, wedge, or augment in 70% of cases when converted to TKA. Similarly, Khan and colleagues²³ found that 26% of patients required bone grafting and 26% required some form of augmentation, and Springer and colleagues³ reported that 68% required a graft, augment, or stem.^3,22 Using data from the New Zealand Joint Registry, Pearse and colleagues⁵ reported that revision TKA components were necessary in 28% of patients and concluded that converting a UKA to TKA gives a less reliable result than primary TKA, and with functional results that are not significantly better than a revision from a TKA.

Conservative tibial resection during UKA minimizes the complexity and concerns of bone loss upon conversion to TKA. Schwarzkopf and colleagues⁹ found 96.6% of patients with conservative tibial resection received a primary TKA implant, without augments or stems. Furthermore, patients with a primary TKA implant showed improved tibial survivorship, with revision as an end point, compared with patients who received a TKA implant that required stems and augments or bone graft for support.⁹ Also emphasizing the importance of minimal tibial resection, O’Donnell and colleagues⁸ compared a cohort of patients undergoing conversion of a minimal resection resurfacing onlay-type UKA to TKA with a cohort of patients undergoing primary TKA. They found that 40% of patients required bone grafting for contained defects, 3.6% required metal augments, and 1.8% required stems.⁸ There was no significant difference between the groups in terms of range of motion, functional outcome, or radiologic outcomes. The authors concluded that revision of minimal resection resurfacing implants to TKA is associated with similar results to primary TKA and is superior to revision of UKA with greater bone loss. Prior studies have shown that one of the advantages of robotic-assisted UKA is the accuracy and precision of bone resection. The present study supports this premise by showing that tibial resection is significantly more conservative using robotic-assisted techniques when using tibial component thickness as a surrogate for extent of bone resection. While our study did not address implant durability or the impact of conservative resection on conversion to TKA, studies referenced above suggest that the conservative nature of bone preparation would have a relevant impact on the revision of the implant to TKA.

Our study is a retrospective case series that reports tibial component thickness as a surrogate for volume of tibial resection during UKA. While the implication is that more conservative tibial resection may optimize durability and ease of conversion to TKA, future study will be needed to compare robotic-assisted and conventional cases of UKA upon conversion to TKA in order to ascertain whether the more conventional resections of robotic-assisted UKA in fact lead to revision that is comparable with primary TKA in terms of bone loss at the time of revision, components utilized, the need for bone graft, augments, or stems, and clinical outcomes. Given the method of data collection in this study, we could not control for clinical deformity, selection bias, surgeon experience, or medial vs lateral knee compartments. These potential confounders represent weaknesses of this study.

In conclusion, conversion of UKA to TKA may be associated with significant osseous insufficiency, which may compromise patient outcomes in comparison to primary TKA. Studies have shown that UKA conversion to TKA is comparable to primary TKA when minimal tibial resection is performed during the UKA, and the need for augmentation, grafting or stems is increased with more aggressive tibial resection. This study has shown that when robotic assistance is utilized, tibial resection is more precise, less variable, and more conservative compared to conventional techniques.

Am J Orthop. 2016;45(7):E465-E468. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Leg-length discrepancy (LLD) is common in the general population¹ and particularly in patients with degenerative joint diseases of the hip and knee.² Common complications of LLD include femoral, sciatic, and peroneal nerve palsy; lower back pain; gait abnormalities³; and general dissatisfaction. LLD is a concern for orthopedic surgeons who perform total knee arthroplasty (TKA) because limb lengthening is common after this procedure.^4,5 Surgeons are aware of the limb lengthening that occurs during TKA,^4,5 and studies have confirmed that LLD usually decreases after TKA.^4,5

Despite surgeons’ best efforts, some patients still perceive LLD after surgery, though the incidence of perceived LLD in patients who have had TKA has not been well documented. Aside from actual, objectively measured LLD, there may be other factors that lead patients to perceive LLD. Study results have suggested that preoperative varus–valgus alignment of the knee joint may correlate with how much an operative leg is lengthened after TKA^4,5; however, the outcome investigated was objective LLD measurements, not perceived LLD. Understanding the factors that may influence patients’ ability to perceive LLD would allow surgeons to preoperatively identify patients who are at higher risk for postoperative perceived LLD. This information, along with expected time to resolution of postoperative perceived LLD, would allow surgeons to educate their patients accordingly.

We conducted a study to determine the incidence of perceived LLD before and after primary TKA in patients with unilateral osteoarthritis and to determine the correlation between mechanical axis of the knee and perceived LLD before and after surgery. Given that surgery may correct mechanical axis misalignment, we investigated the correlation between this correction and its ability to change patients’ preoperative and postoperative perceived LLD. We hypothesized that a large correction of mechanical axis would lead patients to perceive LLD after surgery. The relationship of body mass index (BMI) and age to patients’ perceived LLD was also assessed. The incidence and time frame of resolution of postoperative perceived LLD were determined.

Methods

Approval for this study was received from the Institutional Review Board at our institution, Rush University Medical Center in Chicago, Illinois. Seventy-three patients undergoing primary TKA performed by 3 surgeons at 2 institutions between February 2010 and January 2013 were prospectively enrolled. Inclusion criteria were age 18 years to 90 years and primary TKA for unilateral osteoarthritis; exclusion criteria were allergy or intolerance to the study materials, operative treatment of affected joint or its underlying etiology within prior month, previous surgeries (other than arthroscopy) on affected joint, previous surgeries (on unaffected lower extremity) that may influence preoperative and postoperative leg lengths, and any substance abuse or dependence within the past 6 months. Patients provided written informed consent for total knee arthroplasty.

All surgeries were performed by Dr. Levine, Dr. Della Valle, and Dr. Sporer using the medial parapatellar or midvastus approach with tourniquet. Similar standard postoperative rehabilitation protocols with early mobilization were used in all cases.

During clinical evaluation, patient demographic data were collected and LLD surveys administered. Patients were asked, before surgery and 3 to 6 weeks, 3 months, 6 months, and 1 year after surgery, if they perceived LLD. A patient who no longer perceived LLD after surgery was no longer followed for this study.

At the preoperative clinic visit and at the 3-month or 6-week postoperative visit, standing mechanical axis radiographs were viewed by 2 of the authors (not the primary surgeons) using PACS (picture archiving and communication system software). The mechanical axis of the operative leg was measured with ImageJ software by taking the angle from the center of the femur to the middle of the ankle joint, with the vertex assigned to the middle of the knee joint.

We used a 2-tailed unpaired t test to determine the relationship of preoperative mechanical axis to perceived LLD (or lack thereof) before surgery. The data were analyzed for separate varus and valgus deformities. Then we determined the relationship of postoperative mechanical axis to perceived LLD (or lack thereof) after surgery. The McNemar test was used to determine the effect of surgery on patients’ LLD perceptions.

To determine the relationship between preoperative-to-postoperative change in mechanical axis and change in LLD perceptions, we divided patients into 4 groups. Group 1 had both preoperative and postoperative perceived LLD, group 2 had no preoperative or postoperative perceived LLD, group 3 had preoperative perceived LLD but no postoperative perceived LLD, and group 4 had postoperative perceived LLD but no preoperative perceived LLD. The absolute value of the difference between preoperative and postoperative mechanical axis was then determined, relative to 180°, to account for changes in varus to valgus deformity before and after surgery and vice versa. Analysis of variance (ANOVA) was used to detect differences between groups. This analysis was then stratified based on BMI and age.

Results

Of the 73 enrolled patients, 2 were excluded from results analysis because of inadequate data—one did not complete the postoperative LLD survey, and the other did not have postoperative standing mechanical axis radiographs—leaving 71 patients (27 men, 44 women) with adequate data. Mean (SD) age of all patients was 65 (8.4) years (range, 47-89 years). Mean (SD) BMI was 35.1 (9.9; range, 20.2-74.8).

Of the 71 patients with adequate data, 18 had preoperative perceived LLD and 53 did not; in addition, 7 had postoperative perceived LLD and 64 did not. All 7 patients with postoperative perceived LLD noted resolution of LLD, at a mean of 8.5 weeks (range, 3 weeks-3 months). There was a significant difference between the 18 patients with preoperative perceived LLD and the 7 with postoperative perceived LLD (P = .035, analyzed with the McNemar test).

Table 1 lists the mean preoperative mechanical axis measurements for patients with and without preoperative perceived LLD.

Discussion

In this study, 18 patients (25%) had preoperative perceived LLD, proving that perceived LLD is common in patients who undergo TKA for unilateral osteoarthritis. Surgeons should give their patients a preoperative survey on perceived LLD, as survey responses may inform and influence surgical decisions and strategies.

Of the 18 patients with preoperative perceived LLD, only 1 had postoperative perceived LLD. That perceived LLD decreased after surgery makes sense given the widely accepted notion that actual LLD is common before primary TKA but in most cases is corrected during surgery.^4,5 As LLD correction during surgery is so successful, surgeons should tell their patients with preoperative perceived LLD that in most cases it will be fixed after TKA.

Although the incidence of perceived LLD decreased after TKA (as mentioned earlier), the decrease seemed to be restricted mostly to patients with preoperative perceived LLD, and the underlying LLD was most probably corrected by the surgery. However, surgery introduced perceived LLD in 6 cases, supporting the notion that it is crucial to understand which patients are at higher risk for postoperative perceived LLD and what if any time frame can be expected for resolution in these cases. In our study, all cases of perceived LLD had resolved by a mean follow-up of 8.5 weeks (range, 3 weeks-3 months). This phenomenon of resolution may be attributed to some of the physical, objective LLD corrections that naturally occur throughout the postoperative course,⁴ though psychological factors may also be involved. Our study results suggest patients should be counseled that, though about 10% of patients perceive LLD after primary TKA, the vast majority of perceived LLD cases resolve within 3 months.

One study goal was to determine the relationship between the mechanical axis of the knee and perceived LLD both before and after surgery. There were no significant relationships. This was also true when cases of varus and valgus deformity were analyzed separately.

Another study goal was to determine if a surgical change in the mechanical alignment of the knee would influence preoperative-to-postoperative LLD perceptions. In our analysis, patients were divided into 4 groups based on their preoperative and postoperative LLD perceptions (see Methods section). ANOVA revealed no significant differences in absolute values of mechanical axis correction among the 4 groups. Likewise, there were no correlations between BMI and age and mechanical axis correction among the groups, suggesting LLD perception is unrelated to any of these variables. Ideally, if a relationship between a threshold knee alignment value and perceived LLD existed, surgeons would be able to counsel patients at higher risk for perceived LLD about how their knee alignment may contribute to their perception. Unfortunately, our study results did not show any significant statistical relationships in this regard.

The problem of LLD in patients undergoing TKA is not new, and much research is needed to determine the correlation between perceived versus actual discrepancies, and why they occur. Our study results confirmed that TKA corrects most cases of preoperative perceived LLD but introduces perceived LLD in other cases. Whether preoperative or postoperative LLD is merely perceived or is in fact an actual discrepancy remains to be seen.

One limitation of this study was its lack of leg-length measurements. Although we studied knee alignment specifically, it would have been useful to compare perceived LLD with measured leg lengths, either clinically or radiographically, especially since leg lengths obviously play a role in any perceived LLD. We used mechanical alignment as a surrogate for actual LLD because we hypothesized that alignment may contribute to patients’ perceived discrepancies.

Another limitation was the relatively small sample. Only 24 cases of perceived LLD were analyzed. Given our low rates of perceived LLD (25% before surgery, 10% after surgery), it is difficult to study a large enough TKA group to establish a statistically significant number of cases. Nevertheless, investigators may use larger groups to establish more meaningful relationships.

A third limitation was that alignment was measured on the operative side but not the contralateral side. As we were focusing on perceived discrepancy, contralateral knee alignment may play an important role. Our study involved patients with unilateral osteoarthritis, so it would be reasonable to assume the nonoperative knee was almost neutral in alignment in most cases. However, given that varus/valgus misalignment is a known risk factor for osteoarthritis,⁶ many of our patients with unilateral disease may very well have had preexisting misalignment of both knees. The undetermined alignment of the nonoperative side may be a confounding variable in the relationship between operative knee alignment and perceived LLD.

Fourth, not all patients were surveyed 3 weeks after surgery. Some were first surveyed at 6 weeks, and it is possible there were cases of transient postoperative LLD that resolved before that point. Therefore, our reported incidence of postoperative LLD could have missed some cases. In addition, our mean 8.5-week period for LLD resolution may not have accounted for these resolved cases of transient perceived LLD.

Am J Orthop. 2016;45(7):E429-E433. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Leg-length discrepancy (LLD) is common in the general population¹ and particularly in patients with degenerative joint diseases of the hip and knee.² Common complications of LLD include femoral, sciatic, and peroneal nerve palsy; lower back pain; gait abnormalities³; and general dissatisfaction. LLD is a concern for orthopedic surgeons who perform total knee arthroplasty (TKA) because limb lengthening is common after this procedure.^4,5 Surgeons are aware of the limb lengthening that occurs during TKA,^4,5 and studies have confirmed that LLD usually decreases after TKA.^4,5

Despite surgeons’ best efforts, some patients still perceive LLD after surgery, though the incidence of perceived LLD in patients who have had TKA has not been well documented. Aside from actual, objectively measured LLD, there may be other factors that lead patients to perceive LLD. Study results have suggested that preoperative varus–valgus alignment of the knee joint may correlate with how much an operative leg is lengthened after TKA^4,5; however, the outcome investigated was objective LLD measurements, not perceived LLD. Understanding the factors that may influence patients’ ability to perceive LLD would allow surgeons to preoperatively identify patients who are at higher risk for postoperative perceived LLD. This information, along with expected time to resolution of postoperative perceived LLD, would allow surgeons to educate their patients accordingly.

We conducted a study to determine the incidence of perceived LLD before and after primary TKA in patients with unilateral osteoarthritis and to determine the correlation between mechanical axis of the knee and perceived LLD before and after surgery. Given that surgery may correct mechanical axis misalignment, we investigated the correlation between this correction and its ability to change patients’ preoperative and postoperative perceived LLD. We hypothesized that a large correction of mechanical axis would lead patients to perceive LLD after surgery. The relationship of body mass index (BMI) and age to patients’ perceived LLD was also assessed. The incidence and time frame of resolution of postoperative perceived LLD were determined.

Methods

Approval for this study was received from the Institutional Review Board at our institution, Rush University Medical Center in Chicago, Illinois. Seventy-three patients undergoing primary TKA performed by 3 surgeons at 2 institutions between February 2010 and January 2013 were prospectively enrolled. Inclusion criteria were age 18 years to 90 years and primary TKA for unilateral osteoarthritis; exclusion criteria were allergy or intolerance to the study materials, operative treatment of affected joint or its underlying etiology within prior month, previous surgeries (other than arthroscopy) on affected joint, previous surgeries (on unaffected lower extremity) that may influence preoperative and postoperative leg lengths, and any substance abuse or dependence within the past 6 months. Patients provided written informed consent for total knee arthroplasty.

All surgeries were performed by Dr. Levine, Dr. Della Valle, and Dr. Sporer using the medial parapatellar or midvastus approach with tourniquet. Similar standard postoperative rehabilitation protocols with early mobilization were used in all cases.

During clinical evaluation, patient demographic data were collected and LLD surveys administered. Patients were asked, before surgery and 3 to 6 weeks, 3 months, 6 months, and 1 year after surgery, if they perceived LLD. A patient who no longer perceived LLD after surgery was no longer followed for this study.

At the preoperative clinic visit and at the 3-month or 6-week postoperative visit, standing mechanical axis radiographs were viewed by 2 of the authors (not the primary surgeons) using PACS (picture archiving and communication system software). The mechanical axis of the operative leg was measured with ImageJ software by taking the angle from the center of the femur to the middle of the ankle joint, with the vertex assigned to the middle of the knee joint.

We used a 2-tailed unpaired t test to determine the relationship of preoperative mechanical axis to perceived LLD (or lack thereof) before surgery. The data were analyzed for separate varus and valgus deformities. Then we determined the relationship of postoperative mechanical axis to perceived LLD (or lack thereof) after surgery. The McNemar test was used to determine the effect of surgery on patients’ LLD perceptions.

To determine the relationship between preoperative-to-postoperative change in mechanical axis and change in LLD perceptions, we divided patients into 4 groups. Group 1 had both preoperative and postoperative perceived LLD, group 2 had no preoperative or postoperative perceived LLD, group 3 had preoperative perceived LLD but no postoperative perceived LLD, and group 4 had postoperative perceived LLD but no preoperative perceived LLD. The absolute value of the difference between preoperative and postoperative mechanical axis was then determined, relative to 180°, to account for changes in varus to valgus deformity before and after surgery and vice versa. Analysis of variance (ANOVA) was used to detect differences between groups. This analysis was then stratified based on BMI and age.

Results

Of the 73 enrolled patients, 2 were excluded from results analysis because of inadequate data—one did not complete the postoperative LLD survey, and the other did not have postoperative standing mechanical axis radiographs—leaving 71 patients (27 men, 44 women) with adequate data. Mean (SD) age of all patients was 65 (8.4) years (range, 47-89 years). Mean (SD) BMI was 35.1 (9.9; range, 20.2-74.8).

Of the 71 patients with adequate data, 18 had preoperative perceived LLD and 53 did not; in addition, 7 had postoperative perceived LLD and 64 did not. All 7 patients with postoperative perceived LLD noted resolution of LLD, at a mean of 8.5 weeks (range, 3 weeks-3 months). There was a significant difference between the 18 patients with preoperative perceived LLD and the 7 with postoperative perceived LLD (P = .035, analyzed with the McNemar test).

Table 1 lists the mean preoperative mechanical axis measurements for patients with and without preoperative perceived LLD.

Discussion

In this study, 18 patients (25%) had preoperative perceived LLD, proving that perceived LLD is common in patients who undergo TKA for unilateral osteoarthritis. Surgeons should give their patients a preoperative survey on perceived LLD, as survey responses may inform and influence surgical decisions and strategies.

Of the 18 patients with preoperative perceived LLD, only 1 had postoperative perceived LLD. That perceived LLD decreased after surgery makes sense given the widely accepted notion that actual LLD is common before primary TKA but in most cases is corrected during surgery.^4,5 As LLD correction during surgery is so successful, surgeons should tell their patients with preoperative perceived LLD that in most cases it will be fixed after TKA.

Although the incidence of perceived LLD decreased after TKA (as mentioned earlier), the decrease seemed to be restricted mostly to patients with preoperative perceived LLD, and the underlying LLD was most probably corrected by the surgery. However, surgery introduced perceived LLD in 6 cases, supporting the notion that it is crucial to understand which patients are at higher risk for postoperative perceived LLD and what if any time frame can be expected for resolution in these cases. In our study, all cases of perceived LLD had resolved by a mean follow-up of 8.5 weeks (range, 3 weeks-3 months). This phenomenon of resolution may be attributed to some of the physical, objective LLD corrections that naturally occur throughout the postoperative course,⁴ though psychological factors may also be involved. Our study results suggest patients should be counseled that, though about 10% of patients perceive LLD after primary TKA, the vast majority of perceived LLD cases resolve within 3 months.

One study goal was to determine the relationship between the mechanical axis of the knee and perceived LLD both before and after surgery. There were no significant relationships. This was also true when cases of varus and valgus deformity were analyzed separately.

Another study goal was to determine if a surgical change in the mechanical alignment of the knee would influence preoperative-to-postoperative LLD perceptions. In our analysis, patients were divided into 4 groups based on their preoperative and postoperative LLD perceptions (see Methods section). ANOVA revealed no significant differences in absolute values of mechanical axis correction among the 4 groups. Likewise, there were no correlations between BMI and age and mechanical axis correction among the groups, suggesting LLD perception is unrelated to any of these variables. Ideally, if a relationship between a threshold knee alignment value and perceived LLD existed, surgeons would be able to counsel patients at higher risk for perceived LLD about how their knee alignment may contribute to their perception. Unfortunately, our study results did not show any significant statistical relationships in this regard.

The problem of LLD in patients undergoing TKA is not new, and much research is needed to determine the correlation between perceived versus actual discrepancies, and why they occur. Our study results confirmed that TKA corrects most cases of preoperative perceived LLD but introduces perceived LLD in other cases. Whether preoperative or postoperative LLD is merely perceived or is in fact an actual discrepancy remains to be seen.

One limitation of this study was its lack of leg-length measurements. Although we studied knee alignment specifically, it would have been useful to compare perceived LLD with measured leg lengths, either clinically or radiographically, especially since leg lengths obviously play a role in any perceived LLD. We used mechanical alignment as a surrogate for actual LLD because we hypothesized that alignment may contribute to patients’ perceived discrepancies.

Another limitation was the relatively small sample. Only 24 cases of perceived LLD were analyzed. Given our low rates of perceived LLD (25% before surgery, 10% after surgery), it is difficult to study a large enough TKA group to establish a statistically significant number of cases. Nevertheless, investigators may use larger groups to establish more meaningful relationships.

A third limitation was that alignment was measured on the operative side but not the contralateral side. As we were focusing on perceived discrepancy, contralateral knee alignment may play an important role. Our study involved patients with unilateral osteoarthritis, so it would be reasonable to assume the nonoperative knee was almost neutral in alignment in most cases. However, given that varus/valgus misalignment is a known risk factor for osteoarthritis,⁶ many of our patients with unilateral disease may very well have had preexisting misalignment of both knees. The undetermined alignment of the nonoperative side may be a confounding variable in the relationship between operative knee alignment and perceived LLD.

Fourth, not all patients were surveyed 3 weeks after surgery. Some were first surveyed at 6 weeks, and it is possible there were cases of transient postoperative LLD that resolved before that point. Therefore, our reported incidence of postoperative LLD could have missed some cases. In addition, our mean 8.5-week period for LLD resolution may not have accounted for these resolved cases of transient perceived LLD.

Am J Orthop. 2016;45(7):E429-E433. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Leg-length discrepancy (LLD) is common in the general population¹ and particularly in patients with degenerative joint diseases of the hip and knee.² Common complications of LLD include femoral, sciatic, and peroneal nerve palsy; lower back pain; gait abnormalities³; and general dissatisfaction. LLD is a concern for orthopedic surgeons who perform total knee arthroplasty (TKA) because limb lengthening is common after this procedure.^4,5 Surgeons are aware of the limb lengthening that occurs during TKA,^4,5 and studies have confirmed that LLD usually decreases after TKA.^4,5

Despite surgeons’ best efforts, some patients still perceive LLD after surgery, though the incidence of perceived LLD in patients who have had TKA has not been well documented. Aside from actual, objectively measured LLD, there may be other factors that lead patients to perceive LLD. Study results have suggested that preoperative varus–valgus alignment of the knee joint may correlate with how much an operative leg is lengthened after TKA^4,5; however, the outcome investigated was objective LLD measurements, not perceived LLD. Understanding the factors that may influence patients’ ability to perceive LLD would allow surgeons to preoperatively identify patients who are at higher risk for postoperative perceived LLD. This information, along with expected time to resolution of postoperative perceived LLD, would allow surgeons to educate their patients accordingly.

We conducted a study to determine the incidence of perceived LLD before and after primary TKA in patients with unilateral osteoarthritis and to determine the correlation between mechanical axis of the knee and perceived LLD before and after surgery. Given that surgery may correct mechanical axis misalignment, we investigated the correlation between this correction and its ability to change patients’ preoperative and postoperative perceived LLD. We hypothesized that a large correction of mechanical axis would lead patients to perceive LLD after surgery. The relationship of body mass index (BMI) and age to patients’ perceived LLD was also assessed. The incidence and time frame of resolution of postoperative perceived LLD were determined.

Methods

Approval for this study was received from the Institutional Review Board at our institution, Rush University Medical Center in Chicago, Illinois. Seventy-three patients undergoing primary TKA performed by 3 surgeons at 2 institutions between February 2010 and January 2013 were prospectively enrolled. Inclusion criteria were age 18 years to 90 years and primary TKA for unilateral osteoarthritis; exclusion criteria were allergy or intolerance to the study materials, operative treatment of affected joint or its underlying etiology within prior month, previous surgeries (other than arthroscopy) on affected joint, previous surgeries (on unaffected lower extremity) that may influence preoperative and postoperative leg lengths, and any substance abuse or dependence within the past 6 months. Patients provided written informed consent for total knee arthroplasty.

All surgeries were performed by Dr. Levine, Dr. Della Valle, and Dr. Sporer using the medial parapatellar or midvastus approach with tourniquet. Similar standard postoperative rehabilitation protocols with early mobilization were used in all cases.

During clinical evaluation, patient demographic data were collected and LLD surveys administered. Patients were asked, before surgery and 3 to 6 weeks, 3 months, 6 months, and 1 year after surgery, if they perceived LLD. A patient who no longer perceived LLD after surgery was no longer followed for this study.

At the preoperative clinic visit and at the 3-month or 6-week postoperative visit, standing mechanical axis radiographs were viewed by 2 of the authors (not the primary surgeons) using PACS (picture archiving and communication system software). The mechanical axis of the operative leg was measured with ImageJ software by taking the angle from the center of the femur to the middle of the ankle joint, with the vertex assigned to the middle of the knee joint.

We used a 2-tailed unpaired t test to determine the relationship of preoperative mechanical axis to perceived LLD (or lack thereof) before surgery. The data were analyzed for separate varus and valgus deformities. Then we determined the relationship of postoperative mechanical axis to perceived LLD (or lack thereof) after surgery. The McNemar test was used to determine the effect of surgery on patients’ LLD perceptions.

To determine the relationship between preoperative-to-postoperative change in mechanical axis and change in LLD perceptions, we divided patients into 4 groups. Group 1 had both preoperative and postoperative perceived LLD, group 2 had no preoperative or postoperative perceived LLD, group 3 had preoperative perceived LLD but no postoperative perceived LLD, and group 4 had postoperative perceived LLD but no preoperative perceived LLD. The absolute value of the difference between preoperative and postoperative mechanical axis was then determined, relative to 180°, to account for changes in varus to valgus deformity before and after surgery and vice versa. Analysis of variance (ANOVA) was used to detect differences between groups. This analysis was then stratified based on BMI and age.

Results

Of the 73 enrolled patients, 2 were excluded from results analysis because of inadequate data—one did not complete the postoperative LLD survey, and the other did not have postoperative standing mechanical axis radiographs—leaving 71 patients (27 men, 44 women) with adequate data. Mean (SD) age of all patients was 65 (8.4) years (range, 47-89 years). Mean (SD) BMI was 35.1 (9.9; range, 20.2-74.8).

Of the 71 patients with adequate data, 18 had preoperative perceived LLD and 53 did not; in addition, 7 had postoperative perceived LLD and 64 did not. All 7 patients with postoperative perceived LLD noted resolution of LLD, at a mean of 8.5 weeks (range, 3 weeks-3 months). There was a significant difference between the 18 patients with preoperative perceived LLD and the 7 with postoperative perceived LLD (P = .035, analyzed with the McNemar test).

Table 1 lists the mean preoperative mechanical axis measurements for patients with and without preoperative perceived LLD.

Discussion

In this study, 18 patients (25%) had preoperative perceived LLD, proving that perceived LLD is common in patients who undergo TKA for unilateral osteoarthritis. Surgeons should give their patients a preoperative survey on perceived LLD, as survey responses may inform and influence surgical decisions and strategies.

Of the 18 patients with preoperative perceived LLD, only 1 had postoperative perceived LLD. That perceived LLD decreased after surgery makes sense given the widely accepted notion that actual LLD is common before primary TKA but in most cases is corrected during surgery.^4,5 As LLD correction during surgery is so successful, surgeons should tell their patients with preoperative perceived LLD that in most cases it will be fixed after TKA.

Although the incidence of perceived LLD decreased after TKA (as mentioned earlier), the decrease seemed to be restricted mostly to patients with preoperative perceived LLD, and the underlying LLD was most probably corrected by the surgery. However, surgery introduced perceived LLD in 6 cases, supporting the notion that it is crucial to understand which patients are at higher risk for postoperative perceived LLD and what if any time frame can be expected for resolution in these cases. In our study, all cases of perceived LLD had resolved by a mean follow-up of 8.5 weeks (range, 3 weeks-3 months). This phenomenon of resolution may be attributed to some of the physical, objective LLD corrections that naturally occur throughout the postoperative course,⁴ though psychological factors may also be involved. Our study results suggest patients should be counseled that, though about 10% of patients perceive LLD after primary TKA, the vast majority of perceived LLD cases resolve within 3 months.

One study goal was to determine the relationship between the mechanical axis of the knee and perceived LLD both before and after surgery. There were no significant relationships. This was also true when cases of varus and valgus deformity were analyzed separately.

Another study goal was to determine if a surgical change in the mechanical alignment of the knee would influence preoperative-to-postoperative LLD perceptions. In our analysis, patients were divided into 4 groups based on their preoperative and postoperative LLD perceptions (see Methods section). ANOVA revealed no significant differences in absolute values of mechanical axis correction among the 4 groups. Likewise, there were no correlations between BMI and age and mechanical axis correction among the groups, suggesting LLD perception is unrelated to any of these variables. Ideally, if a relationship between a threshold knee alignment value and perceived LLD existed, surgeons would be able to counsel patients at higher risk for perceived LLD about how their knee alignment may contribute to their perception. Unfortunately, our study results did not show any significant statistical relationships in this regard.

The problem of LLD in patients undergoing TKA is not new, and much research is needed to determine the correlation between perceived versus actual discrepancies, and why they occur. Our study results confirmed that TKA corrects most cases of preoperative perceived LLD but introduces perceived LLD in other cases. Whether preoperative or postoperative LLD is merely perceived or is in fact an actual discrepancy remains to be seen.

One limitation of this study was its lack of leg-length measurements. Although we studied knee alignment specifically, it would have been useful to compare perceived LLD with measured leg lengths, either clinically or radiographically, especially since leg lengths obviously play a role in any perceived LLD. We used mechanical alignment as a surrogate for actual LLD because we hypothesized that alignment may contribute to patients’ perceived discrepancies.

Another limitation was the relatively small sample. Only 24 cases of perceived LLD were analyzed. Given our low rates of perceived LLD (25% before surgery, 10% after surgery), it is difficult to study a large enough TKA group to establish a statistically significant number of cases. Nevertheless, investigators may use larger groups to establish more meaningful relationships.

A third limitation was that alignment was measured on the operative side but not the contralateral side. As we were focusing on perceived discrepancy, contralateral knee alignment may play an important role. Our study involved patients with unilateral osteoarthritis, so it would be reasonable to assume the nonoperative knee was almost neutral in alignment in most cases. However, given that varus/valgus misalignment is a known risk factor for osteoarthritis,⁶ many of our patients with unilateral disease may very well have had preexisting misalignment of both knees. The undetermined alignment of the nonoperative side may be a confounding variable in the relationship between operative knee alignment and perceived LLD.

Fourth, not all patients were surveyed 3 weeks after surgery. Some were first surveyed at 6 weeks, and it is possible there were cases of transient postoperative LLD that resolved before that point. Therefore, our reported incidence of postoperative LLD could have missed some cases. In addition, our mean 8.5-week period for LLD resolution may not have accounted for these resolved cases of transient perceived LLD.

Am J Orthop. 2016;45(7):E429-E433. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Over the past decade, nationwide attention has focused on mental health conditions associated with military service. Recent legal mandates have led to changes in the DoD, VA, and HHS health systems aimed at increasing access to care, decreasing barriers to care, and expanding research on mental health conditions commonly seen in service members and veterans. On August 31, 2012, President Barack Obama signed the Improving Access to Mental Health Services for Veterans, Service Members, and Military Families executive order, establishing an interagency task force from the VA, DoD, and HHS.¹ The task force was charged with addressing quality of care and provider training in the management of commonly comorbid conditions, including (among other conditions) posttraumatic stress disorder (PTSD) and depression.

Depression and PTSD present major health burdens in both military and veteran cohorts. Overlap in clinical presentation and significant rates of comorbidity complicate effective management of these conditions. This article offers a brief review of the diagnostic and epidemiologic complexities associated with PTSD and depression, a summary of research relevant to these issues, and a description of recent system-level developments within the Military Health System (MHS) designed to improve care through better approaches in identification, management, and research of these conditions.

Diagnostic Uncertainty

Both PTSD and major depressive disorder (MDD) have been recognized as mental health disorders since the American Psychiatric Association’s Diagnostic and Statistical Manual (DSM) discarded its previous etiologically based approach to diagnostic classification in 1980 in favor of a system in which diagnosis is based on observable symptoms.^2,3 With the release of DSM-5 in 2013, the diagnostic criteria for PTSD underwent a substantial transformation.⁴ Previously, PTSD was described as an anxiety disorder, and some of its manifestations overlapped descriptively (and in many cases, etiologically) with anxiety and depressive illnesses.⁵

Clinicians also often described shorter-lived, developmental, formes fruste, or otherwise subsyndromal manifestations of trauma associated with PTSD. In DSM-5, PTSD was removed from the anxiety disorders section and placed in a new category of disorders labeled Trauma and Stressor-Related Disorders. This new category also included reactive attachment disorder (in children), acute stress disorder, adjustment disorders, and unspecified or other trauma and stressor-related disorders. Other major changes to the PTSD diagnostic criteria included modification to the DSM-IV-TR (text revision) trauma definition (making the construct more specific), removal of the requirement for explicit subjective emotional reaction to a traumatic event, and greater emphasis on negative cognitions and mood. Debate surrounds the updated symptom criteria with critics questioning whether there is any improvement in the clinical utility of the diagnosis, especially in light of the substantial policy and practice implications the change engenders.⁶

Recently, Hoge and colleagues examined the psychometric implications of the diagnostic changes (between DSM-IV-TR and DSM-5) in the PTSD definition.⁶ The authors found that although the 2 definitions showed nearly identical association with other psychiatric disorders (including depression) and functional impairment, 30% of soldiers who met DSM-IV-TR criteria for PTSD failed to meet criteria in DSM-5, and another 20% met only DSM-5 criteria. Recognizing discordance in PTSD and associated diagnoses, the U.S. Army Medical Command mandated that its clinicians familiarize themselves with the controversies surrounding the discordant diagnoses and coding of subthreshold PTSD.⁷

Adding to the problem of diagnostic uncertainty, the clinical presentation of MDD includes significant overlap with that of PTSD. Specifically, symptoms of guilt, diminished interests, problems with concentration, and sleep disturbances are descriptive of both disorders. Furthermore, the criteria set for several subthreshold forms of MDD evidence considerable overlap with PTSD symptoms. For example, diagnostic criteria for disruptive mood dysregulation disorder include behavioral outbursts and irritability, and diagnostic criteria for dysthymia include sleep disturbances and concentration problems.

Adjustment disorders are categorized as trauma and stressor-related disorders in DSM-5 and hold many emotional and behavioral symptoms in common with PTSD. The “acute” and “chronic” adjustment disorder specifiers contribute to problems in diagnostic certainty for PTSD. In general, issues pertaining to diagnostic uncertainty and overlap likely reflect the limits of using a diagnostic classification system that relies exclusively on observational and subjective reports of psychological symptoms.^8,9

In a treatment environment where a veteran or active-duty patient has presented for care, in the face of these shared symptom sets, clinicians frequently offer initial diagnoses. These diagnoses are often based on perceived etiologic factors derived from patients’ descriptions of stressors encountered during military service. This tendency likely contributes to considerable inconsistencies and potential inaccuracies in diagnoses, and much of the variance can be attributed to the clinicians’ degree of familiarity with military exposures, perceptions of what constitutes trauma, and outside pressure to assign or avoid specific diagnoses.

Importantly, the phenomenologic differences between PTSD and depressive disorders increase the likelihood of poorly aligned and inconsistent treatment plans, and this lack of clarity may, in turn, compromise effective patient care. To address some of these diagnostic challenges, the VA and DoD incorporate military culture training into clinicians’ curriculum to increase provider familiarity with the common stressors and challenges of military life, mandate the use of validated measures to support diagnostic decision making, and regularly review policies that influence diagnostic practices.

Epidemiology

The prevalence rates for PTSD are increasing in the military, possibly stemming from the demands on service members engaged in years’ long wars. Despite the increased attention on this phenomenon, research has demonstrated that the majority of service members who deploy do not develop PTSD or significant trauma-related functional impairment.¹⁰ Furthermore, many cases of PTSD diagnosed in the MHS stem from traumatic experiences other than combat exposure, including childhood abuse and neglect, sexual and other assaults, accidents and health care exposures, domestic abuse, and bullying. Depression arguably has received less attention despite comparable prevalence rates in military populations, high co-occurrence of PTSD and depression, and depression being associated with a greater odds ratio for mortality that includes death by suicide in military service members.¹¹

Estimates of the prevalence of PTSD from the U.S. Army suggest that it exists in 3% to 6% of military members who have not deployed and in 6% to 25% of service members with combat deployment histories. The frequency and intensity of combat are strong predictors of risk.⁷ A recent epidemiologic study using inpatient and outpatient encounter records showed that the prevalence of PTSD in the active military component was 2.0% in the middle of calendar year (CY) 2010; a two-thirds increase from 1.2% in CY 2007.¹² The incidence of PTSD

Epidemiologic studies and prevalence/incidence rates derived from administrative data rely on strict case definitions. Consequently, such administrative investigations include data only from service members

PTSD and Depression Treatment

Despite the high rates of PTSD and MDD comorbidity, few treatments have been developed for and tested on an exclusively comorbid sample of patients.¹³ However, psychopharmacologic agents targeting depression have been applied to the treatment of PTSD, and PTSD psychotherapy trials typically include depression response as a secondary outcome. The generalizability of findings to a truly comorbid population may be limited based on study sampling frames and the unique characteristics of patients with comorbid PTSD and depression.^14-16 Several psychopharmacologic treatments for depression have been evaluated as frontline treatments for PTSD. The 3 pharmacologic treatments that demonstrate efficacy in treating PTSD include fluoxetine, paroxetine, and venlafaxine.¹⁷

Although these pharmacologic agents represent good candidate treatments for comorbid patients, the effect size of pharmacologic treatments are generally smaller than those of psychotherapeutic treatments for PTSD.^17,18 This observation, however, is based on indirect comparisons, and a recent systematic review concluded that the evidence was insufficient to determine the comparative effectiveness between psychotherapy and pharmacotherapy for PTSD.¹⁹ Evidence indicates that trauma-focused cognitive behavioral therapies consistently demonstrate efficacy and effectiveness in treating PTSD.^19,20 These treatments also have been shown to significantly reduce depressive symptoms among PTSD samples.²¹

Based on strong bodies of evidence, these pharmacologic and psychological treatments have received the highest level of recommendation in the VA and DoD.^22,23 Accordingly, both agencies have invested considerable resources in large-scale efforts to improve patient access to these particular treatments. Despite these impressive implementation efforts, however, the limitations of relying exclusively on these treatments as frontline approaches within large health care systems have become evident.^24-26

Penetration of Therapies

Penetration of these evidence-based treatments (EBTs) within the DoD and VHA remains limited. For instance, one study showed that VA clinicians in mental health specialty care clinics may provide only about 4 hours of EBT per week.²⁷

Other reports suggest that only about 60% of treatment-seeking patients in PTSD clinics receive any type of evidence-based therapy and that within-session care quality is questionable based on a systematic review of chart notes.^28,29 Attrition in trauma-focused therapy is a recognized limitation, with 1 out of 3 treatment-seeking patients not completing a full dose of evidence-based treatment.^30-33 Large-scale analyses of VHA and DoD utilization data suggest that the majority of PTSD patients do not receive a sufficient number of sessions to be characterized as an adequate dose of EBT, with a majority of dropouts occur- ring after just a few sessions.^34-37

Hoge and colleagues found that < 50% of soldiers meeting criteria for PTSD received any mental health care within the prior 6 months with one-quarter of those patients dropping out of care prematurely.³⁸ Among a large cohort of soldiers engaged in care for the treatment of PTSD, only about 40% received a number of EBT treatment sessions that could qualify as an adequate dose.³⁸ Thus, although major advancements in the development and implementation of effective treatments for PTSD and depression have occurred, the penetration of these treatments is limited, and the majority of patients in need of treatment potentially receive inadequate care.³⁹

System level approaches that integrate behavioral health services into the primary care system have been proposed to address these care gaps for service members and veterans.^40-42 Fundamentally, system-level approaches seek to improve the reach and effectiveness of care through large-scale screening efforts, a greater emphasis on the quality of patient care, and enhanced care continuity across episodes of treatment.

Primary Care

With the primary care setting considered the de facto mental health system, integrated approaches enhance the reach of care by incorporating uniform mental health screening and referral for patients coming through primary care. Specific evidence-based treatments can be integrated into this approach within a stepped-care framework that aims to match patients strategically to the right type of care and leverage specialty care resources as needed. Integrated care approaches for the treatment of PTSD and depression have been developed and evaluated inside and outside of the MHS. Findings indicate that integrated treatment approaches can improve care access, care continuity, patient satisfaction, quality of care,and in several trials, PTSD and depression outcomes.^43-47

Recently, an integrated care approach targeting U.S. Army soldiers who screened positive for PTSD or depression in primary care was evaluated in a multisite effectiveness trial.⁴⁸ Patients randomized to the treatment approach experienced significant improvements in both PTSD and depression symptoms relative to patients in usual care.⁴³ In addition, patients treated in this care model received significantly more mental health services; the patterns of care indicated that patients with comorbid PTSD and depression were more likely to be triaged to specialty care, whereas patients with a single diagnosis were more likely to be managed in primary care.⁴⁹ This trial suggests that integrated care models feasibly can be implemented in the U.S. Army care system, yielding increased uptake of mental health care, more efficiently matched care based on patient comorbidities, and improved PTSD and depression outcomes.

Treatment Research

The MHS supports a large portfolio of research in PTSD and depression through DoD/VA research consortia (eg, the Congressionally Directed Medical Research Program, the Consortium to Alleviate PTSD, the Injury and Traumatic Stress Clinical Consortium). The U.S. Army Medical Research and Materiel Command (USAMRMC) executes and manages the portfolio of research, relying on a joint program committee of DoD and non-DoD experts to make funding recommendations based on identified research priorities, policy guidance, and knowledge translation needs.

Health systems research on PTSD and MDD in federal health care settings is expanding. For example, the RAND Corporation recently evaluated a candidate set of quality measures for PTSD and MDD, using an operational definition of an episode of care.³⁷ This work is intended to inform efforts to measure and improve the quality of care for PTSD and depression across the enterprise.

The DoD Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury is simultaneously completing an inferential assessment of adjunctive mental health care services, many focused on PTSD and depression, throughout the health care enterprise. Along with the substantial resources devoted to research on PTSD and depression, the MHS is implementing strategies to improve the system of care for service members with mental health conditions.

Army Care System Innovations

The U.S. Army is engaged in a variety of strategies to improve the identification of patients with mental health conditions, increase access to mental health services, and enhance the quality of care that soldiers receive for PTSD and depression. To improve the coordination of mental health care, the U.S. Army Medical Command implemented a wide-scale innovative transformation of its mental health care system through the establishment of the Behavioral Health Service Line program management office.

This move eliminated separate departments of psychiatry, psychology, and social work in favor of integrated behavioral health departments that are now responsible for all mental health care delivered to soldiers, including inpatient, outpatient, partial hospitalization, residential, embedded care in garrison, and primary care settings. This transformation ensured coordination of care for soldiers, eliminating potential miscommunication with patients, commands, and other clinicians while clearly defining performance indicators in process (eg, productivity, scheduling, access to care, and patient satisfaction) and outcome measures.⁴⁹ In conjunction with the development of its service line, the U.S. Army created a Behavioral Health Data Portal (BHDP), an electronic and standardized means to assess clinical outcomes for common conditions.

To promote higher quality mental health care, the Office of the Surgeon General of the U.S. Army provided direct guidance on the treatment of PTSD and depression. U.S. Army policy mandates that providers treating mental health conditions adhere to the VA/DoD clinical practice guidelines (CPGs) and that soldiers with PTSD and depression be offered treatments with the highest level of scientific support and that outcome measures be routinely administered. In line with the CPGs, U.S. Army policy also recommends the use of both integrated and embedded mental health care approaches to address PTSD, depression, and other common physical and psychological health conditions.

To reduce stigma and improve mental health care access, the U.S. Army began implementing integrated care approaches in 2007 with its Re-Engineering Systems of Primary Care Treatment in the Military (RESPECT-Mil) program, an evidence-based collaborative care model.^51-55 This approach included structured screening and diagnostic procedures, predictable follow-up schedules for patients, and the coordination of the divisions of responsibility among and between primary care providers, paraprofessionals, and behavioral health care providers. From 2007 to 2013, this collaborative care model was rolled out across 96 clinics worldwide and provided PTSD and depression screening to more than 1 million encounters per year.^52,53

More recently, the U.S. Army led DoD in integrating behavioral health personnel in patient centered medical homes (PCMH) in compliance with DoD Instruction 6490.15.⁵⁶ This hybrid integrated care model combines collaborative care elements developed in the RESPECT-Mil program with elements of the U.S. Air Force Behavioral Health Optimization project colocating behavioral health providers in primary care settings to provide brief consultative services.

MHS Care Enhancements

Many of the innovations deployed throughout the U.S. Army system of behavioral health care have driven changes across the MHS as a whole. The DoD and the VA have made substantive systemwide policy and practice changes to improve care for beneficiaries with PTSD, depression, and comorbid PTSD and depression. In particular, significant implementation efforts have addressed population screening strategies, outcome monitoring to support measurement-based care, increased access to effective care, and revision of the disability evaluation system.

To improve the identification and referral of soldiers with deployment-related mental health concerns, the DoD implemented a comprehensive program that screens service members prior to deployment, immediately on redeployment, and then again 6 months after returning from deployment. Additionally, annual primary care- based screening requirements have been instituted as part of the DoD PCMH initiative. Both deployment-related and primary care-based screenings include an instrumentation to detect symptoms of PTSD and depression and extend the reach of mental health screening to the entire MHS population.

Building on the success of BHDP, former Assistant Secretary of Defense for Health Affairs Jonathan Woodson mandated BHDP use across the MHS for all patients in DoD behavioral health clinics and the use of outcome measures for the treatment of PTSD, anxiety, depression, and alcohol use disorders.⁵⁷ A DoD-wide requirement to use the PTSD checklist and patient health questionnaire to monitor PTSD and depression symptoms at mental health intakes and regularly at follow-up visits is being implemented. The Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury, through its Practice-Based Implementation Network (underwritten by a Joint Incentive Fund managed between DoD and VA), has worked across the MHS and the VA to facilitate the implementation, uptake, and adoption of this initiative.

The DoD established the Center for Deployment Psychology (CDP) in 2006 to promote clinician training in EBTs with the aim of increasing service members’ access to effective psychological treatments. Since its inception, the CDP has provided EBT training to more than 40,000 behavioral health providers. Although the impact of these and other efforts on improving the quality of care that patients receive is unknown, a recent study documented widespread self-reported usage of EBT components in U.S. Army clinics and that providers formally trained in EBTs were more likely to deliver EBTs.⁵⁸

Finally, systemwide changes to the VA Schedule of Ratings for Disability (VASRD) and integration of DoD and VA disability evaluation systems have led to shifts in diagnosis toward PTSD that usually merit a minimum 50% disability rating. Mandates in law require military clinicians to evaluate patients who have deployed for PTSD and TBI prior to taking any actions associated with administrative separation. The practice of attributing PTSD symptoms to character pathology or personality disorders, even when these symptoms did not clearly manifest or worsen with military service, has likely been eliminated from practice in military and veteran populations.

Robust policy changes to limit personality disorder discharges started in fiscal year 2007, when there were 4,127 personality disorder separations across DoD. This number was reduced to 300 within 5 years. Policy changes regarding separation not only seem to have affected discharges, but also may have shaped diagnostic practice. The incidence rate of personality disorder diagnoses declined from 513 per 100,000 person-years in 2007 to 284 per 100,000 person-years by 2011.⁵⁹ The VASRD recognizes chronic adjustment disorder as a disability, and the National Defense Authorization Act of 2008 mandated that DoD follow disability guidelines promulgated by VA.

As stated in the memorandum Clinical Policy Guidance for Assessment and Treatment of Post-Traumatic Stress Disorders (August 24, 2012), DoD recognizes chronic adjustment disorder as an unfitting condition that merits referral to its disability evaluation system.⁶⁰ Acute adjustment disorders may still lead to administrative separations, as many service members manifest emotional symptoms stemming from the failure to adjust to the routine vicissitudes of military life. Finally, many court jurisdictions, including veteran’s courts, military courts, and commanders empowered to adjudicate nonjudicial infractions under the Uniform Code of Military Justice, have recognized PTSD as grounds for the mitigation of penalties associated with a wide array of criminal and administrative infractions.

Conclusion

In response to the increased mental health burden following a decade of war and the associated pressures stemming from federal mandates, the MHS has invested unprecedented resources into improving care for military service members. The U.S. Army has played a prominent role in this endeavor by investing in clinical research efforts to accelerate discovery on the causes and cures for these conditions, enacting policies that mandate best practices, and implementing evidence-based care approaches across the system of care. Despite this progress, however, understanding and effectively treating the most prevalent mental health conditions remain a challenge across the DoD and VHA health care systems. Many service members and veterans still do not receive timely, high-quality care for PTSD, depression, and other common comorbidities associated with military experience, and controversies in diagnostic clarification abound.

In short, great strides have been made, yet there is still a large distance to go. The vision of an effective, efficient, comprehensive care system for mental health conditions will continue to be pursued and achieved through collaborations across key agencies and the scientific community, implementation of health system approaches that support population care, and the sustained efforts of dedicated clinicians, staff, and clinic leaders who deliver the care to our service members and veterans.

Over the past decade, nationwide attention has focused on mental health conditions associated with military service. Recent legal mandates have led to changes in the DoD, VA, and HHS health systems aimed at increasing access to care, decreasing barriers to care, and expanding research on mental health conditions commonly seen in service members and veterans. On August 31, 2012, President Barack Obama signed the Improving Access to Mental Health Services for Veterans, Service Members, and Military Families executive order, establishing an interagency task force from the VA, DoD, and HHS.¹ The task force was charged with addressing quality of care and provider training in the management of commonly comorbid conditions, including (among other conditions) posttraumatic stress disorder (PTSD) and depression.

Depression and PTSD present major health burdens in both military and veteran cohorts. Overlap in clinical presentation and significant rates of comorbidity complicate effective management of these conditions. This article offers a brief review of the diagnostic and epidemiologic complexities associated with PTSD and depression, a summary of research relevant to these issues, and a description of recent system-level developments within the Military Health System (MHS) designed to improve care through better approaches in identification, management, and research of these conditions.

Diagnostic Uncertainty

Both PTSD and major depressive disorder (MDD) have been recognized as mental health disorders since the American Psychiatric Association’s Diagnostic and Statistical Manual (DSM) discarded its previous etiologically based approach to diagnostic classification in 1980 in favor of a system in which diagnosis is based on observable symptoms.^2,3 With the release of DSM-5 in 2013, the diagnostic criteria for PTSD underwent a substantial transformation.⁴ Previously, PTSD was described as an anxiety disorder, and some of its manifestations overlapped descriptively (and in many cases, etiologically) with anxiety and depressive illnesses.⁵

Clinicians also often described shorter-lived, developmental, formes fruste, or otherwise subsyndromal manifestations of trauma associated with PTSD. In DSM-5, PTSD was removed from the anxiety disorders section and placed in a new category of disorders labeled Trauma and Stressor-Related Disorders. This new category also included reactive attachment disorder (in children), acute stress disorder, adjustment disorders, and unspecified or other trauma and stressor-related disorders. Other major changes to the PTSD diagnostic criteria included modification to the DSM-IV-TR (text revision) trauma definition (making the construct more specific), removal of the requirement for explicit subjective emotional reaction to a traumatic event, and greater emphasis on negative cognitions and mood. Debate surrounds the updated symptom criteria with critics questioning whether there is any improvement in the clinical utility of the diagnosis, especially in light of the substantial policy and practice implications the change engenders.⁶

Recently, Hoge and colleagues examined the psychometric implications of the diagnostic changes (between DSM-IV-TR and DSM-5) in the PTSD definition.⁶ The authors found that although the 2 definitions showed nearly identical association with other psychiatric disorders (including depression) and functional impairment, 30% of soldiers who met DSM-IV-TR criteria for PTSD failed to meet criteria in DSM-5, and another 20% met only DSM-5 criteria. Recognizing discordance in PTSD and associated diagnoses, the U.S. Army Medical Command mandated that its clinicians familiarize themselves with the controversies surrounding the discordant diagnoses and coding of subthreshold PTSD.⁷

Adding to the problem of diagnostic uncertainty, the clinical presentation of MDD includes significant overlap with that of PTSD. Specifically, symptoms of guilt, diminished interests, problems with concentration, and sleep disturbances are descriptive of both disorders. Furthermore, the criteria set for several subthreshold forms of MDD evidence considerable overlap with PTSD symptoms. For example, diagnostic criteria for disruptive mood dysregulation disorder include behavioral outbursts and irritability, and diagnostic criteria for dysthymia include sleep disturbances and concentration problems.

Adjustment disorders are categorized as trauma and stressor-related disorders in DSM-5 and hold many emotional and behavioral symptoms in common with PTSD. The “acute” and “chronic” adjustment disorder specifiers contribute to problems in diagnostic certainty for PTSD. In general, issues pertaining to diagnostic uncertainty and overlap likely reflect the limits of using a diagnostic classification system that relies exclusively on observational and subjective reports of psychological symptoms.^8,9

In a treatment environment where a veteran or active-duty patient has presented for care, in the face of these shared symptom sets, clinicians frequently offer initial diagnoses. These diagnoses are often based on perceived etiologic factors derived from patients’ descriptions of stressors encountered during military service. This tendency likely contributes to considerable inconsistencies and potential inaccuracies in diagnoses, and much of the variance can be attributed to the clinicians’ degree of familiarity with military exposures, perceptions of what constitutes trauma, and outside pressure to assign or avoid specific diagnoses.

Importantly, the phenomenologic differences between PTSD and depressive disorders increase the likelihood of poorly aligned and inconsistent treatment plans, and this lack of clarity may, in turn, compromise effective patient care. To address some of these diagnostic challenges, the VA and DoD incorporate military culture training into clinicians’ curriculum to increase provider familiarity with the common stressors and challenges of military life, mandate the use of validated measures to support diagnostic decision making, and regularly review policies that influence diagnostic practices.

Epidemiology

The prevalence rates for PTSD are increasing in the military, possibly stemming from the demands on service members engaged in years’ long wars. Despite the increased attention on this phenomenon, research has demonstrated that the majority of service members who deploy do not develop PTSD or significant trauma-related functional impairment.¹⁰ Furthermore, many cases of PTSD diagnosed in the MHS stem from traumatic experiences other than combat exposure, including childhood abuse and neglect, sexual and other assaults, accidents and health care exposures, domestic abuse, and bullying. Depression arguably has received less attention despite comparable prevalence rates in military populations, high co-occurrence of PTSD and depression, and depression being associated with a greater odds ratio for mortality that includes death by suicide in military service members.¹¹

Estimates of the prevalence of PTSD from the U.S. Army suggest that it exists in 3% to 6% of military members who have not deployed and in 6% to 25% of service members with combat deployment histories. The frequency and intensity of combat are strong predictors of risk.⁷ A recent epidemiologic study using inpatient and outpatient encounter records showed that the prevalence of PTSD in the active military component was 2.0% in the middle of calendar year (CY) 2010; a two-thirds increase from 1.2% in CY 2007.¹² The incidence of PTSD

Epidemiologic studies and prevalence/incidence rates derived from administrative data rely on strict case definitions. Consequently, such administrative investigations include data only from service members

PTSD and Depression Treatment

Despite the high rates of PTSD and MDD comorbidity, few treatments have been developed for and tested on an exclusively comorbid sample of patients.¹³ However, psychopharmacologic agents targeting depression have been applied to the treatment of PTSD, and PTSD psychotherapy trials typically include depression response as a secondary outcome. The generalizability of findings to a truly comorbid population may be limited based on study sampling frames and the unique characteristics of patients with comorbid PTSD and depression.^14-16 Several psychopharmacologic treatments for depression have been evaluated as frontline treatments for PTSD. The 3 pharmacologic treatments that demonstrate efficacy in treating PTSD include fluoxetine, paroxetine, and venlafaxine.¹⁷

Although these pharmacologic agents represent good candidate treatments for comorbid patients, the effect size of pharmacologic treatments are generally smaller than those of psychotherapeutic treatments for PTSD.^17,18 This observation, however, is based on indirect comparisons, and a recent systematic review concluded that the evidence was insufficient to determine the comparative effectiveness between psychotherapy and pharmacotherapy for PTSD.¹⁹ Evidence indicates that trauma-focused cognitive behavioral therapies consistently demonstrate efficacy and effectiveness in treating PTSD.^19,20 These treatments also have been shown to significantly reduce depressive symptoms among PTSD samples.²¹

Based on strong bodies of evidence, these pharmacologic and psychological treatments have received the highest level of recommendation in the VA and DoD.^22,23 Accordingly, both agencies have invested considerable resources in large-scale efforts to improve patient access to these particular treatments. Despite these impressive implementation efforts, however, the limitations of relying exclusively on these treatments as frontline approaches within large health care systems have become evident.^24-26

Penetration of Therapies

Penetration of these evidence-based treatments (EBTs) within the DoD and VHA remains limited. For instance, one study showed that VA clinicians in mental health specialty care clinics may provide only about 4 hours of EBT per week.²⁷

Other reports suggest that only about 60% of treatment-seeking patients in PTSD clinics receive any type of evidence-based therapy and that within-session care quality is questionable based on a systematic review of chart notes.^28,29 Attrition in trauma-focused therapy is a recognized limitation, with 1 out of 3 treatment-seeking patients not completing a full dose of evidence-based treatment.^30-33 Large-scale analyses of VHA and DoD utilization data suggest that the majority of PTSD patients do not receive a sufficient number of sessions to be characterized as an adequate dose of EBT, with a majority of dropouts occur- ring after just a few sessions.^34-37

Hoge and colleagues found that < 50% of soldiers meeting criteria for PTSD received any mental health care within the prior 6 months with one-quarter of those patients dropping out of care prematurely.³⁸ Among a large cohort of soldiers engaged in care for the treatment of PTSD, only about 40% received a number of EBT treatment sessions that could qualify as an adequate dose.³⁸ Thus, although major advancements in the development and implementation of effective treatments for PTSD and depression have occurred, the penetration of these treatments is limited, and the majority of patients in need of treatment potentially receive inadequate care.³⁹

System level approaches that integrate behavioral health services into the primary care system have been proposed to address these care gaps for service members and veterans.^40-42 Fundamentally, system-level approaches seek to improve the reach and effectiveness of care through large-scale screening efforts, a greater emphasis on the quality of patient care, and enhanced care continuity across episodes of treatment.

Primary Care

With the primary care setting considered the de facto mental health system, integrated approaches enhance the reach of care by incorporating uniform mental health screening and referral for patients coming through primary care. Specific evidence-based treatments can be integrated into this approach within a stepped-care framework that aims to match patients strategically to the right type of care and leverage specialty care resources as needed. Integrated care approaches for the treatment of PTSD and depression have been developed and evaluated inside and outside of the MHS. Findings indicate that integrated treatment approaches can improve care access, care continuity, patient satisfaction, quality of care,and in several trials, PTSD and depression outcomes.^43-47

Recently, an integrated care approach targeting U.S. Army soldiers who screened positive for PTSD or depression in primary care was evaluated in a multisite effectiveness trial.⁴⁸ Patients randomized to the treatment approach experienced significant improvements in both PTSD and depression symptoms relative to patients in usual care.⁴³ In addition, patients treated in this care model received significantly more mental health services; the patterns of care indicated that patients with comorbid PTSD and depression were more likely to be triaged to specialty care, whereas patients with a single diagnosis were more likely to be managed in primary care.⁴⁹ This trial suggests that integrated care models feasibly can be implemented in the U.S. Army care system, yielding increased uptake of mental health care, more efficiently matched care based on patient comorbidities, and improved PTSD and depression outcomes.

Treatment Research

The MHS supports a large portfolio of research in PTSD and depression through DoD/VA research consortia (eg, the Congressionally Directed Medical Research Program, the Consortium to Alleviate PTSD, the Injury and Traumatic Stress Clinical Consortium). The U.S. Army Medical Research and Materiel Command (USAMRMC) executes and manages the portfolio of research, relying on a joint program committee of DoD and non-DoD experts to make funding recommendations based on identified research priorities, policy guidance, and knowledge translation needs.

Health systems research on PTSD and MDD in federal health care settings is expanding. For example, the RAND Corporation recently evaluated a candidate set of quality measures for PTSD and MDD, using an operational definition of an episode of care.³⁷ This work is intended to inform efforts to measure and improve the quality of care for PTSD and depression across the enterprise.

The DoD Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury is simultaneously completing an inferential assessment of adjunctive mental health care services, many focused on PTSD and depression, throughout the health care enterprise. Along with the substantial resources devoted to research on PTSD and depression, the MHS is implementing strategies to improve the system of care for service members with mental health conditions.

Army Care System Innovations

The U.S. Army is engaged in a variety of strategies to improve the identification of patients with mental health conditions, increase access to mental health services, and enhance the quality of care that soldiers receive for PTSD and depression. To improve the coordination of mental health care, the U.S. Army Medical Command implemented a wide-scale innovative transformation of its mental health care system through the establishment of the Behavioral Health Service Line program management office.

This move eliminated separate departments of psychiatry, psychology, and social work in favor of integrated behavioral health departments that are now responsible for all mental health care delivered to soldiers, including inpatient, outpatient, partial hospitalization, residential, embedded care in garrison, and primary care settings. This transformation ensured coordination of care for soldiers, eliminating potential miscommunication with patients, commands, and other clinicians while clearly defining performance indicators in process (eg, productivity, scheduling, access to care, and patient satisfaction) and outcome measures.⁴⁹ In conjunction with the development of its service line, the U.S. Army created a Behavioral Health Data Portal (BHDP), an electronic and standardized means to assess clinical outcomes for common conditions.

To promote higher quality mental health care, the Office of the Surgeon General of the U.S. Army provided direct guidance on the treatment of PTSD and depression. U.S. Army policy mandates that providers treating mental health conditions adhere to the VA/DoD clinical practice guidelines (CPGs) and that soldiers with PTSD and depression be offered treatments with the highest level of scientific support and that outcome measures be routinely administered. In line with the CPGs, U.S. Army policy also recommends the use of both integrated and embedded mental health care approaches to address PTSD, depression, and other common physical and psychological health conditions.

To reduce stigma and improve mental health care access, the U.S. Army began implementing integrated care approaches in 2007 with its Re-Engineering Systems of Primary Care Treatment in the Military (RESPECT-Mil) program, an evidence-based collaborative care model.^51-55 This approach included structured screening and diagnostic procedures, predictable follow-up schedules for patients, and the coordination of the divisions of responsibility among and between primary care providers, paraprofessionals, and behavioral health care providers. From 2007 to 2013, this collaborative care model was rolled out across 96 clinics worldwide and provided PTSD and depression screening to more than 1 million encounters per year.^52,53

More recently, the U.S. Army led DoD in integrating behavioral health personnel in patient centered medical homes (PCMH) in compliance with DoD Instruction 6490.15.⁵⁶ This hybrid integrated care model combines collaborative care elements developed in the RESPECT-Mil program with elements of the U.S. Air Force Behavioral Health Optimization project colocating behavioral health providers in primary care settings to provide brief consultative services.

MHS Care Enhancements

Many of the innovations deployed throughout the U.S. Army system of behavioral health care have driven changes across the MHS as a whole. The DoD and the VA have made substantive systemwide policy and practice changes to improve care for beneficiaries with PTSD, depression, and comorbid PTSD and depression. In particular, significant implementation efforts have addressed population screening strategies, outcome monitoring to support measurement-based care, increased access to effective care, and revision of the disability evaluation system.

To improve the identification and referral of soldiers with deployment-related mental health concerns, the DoD implemented a comprehensive program that screens service members prior to deployment, immediately on redeployment, and then again 6 months after returning from deployment. Additionally, annual primary care- based screening requirements have been instituted as part of the DoD PCMH initiative. Both deployment-related and primary care-based screenings include an instrumentation to detect symptoms of PTSD and depression and extend the reach of mental health screening to the entire MHS population.

Building on the success of BHDP, former Assistant Secretary of Defense for Health Affairs Jonathan Woodson mandated BHDP use across the MHS for all patients in DoD behavioral health clinics and the use of outcome measures for the treatment of PTSD, anxiety, depression, and alcohol use disorders.⁵⁷ A DoD-wide requirement to use the PTSD checklist and patient health questionnaire to monitor PTSD and depression symptoms at mental health intakes and regularly at follow-up visits is being implemented. The Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury, through its Practice-Based Implementation Network (underwritten by a Joint Incentive Fund managed between DoD and VA), has worked across the MHS and the VA to facilitate the implementation, uptake, and adoption of this initiative.

The DoD established the Center for Deployment Psychology (CDP) in 2006 to promote clinician training in EBTs with the aim of increasing service members’ access to effective psychological treatments. Since its inception, the CDP has provided EBT training to more than 40,000 behavioral health providers. Although the impact of these and other efforts on improving the quality of care that patients receive is unknown, a recent study documented widespread self-reported usage of EBT components in U.S. Army clinics and that providers formally trained in EBTs were more likely to deliver EBTs.⁵⁸

Finally, systemwide changes to the VA Schedule of Ratings for Disability (VASRD) and integration of DoD and VA disability evaluation systems have led to shifts in diagnosis toward PTSD that usually merit a minimum 50% disability rating. Mandates in law require military clinicians to evaluate patients who have deployed for PTSD and TBI prior to taking any actions associated with administrative separation. The practice of attributing PTSD symptoms to character pathology or personality disorders, even when these symptoms did not clearly manifest or worsen with military service, has likely been eliminated from practice in military and veteran populations.

Robust policy changes to limit personality disorder discharges started in fiscal year 2007, when there were 4,127 personality disorder separations across DoD. This number was reduced to 300 within 5 years. Policy changes regarding separation not only seem to have affected discharges, but also may have shaped diagnostic practice. The incidence rate of personality disorder diagnoses declined from 513 per 100,000 person-years in 2007 to 284 per 100,000 person-years by 2011.⁵⁹ The VASRD recognizes chronic adjustment disorder as a disability, and the National Defense Authorization Act of 2008 mandated that DoD follow disability guidelines promulgated by VA.

As stated in the memorandum Clinical Policy Guidance for Assessment and Treatment of Post-Traumatic Stress Disorders (August 24, 2012), DoD recognizes chronic adjustment disorder as an unfitting condition that merits referral to its disability evaluation system.⁶⁰ Acute adjustment disorders may still lead to administrative separations, as many service members manifest emotional symptoms stemming from the failure to adjust to the routine vicissitudes of military life. Finally, many court jurisdictions, including veteran’s courts, military courts, and commanders empowered to adjudicate nonjudicial infractions under the Uniform Code of Military Justice, have recognized PTSD as grounds for the mitigation of penalties associated with a wide array of criminal and administrative infractions.

Conclusion

In response to the increased mental health burden following a decade of war and the associated pressures stemming from federal mandates, the MHS has invested unprecedented resources into improving care for military service members. The U.S. Army has played a prominent role in this endeavor by investing in clinical research efforts to accelerate discovery on the causes and cures for these conditions, enacting policies that mandate best practices, and implementing evidence-based care approaches across the system of care. Despite this progress, however, understanding and effectively treating the most prevalent mental health conditions remain a challenge across the DoD and VHA health care systems. Many service members and veterans still do not receive timely, high-quality care for PTSD, depression, and other common comorbidities associated with military experience, and controversies in diagnostic clarification abound.

In short, great strides have been made, yet there is still a large distance to go. The vision of an effective, efficient, comprehensive care system for mental health conditions will continue to be pursued and achieved through collaborations across key agencies and the scientific community, implementation of health system approaches that support population care, and the sustained efforts of dedicated clinicians, staff, and clinic leaders who deliver the care to our service members and veterans.

Over the past decade, nationwide attention has focused on mental health conditions associated with military service. Recent legal mandates have led to changes in the DoD, VA, and HHS health systems aimed at increasing access to care, decreasing barriers to care, and expanding research on mental health conditions commonly seen in service members and veterans. On August 31, 2012, President Barack Obama signed the Improving Access to Mental Health Services for Veterans, Service Members, and Military Families executive order, establishing an interagency task force from the VA, DoD, and HHS.¹ The task force was charged with addressing quality of care and provider training in the management of commonly comorbid conditions, including (among other conditions) posttraumatic stress disorder (PTSD) and depression.

Depression and PTSD present major health burdens in both military and veteran cohorts. Overlap in clinical presentation and significant rates of comorbidity complicate effective management of these conditions. This article offers a brief review of the diagnostic and epidemiologic complexities associated with PTSD and depression, a summary of research relevant to these issues, and a description of recent system-level developments within the Military Health System (MHS) designed to improve care through better approaches in identification, management, and research of these conditions.

Diagnostic Uncertainty

Both PTSD and major depressive disorder (MDD) have been recognized as mental health disorders since the American Psychiatric Association’s Diagnostic and Statistical Manual (DSM) discarded its previous etiologically based approach to diagnostic classification in 1980 in favor of a system in which diagnosis is based on observable symptoms.^2,3 With the release of DSM-5 in 2013, the diagnostic criteria for PTSD underwent a substantial transformation.⁴ Previously, PTSD was described as an anxiety disorder, and some of its manifestations overlapped descriptively (and in many cases, etiologically) with anxiety and depressive illnesses.⁵

Clinicians also often described shorter-lived, developmental, formes fruste, or otherwise subsyndromal manifestations of trauma associated with PTSD. In DSM-5, PTSD was removed from the anxiety disorders section and placed in a new category of disorders labeled Trauma and Stressor-Related Disorders. This new category also included reactive attachment disorder (in children), acute stress disorder, adjustment disorders, and unspecified or other trauma and stressor-related disorders. Other major changes to the PTSD diagnostic criteria included modification to the DSM-IV-TR (text revision) trauma definition (making the construct more specific), removal of the requirement for explicit subjective emotional reaction to a traumatic event, and greater emphasis on negative cognitions and mood. Debate surrounds the updated symptom criteria with critics questioning whether there is any improvement in the clinical utility of the diagnosis, especially in light of the substantial policy and practice implications the change engenders.⁶

Recently, Hoge and colleagues examined the psychometric implications of the diagnostic changes (between DSM-IV-TR and DSM-5) in the PTSD definition.⁶ The authors found that although the 2 definitions showed nearly identical association with other psychiatric disorders (including depression) and functional impairment, 30% of soldiers who met DSM-IV-TR criteria for PTSD failed to meet criteria in DSM-5, and another 20% met only DSM-5 criteria. Recognizing discordance in PTSD and associated diagnoses, the U.S. Army Medical Command mandated that its clinicians familiarize themselves with the controversies surrounding the discordant diagnoses and coding of subthreshold PTSD.⁷

Adding to the problem of diagnostic uncertainty, the clinical presentation of MDD includes significant overlap with that of PTSD. Specifically, symptoms of guilt, diminished interests, problems with concentration, and sleep disturbances are descriptive of both disorders. Furthermore, the criteria set for several subthreshold forms of MDD evidence considerable overlap with PTSD symptoms. For example, diagnostic criteria for disruptive mood dysregulation disorder include behavioral outbursts and irritability, and diagnostic criteria for dysthymia include sleep disturbances and concentration problems.

Adjustment disorders are categorized as trauma and stressor-related disorders in DSM-5 and hold many emotional and behavioral symptoms in common with PTSD. The “acute” and “chronic” adjustment disorder specifiers contribute to problems in diagnostic certainty for PTSD. In general, issues pertaining to diagnostic uncertainty and overlap likely reflect the limits of using a diagnostic classification system that relies exclusively on observational and subjective reports of psychological symptoms.^8,9

In a treatment environment where a veteran or active-duty patient has presented for care, in the face of these shared symptom sets, clinicians frequently offer initial diagnoses. These diagnoses are often based on perceived etiologic factors derived from patients’ descriptions of stressors encountered during military service. This tendency likely contributes to considerable inconsistencies and potential inaccuracies in diagnoses, and much of the variance can be attributed to the clinicians’ degree of familiarity with military exposures, perceptions of what constitutes trauma, and outside pressure to assign or avoid specific diagnoses.

Importantly, the phenomenologic differences between PTSD and depressive disorders increase the likelihood of poorly aligned and inconsistent treatment plans, and this lack of clarity may, in turn, compromise effective patient care. To address some of these diagnostic challenges, the VA and DoD incorporate military culture training into clinicians’ curriculum to increase provider familiarity with the common stressors and challenges of military life, mandate the use of validated measures to support diagnostic decision making, and regularly review policies that influence diagnostic practices.

Epidemiology

The prevalence rates for PTSD are increasing in the military, possibly stemming from the demands on service members engaged in years’ long wars. Despite the increased attention on this phenomenon, research has demonstrated that the majority of service members who deploy do not develop PTSD or significant trauma-related functional impairment.¹⁰ Furthermore, many cases of PTSD diagnosed in the MHS stem from traumatic experiences other than combat exposure, including childhood abuse and neglect, sexual and other assaults, accidents and health care exposures, domestic abuse, and bullying. Depression arguably has received less attention despite comparable prevalence rates in military populations, high co-occurrence of PTSD and depression, and depression being associated with a greater odds ratio for mortality that includes death by suicide in military service members.¹¹

Estimates of the prevalence of PTSD from the U.S. Army suggest that it exists in 3% to 6% of military members who have not deployed and in 6% to 25% of service members with combat deployment histories. The frequency and intensity of combat are strong predictors of risk.⁷ A recent epidemiologic study using inpatient and outpatient encounter records showed that the prevalence of PTSD in the active military component was 2.0% in the middle of calendar year (CY) 2010; a two-thirds increase from 1.2% in CY 2007.¹² The incidence of PTSD

Epidemiologic studies and prevalence/incidence rates derived from administrative data rely on strict case definitions. Consequently, such administrative investigations include data only from service members

PTSD and Depression Treatment

Despite the high rates of PTSD and MDD comorbidity, few treatments have been developed for and tested on an exclusively comorbid sample of patients.¹³ However, psychopharmacologic agents targeting depression have been applied to the treatment of PTSD, and PTSD psychotherapy trials typically include depression response as a secondary outcome. The generalizability of findings to a truly comorbid population may be limited based on study sampling frames and the unique characteristics of patients with comorbid PTSD and depression.^14-16 Several psychopharmacologic treatments for depression have been evaluated as frontline treatments for PTSD. The 3 pharmacologic treatments that demonstrate efficacy in treating PTSD include fluoxetine, paroxetine, and venlafaxine.¹⁷

Although these pharmacologic agents represent good candidate treatments for comorbid patients, the effect size of pharmacologic treatments are generally smaller than those of psychotherapeutic treatments for PTSD.^17,18 This observation, however, is based on indirect comparisons, and a recent systematic review concluded that the evidence was insufficient to determine the comparative effectiveness between psychotherapy and pharmacotherapy for PTSD.¹⁹ Evidence indicates that trauma-focused cognitive behavioral therapies consistently demonstrate efficacy and effectiveness in treating PTSD.^19,20 These treatments also have been shown to significantly reduce depressive symptoms among PTSD samples.²¹

Based on strong bodies of evidence, these pharmacologic and psychological treatments have received the highest level of recommendation in the VA and DoD.^22,23 Accordingly, both agencies have invested considerable resources in large-scale efforts to improve patient access to these particular treatments. Despite these impressive implementation efforts, however, the limitations of relying exclusively on these treatments as frontline approaches within large health care systems have become evident.^24-26

Penetration of Therapies

Penetration of these evidence-based treatments (EBTs) within the DoD and VHA remains limited. For instance, one study showed that VA clinicians in mental health specialty care clinics may provide only about 4 hours of EBT per week.²⁷

Other reports suggest that only about 60% of treatment-seeking patients in PTSD clinics receive any type of evidence-based therapy and that within-session care quality is questionable based on a systematic review of chart notes.^28,29 Attrition in trauma-focused therapy is a recognized limitation, with 1 out of 3 treatment-seeking patients not completing a full dose of evidence-based treatment.^30-33 Large-scale analyses of VHA and DoD utilization data suggest that the majority of PTSD patients do not receive a sufficient number of sessions to be characterized as an adequate dose of EBT, with a majority of dropouts occur- ring after just a few sessions.^34-37

Hoge and colleagues found that < 50% of soldiers meeting criteria for PTSD received any mental health care within the prior 6 months with one-quarter of those patients dropping out of care prematurely.³⁸ Among a large cohort of soldiers engaged in care for the treatment of PTSD, only about 40% received a number of EBT treatment sessions that could qualify as an adequate dose.³⁸ Thus, although major advancements in the development and implementation of effective treatments for PTSD and depression have occurred, the penetration of these treatments is limited, and the majority of patients in need of treatment potentially receive inadequate care.³⁹

System level approaches that integrate behavioral health services into the primary care system have been proposed to address these care gaps for service members and veterans.^40-42 Fundamentally, system-level approaches seek to improve the reach and effectiveness of care through large-scale screening efforts, a greater emphasis on the quality of patient care, and enhanced care continuity across episodes of treatment.

Primary Care

With the primary care setting considered the de facto mental health system, integrated approaches enhance the reach of care by incorporating uniform mental health screening and referral for patients coming through primary care. Specific evidence-based treatments can be integrated into this approach within a stepped-care framework that aims to match patients strategically to the right type of care and leverage specialty care resources as needed. Integrated care approaches for the treatment of PTSD and depression have been developed and evaluated inside and outside of the MHS. Findings indicate that integrated treatment approaches can improve care access, care continuity, patient satisfaction, quality of care,and in several trials, PTSD and depression outcomes.^43-47

Recently, an integrated care approach targeting U.S. Army soldiers who screened positive for PTSD or depression in primary care was evaluated in a multisite effectiveness trial.⁴⁸ Patients randomized to the treatment approach experienced significant improvements in both PTSD and depression symptoms relative to patients in usual care.⁴³ In addition, patients treated in this care model received significantly more mental health services; the patterns of care indicated that patients with comorbid PTSD and depression were more likely to be triaged to specialty care, whereas patients with a single diagnosis were more likely to be managed in primary care.⁴⁹ This trial suggests that integrated care models feasibly can be implemented in the U.S. Army care system, yielding increased uptake of mental health care, more efficiently matched care based on patient comorbidities, and improved PTSD and depression outcomes.

Treatment Research

The MHS supports a large portfolio of research in PTSD and depression through DoD/VA research consortia (eg, the Congressionally Directed Medical Research Program, the Consortium to Alleviate PTSD, the Injury and Traumatic Stress Clinical Consortium). The U.S. Army Medical Research and Materiel Command (USAMRMC) executes and manages the portfolio of research, relying on a joint program committee of DoD and non-DoD experts to make funding recommendations based on identified research priorities, policy guidance, and knowledge translation needs.

Health systems research on PTSD and MDD in federal health care settings is expanding. For example, the RAND Corporation recently evaluated a candidate set of quality measures for PTSD and MDD, using an operational definition of an episode of care.³⁷ This work is intended to inform efforts to measure and improve the quality of care for PTSD and depression across the enterprise.

The DoD Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury is simultaneously completing an inferential assessment of adjunctive mental health care services, many focused on PTSD and depression, throughout the health care enterprise. Along with the substantial resources devoted to research on PTSD and depression, the MHS is implementing strategies to improve the system of care for service members with mental health conditions.

Army Care System Innovations

The U.S. Army is engaged in a variety of strategies to improve the identification of patients with mental health conditions, increase access to mental health services, and enhance the quality of care that soldiers receive for PTSD and depression. To improve the coordination of mental health care, the U.S. Army Medical Command implemented a wide-scale innovative transformation of its mental health care system through the establishment of the Behavioral Health Service Line program management office.

This move eliminated separate departments of psychiatry, psychology, and social work in favor of integrated behavioral health departments that are now responsible for all mental health care delivered to soldiers, including inpatient, outpatient, partial hospitalization, residential, embedded care in garrison, and primary care settings. This transformation ensured coordination of care for soldiers, eliminating potential miscommunication with patients, commands, and other clinicians while clearly defining performance indicators in process (eg, productivity, scheduling, access to care, and patient satisfaction) and outcome measures.⁴⁹ In conjunction with the development of its service line, the U.S. Army created a Behavioral Health Data Portal (BHDP), an electronic and standardized means to assess clinical outcomes for common conditions.

To promote higher quality mental health care, the Office of the Surgeon General of the U.S. Army provided direct guidance on the treatment of PTSD and depression. U.S. Army policy mandates that providers treating mental health conditions adhere to the VA/DoD clinical practice guidelines (CPGs) and that soldiers with PTSD and depression be offered treatments with the highest level of scientific support and that outcome measures be routinely administered. In line with the CPGs, U.S. Army policy also recommends the use of both integrated and embedded mental health care approaches to address PTSD, depression, and other common physical and psychological health conditions.

To reduce stigma and improve mental health care access, the U.S. Army began implementing integrated care approaches in 2007 with its Re-Engineering Systems of Primary Care Treatment in the Military (RESPECT-Mil) program, an evidence-based collaborative care model.^51-55 This approach included structured screening and diagnostic procedures, predictable follow-up schedules for patients, and the coordination of the divisions of responsibility among and between primary care providers, paraprofessionals, and behavioral health care providers. From 2007 to 2013, this collaborative care model was rolled out across 96 clinics worldwide and provided PTSD and depression screening to more than 1 million encounters per year.^52,53

More recently, the U.S. Army led DoD in integrating behavioral health personnel in patient centered medical homes (PCMH) in compliance with DoD Instruction 6490.15.⁵⁶ This hybrid integrated care model combines collaborative care elements developed in the RESPECT-Mil program with elements of the U.S. Air Force Behavioral Health Optimization project colocating behavioral health providers in primary care settings to provide brief consultative services.

MHS Care Enhancements

Many of the innovations deployed throughout the U.S. Army system of behavioral health care have driven changes across the MHS as a whole. The DoD and the VA have made substantive systemwide policy and practice changes to improve care for beneficiaries with PTSD, depression, and comorbid PTSD and depression. In particular, significant implementation efforts have addressed population screening strategies, outcome monitoring to support measurement-based care, increased access to effective care, and revision of the disability evaluation system.

To improve the identification and referral of soldiers with deployment-related mental health concerns, the DoD implemented a comprehensive program that screens service members prior to deployment, immediately on redeployment, and then again 6 months after returning from deployment. Additionally, annual primary care- based screening requirements have been instituted as part of the DoD PCMH initiative. Both deployment-related and primary care-based screenings include an instrumentation to detect symptoms of PTSD and depression and extend the reach of mental health screening to the entire MHS population.

Building on the success of BHDP, former Assistant Secretary of Defense for Health Affairs Jonathan Woodson mandated BHDP use across the MHS for all patients in DoD behavioral health clinics and the use of outcome measures for the treatment of PTSD, anxiety, depression, and alcohol use disorders.⁵⁷ A DoD-wide requirement to use the PTSD checklist and patient health questionnaire to monitor PTSD and depression symptoms at mental health intakes and regularly at follow-up visits is being implemented. The Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury, through its Practice-Based Implementation Network (underwritten by a Joint Incentive Fund managed between DoD and VA), has worked across the MHS and the VA to facilitate the implementation, uptake, and adoption of this initiative.

The DoD established the Center for Deployment Psychology (CDP) in 2006 to promote clinician training in EBTs with the aim of increasing service members’ access to effective psychological treatments. Since its inception, the CDP has provided EBT training to more than 40,000 behavioral health providers. Although the impact of these and other efforts on improving the quality of care that patients receive is unknown, a recent study documented widespread self-reported usage of EBT components in U.S. Army clinics and that providers formally trained in EBTs were more likely to deliver EBTs.⁵⁸

Finally, systemwide changes to the VA Schedule of Ratings for Disability (VASRD) and integration of DoD and VA disability evaluation systems have led to shifts in diagnosis toward PTSD that usually merit a minimum 50% disability rating. Mandates in law require military clinicians to evaluate patients who have deployed for PTSD and TBI prior to taking any actions associated with administrative separation. The practice of attributing PTSD symptoms to character pathology or personality disorders, even when these symptoms did not clearly manifest or worsen with military service, has likely been eliminated from practice in military and veteran populations.

Robust policy changes to limit personality disorder discharges started in fiscal year 2007, when there were 4,127 personality disorder separations across DoD. This number was reduced to 300 within 5 years. Policy changes regarding separation not only seem to have affected discharges, but also may have shaped diagnostic practice. The incidence rate of personality disorder diagnoses declined from 513 per 100,000 person-years in 2007 to 284 per 100,000 person-years by 2011.⁵⁹ The VASRD recognizes chronic adjustment disorder as a disability, and the National Defense Authorization Act of 2008 mandated that DoD follow disability guidelines promulgated by VA.

As stated in the memorandum Clinical Policy Guidance for Assessment and Treatment of Post-Traumatic Stress Disorders (August 24, 2012), DoD recognizes chronic adjustment disorder as an unfitting condition that merits referral to its disability evaluation system.⁶⁰ Acute adjustment disorders may still lead to administrative separations, as many service members manifest emotional symptoms stemming from the failure to adjust to the routine vicissitudes of military life. Finally, many court jurisdictions, including veteran’s courts, military courts, and commanders empowered to adjudicate nonjudicial infractions under the Uniform Code of Military Justice, have recognized PTSD as grounds for the mitigation of penalties associated with a wide array of criminal and administrative infractions.

Conclusion

In response to the increased mental health burden following a decade of war and the associated pressures stemming from federal mandates, the MHS has invested unprecedented resources into improving care for military service members. The U.S. Army has played a prominent role in this endeavor by investing in clinical research efforts to accelerate discovery on the causes and cures for these conditions, enacting policies that mandate best practices, and implementing evidence-based care approaches across the system of care. Despite this progress, however, understanding and effectively treating the most prevalent mental health conditions remain a challenge across the DoD and VHA health care systems. Many service members and veterans still do not receive timely, high-quality care for PTSD, depression, and other common comorbidities associated with military experience, and controversies in diagnostic clarification abound.

In short, great strides have been made, yet there is still a large distance to go. The vision of an effective, efficient, comprehensive care system for mental health conditions will continue to be pursued and achieved through collaborations across key agencies and the scientific community, implementation of health system approaches that support population care, and the sustained efforts of dedicated clinicians, staff, and clinic leaders who deliver the care to our service members and veterans.

Risk factors for dislocation after reverse total shoulder arthroplasty (RTSA) are not clearly defined. Prosthetic dislocation can result in poor patient satisfaction, worse functional outcomes, and return to the operating room.^1-3 As a result, identification of modifiable risk factors for complications represents an important research initiative for shoulder surgeons.

There is a paucity of literature devoted to the study of dislocation after RTSA. Chalmers and colleagues⁴ found a 2.9% (11/385) incidence of early dislocation within 3 months after index surgery—an improvement over the 15.8% reported for early instability over the period 2004–2006.⁵ As prosthesis design has improved and surgeons have become more comfortable with the RTSA prosthesis, surgical indications have expanded,^6,7 and dislocation rates appear to have decreased. Although the most common indication for RTSA continues to be cuff tear arthropathy (CTA),⁶ there has been increased use in rheumatoid arthritis^8-10; proximal humerus fractures, especially in cases of poor bone quality and unreliable fixation of tuberosities^11-13; and failed previous shoulder reconstruction.^14,15 As RTSA is performed more often, limiting the complications will become more important for both patient care and economics.

We conducted a study to analyze dislocation rates at our institution and to identify both modifiable and nonmodifiable risk factors for dislocation after RTSA. By identifying risk factors for dislocation, we will be able to implement additional perioperative clinical measures to reduce the incidence of dislocation.

Materials and Methods

This retrospective study of dislocation after RTSA was conducted at the Rothman Institute of Orthopedics and Methodist Hospital (Thomas Jefferson University Hospitals, Philadelphia, PA). After obtaining Institutional Review Board approval for the study, we searched our institution’s electronic database of shoulder arthroplasties to identify all RTSAs performed at our 2 large-volume urban institutions between September 27, 2010 and December 31, 2013. For the record search, International Classification of Diseases, Ninth Revision (ICD-9) codes were used (Table 1).

The medical records of each patient were used to identify independent variables that could be associated with dislocation rate. Demographic variables included sex, age, and race. Preoperative clinical data included body mass index (BMI), etiology of shoulder disease leading to RTSA, individual comorbidities, and Charlson Comorbidity Index (CCI)¹⁶ modified to be used with ICD-9 codes.¹⁷ In addition, prior shoulder surgery history and arthroplasty type (primary or revision) were determined. Postoperative considerations were time to dislocation, mechanism of dislocation, and intervention(s) needed for dislocation. Although the institutional database did not include operative variables such as prosthesis type and surgical approach, all 6 surgeons in this study were using a standard deltopectoral approach in beach-chair position with a Grammont style prosthesis for RTSA cases.

Descriptive statistics for RTSA patients and the dislocation subpopulation were compiled. Bivariate analysis was used to evaluate which of the previously described variables influenced dislocation rates. Last, multivariate logistic regression analysis was performed to evaluate which factors were independent predictors of dislocation. We included demographic variables (age, sex, ethnicity), clinical variables (BMI, individual comorbidities, CCI), and surgical variables (primary vs revision, diagnosis at time of surgery). All statistical analyses were performed with Excel 2013 (Microsoft) and SPSS Statistics Version 20.0 (SPSS Inc.).

Results

From the database, we identified 487 patients who underwent 510 RTSAs during the study period. These surgeries were performed by 6 shoulder and elbow fellowship–trained surgeons. Of the 510 RTSAs, 393 (77.1%) were primary cases, and 117 (22.9%) were revision cases.

Of the 510 shoulders that underwent RTSA, 15 (2.9%; 14 patients) dislocated. Of these 15 cases, 5 were primary (1.3% of all primary cases) and 10 were revision (8.5% of all revision cases). Mean time from index surgery to diagnosis of dislocation was 58.2 days (range, 0-319 days). One dislocation occurred immediately after surgery, 2 after falls, 4 from patient-identified low-energy mechanisms of injury, and 8 without known inciting events. Nine dislocations (60%) did not have a subscapularis repair (7 were irreparable, 2 underwent subscapularis peel without repair), and the other 6 were repaired primarily (Table 2).

Discussion

With more RTSAs being performed, evaluation of their common complications becomes increasingly important.¹⁸ We found a 3.0% rate of dislocation after RTSA, which is consistent with the most recently reported incidence⁴ and falls within the previously described range of 0% to 8.6%.^19-26 Of the clinical risk factors identified in this study, those previously described were prior surgery, subscapularis insufficiency, higher BMI, and male sex.⁴ However, our finding of lower risk of dislocation after RTSA for primary rotator cuff pathology was not previously described. Although Chalmers and colleagues⁴ did not report this lower risk, 3 (27.3%) of their 11 patients with dislocation had primary CTA, compared with 1 (6.7%) of 15 patients in the present study.⁴ Our literature review did not identify any studies that independently reported the dislocation rate in patients who underwent RTSA for rotator cuff failure.

The risk factors of subscapularis irreparability and revision surgery suggest the importance of the soft-tissue envelope and bony anatomy in dislocation prevention. Previous analyses have suggested implant malpositioning,^27,28 poor subscapularis quality,²⁹ and inadequate muscle tensioning^5,30-32 as risk factors for RTSA. Patients with an irreparable subscapularis tendon have often had multiple surgeries with compromise to the muscle/soft-tissue envelope or bony anatomy of the shoulder. A biomechanical study by Gutiérrez and colleagues³¹ found the compressive forces of the soft tissue at the glenohumeral joint to be the most important contributor to stability in the RTSA prosthesis. In clinical studies, the role of the subscapularis in preventing instability after RTSA remains unclear. Edwards and colleagues²⁹ prospectively compared dislocation rates in patients with reparable and irreparable subscapularis tendons during RTSA and found a higher rate of dislocation in the irreparable subscapularis group. Of note, patients in the irreparable subscapularis group also had more complex diagnoses, including proximal humeral nonunion, fixed glenohumeral dislocation, and failed prior arthroplasty. Clark and colleagues³³ retrospectively analyzed subscapularis repair in 2 RTSA groups and found no appreciable effect on complication rate, dislocation events, range-of-motion gains, or pain relief.

Our finding that higher BMI is an independent risk factor was previously described.⁴ The association is unclear but could be related to implant positioning, difficulty in intraoperative assessment of muscle tensioning, or body habitus that may generate a lever arm for impingement and dislocation when the arm is in adduction. Last, our finding that male sex is a risk factor for dislocation approached significance, and this relationship was previously reported.⁴ This could be attributable to a higher rate of activity or of indolent infection in male patients.^34,35Besides studying risk factors for dislocation after RTSA, we investigated treatment. None of our patients were treated successfully and definitively with closed reduction in the clinic. This finding diverges from findings in studies by Teusink and colleagues² and Chalmers and colleagues,⁴who respectively reported 62% and 44% rates of success with closed reduction. Our cohort of 14 patients with 15 dislocations required a total of 17 trips to the operating room after dislocation. This significantly higher rate of return to the operating room suggests that dislocation after RTSA may be a more costly and morbid problem than has been previously described.

This study had several weaknesses. Despite its large consecutive series of patients, the study was retrospective, and several variables that would be documented and controlled in a prospective study could not be measured here. Specifically, neither preoperative physical examination nor patient-specific assessments of pain or function were consistently obtained. Similarly, postoperative patient-specific instruments of outcomes evaluation were not obtained consistently, so results of patients with dislocation could not be compared with those of a control group. In addition, preoperative and postoperative radiographs were not consistently present in our electronic medical records, so the influence of preoperative bony anatomy, intraoperative limb lengthening, and any implant malpositioning could not be determined. Furthermore, operative details, such as reparability of the subscapularis, were not fully available for the control group and could not be included in statistical analysis. In addition, that the known dislocation risk factor of male sex⁴ was identified here but was not significant in multivariate regression analysis suggests that this study may not have been adequately powered to identify a significant difference in dislocation rate between the sexes. Last, though our results suggested associations between the aforementioned variables and dislocation after RTSA, a truly causative relationship could not be confirmed with this study design or analysis. Therefore, our study findings are hypothesis-generating and may indicate a benefit to greater deltoid tensioning, use of retentive liners, or more conservative rehabilitation protocols for high-risk patients.

Conclusion

Dislocation after RTSA is an uncommon complication that often requires a return to the operating room. This study identified a modifiable risk factor (higher BMI) and 3 nonmodifiable risk factors (male sex, subscapularis insufficiency, revision surgery) for dislocation after RTSA. In contrast, patients who undergo RTSA for primary rotator cuff pathology are unlikely to dislocate after surgery. This low risk of dislocation after RTSA for primary cuff pathology was not previously described. Patients in the higher risk category may benefit from preoperative lifestyle modification, intraoperative techniques for increasing stability, and more conservative therapy after surgery. In addition, unlike previous investigations, this study did not find closed reduction in the clinic alone to be successful in definitively treating this patient population.

Am J Orthop. 2016;45(7):E444-E450. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Risk factors for dislocation after reverse total shoulder arthroplasty (RTSA) are not clearly defined. Prosthetic dislocation can result in poor patient satisfaction, worse functional outcomes, and return to the operating room.^1-3 As a result, identification of modifiable risk factors for complications represents an important research initiative for shoulder surgeons.

There is a paucity of literature devoted to the study of dislocation after RTSA. Chalmers and colleagues⁴ found a 2.9% (11/385) incidence of early dislocation within 3 months after index surgery—an improvement over the 15.8% reported for early instability over the period 2004–2006.⁵ As prosthesis design has improved and surgeons have become more comfortable with the RTSA prosthesis, surgical indications have expanded,^6,7 and dislocation rates appear to have decreased. Although the most common indication for RTSA continues to be cuff tear arthropathy (CTA),⁶ there has been increased use in rheumatoid arthritis^8-10; proximal humerus fractures, especially in cases of poor bone quality and unreliable fixation of tuberosities^11-13; and failed previous shoulder reconstruction.^14,15 As RTSA is performed more often, limiting the complications will become more important for both patient care and economics.

We conducted a study to analyze dislocation rates at our institution and to identify both modifiable and nonmodifiable risk factors for dislocation after RTSA. By identifying risk factors for dislocation, we will be able to implement additional perioperative clinical measures to reduce the incidence of dislocation.

Materials and Methods

This retrospective study of dislocation after RTSA was conducted at the Rothman Institute of Orthopedics and Methodist Hospital (Thomas Jefferson University Hospitals, Philadelphia, PA). After obtaining Institutional Review Board approval for the study, we searched our institution’s electronic database of shoulder arthroplasties to identify all RTSAs performed at our 2 large-volume urban institutions between September 27, 2010 and December 31, 2013. For the record search, International Classification of Diseases, Ninth Revision (ICD-9) codes were used (Table 1).

The medical records of each patient were used to identify independent variables that could be associated with dislocation rate. Demographic variables included sex, age, and race. Preoperative clinical data included body mass index (BMI), etiology of shoulder disease leading to RTSA, individual comorbidities, and Charlson Comorbidity Index (CCI)¹⁶ modified to be used with ICD-9 codes.¹⁷ In addition, prior shoulder surgery history and arthroplasty type (primary or revision) were determined. Postoperative considerations were time to dislocation, mechanism of dislocation, and intervention(s) needed for dislocation. Although the institutional database did not include operative variables such as prosthesis type and surgical approach, all 6 surgeons in this study were using a standard deltopectoral approach in beach-chair position with a Grammont style prosthesis for RTSA cases.

Descriptive statistics for RTSA patients and the dislocation subpopulation were compiled. Bivariate analysis was used to evaluate which of the previously described variables influenced dislocation rates. Last, multivariate logistic regression analysis was performed to evaluate which factors were independent predictors of dislocation. We included demographic variables (age, sex, ethnicity), clinical variables (BMI, individual comorbidities, CCI), and surgical variables (primary vs revision, diagnosis at time of surgery). All statistical analyses were performed with Excel 2013 (Microsoft) and SPSS Statistics Version 20.0 (SPSS Inc.).

Results

From the database, we identified 487 patients who underwent 510 RTSAs during the study period. These surgeries were performed by 6 shoulder and elbow fellowship–trained surgeons. Of the 510 RTSAs, 393 (77.1%) were primary cases, and 117 (22.9%) were revision cases.

Of the 510 shoulders that underwent RTSA, 15 (2.9%; 14 patients) dislocated. Of these 15 cases, 5 were primary (1.3% of all primary cases) and 10 were revision (8.5% of all revision cases). Mean time from index surgery to diagnosis of dislocation was 58.2 days (range, 0-319 days). One dislocation occurred immediately after surgery, 2 after falls, 4 from patient-identified low-energy mechanisms of injury, and 8 without known inciting events. Nine dislocations (60%) did not have a subscapularis repair (7 were irreparable, 2 underwent subscapularis peel without repair), and the other 6 were repaired primarily (Table 2).

Discussion

With more RTSAs being performed, evaluation of their common complications becomes increasingly important.¹⁸ We found a 3.0% rate of dislocation after RTSA, which is consistent with the most recently reported incidence⁴ and falls within the previously described range of 0% to 8.6%.^19-26 Of the clinical risk factors identified in this study, those previously described were prior surgery, subscapularis insufficiency, higher BMI, and male sex.⁴ However, our finding of lower risk of dislocation after RTSA for primary rotator cuff pathology was not previously described. Although Chalmers and colleagues⁴ did not report this lower risk, 3 (27.3%) of their 11 patients with dislocation had primary CTA, compared with 1 (6.7%) of 15 patients in the present study.⁴ Our literature review did not identify any studies that independently reported the dislocation rate in patients who underwent RTSA for rotator cuff failure.

The risk factors of subscapularis irreparability and revision surgery suggest the importance of the soft-tissue envelope and bony anatomy in dislocation prevention. Previous analyses have suggested implant malpositioning,^27,28 poor subscapularis quality,²⁹ and inadequate muscle tensioning^5,30-32 as risk factors for RTSA. Patients with an irreparable subscapularis tendon have often had multiple surgeries with compromise to the muscle/soft-tissue envelope or bony anatomy of the shoulder. A biomechanical study by Gutiérrez and colleagues³¹ found the compressive forces of the soft tissue at the glenohumeral joint to be the most important contributor to stability in the RTSA prosthesis. In clinical studies, the role of the subscapularis in preventing instability after RTSA remains unclear. Edwards and colleagues²⁹ prospectively compared dislocation rates in patients with reparable and irreparable subscapularis tendons during RTSA and found a higher rate of dislocation in the irreparable subscapularis group. Of note, patients in the irreparable subscapularis group also had more complex diagnoses, including proximal humeral nonunion, fixed glenohumeral dislocation, and failed prior arthroplasty. Clark and colleagues³³ retrospectively analyzed subscapularis repair in 2 RTSA groups and found no appreciable effect on complication rate, dislocation events, range-of-motion gains, or pain relief.

Our finding that higher BMI is an independent risk factor was previously described.⁴ The association is unclear but could be related to implant positioning, difficulty in intraoperative assessment of muscle tensioning, or body habitus that may generate a lever arm for impingement and dislocation when the arm is in adduction. Last, our finding that male sex is a risk factor for dislocation approached significance, and this relationship was previously reported.⁴ This could be attributable to a higher rate of activity or of indolent infection in male patients.^34,35Besides studying risk factors for dislocation after RTSA, we investigated treatment. None of our patients were treated successfully and definitively with closed reduction in the clinic. This finding diverges from findings in studies by Teusink and colleagues² and Chalmers and colleagues,⁴who respectively reported 62% and 44% rates of success with closed reduction. Our cohort of 14 patients with 15 dislocations required a total of 17 trips to the operating room after dislocation. This significantly higher rate of return to the operating room suggests that dislocation after RTSA may be a more costly and morbid problem than has been previously described.

This study had several weaknesses. Despite its large consecutive series of patients, the study was retrospective, and several variables that would be documented and controlled in a prospective study could not be measured here. Specifically, neither preoperative physical examination nor patient-specific assessments of pain or function were consistently obtained. Similarly, postoperative patient-specific instruments of outcomes evaluation were not obtained consistently, so results of patients with dislocation could not be compared with those of a control group. In addition, preoperative and postoperative radiographs were not consistently present in our electronic medical records, so the influence of preoperative bony anatomy, intraoperative limb lengthening, and any implant malpositioning could not be determined. Furthermore, operative details, such as reparability of the subscapularis, were not fully available for the control group and could not be included in statistical analysis. In addition, that the known dislocation risk factor of male sex⁴ was identified here but was not significant in multivariate regression analysis suggests that this study may not have been adequately powered to identify a significant difference in dislocation rate between the sexes. Last, though our results suggested associations between the aforementioned variables and dislocation after RTSA, a truly causative relationship could not be confirmed with this study design or analysis. Therefore, our study findings are hypothesis-generating and may indicate a benefit to greater deltoid tensioning, use of retentive liners, or more conservative rehabilitation protocols for high-risk patients.

Conclusion

Dislocation after RTSA is an uncommon complication that often requires a return to the operating room. This study identified a modifiable risk factor (higher BMI) and 3 nonmodifiable risk factors (male sex, subscapularis insufficiency, revision surgery) for dislocation after RTSA. In contrast, patients who undergo RTSA for primary rotator cuff pathology are unlikely to dislocate after surgery. This low risk of dislocation after RTSA for primary cuff pathology was not previously described. Patients in the higher risk category may benefit from preoperative lifestyle modification, intraoperative techniques for increasing stability, and more conservative therapy after surgery. In addition, unlike previous investigations, this study did not find closed reduction in the clinic alone to be successful in definitively treating this patient population.

Am J Orthop. 2016;45(7):E444-E450. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Risk factors for dislocation after reverse total shoulder arthroplasty (RTSA) are not clearly defined. Prosthetic dislocation can result in poor patient satisfaction, worse functional outcomes, and return to the operating room.^1-3 As a result, identification of modifiable risk factors for complications represents an important research initiative for shoulder surgeons.

There is a paucity of literature devoted to the study of dislocation after RTSA. Chalmers and colleagues⁴ found a 2.9% (11/385) incidence of early dislocation within 3 months after index surgery—an improvement over the 15.8% reported for early instability over the period 2004–2006.⁵ As prosthesis design has improved and surgeons have become more comfortable with the RTSA prosthesis, surgical indications have expanded,^6,7 and dislocation rates appear to have decreased. Although the most common indication for RTSA continues to be cuff tear arthropathy (CTA),⁶ there has been increased use in rheumatoid arthritis^8-10; proximal humerus fractures, especially in cases of poor bone quality and unreliable fixation of tuberosities^11-13; and failed previous shoulder reconstruction.^14,15 As RTSA is performed more often, limiting the complications will become more important for both patient care and economics.

We conducted a study to analyze dislocation rates at our institution and to identify both modifiable and nonmodifiable risk factors for dislocation after RTSA. By identifying risk factors for dislocation, we will be able to implement additional perioperative clinical measures to reduce the incidence of dislocation.

Materials and Methods

This retrospective study of dislocation after RTSA was conducted at the Rothman Institute of Orthopedics and Methodist Hospital (Thomas Jefferson University Hospitals, Philadelphia, PA). After obtaining Institutional Review Board approval for the study, we searched our institution’s electronic database of shoulder arthroplasties to identify all RTSAs performed at our 2 large-volume urban institutions between September 27, 2010 and December 31, 2013. For the record search, International Classification of Diseases, Ninth Revision (ICD-9) codes were used (Table 1).

The medical records of each patient were used to identify independent variables that could be associated with dislocation rate. Demographic variables included sex, age, and race. Preoperative clinical data included body mass index (BMI), etiology of shoulder disease leading to RTSA, individual comorbidities, and Charlson Comorbidity Index (CCI)¹⁶ modified to be used with ICD-9 codes.¹⁷ In addition, prior shoulder surgery history and arthroplasty type (primary or revision) were determined. Postoperative considerations were time to dislocation, mechanism of dislocation, and intervention(s) needed for dislocation. Although the institutional database did not include operative variables such as prosthesis type and surgical approach, all 6 surgeons in this study were using a standard deltopectoral approach in beach-chair position with a Grammont style prosthesis for RTSA cases.

Descriptive statistics for RTSA patients and the dislocation subpopulation were compiled. Bivariate analysis was used to evaluate which of the previously described variables influenced dislocation rates. Last, multivariate logistic regression analysis was performed to evaluate which factors were independent predictors of dislocation. We included demographic variables (age, sex, ethnicity), clinical variables (BMI, individual comorbidities, CCI), and surgical variables (primary vs revision, diagnosis at time of surgery). All statistical analyses were performed with Excel 2013 (Microsoft) and SPSS Statistics Version 20.0 (SPSS Inc.).

Results

From the database, we identified 487 patients who underwent 510 RTSAs during the study period. These surgeries were performed by 6 shoulder and elbow fellowship–trained surgeons. Of the 510 RTSAs, 393 (77.1%) were primary cases, and 117 (22.9%) were revision cases.

Of the 510 shoulders that underwent RTSA, 15 (2.9%; 14 patients) dislocated. Of these 15 cases, 5 were primary (1.3% of all primary cases) and 10 were revision (8.5% of all revision cases). Mean time from index surgery to diagnosis of dislocation was 58.2 days (range, 0-319 days). One dislocation occurred immediately after surgery, 2 after falls, 4 from patient-identified low-energy mechanisms of injury, and 8 without known inciting events. Nine dislocations (60%) did not have a subscapularis repair (7 were irreparable, 2 underwent subscapularis peel without repair), and the other 6 were repaired primarily (Table 2).

Discussion

With more RTSAs being performed, evaluation of their common complications becomes increasingly important.¹⁸ We found a 3.0% rate of dislocation after RTSA, which is consistent with the most recently reported incidence⁴ and falls within the previously described range of 0% to 8.6%.^19-26 Of the clinical risk factors identified in this study, those previously described were prior surgery, subscapularis insufficiency, higher BMI, and male sex.⁴ However, our finding of lower risk of dislocation after RTSA for primary rotator cuff pathology was not previously described. Although Chalmers and colleagues⁴ did not report this lower risk, 3 (27.3%) of their 11 patients with dislocation had primary CTA, compared with 1 (6.7%) of 15 patients in the present study.⁴ Our literature review did not identify any studies that independently reported the dislocation rate in patients who underwent RTSA for rotator cuff failure.

The risk factors of subscapularis irreparability and revision surgery suggest the importance of the soft-tissue envelope and bony anatomy in dislocation prevention. Previous analyses have suggested implant malpositioning,^27,28 poor subscapularis quality,²⁹ and inadequate muscle tensioning^5,30-32 as risk factors for RTSA. Patients with an irreparable subscapularis tendon have often had multiple surgeries with compromise to the muscle/soft-tissue envelope or bony anatomy of the shoulder. A biomechanical study by Gutiérrez and colleagues³¹ found the compressive forces of the soft tissue at the glenohumeral joint to be the most important contributor to stability in the RTSA prosthesis. In clinical studies, the role of the subscapularis in preventing instability after RTSA remains unclear. Edwards and colleagues²⁹ prospectively compared dislocation rates in patients with reparable and irreparable subscapularis tendons during RTSA and found a higher rate of dislocation in the irreparable subscapularis group. Of note, patients in the irreparable subscapularis group also had more complex diagnoses, including proximal humeral nonunion, fixed glenohumeral dislocation, and failed prior arthroplasty. Clark and colleagues³³ retrospectively analyzed subscapularis repair in 2 RTSA groups and found no appreciable effect on complication rate, dislocation events, range-of-motion gains, or pain relief.

Our finding that higher BMI is an independent risk factor was previously described.⁴ The association is unclear but could be related to implant positioning, difficulty in intraoperative assessment of muscle tensioning, or body habitus that may generate a lever arm for impingement and dislocation when the arm is in adduction. Last, our finding that male sex is a risk factor for dislocation approached significance, and this relationship was previously reported.⁴ This could be attributable to a higher rate of activity or of indolent infection in male patients.^34,35Besides studying risk factors for dislocation after RTSA, we investigated treatment. None of our patients were treated successfully and definitively with closed reduction in the clinic. This finding diverges from findings in studies by Teusink and colleagues² and Chalmers and colleagues,⁴who respectively reported 62% and 44% rates of success with closed reduction. Our cohort of 14 patients with 15 dislocations required a total of 17 trips to the operating room after dislocation. This significantly higher rate of return to the operating room suggests that dislocation after RTSA may be a more costly and morbid problem than has been previously described.

This study had several weaknesses. Despite its large consecutive series of patients, the study was retrospective, and several variables that would be documented and controlled in a prospective study could not be measured here. Specifically, neither preoperative physical examination nor patient-specific assessments of pain or function were consistently obtained. Similarly, postoperative patient-specific instruments of outcomes evaluation were not obtained consistently, so results of patients with dislocation could not be compared with those of a control group. In addition, preoperative and postoperative radiographs were not consistently present in our electronic medical records, so the influence of preoperative bony anatomy, intraoperative limb lengthening, and any implant malpositioning could not be determined. Furthermore, operative details, such as reparability of the subscapularis, were not fully available for the control group and could not be included in statistical analysis. In addition, that the known dislocation risk factor of male sex⁴ was identified here but was not significant in multivariate regression analysis suggests that this study may not have been adequately powered to identify a significant difference in dislocation rate between the sexes. Last, though our results suggested associations between the aforementioned variables and dislocation after RTSA, a truly causative relationship could not be confirmed with this study design or analysis. Therefore, our study findings are hypothesis-generating and may indicate a benefit to greater deltoid tensioning, use of retentive liners, or more conservative rehabilitation protocols for high-risk patients.

Conclusion

Dislocation after RTSA is an uncommon complication that often requires a return to the operating room. This study identified a modifiable risk factor (higher BMI) and 3 nonmodifiable risk factors (male sex, subscapularis insufficiency, revision surgery) for dislocation after RTSA. In contrast, patients who undergo RTSA for primary rotator cuff pathology are unlikely to dislocate after surgery. This low risk of dislocation after RTSA for primary cuff pathology was not previously described. Patients in the higher risk category may benefit from preoperative lifestyle modification, intraoperative techniques for increasing stability, and more conservative therapy after surgery. In addition, unlike previous investigations, this study did not find closed reduction in the clinic alone to be successful in definitively treating this patient population.

Am J Orthop. 2016;45(7):E444-E450. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

The rate of medical visits for rotator cuff pathology and the US incidence of arthroscopic rotator cuff repair (RCR) have increased over the past 10 years.¹ The increased use of RCR has been justified with improved patient outcomes.^2,3 Advances in surgical techniques and instrumentation have contributed to better outcomes for patients with rotator cuff pathology.^3-5 Several studies have validated RCR with functional outcome measures, cost–benefit analysis, and health-related quality-of-life measurements.^6-9

Healthcare reimbursement models are being changed to include capitated care, pay for performance, and penalties.¹⁰ Given the changing healthcare climate and the increasing incidence of RCR, it is becoming increasingly important for orthopedic surgeons to critically evaluate and modify their practice and procedures to decrease costs without compromising outcomes.¹¹ RCR outcome studies have focused on comparing open/mini-open with arthroscopic techniques, and single-row with double-row techniques, among others.^4,12-18 Furthermore, several studies on the cost-effectiveness of these surgical techniques have been conducted.^19-21Arthroscopic anchorless (transosseous [TO]) RCR, which is increasingly popular,²² combines the minimal invasiveness of arthroscopic procedures with the biomechanical strength of open TO repair. In addition, this technique avoids the potential complications and costs associated with suture anchors, such as anchor pullout and greater tuberosity osteolysis.^22,23 Several studies have documented the effectiveness of this technique.^24-26 Biomechanical and clinical outcome data supporting arthroscopic TO-RCR have been published, but there are no reports of studies that have analyzed the cost savings associated with this technique.

In this study, we compared implant costs associated with arthroscopic TO-RCR and arthroscopic TO-equivalent (TOE) RCR. We also evaluated these techniques’ operative time and outcomes. Our hypothesis was that arthroscopic TO-RCR can be performed at lower cost and without increasing operative time or compromising outcomes.

Materials and Methods

Our Institutional Review Board approved this study. Between February 2013 and January 2014, participating surgeons performed 43 arthroscopic TO-RCRs that met the study’s inclusion criteria. Twenty-one of the 43 patients enrolled and became the study group. The control group of 21 patients, who underwent arthroscopic TOE-RCR the preceding year (between January 2012 and January 2013), was matched to the study group on tear size and concomitant procedures, including biceps treatment, labral treatment, acromioplasty, and distal clavicle excision (Table 1).

The primary outcome measure was implant cost (amount paid by institution). Cost was determined and reported by an independent third party using Cerner Surginet as the operating room documentation system and McKessen Pathways Materials Management System for item pricing.

All arthroscopic RCRs were performed by 1 of 3 orthopedic surgeons fellowship-trained in either sports medicine or shoulder and elbow surgery. Using the Cofield classification,²⁷ the treating surgeon recorded the size of the rotator cuff tear: small (<1 cm), medium (1-3 cm), large (3-5 cm), massive (>5 cm). The surgeon also recorded the number of suture anchors used, repair technique, biceps treatment, execution of subacromial decompression, execution of distal clavicle excision, and intraoperative complications. TO repair surgical technique is described in the next section. TOE repair was double-row repair with suture anchors. The number of suture anchors varied by tear size: small (3 anchors), medium (2-5 anchors), large (4-6 anchors), massive (4-5 anchors).

Secondary outcome measures were operative time (time from cut to close) and scores on pain VAS (visual analog scale), SANE (Single Assessment Numeric Evaluation), and SST (Simple Shoulder Test). Demographic information was also obtained: age, sex, body mass index, smoking status (Table 1). All patients were asked to fill out questionnaires before surgery and 3, 6, and >12 months after surgery. Outcome surveys were scored by a single research coordinator, who recorded each patient’s outcome scores at the preoperative and postoperative intervals. Follow-up of >12 months was reached by 17 (81%) of the 21 TO patients and 14 (67%) of the 21 TOE patients. For >12 months, the overall rate of follow-up was 74%.

All patients followed the same postoperative rehabilitation protocol: sling immobilization with pendulums for 6 weeks starting at 2 weeks, passive range of motion starting at 6 weeks, and active range of motion starting at 8 weeks. At 3 months, they were allowed progressive resistant exercises with a 10-pound limit, and at 4.5 months they progressed to a 20-pound limit. At 6 months, they were cleared for discharge.

Surgical Technique: Arthroscopic Transosseous Repair

Surgery was performed with the patient in either the beach-chair position or the lateral decubitus position, based on surgeon preference. Our technique is similar to what has been described in the past.^22,28 The glenohumeral joint is accessed through a standard posterior portal, followed by an anterior accessory portal through the rotator interval. Standard diagnostic arthroscopy is performed and intra-articular pathology addressed. Next, the scope is placed in the subacromial space through the posterior portal. A lateral subacromial portal is established and cannulated, and a bursectomy performed. The scope is then placed in a posterolateral portal for better visualization of the rotator cuff tear. The greater tuberosity is débrided with a curette to prepare the bed for repair. An ArthroTunneler (Tornier) is used to pass sutures through the greater tuberosity. For standard 2-tunnel repair, 3 sutures are placed through each tunnel. All 6 sutures are next passed (using a suture passer) through the rotator cuff. The second and fifth suture ends that are passed through the cuff are brought out through the cannula and tied together. They are then brought into the shoulder by pulling on the opposite ends and tied alongside the greater tuberosity to create a box stitch. The box stitch acts as a medial row fixation and as a rip stitch that strengthens the vertical mattress sutures against pullout. The other 4 sutures are tied in vertical mattress configuration.

Statistical Analysis

After obtaining the TO and TOE implant costs, we compared them using a generalized linear model with negative binomial distribution and an identity link function so returned parameters were in additive dollars. This comparison included evaluation of tear size and concomitant procedures. Operative times for TO and TOE were obtained and evaluated, and then compared using time-to-event analysis and the log-rank test. Outcome scores were obtained from patients at baseline and 3, 6, and >12 months after surgery and were compared using a linear mixed model that identified change in outcome scores over time, and difference in outcome scores between the TO and TOE groups.

Results

Table 1 lists patient demographics, including age, sex, body mass index, smoking status, and concomitant procedures. The TO and TOE groups had identical tear-size distributions. In addition, they had similar numbers of concomitant procedures, though our study was underpowered to confirm equivalence. Treatment techniques differed: more biceps tenodesis cases in the TO group (n = 12) than in the TOE group (n = 2) and more biceps tenotomy cases in the TOE group (n = 8) than in the TO group (n = 1).

TO implant cost was significantly lower than TOE implant cost for all tear sizes and independent of concomitant procedures (Figure 1).

Discussion

RCR is one of the most common orthopedic surgical procedures, and its use has increased over the past decade.^9,21 This increase coincides with the emergence of new repair techniques and implants. These advancements come at a cost. Given the increasingly cost-conscious healthcare environment and its changing reimbursement models, now surgeons must evaluate the economics of their surgical procedures in an attempt to decrease costs without compromising outcomes. We hypothesized that arthroscopic TO-RCR can be performed at lower cost relative to arthroscopic TOE-RCR and without increasing operative time or compromising short-term outcomes.

Studies on the cost-effectiveness of different RCR techniques have been conducted.^19-21 Adla and colleagues¹⁹ found that open RCR was more cost-effective than arthroscopic RCR, with most of the difference attributable to disposables and suture anchors. Genuario and colleagues²¹ found that double-row RCR was not as cost-effective as single-row RCR in treating tears of any size. They attributed the difference to 2 more anchors and about 15 more minutes in the operating room.

The increased interest in healthcare costs and the understanding that a substantial part of the cost of arthroscopic RCR is attributable to implants (suture anchors, specifically) led to recent efforts to eliminate the need for anchors. Newly available instrumentation was designed to assist in arthroscopic anchorless repair constructs using the concepts of traditional TO repair.²² Although still considered to be the RCR gold standard, TO fixation has been used less often in recent years, owing to the shift from open to arthroscopic surgery.²⁴ Arthroscopic TO-RCR allows for all the benefits of arthroscopic surgery, plus the biological and mechanical benefits of traditional open or mini-open TO repair. In addition, this technique eliminates the cost of anchors. Kummer and colleagues²⁵ confirmed with biomechanical testing that arthroscopic TO repair and double-row TOE repair are similar in strength, with a trend of less tendon displacement in the TO group.

Our study results support the hypothesis that arthroscopic TO repair provides significant cost savings over tear size–matched arthroscopic TOE repair. Implant cost was substantially higher for TOE repair than for TO repair. Mean (SD) total savings of $946.91 ($100.70) (P < .0001) can be realized performing TO rather than TOE repair. In the United States, where about 250,000 RCRs are performed each year, the use of TO repair would result in an annual savings of almost $250 million.⁶Operative time was analyzed as well. Running an operating room in the United States costs an estimated $62 per minute (range, $22-$133 per minute).²⁹ Much of this cost is indirect, unrelated to the surgery (eg, capital investment, personnel, insurance), and is being paid even when the operating room is not in use. Therefore, for the hospital’s bottom line, operative time savings are less important than direct cost savings (supplies, implants). However, operative time has more of an effect on the surgeon’s bottom line, and longer procedures reduce the number of surgeries that can be performed and billed. We found no significant difference in operative time between TO and TOE repairs. Critical evaluation revealed that operative time was 5.96 minutes shorter for TOE repairs, but this difference was not significant (P = .677).

Our study results showed no significant difference in clinical outcomes between TO and TOE repair patients. Both groups’ outcome scores improved. At all follow-ups, both groups’ VAS, SANE, and SST scores were significantly improved. Overall, this is the first study to validate the proposed cost benefit of arthroscopic TO repair and confirm no compromise in patient outcomes.

This study had limitations. First, it enrolled relatively few patients, particularly those with small tears. In addition, despite the fact that patients were matched on tear size and concomitant procedures, the groups differed in their biceps pathology treatments. Of the 13 TO patients who had biceps treatment, 12 underwent tenodesis (1 had tenotomy); in contrast, of the 10 TOE patients who had biceps treatment, only 2 underwent tenodesis (8 had tenotomy). The difference is explained by the consecutive course of this study and the increasing popularity of tenodesis over tenotomy. The TOE group underwent surgery before the TO group did, at a time when the involved surgeons were routinely performing tenotomy more than tenodesis. We did not include the costs of implants related to biceps treatment in our analysis, as our focus was on the implant cost of RCR. As for operative time, biceps tenodesis would be expected to extend surgery and potentially affect the comparison of operative times between the TO and TOE groups. However, despite the fact that 12 of the 13 TO patients underwent biceps tenodesis, there was no significant difference in overall operative time. Last, regarding the effect of biceps treatment on clinical outcomes, there are no data showing improved outcomes with tenodesis over tenotomy in the setting of RCR.

A final limitation is lack of data from longer term (>12 months) follow-up for all patients. Our analysis included cost and operative time data for all 42 enrolled patients, but our clinical outcome data represent only 74% of the patients enrolled. Eleven of the 42 patients were lost to follow-up at >12 months, and outcome scores could not be obtained, despite multiple attempts at contact (phone, mail, email). The study design and primary outcome variable focused on cost analysis rather than clinical outcomes. Nevertheless, our data support our hypothesis that there is no difference in clinical outcomes between TO and TOE repairs.

Conclusion

Arthroscopic TO-RCR provides significant cost savings over arthroscopic TOE-RCR without increasing operative time or compromising outcomes. Arthroscopic TO-RCR may have an important role in the evolving healthcare environment and its changing reimbursement models.

Am J Orthop. 2016;45(7):E415-E420. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

The rate of medical visits for rotator cuff pathology and the US incidence of arthroscopic rotator cuff repair (RCR) have increased over the past 10 years.¹ The increased use of RCR has been justified with improved patient outcomes.^2,3 Advances in surgical techniques and instrumentation have contributed to better outcomes for patients with rotator cuff pathology.^3-5 Several studies have validated RCR with functional outcome measures, cost–benefit analysis, and health-related quality-of-life measurements.^6-9

Healthcare reimbursement models are being changed to include capitated care, pay for performance, and penalties.¹⁰ Given the changing healthcare climate and the increasing incidence of RCR, it is becoming increasingly important for orthopedic surgeons to critically evaluate and modify their practice and procedures to decrease costs without compromising outcomes.¹¹ RCR outcome studies have focused on comparing open/mini-open with arthroscopic techniques, and single-row with double-row techniques, among others.^4,12-18 Furthermore, several studies on the cost-effectiveness of these surgical techniques have been conducted.^19-21Arthroscopic anchorless (transosseous [TO]) RCR, which is increasingly popular,²² combines the minimal invasiveness of arthroscopic procedures with the biomechanical strength of open TO repair. In addition, this technique avoids the potential complications and costs associated with suture anchors, such as anchor pullout and greater tuberosity osteolysis.^22,23 Several studies have documented the effectiveness of this technique.^24-26 Biomechanical and clinical outcome data supporting arthroscopic TO-RCR have been published, but there are no reports of studies that have analyzed the cost savings associated with this technique.

In this study, we compared implant costs associated with arthroscopic TO-RCR and arthroscopic TO-equivalent (TOE) RCR. We also evaluated these techniques’ operative time and outcomes. Our hypothesis was that arthroscopic TO-RCR can be performed at lower cost and without increasing operative time or compromising outcomes.

Materials and Methods

Our Institutional Review Board approved this study. Between February 2013 and January 2014, participating surgeons performed 43 arthroscopic TO-RCRs that met the study’s inclusion criteria. Twenty-one of the 43 patients enrolled and became the study group. The control group of 21 patients, who underwent arthroscopic TOE-RCR the preceding year (between January 2012 and January 2013), was matched to the study group on tear size and concomitant procedures, including biceps treatment, labral treatment, acromioplasty, and distal clavicle excision (Table 1).

The primary outcome measure was implant cost (amount paid by institution). Cost was determined and reported by an independent third party using Cerner Surginet as the operating room documentation system and McKessen Pathways Materials Management System for item pricing.

All arthroscopic RCRs were performed by 1 of 3 orthopedic surgeons fellowship-trained in either sports medicine or shoulder and elbow surgery. Using the Cofield classification,²⁷ the treating surgeon recorded the size of the rotator cuff tear: small (<1 cm), medium (1-3 cm), large (3-5 cm), massive (>5 cm). The surgeon also recorded the number of suture anchors used, repair technique, biceps treatment, execution of subacromial decompression, execution of distal clavicle excision, and intraoperative complications. TO repair surgical technique is described in the next section. TOE repair was double-row repair with suture anchors. The number of suture anchors varied by tear size: small (3 anchors), medium (2-5 anchors), large (4-6 anchors), massive (4-5 anchors).

Secondary outcome measures were operative time (time from cut to close) and scores on pain VAS (visual analog scale), SANE (Single Assessment Numeric Evaluation), and SST (Simple Shoulder Test). Demographic information was also obtained: age, sex, body mass index, smoking status (Table 1). All patients were asked to fill out questionnaires before surgery and 3, 6, and >12 months after surgery. Outcome surveys were scored by a single research coordinator, who recorded each patient’s outcome scores at the preoperative and postoperative intervals. Follow-up of >12 months was reached by 17 (81%) of the 21 TO patients and 14 (67%) of the 21 TOE patients. For >12 months, the overall rate of follow-up was 74%.

All patients followed the same postoperative rehabilitation protocol: sling immobilization with pendulums for 6 weeks starting at 2 weeks, passive range of motion starting at 6 weeks, and active range of motion starting at 8 weeks. At 3 months, they were allowed progressive resistant exercises with a 10-pound limit, and at 4.5 months they progressed to a 20-pound limit. At 6 months, they were cleared for discharge.

Surgical Technique: Arthroscopic Transosseous Repair

Surgery was performed with the patient in either the beach-chair position or the lateral decubitus position, based on surgeon preference. Our technique is similar to what has been described in the past.^22,28 The glenohumeral joint is accessed through a standard posterior portal, followed by an anterior accessory portal through the rotator interval. Standard diagnostic arthroscopy is performed and intra-articular pathology addressed. Next, the scope is placed in the subacromial space through the posterior portal. A lateral subacromial portal is established and cannulated, and a bursectomy performed. The scope is then placed in a posterolateral portal for better visualization of the rotator cuff tear. The greater tuberosity is débrided with a curette to prepare the bed for repair. An ArthroTunneler (Tornier) is used to pass sutures through the greater tuberosity. For standard 2-tunnel repair, 3 sutures are placed through each tunnel. All 6 sutures are next passed (using a suture passer) through the rotator cuff. The second and fifth suture ends that are passed through the cuff are brought out through the cannula and tied together. They are then brought into the shoulder by pulling on the opposite ends and tied alongside the greater tuberosity to create a box stitch. The box stitch acts as a medial row fixation and as a rip stitch that strengthens the vertical mattress sutures against pullout. The other 4 sutures are tied in vertical mattress configuration.

Statistical Analysis

After obtaining the TO and TOE implant costs, we compared them using a generalized linear model with negative binomial distribution and an identity link function so returned parameters were in additive dollars. This comparison included evaluation of tear size and concomitant procedures. Operative times for TO and TOE were obtained and evaluated, and then compared using time-to-event analysis and the log-rank test. Outcome scores were obtained from patients at baseline and 3, 6, and >12 months after surgery and were compared using a linear mixed model that identified change in outcome scores over time, and difference in outcome scores between the TO and TOE groups.

Results

Table 1 lists patient demographics, including age, sex, body mass index, smoking status, and concomitant procedures. The TO and TOE groups had identical tear-size distributions. In addition, they had similar numbers of concomitant procedures, though our study was underpowered to confirm equivalence. Treatment techniques differed: more biceps tenodesis cases in the TO group (n = 12) than in the TOE group (n = 2) and more biceps tenotomy cases in the TOE group (n = 8) than in the TO group (n = 1).

TO implant cost was significantly lower than TOE implant cost for all tear sizes and independent of concomitant procedures (Figure 1).

Discussion

RCR is one of the most common orthopedic surgical procedures, and its use has increased over the past decade.^9,21 This increase coincides with the emergence of new repair techniques and implants. These advancements come at a cost. Given the increasingly cost-conscious healthcare environment and its changing reimbursement models, now surgeons must evaluate the economics of their surgical procedures in an attempt to decrease costs without compromising outcomes. We hypothesized that arthroscopic TO-RCR can be performed at lower cost relative to arthroscopic TOE-RCR and without increasing operative time or compromising short-term outcomes.

Studies on the cost-effectiveness of different RCR techniques have been conducted.^19-21 Adla and colleagues¹⁹ found that open RCR was more cost-effective than arthroscopic RCR, with most of the difference attributable to disposables and suture anchors. Genuario and colleagues²¹ found that double-row RCR was not as cost-effective as single-row RCR in treating tears of any size. They attributed the difference to 2 more anchors and about 15 more minutes in the operating room.

The increased interest in healthcare costs and the understanding that a substantial part of the cost of arthroscopic RCR is attributable to implants (suture anchors, specifically) led to recent efforts to eliminate the need for anchors. Newly available instrumentation was designed to assist in arthroscopic anchorless repair constructs using the concepts of traditional TO repair.²² Although still considered to be the RCR gold standard, TO fixation has been used less often in recent years, owing to the shift from open to arthroscopic surgery.²⁴ Arthroscopic TO-RCR allows for all the benefits of arthroscopic surgery, plus the biological and mechanical benefits of traditional open or mini-open TO repair. In addition, this technique eliminates the cost of anchors. Kummer and colleagues²⁵ confirmed with biomechanical testing that arthroscopic TO repair and double-row TOE repair are similar in strength, with a trend of less tendon displacement in the TO group.

Our study results support the hypothesis that arthroscopic TO repair provides significant cost savings over tear size–matched arthroscopic TOE repair. Implant cost was substantially higher for TOE repair than for TO repair. Mean (SD) total savings of $946.91 ($100.70) (P < .0001) can be realized performing TO rather than TOE repair. In the United States, where about 250,000 RCRs are performed each year, the use of TO repair would result in an annual savings of almost $250 million.⁶Operative time was analyzed as well. Running an operating room in the United States costs an estimated $62 per minute (range, $22-$133 per minute).²⁹ Much of this cost is indirect, unrelated to the surgery (eg, capital investment, personnel, insurance), and is being paid even when the operating room is not in use. Therefore, for the hospital’s bottom line, operative time savings are less important than direct cost savings (supplies, implants). However, operative time has more of an effect on the surgeon’s bottom line, and longer procedures reduce the number of surgeries that can be performed and billed. We found no significant difference in operative time between TO and TOE repairs. Critical evaluation revealed that operative time was 5.96 minutes shorter for TOE repairs, but this difference was not significant (P = .677).

Our study results showed no significant difference in clinical outcomes between TO and TOE repair patients. Both groups’ outcome scores improved. At all follow-ups, both groups’ VAS, SANE, and SST scores were significantly improved. Overall, this is the first study to validate the proposed cost benefit of arthroscopic TO repair and confirm no compromise in patient outcomes.

This study had limitations. First, it enrolled relatively few patients, particularly those with small tears. In addition, despite the fact that patients were matched on tear size and concomitant procedures, the groups differed in their biceps pathology treatments. Of the 13 TO patients who had biceps treatment, 12 underwent tenodesis (1 had tenotomy); in contrast, of the 10 TOE patients who had biceps treatment, only 2 underwent tenodesis (8 had tenotomy). The difference is explained by the consecutive course of this study and the increasing popularity of tenodesis over tenotomy. The TOE group underwent surgery before the TO group did, at a time when the involved surgeons were routinely performing tenotomy more than tenodesis. We did not include the costs of implants related to biceps treatment in our analysis, as our focus was on the implant cost of RCR. As for operative time, biceps tenodesis would be expected to extend surgery and potentially affect the comparison of operative times between the TO and TOE groups. However, despite the fact that 12 of the 13 TO patients underwent biceps tenodesis, there was no significant difference in overall operative time. Last, regarding the effect of biceps treatment on clinical outcomes, there are no data showing improved outcomes with tenodesis over tenotomy in the setting of RCR.

A final limitation is lack of data from longer term (>12 months) follow-up for all patients. Our analysis included cost and operative time data for all 42 enrolled patients, but our clinical outcome data represent only 74% of the patients enrolled. Eleven of the 42 patients were lost to follow-up at >12 months, and outcome scores could not be obtained, despite multiple attempts at contact (phone, mail, email). The study design and primary outcome variable focused on cost analysis rather than clinical outcomes. Nevertheless, our data support our hypothesis that there is no difference in clinical outcomes between TO and TOE repairs.

Conclusion

Arthroscopic TO-RCR provides significant cost savings over arthroscopic TOE-RCR without increasing operative time or compromising outcomes. Arthroscopic TO-RCR may have an important role in the evolving healthcare environment and its changing reimbursement models.

Am J Orthop. 2016;45(7):E415-E420. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

The rate of medical visits for rotator cuff pathology and the US incidence of arthroscopic rotator cuff repair (RCR) have increased over the past 10 years.¹ The increased use of RCR has been justified with improved patient outcomes.^2,3 Advances in surgical techniques and instrumentation have contributed to better outcomes for patients with rotator cuff pathology.^3-5 Several studies have validated RCR with functional outcome measures, cost–benefit analysis, and health-related quality-of-life measurements.^6-9

Healthcare reimbursement models are being changed to include capitated care, pay for performance, and penalties.¹⁰ Given the changing healthcare climate and the increasing incidence of RCR, it is becoming increasingly important for orthopedic surgeons to critically evaluate and modify their practice and procedures to decrease costs without compromising outcomes.¹¹ RCR outcome studies have focused on comparing open/mini-open with arthroscopic techniques, and single-row with double-row techniques, among others.^4,12-18 Furthermore, several studies on the cost-effectiveness of these surgical techniques have been conducted.^19-21Arthroscopic anchorless (transosseous [TO]) RCR, which is increasingly popular,²² combines the minimal invasiveness of arthroscopic procedures with the biomechanical strength of open TO repair. In addition, this technique avoids the potential complications and costs associated with suture anchors, such as anchor pullout and greater tuberosity osteolysis.^22,23 Several studies have documented the effectiveness of this technique.^24-26 Biomechanical and clinical outcome data supporting arthroscopic TO-RCR have been published, but there are no reports of studies that have analyzed the cost savings associated with this technique.

In this study, we compared implant costs associated with arthroscopic TO-RCR and arthroscopic TO-equivalent (TOE) RCR. We also evaluated these techniques’ operative time and outcomes. Our hypothesis was that arthroscopic TO-RCR can be performed at lower cost and without increasing operative time or compromising outcomes.

Materials and Methods

Our Institutional Review Board approved this study. Between February 2013 and January 2014, participating surgeons performed 43 arthroscopic TO-RCRs that met the study’s inclusion criteria. Twenty-one of the 43 patients enrolled and became the study group. The control group of 21 patients, who underwent arthroscopic TOE-RCR the preceding year (between January 2012 and January 2013), was matched to the study group on tear size and concomitant procedures, including biceps treatment, labral treatment, acromioplasty, and distal clavicle excision (Table 1).

The primary outcome measure was implant cost (amount paid by institution). Cost was determined and reported by an independent third party using Cerner Surginet as the operating room documentation system and McKessen Pathways Materials Management System for item pricing.

All arthroscopic RCRs were performed by 1 of 3 orthopedic surgeons fellowship-trained in either sports medicine or shoulder and elbow surgery. Using the Cofield classification,²⁷ the treating surgeon recorded the size of the rotator cuff tear: small (<1 cm), medium (1-3 cm), large (3-5 cm), massive (>5 cm). The surgeon also recorded the number of suture anchors used, repair technique, biceps treatment, execution of subacromial decompression, execution of distal clavicle excision, and intraoperative complications. TO repair surgical technique is described in the next section. TOE repair was double-row repair with suture anchors. The number of suture anchors varied by tear size: small (3 anchors), medium (2-5 anchors), large (4-6 anchors), massive (4-5 anchors).

Secondary outcome measures were operative time (time from cut to close) and scores on pain VAS (visual analog scale), SANE (Single Assessment Numeric Evaluation), and SST (Simple Shoulder Test). Demographic information was also obtained: age, sex, body mass index, smoking status (Table 1). All patients were asked to fill out questionnaires before surgery and 3, 6, and >12 months after surgery. Outcome surveys were scored by a single research coordinator, who recorded each patient’s outcome scores at the preoperative and postoperative intervals. Follow-up of >12 months was reached by 17 (81%) of the 21 TO patients and 14 (67%) of the 21 TOE patients. For >12 months, the overall rate of follow-up was 74%.

All patients followed the same postoperative rehabilitation protocol: sling immobilization with pendulums for 6 weeks starting at 2 weeks, passive range of motion starting at 6 weeks, and active range of motion starting at 8 weeks. At 3 months, they were allowed progressive resistant exercises with a 10-pound limit, and at 4.5 months they progressed to a 20-pound limit. At 6 months, they were cleared for discharge.

Surgical Technique: Arthroscopic Transosseous Repair

Surgery was performed with the patient in either the beach-chair position or the lateral decubitus position, based on surgeon preference. Our technique is similar to what has been described in the past.^22,28 The glenohumeral joint is accessed through a standard posterior portal, followed by an anterior accessory portal through the rotator interval. Standard diagnostic arthroscopy is performed and intra-articular pathology addressed. Next, the scope is placed in the subacromial space through the posterior portal. A lateral subacromial portal is established and cannulated, and a bursectomy performed. The scope is then placed in a posterolateral portal for better visualization of the rotator cuff tear. The greater tuberosity is débrided with a curette to prepare the bed for repair. An ArthroTunneler (Tornier) is used to pass sutures through the greater tuberosity. For standard 2-tunnel repair, 3 sutures are placed through each tunnel. All 6 sutures are next passed (using a suture passer) through the rotator cuff. The second and fifth suture ends that are passed through the cuff are brought out through the cannula and tied together. They are then brought into the shoulder by pulling on the opposite ends and tied alongside the greater tuberosity to create a box stitch. The box stitch acts as a medial row fixation and as a rip stitch that strengthens the vertical mattress sutures against pullout. The other 4 sutures are tied in vertical mattress configuration.

Statistical Analysis

After obtaining the TO and TOE implant costs, we compared them using a generalized linear model with negative binomial distribution and an identity link function so returned parameters were in additive dollars. This comparison included evaluation of tear size and concomitant procedures. Operative times for TO and TOE were obtained and evaluated, and then compared using time-to-event analysis and the log-rank test. Outcome scores were obtained from patients at baseline and 3, 6, and >12 months after surgery and were compared using a linear mixed model that identified change in outcome scores over time, and difference in outcome scores between the TO and TOE groups.

Results

Table 1 lists patient demographics, including age, sex, body mass index, smoking status, and concomitant procedures. The TO and TOE groups had identical tear-size distributions. In addition, they had similar numbers of concomitant procedures, though our study was underpowered to confirm equivalence. Treatment techniques differed: more biceps tenodesis cases in the TO group (n = 12) than in the TOE group (n = 2) and more biceps tenotomy cases in the TOE group (n = 8) than in the TO group (n = 1).

TO implant cost was significantly lower than TOE implant cost for all tear sizes and independent of concomitant procedures (Figure 1).

Discussion

RCR is one of the most common orthopedic surgical procedures, and its use has increased over the past decade.^9,21 This increase coincides with the emergence of new repair techniques and implants. These advancements come at a cost. Given the increasingly cost-conscious healthcare environment and its changing reimbursement models, now surgeons must evaluate the economics of their surgical procedures in an attempt to decrease costs without compromising outcomes. We hypothesized that arthroscopic TO-RCR can be performed at lower cost relative to arthroscopic TOE-RCR and without increasing operative time or compromising short-term outcomes.

Studies on the cost-effectiveness of different RCR techniques have been conducted.^19-21 Adla and colleagues¹⁹ found that open RCR was more cost-effective than arthroscopic RCR, with most of the difference attributable to disposables and suture anchors. Genuario and colleagues²¹ found that double-row RCR was not as cost-effective as single-row RCR in treating tears of any size. They attributed the difference to 2 more anchors and about 15 more minutes in the operating room.

The increased interest in healthcare costs and the understanding that a substantial part of the cost of arthroscopic RCR is attributable to implants (suture anchors, specifically) led to recent efforts to eliminate the need for anchors. Newly available instrumentation was designed to assist in arthroscopic anchorless repair constructs using the concepts of traditional TO repair.²² Although still considered to be the RCR gold standard, TO fixation has been used less often in recent years, owing to the shift from open to arthroscopic surgery.²⁴ Arthroscopic TO-RCR allows for all the benefits of arthroscopic surgery, plus the biological and mechanical benefits of traditional open or mini-open TO repair. In addition, this technique eliminates the cost of anchors. Kummer and colleagues²⁵ confirmed with biomechanical testing that arthroscopic TO repair and double-row TOE repair are similar in strength, with a trend of less tendon displacement in the TO group.

Our study results support the hypothesis that arthroscopic TO repair provides significant cost savings over tear size–matched arthroscopic TOE repair. Implant cost was substantially higher for TOE repair than for TO repair. Mean (SD) total savings of $946.91 ($100.70) (P < .0001) can be realized performing TO rather than TOE repair. In the United States, where about 250,000 RCRs are performed each year, the use of TO repair would result in an annual savings of almost $250 million.⁶Operative time was analyzed as well. Running an operating room in the United States costs an estimated $62 per minute (range, $22-$133 per minute).²⁹ Much of this cost is indirect, unrelated to the surgery (eg, capital investment, personnel, insurance), and is being paid even when the operating room is not in use. Therefore, for the hospital’s bottom line, operative time savings are less important than direct cost savings (supplies, implants). However, operative time has more of an effect on the surgeon’s bottom line, and longer procedures reduce the number of surgeries that can be performed and billed. We found no significant difference in operative time between TO and TOE repairs. Critical evaluation revealed that operative time was 5.96 minutes shorter for TOE repairs, but this difference was not significant (P = .677).

Our study results showed no significant difference in clinical outcomes between TO and TOE repair patients. Both groups’ outcome scores improved. At all follow-ups, both groups’ VAS, SANE, and SST scores were significantly improved. Overall, this is the first study to validate the proposed cost benefit of arthroscopic TO repair and confirm no compromise in patient outcomes.

This study had limitations. First, it enrolled relatively few patients, particularly those with small tears. In addition, despite the fact that patients were matched on tear size and concomitant procedures, the groups differed in their biceps pathology treatments. Of the 13 TO patients who had biceps treatment, 12 underwent tenodesis (1 had tenotomy); in contrast, of the 10 TOE patients who had biceps treatment, only 2 underwent tenodesis (8 had tenotomy). The difference is explained by the consecutive course of this study and the increasing popularity of tenodesis over tenotomy. The TOE group underwent surgery before the TO group did, at a time when the involved surgeons were routinely performing tenotomy more than tenodesis. We did not include the costs of implants related to biceps treatment in our analysis, as our focus was on the implant cost of RCR. As for operative time, biceps tenodesis would be expected to extend surgery and potentially affect the comparison of operative times between the TO and TOE groups. However, despite the fact that 12 of the 13 TO patients underwent biceps tenodesis, there was no significant difference in overall operative time. Last, regarding the effect of biceps treatment on clinical outcomes, there are no data showing improved outcomes with tenodesis over tenotomy in the setting of RCR.

A final limitation is lack of data from longer term (>12 months) follow-up for all patients. Our analysis included cost and operative time data for all 42 enrolled patients, but our clinical outcome data represent only 74% of the patients enrolled. Eleven of the 42 patients were lost to follow-up at >12 months, and outcome scores could not be obtained, despite multiple attempts at contact (phone, mail, email). The study design and primary outcome variable focused on cost analysis rather than clinical outcomes. Nevertheless, our data support our hypothesis that there is no difference in clinical outcomes between TO and TOE repairs.

Conclusion

Arthroscopic TO-RCR provides significant cost savings over arthroscopic TOE-RCR without increasing operative time or compromising outcomes. Arthroscopic TO-RCR may have an important role in the evolving healthcare environment and its changing reimbursement models.

Am J Orthop. 2016;45(7):E415-E420. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

The annual number of total shoulder arthroplasties (TSAs) is rising with the growing elderly population and development of new technologies such as reverse shoulder arthroplasty.¹ In 2008, 47,000 shoulder arthroplasties were performed in the US compared with 19,000 in 1998.¹ As of 2011, there were 53,000 shoulder arthroplasties performed annually.² Pain control after shoulder procedures, particularly TSA, is challenging. ³

Several modalities exist to manage pain after shoulder arthroplasty. The interscalene brachial plexus nerve block is considered the “gold standard” for shoulder analgesia. A new approach is the periarticular injection method, in which the surgeon administers a local anesthetic intraoperatively. Liposomal bupivacaine (Exparel, Pacira Pharmaceuticals, Inc.) is a nonopioid anesthetic that has been shown to improve pain control, shorten hospital stays, and decrease costs for total knee and hip arthroplasty compared with nerve blocks.^4-6 Patients who were treated with liposomal bupivacaine consumed less opioid medication than a placebo group.⁷

Our purpose was to compare intraoperative local liposomal bupivacaine injection with preoperative single-shot interscalene nerve block (ISNB) in terms of pain control, opioid use, and length of hospital stay (LOS) after shoulder arthroplasty. We hypothesized that patients in the liposomal bupivacaine group would have lower pain scores, less opioid use, and shorter LOS compared with patients in the ISNB group.

Methods

A retrospective cohort analysis was conducted with 58 patients who underwent shoulder arthroplasty by 1 surgeon at our academically affiliated community hospital from January 2012 through January 2015. ISNBs were the standard at the beginning of the study period and were used until Exparel became available on the hospital formulary in 2013. We began using Exparel for all shoulder arthroplasties in November 2013. No other changes were made in the perioperative management of our arthroplasty patients during this period. Patients who underwent TSA, reverse TSA, or hemiarthroplasty of the shoulder were included. Patients who underwent revision TSA were excluded. Twenty-one patients received ISNBs and 37 received liposomal bupivacaine injections. This study was approved by our Institutional Review Board.

Baseline data for each patient were age, sex, body mass index, and the American Society of Anesthesiologists (ASA) Physical Status Classification. The primary outcome measure was the numeric rating scale (NRS) pain score at 4 post-operative time intervals. The NRS pain score has a range of 0 to 10, with 10 representing severe pain. Data were gathered from nursing and physical therapy notes in patient charts. The postoperative time intervals were 0 to 1 hour, 8 to 14 hours, 18 to 24 hours, and 27 to 36 hours. Available NRS scores for these time intervals were averaged. Patients were included if they had pain scores for at least 3 of the postoperative time intervals documented in their charts. Secondary outcome measures were LOS and opioid consumption during hospital admission. Intravenous acetaminophen use was also measured in both groups. All data on opioids were converted to oral morphine equivalents using the method described by Schneider and colleagues.⁸

A board-certified, fellowship-trained anesthesiologist, experienced in regional anesthesia, administered the single-shot ISNB before surgery. The block was administered under ultrasound guidance using a 44-mm, 22-gauge needle with the patient in the supine position. No indwelling catheter was used. The medication consisted of 30 mL of 5% ropivacaine (5 mg/mL). The surgeon injected liposomal bupivacaine (266 mg diluted into 40 mL of injectable saline) near the end of the procedure throughout the pericapsular area and multiple layers of the wound, per manufacturer guidelines.⁹ A 60-mL syringe with a 20-gauge needle was used. All operations were performed by 1 board-certified, fellowship-trained surgeon using a standard deltopectoral approach with the same surgical equipment. The same postoperative pain protocol was used for all patients, including intravenous acetaminophen and patient-controlled analgesia. Additional oral pain medication was provided as needed for all patients. Physical therapy protocols were identical between groups.

Statistical Analysis

Mean patient ages in the 2 treatment groups were compared using the Student t test. Sex distribution and the ASA scores were compared using a χ² test and a Fisher exact test, respectively. Arthroplasty types were compared using a Fisher exact test. The medians and interquartile ranges of the NRS scores at each time point measured were tabulated by treatment group, and at each time point the difference between groups was tested using nonparametric rank sum tests.

We tested the longitudinal trajectory of NRS scores over time, accounting for repeated measurements in the same patients using linear mixed model analysis. Treatment group, time period as a categorical variable, and the interaction between treatment and time period were included as fixed effects, and patient identification number was included as the random effect. An initial omnibus test was performed for all treatment and treatment-by-time interaction effects. Subsequently, the treatment-by-time interaction was tested for each of the time periods. The association of day of discharge (as a categorical variable) with treatment was tested using the Fisher exact test. All analyses were conducted using Stata, version 13, software (StataCorp LP). P values <.05 were considered significant.

Sample Size Analysis

We calculated the minimum detectable effect size with 80% power at an alpha level of 0.05 for the nonparametric rank sum test in terms of the proportion of every possible pair of patients treated with the 2 treatments, where the patient treated with liposomal bupivacaine has a lower pain score than the patient treated with ISNB. For pain score at 18 to 24 hours, the sample sizes of 33 patients treated with liposomal bupivacaine and 20 treated with ISNB, the minimum detectable effect size is 73%.

Results

Fifty-eight patient charts (21 in the ISNB group and 37 in the liposomal bupivacaine group) were reviewed for the study. Patient sex distribution, mean age, mean body mass index, and mean baseline ASA scores were not statistically different (Table 1).

The primary outcome measure, NRS pain score, showed no significant differences between groups at 0 to 1 hour after surgery (P = .99) or 8 to 14 hours after surgery (P = .208).

Discussion

Postoperative pain control after shoulder arthroplasty can be challenging, and several modalities have been tried in various combinations to minimize pain and decrease adverse effects of opioid medications. The most common method for pain relief after shoulder arthroplasty is the ISNB. Several studies of ISNBs have shown improved pain control after shoulder arthroplasty with associated decreased opioid consumption and related side effects.¹⁰ Patient rehabilitation and satisfaction have improved with the increasing use of peripheral nerve blocks.¹¹

Despite the well-established benefits of ISNBs, several limitations exist. Although the superior portion of the shoulder is well covered by an ISNB, the inferior portion of the brachial plexus can remain uncovered or only partially covered.¹² Complications of ISNBs include hemidiaphragmatic paresis, rebound pain 24 hours after surgery,¹³ chronic neurologic complications,¹⁴ and substantial respiratory and cardiovascular events.¹⁵ Nerve blocks also require additional time and resources in the perioperative period, including an anesthesiologist with specialized training, assistants, and ultrasonography or nerve stimulation equipment contraindicated in patients taking blood thinners.¹⁶

Periarticular injections of local anesthetics have also shown promise in reducing pain after arthroplasty.⁴ Benefits include an enhanced safety profile because local injection avoids the concurrent blockade of the phrenic nerve and recurrent laryngeal nerve and has not been associated with the risk of peripheral neuropathies. Further, local injection is a simple technique that can be performed during surgery without additional personnel or expertise. A limitation of this approach is the relatively short duration of effectiveness of the local anesthetic and uncertainty regarding the best agent and the ideal volume of injection.⁶ Liposomal bupivacaine is a new agent (approved by the US Food and Drug Administration in 2011¹⁷) with a sustained release over 72 to 96 hours.¹⁸ The most common adverse effects of liposomal bupivacaine are nausea, vomiting, constipation, pyrexia, dizziness, and headache.¹⁹ Chondrotoxicity and granulomatous inflammation are more serious, yet rare, complications of liposomal bupivacaine.²⁰

We found that liposomal bupivacaine injections were associated with lower pain scores compared with ISNB at 18 to 24 hours after surgery. This correlated with less opioid consumption in the liposomal bupivacaine group than in the ISNB group on the second postoperative day. These differences in pain values are consistent with the known pharmacokinetics of liposomal bupivacaine.¹⁸ Peak plasma levels normally occur approximately 24 hours after injection, leaving the early postoperative period relatively uncovered by anesthetic agent. This finding of relatively poor pain control early after surgery has also been noted in patients undergoing knee arthroplasty.⁵ On the basis of the findings of this study, we have added standard bupivacaine injections to our separate liposomal bupivacaine injection to cover early postoperative pain. Opioid consumption was significantly lower in the liposomal bupivacaine group than in the ISNB group on postoperative days 2 and 3. We did not measure adverse events related to opioid consumption, so we cannot comment on whether the decreased opioid consumption was associated with the rate of adverse events. However, other studies^21,22 have established this relationship.

We found the liposomal bupivacaine group to have earlier discharges to home. Sixteen of 37 patients in the liposomal bupivacaine group compared with 2 of 21 patients in the ISNB group were discharged on the day after surgery. A mean reduction in LOS of 18 hours for the liposomal bupivacaine group was statistically significant (P = .012). This reduction in LOS has important implications for hospitals and value analysis committees considering whether to keep a new, more expensive local anesthetic on formulary. Savings from reduced LOS and improvements in patient satisfaction may justify the expense (approximately $300 per 266-mg vial) of Exparel.

From a societal cost perspective, liposomal bupivacaine is more economical compared with ISNB, which adds approximately $1500 to the cost of anesthesia per patient.²³ Eliminating the costs associated with ISNB administration in shoulder arthroplasties could result in substantial savings to our healthcare system. More research examining time savings and exact costs of each procedure is needed to determine the true cost effectiveness of each approach.

Limitations of our study include the retrospective design, relatively small numbers of patients in each group, missing data for some patients at various time points, variation in the types of procedures in each group, and lack of long-term outcome measures. It is important to note that we did not confirm the success of the nerve block after administration. However, this study reflects the effectiveness of each of the modalities in actual clinical conditions (as opposed to a controlled experimental setting). The actual effectiveness of a nerve block varies, even when performed by an experienced anesthesiologist with ultrasound guidance. Furthermore, immediate postoperative pain scores in the nerve block group are consistent with those of prior research reporting pain values ranging from 4 to 5 and a mean duration of effect ranging from 9 to 14 hours.^23,24 Additionally, the patients, surgeon, and nursing team were not blinded to the treatment group. Although we did note a significant difference in the types of procedures between groups, this finding is related to the greater number of hemiarthroplasties performed in the ISNB group (N = 5) compared with the liposomal group (N = 1). Because of this variation and the decreased invasiveness of hemiarthroplasties, the bias is against the liposomal group. Finally, our primary outcome variable was pain, which is a subjective, self-reported measure. However, our opioid consumption data and LOS data corroborate the improved pain scores in the liposomal bupivacaine group.

Limiting the study to a single surgeon may limit external validity. Another limitation is the lack of data on adverse events related to opioid medication use. There was no additional experimental group to determine whether less expensive local anesthetics injected locally would perform similarly to liposomal bupivacaine. In total knee arthroplasty, periarticular injections of liposomal bupivacaine were not as effective as less expensive periarticular injections.²⁵ It is unclear which agents (and in what doses or combinations) should be used for periarticular injections. Finally, we acknowledge that our retrospective study design cannot account for all potential factors affecting discharge time.

This is the first comparative study of liposomal bupivacaine and ISNB in TSA. The study design allowed us to control for variables such as surgical technique, postoperative protocols (including use and type of sling), and use of other pain modalities such as patient-controlled analgesia and intravenous acetaminophen that are likely to affect postoperative pain and LOS. This study provides preliminary data that confirm relative equipoise between liposomal bupivacaine and ISNB, which is needed for the ethical conduct of a randomized controlled trial. Such a trial would allow for a more robust comparison, and this retrospective study provides appropriate pilot data on which to base this design and the clinical information needed to counsel patients during enrollment.

Our results suggest that liposomal bupivacaine may provide superior or similar pain relief compared with ISNB after shoulder arthroplasty. Additionally, the use of liposomal bupivacaine was associated with decreased opioid consumption and earlier discharge to home compared with ISNB. These findings have important implications for pain control after TSA because pain represents a major concern for patients and providers after surgery. In addition to clinical improvements, use of liposomal bupivacaine may save time and eliminate costs associated with administering nerve blocks. Local injection may also be used in patients who are contraindicated for ISNB such as those with obesity, pulmonary disease, or peripheral neuropathy. Although we cannot definitively suggest that liposomal bupivacaine is superior to the current gold standard ISNB for pain control after shoulder arthroplasty, our results suggest a relative clinical equipoise between these modalities. Larger analytical studies, including randomized trials, should be performed to explore the potential benefits of liposomal bupivacaine injections for pain control after shoulder arthroplasty.

Am J Orthop. 2016;45(7):424-430. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

The annual number of total shoulder arthroplasties (TSAs) is rising with the growing elderly population and development of new technologies such as reverse shoulder arthroplasty.¹ In 2008, 47,000 shoulder arthroplasties were performed in the US compared with 19,000 in 1998.¹ As of 2011, there were 53,000 shoulder arthroplasties performed annually.² Pain control after shoulder procedures, particularly TSA, is challenging. ³

Several modalities exist to manage pain after shoulder arthroplasty. The interscalene brachial plexus nerve block is considered the “gold standard” for shoulder analgesia. A new approach is the periarticular injection method, in which the surgeon administers a local anesthetic intraoperatively. Liposomal bupivacaine (Exparel, Pacira Pharmaceuticals, Inc.) is a nonopioid anesthetic that has been shown to improve pain control, shorten hospital stays, and decrease costs for total knee and hip arthroplasty compared with nerve blocks.^4-6 Patients who were treated with liposomal bupivacaine consumed less opioid medication than a placebo group.⁷

Our purpose was to compare intraoperative local liposomal bupivacaine injection with preoperative single-shot interscalene nerve block (ISNB) in terms of pain control, opioid use, and length of hospital stay (LOS) after shoulder arthroplasty. We hypothesized that patients in the liposomal bupivacaine group would have lower pain scores, less opioid use, and shorter LOS compared with patients in the ISNB group.

Methods

A retrospective cohort analysis was conducted with 58 patients who underwent shoulder arthroplasty by 1 surgeon at our academically affiliated community hospital from January 2012 through January 2015. ISNBs were the standard at the beginning of the study period and were used until Exparel became available on the hospital formulary in 2013. We began using Exparel for all shoulder arthroplasties in November 2013. No other changes were made in the perioperative management of our arthroplasty patients during this period. Patients who underwent TSA, reverse TSA, or hemiarthroplasty of the shoulder were included. Patients who underwent revision TSA were excluded. Twenty-one patients received ISNBs and 37 received liposomal bupivacaine injections. This study was approved by our Institutional Review Board.

Baseline data for each patient were age, sex, body mass index, and the American Society of Anesthesiologists (ASA) Physical Status Classification. The primary outcome measure was the numeric rating scale (NRS) pain score at 4 post-operative time intervals. The NRS pain score has a range of 0 to 10, with 10 representing severe pain. Data were gathered from nursing and physical therapy notes in patient charts. The postoperative time intervals were 0 to 1 hour, 8 to 14 hours, 18 to 24 hours, and 27 to 36 hours. Available NRS scores for these time intervals were averaged. Patients were included if they had pain scores for at least 3 of the postoperative time intervals documented in their charts. Secondary outcome measures were LOS and opioid consumption during hospital admission. Intravenous acetaminophen use was also measured in both groups. All data on opioids were converted to oral morphine equivalents using the method described by Schneider and colleagues.⁸

A board-certified, fellowship-trained anesthesiologist, experienced in regional anesthesia, administered the single-shot ISNB before surgery. The block was administered under ultrasound guidance using a 44-mm, 22-gauge needle with the patient in the supine position. No indwelling catheter was used. The medication consisted of 30 mL of 5% ropivacaine (5 mg/mL). The surgeon injected liposomal bupivacaine (266 mg diluted into 40 mL of injectable saline) near the end of the procedure throughout the pericapsular area and multiple layers of the wound, per manufacturer guidelines.⁹ A 60-mL syringe with a 20-gauge needle was used. All operations were performed by 1 board-certified, fellowship-trained surgeon using a standard deltopectoral approach with the same surgical equipment. The same postoperative pain protocol was used for all patients, including intravenous acetaminophen and patient-controlled analgesia. Additional oral pain medication was provided as needed for all patients. Physical therapy protocols were identical between groups.

Statistical Analysis

Mean patient ages in the 2 treatment groups were compared using the Student t test. Sex distribution and the ASA scores were compared using a χ² test and a Fisher exact test, respectively. Arthroplasty types were compared using a Fisher exact test. The medians and interquartile ranges of the NRS scores at each time point measured were tabulated by treatment group, and at each time point the difference between groups was tested using nonparametric rank sum tests.

We tested the longitudinal trajectory of NRS scores over time, accounting for repeated measurements in the same patients using linear mixed model analysis. Treatment group, time period as a categorical variable, and the interaction between treatment and time period were included as fixed effects, and patient identification number was included as the random effect. An initial omnibus test was performed for all treatment and treatment-by-time interaction effects. Subsequently, the treatment-by-time interaction was tested for each of the time periods. The association of day of discharge (as a categorical variable) with treatment was tested using the Fisher exact test. All analyses were conducted using Stata, version 13, software (StataCorp LP). P values <.05 were considered significant.

Sample Size Analysis

We calculated the minimum detectable effect size with 80% power at an alpha level of 0.05 for the nonparametric rank sum test in terms of the proportion of every possible pair of patients treated with the 2 treatments, where the patient treated with liposomal bupivacaine has a lower pain score than the patient treated with ISNB. For pain score at 18 to 24 hours, the sample sizes of 33 patients treated with liposomal bupivacaine and 20 treated with ISNB, the minimum detectable effect size is 73%.

Results

Fifty-eight patient charts (21 in the ISNB group and 37 in the liposomal bupivacaine group) were reviewed for the study. Patient sex distribution, mean age, mean body mass index, and mean baseline ASA scores were not statistically different (Table 1).

The primary outcome measure, NRS pain score, showed no significant differences between groups at 0 to 1 hour after surgery (P = .99) or 8 to 14 hours after surgery (P = .208).

Discussion

Postoperative pain control after shoulder arthroplasty can be challenging, and several modalities have been tried in various combinations to minimize pain and decrease adverse effects of opioid medications. The most common method for pain relief after shoulder arthroplasty is the ISNB. Several studies of ISNBs have shown improved pain control after shoulder arthroplasty with associated decreased opioid consumption and related side effects.¹⁰ Patient rehabilitation and satisfaction have improved with the increasing use of peripheral nerve blocks.¹¹

Despite the well-established benefits of ISNBs, several limitations exist. Although the superior portion of the shoulder is well covered by an ISNB, the inferior portion of the brachial plexus can remain uncovered or only partially covered.¹² Complications of ISNBs include hemidiaphragmatic paresis, rebound pain 24 hours after surgery,¹³ chronic neurologic complications,¹⁴ and substantial respiratory and cardiovascular events.¹⁵ Nerve blocks also require additional time and resources in the perioperative period, including an anesthesiologist with specialized training, assistants, and ultrasonography or nerve stimulation equipment contraindicated in patients taking blood thinners.¹⁶

Periarticular injections of local anesthetics have also shown promise in reducing pain after arthroplasty.⁴ Benefits include an enhanced safety profile because local injection avoids the concurrent blockade of the phrenic nerve and recurrent laryngeal nerve and has not been associated with the risk of peripheral neuropathies. Further, local injection is a simple technique that can be performed during surgery without additional personnel or expertise. A limitation of this approach is the relatively short duration of effectiveness of the local anesthetic and uncertainty regarding the best agent and the ideal volume of injection.⁶ Liposomal bupivacaine is a new agent (approved by the US Food and Drug Administration in 2011¹⁷) with a sustained release over 72 to 96 hours.¹⁸ The most common adverse effects of liposomal bupivacaine are nausea, vomiting, constipation, pyrexia, dizziness, and headache.¹⁹ Chondrotoxicity and granulomatous inflammation are more serious, yet rare, complications of liposomal bupivacaine.²⁰

We found that liposomal bupivacaine injections were associated with lower pain scores compared with ISNB at 18 to 24 hours after surgery. This correlated with less opioid consumption in the liposomal bupivacaine group than in the ISNB group on the second postoperative day. These differences in pain values are consistent with the known pharmacokinetics of liposomal bupivacaine.¹⁸ Peak plasma levels normally occur approximately 24 hours after injection, leaving the early postoperative period relatively uncovered by anesthetic agent. This finding of relatively poor pain control early after surgery has also been noted in patients undergoing knee arthroplasty.⁵ On the basis of the findings of this study, we have added standard bupivacaine injections to our separate liposomal bupivacaine injection to cover early postoperative pain. Opioid consumption was significantly lower in the liposomal bupivacaine group than in the ISNB group on postoperative days 2 and 3. We did not measure adverse events related to opioid consumption, so we cannot comment on whether the decreased opioid consumption was associated with the rate of adverse events. However, other studies^21,22 have established this relationship.

We found the liposomal bupivacaine group to have earlier discharges to home. Sixteen of 37 patients in the liposomal bupivacaine group compared with 2 of 21 patients in the ISNB group were discharged on the day after surgery. A mean reduction in LOS of 18 hours for the liposomal bupivacaine group was statistically significant (P = .012). This reduction in LOS has important implications for hospitals and value analysis committees considering whether to keep a new, more expensive local anesthetic on formulary. Savings from reduced LOS and improvements in patient satisfaction may justify the expense (approximately $300 per 266-mg vial) of Exparel.

From a societal cost perspective, liposomal bupivacaine is more economical compared with ISNB, which adds approximately $1500 to the cost of anesthesia per patient.²³ Eliminating the costs associated with ISNB administration in shoulder arthroplasties could result in substantial savings to our healthcare system. More research examining time savings and exact costs of each procedure is needed to determine the true cost effectiveness of each approach.

Limitations of our study include the retrospective design, relatively small numbers of patients in each group, missing data for some patients at various time points, variation in the types of procedures in each group, and lack of long-term outcome measures. It is important to note that we did not confirm the success of the nerve block after administration. However, this study reflects the effectiveness of each of the modalities in actual clinical conditions (as opposed to a controlled experimental setting). The actual effectiveness of a nerve block varies, even when performed by an experienced anesthesiologist with ultrasound guidance. Furthermore, immediate postoperative pain scores in the nerve block group are consistent with those of prior research reporting pain values ranging from 4 to 5 and a mean duration of effect ranging from 9 to 14 hours.^23,24 Additionally, the patients, surgeon, and nursing team were not blinded to the treatment group. Although we did note a significant difference in the types of procedures between groups, this finding is related to the greater number of hemiarthroplasties performed in the ISNB group (N = 5) compared with the liposomal group (N = 1). Because of this variation and the decreased invasiveness of hemiarthroplasties, the bias is against the liposomal group. Finally, our primary outcome variable was pain, which is a subjective, self-reported measure. However, our opioid consumption data and LOS data corroborate the improved pain scores in the liposomal bupivacaine group.

Limiting the study to a single surgeon may limit external validity. Another limitation is the lack of data on adverse events related to opioid medication use. There was no additional experimental group to determine whether less expensive local anesthetics injected locally would perform similarly to liposomal bupivacaine. In total knee arthroplasty, periarticular injections of liposomal bupivacaine were not as effective as less expensive periarticular injections.²⁵ It is unclear which agents (and in what doses or combinations) should be used for periarticular injections. Finally, we acknowledge that our retrospective study design cannot account for all potential factors affecting discharge time.

This is the first comparative study of liposomal bupivacaine and ISNB in TSA. The study design allowed us to control for variables such as surgical technique, postoperative protocols (including use and type of sling), and use of other pain modalities such as patient-controlled analgesia and intravenous acetaminophen that are likely to affect postoperative pain and LOS. This study provides preliminary data that confirm relative equipoise between liposomal bupivacaine and ISNB, which is needed for the ethical conduct of a randomized controlled trial. Such a trial would allow for a more robust comparison, and this retrospective study provides appropriate pilot data on which to base this design and the clinical information needed to counsel patients during enrollment.

Our results suggest that liposomal bupivacaine may provide superior or similar pain relief compared with ISNB after shoulder arthroplasty. Additionally, the use of liposomal bupivacaine was associated with decreased opioid consumption and earlier discharge to home compared with ISNB. These findings have important implications for pain control after TSA because pain represents a major concern for patients and providers after surgery. In addition to clinical improvements, use of liposomal bupivacaine may save time and eliminate costs associated with administering nerve blocks. Local injection may also be used in patients who are contraindicated for ISNB such as those with obesity, pulmonary disease, or peripheral neuropathy. Although we cannot definitively suggest that liposomal bupivacaine is superior to the current gold standard ISNB for pain control after shoulder arthroplasty, our results suggest a relative clinical equipoise between these modalities. Larger analytical studies, including randomized trials, should be performed to explore the potential benefits of liposomal bupivacaine injections for pain control after shoulder arthroplasty.

Am J Orthop. 2016;45(7):424-430. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

The annual number of total shoulder arthroplasties (TSAs) is rising with the growing elderly population and development of new technologies such as reverse shoulder arthroplasty.¹ In 2008, 47,000 shoulder arthroplasties were performed in the US compared with 19,000 in 1998.¹ As of 2011, there were 53,000 shoulder arthroplasties performed annually.² Pain control after shoulder procedures, particularly TSA, is challenging. ³

Several modalities exist to manage pain after shoulder arthroplasty. The interscalene brachial plexus nerve block is considered the “gold standard” for shoulder analgesia. A new approach is the periarticular injection method, in which the surgeon administers a local anesthetic intraoperatively. Liposomal bupivacaine (Exparel, Pacira Pharmaceuticals, Inc.) is a nonopioid anesthetic that has been shown to improve pain control, shorten hospital stays, and decrease costs for total knee and hip arthroplasty compared with nerve blocks.^4-6 Patients who were treated with liposomal bupivacaine consumed less opioid medication than a placebo group.⁷

Our purpose was to compare intraoperative local liposomal bupivacaine injection with preoperative single-shot interscalene nerve block (ISNB) in terms of pain control, opioid use, and length of hospital stay (LOS) after shoulder arthroplasty. We hypothesized that patients in the liposomal bupivacaine group would have lower pain scores, less opioid use, and shorter LOS compared with patients in the ISNB group.

Methods

A retrospective cohort analysis was conducted with 58 patients who underwent shoulder arthroplasty by 1 surgeon at our academically affiliated community hospital from January 2012 through January 2015. ISNBs were the standard at the beginning of the study period and were used until Exparel became available on the hospital formulary in 2013. We began using Exparel for all shoulder arthroplasties in November 2013. No other changes were made in the perioperative management of our arthroplasty patients during this period. Patients who underwent TSA, reverse TSA, or hemiarthroplasty of the shoulder were included. Patients who underwent revision TSA were excluded. Twenty-one patients received ISNBs and 37 received liposomal bupivacaine injections. This study was approved by our Institutional Review Board.

Baseline data for each patient were age, sex, body mass index, and the American Society of Anesthesiologists (ASA) Physical Status Classification. The primary outcome measure was the numeric rating scale (NRS) pain score at 4 post-operative time intervals. The NRS pain score has a range of 0 to 10, with 10 representing severe pain. Data were gathered from nursing and physical therapy notes in patient charts. The postoperative time intervals were 0 to 1 hour, 8 to 14 hours, 18 to 24 hours, and 27 to 36 hours. Available NRS scores for these time intervals were averaged. Patients were included if they had pain scores for at least 3 of the postoperative time intervals documented in their charts. Secondary outcome measures were LOS and opioid consumption during hospital admission. Intravenous acetaminophen use was also measured in both groups. All data on opioids were converted to oral morphine equivalents using the method described by Schneider and colleagues.⁸

A board-certified, fellowship-trained anesthesiologist, experienced in regional anesthesia, administered the single-shot ISNB before surgery. The block was administered under ultrasound guidance using a 44-mm, 22-gauge needle with the patient in the supine position. No indwelling catheter was used. The medication consisted of 30 mL of 5% ropivacaine (5 mg/mL). The surgeon injected liposomal bupivacaine (266 mg diluted into 40 mL of injectable saline) near the end of the procedure throughout the pericapsular area and multiple layers of the wound, per manufacturer guidelines.⁹ A 60-mL syringe with a 20-gauge needle was used. All operations were performed by 1 board-certified, fellowship-trained surgeon using a standard deltopectoral approach with the same surgical equipment. The same postoperative pain protocol was used for all patients, including intravenous acetaminophen and patient-controlled analgesia. Additional oral pain medication was provided as needed for all patients. Physical therapy protocols were identical between groups.

Statistical Analysis

Mean patient ages in the 2 treatment groups were compared using the Student t test. Sex distribution and the ASA scores were compared using a χ² test and a Fisher exact test, respectively. Arthroplasty types were compared using a Fisher exact test. The medians and interquartile ranges of the NRS scores at each time point measured were tabulated by treatment group, and at each time point the difference between groups was tested using nonparametric rank sum tests.

We tested the longitudinal trajectory of NRS scores over time, accounting for repeated measurements in the same patients using linear mixed model analysis. Treatment group, time period as a categorical variable, and the interaction between treatment and time period were included as fixed effects, and patient identification number was included as the random effect. An initial omnibus test was performed for all treatment and treatment-by-time interaction effects. Subsequently, the treatment-by-time interaction was tested for each of the time periods. The association of day of discharge (as a categorical variable) with treatment was tested using the Fisher exact test. All analyses were conducted using Stata, version 13, software (StataCorp LP). P values <.05 were considered significant.

Sample Size Analysis

We calculated the minimum detectable effect size with 80% power at an alpha level of 0.05 for the nonparametric rank sum test in terms of the proportion of every possible pair of patients treated with the 2 treatments, where the patient treated with liposomal bupivacaine has a lower pain score than the patient treated with ISNB. For pain score at 18 to 24 hours, the sample sizes of 33 patients treated with liposomal bupivacaine and 20 treated with ISNB, the minimum detectable effect size is 73%.

Results

Fifty-eight patient charts (21 in the ISNB group and 37 in the liposomal bupivacaine group) were reviewed for the study. Patient sex distribution, mean age, mean body mass index, and mean baseline ASA scores were not statistically different (Table 1).

The primary outcome measure, NRS pain score, showed no significant differences between groups at 0 to 1 hour after surgery (P = .99) or 8 to 14 hours after surgery (P = .208).

Discussion

Postoperative pain control after shoulder arthroplasty can be challenging, and several modalities have been tried in various combinations to minimize pain and decrease adverse effects of opioid medications. The most common method for pain relief after shoulder arthroplasty is the ISNB. Several studies of ISNBs have shown improved pain control after shoulder arthroplasty with associated decreased opioid consumption and related side effects.¹⁰ Patient rehabilitation and satisfaction have improved with the increasing use of peripheral nerve blocks.¹¹

Despite the well-established benefits of ISNBs, several limitations exist. Although the superior portion of the shoulder is well covered by an ISNB, the inferior portion of the brachial plexus can remain uncovered or only partially covered.¹² Complications of ISNBs include hemidiaphragmatic paresis, rebound pain 24 hours after surgery,¹³ chronic neurologic complications,¹⁴ and substantial respiratory and cardiovascular events.¹⁵ Nerve blocks also require additional time and resources in the perioperative period, including an anesthesiologist with specialized training, assistants, and ultrasonography or nerve stimulation equipment contraindicated in patients taking blood thinners.¹⁶

Periarticular injections of local anesthetics have also shown promise in reducing pain after arthroplasty.⁴ Benefits include an enhanced safety profile because local injection avoids the concurrent blockade of the phrenic nerve and recurrent laryngeal nerve and has not been associated with the risk of peripheral neuropathies. Further, local injection is a simple technique that can be performed during surgery without additional personnel or expertise. A limitation of this approach is the relatively short duration of effectiveness of the local anesthetic and uncertainty regarding the best agent and the ideal volume of injection.⁶ Liposomal bupivacaine is a new agent (approved by the US Food and Drug Administration in 2011¹⁷) with a sustained release over 72 to 96 hours.¹⁸ The most common adverse effects of liposomal bupivacaine are nausea, vomiting, constipation, pyrexia, dizziness, and headache.¹⁹ Chondrotoxicity and granulomatous inflammation are more serious, yet rare, complications of liposomal bupivacaine.²⁰

We found that liposomal bupivacaine injections were associated with lower pain scores compared with ISNB at 18 to 24 hours after surgery. This correlated with less opioid consumption in the liposomal bupivacaine group than in the ISNB group on the second postoperative day. These differences in pain values are consistent with the known pharmacokinetics of liposomal bupivacaine.¹⁸ Peak plasma levels normally occur approximately 24 hours after injection, leaving the early postoperative period relatively uncovered by anesthetic agent. This finding of relatively poor pain control early after surgery has also been noted in patients undergoing knee arthroplasty.⁵ On the basis of the findings of this study, we have added standard bupivacaine injections to our separate liposomal bupivacaine injection to cover early postoperative pain. Opioid consumption was significantly lower in the liposomal bupivacaine group than in the ISNB group on postoperative days 2 and 3. We did not measure adverse events related to opioid consumption, so we cannot comment on whether the decreased opioid consumption was associated with the rate of adverse events. However, other studies^21,22 have established this relationship.

We found the liposomal bupivacaine group to have earlier discharges to home. Sixteen of 37 patients in the liposomal bupivacaine group compared with 2 of 21 patients in the ISNB group were discharged on the day after surgery. A mean reduction in LOS of 18 hours for the liposomal bupivacaine group was statistically significant (P = .012). This reduction in LOS has important implications for hospitals and value analysis committees considering whether to keep a new, more expensive local anesthetic on formulary. Savings from reduced LOS and improvements in patient satisfaction may justify the expense (approximately $300 per 266-mg vial) of Exparel.

From a societal cost perspective, liposomal bupivacaine is more economical compared with ISNB, which adds approximately $1500 to the cost of anesthesia per patient.²³ Eliminating the costs associated with ISNB administration in shoulder arthroplasties could result in substantial savings to our healthcare system. More research examining time savings and exact costs of each procedure is needed to determine the true cost effectiveness of each approach.

Limitations of our study include the retrospective design, relatively small numbers of patients in each group, missing data for some patients at various time points, variation in the types of procedures in each group, and lack of long-term outcome measures. It is important to note that we did not confirm the success of the nerve block after administration. However, this study reflects the effectiveness of each of the modalities in actual clinical conditions (as opposed to a controlled experimental setting). The actual effectiveness of a nerve block varies, even when performed by an experienced anesthesiologist with ultrasound guidance. Furthermore, immediate postoperative pain scores in the nerve block group are consistent with those of prior research reporting pain values ranging from 4 to 5 and a mean duration of effect ranging from 9 to 14 hours.^23,24 Additionally, the patients, surgeon, and nursing team were not blinded to the treatment group. Although we did note a significant difference in the types of procedures between groups, this finding is related to the greater number of hemiarthroplasties performed in the ISNB group (N = 5) compared with the liposomal group (N = 1). Because of this variation and the decreased invasiveness of hemiarthroplasties, the bias is against the liposomal group. Finally, our primary outcome variable was pain, which is a subjective, self-reported measure. However, our opioid consumption data and LOS data corroborate the improved pain scores in the liposomal bupivacaine group.

Limiting the study to a single surgeon may limit external validity. Another limitation is the lack of data on adverse events related to opioid medication use. There was no additional experimental group to determine whether less expensive local anesthetics injected locally would perform similarly to liposomal bupivacaine. In total knee arthroplasty, periarticular injections of liposomal bupivacaine were not as effective as less expensive periarticular injections.²⁵ It is unclear which agents (and in what doses or combinations) should be used for periarticular injections. Finally, we acknowledge that our retrospective study design cannot account for all potential factors affecting discharge time.

This is the first comparative study of liposomal bupivacaine and ISNB in TSA. The study design allowed us to control for variables such as surgical technique, postoperative protocols (including use and type of sling), and use of other pain modalities such as patient-controlled analgesia and intravenous acetaminophen that are likely to affect postoperative pain and LOS. This study provides preliminary data that confirm relative equipoise between liposomal bupivacaine and ISNB, which is needed for the ethical conduct of a randomized controlled trial. Such a trial would allow for a more robust comparison, and this retrospective study provides appropriate pilot data on which to base this design and the clinical information needed to counsel patients during enrollment.

Our results suggest that liposomal bupivacaine may provide superior or similar pain relief compared with ISNB after shoulder arthroplasty. Additionally, the use of liposomal bupivacaine was associated with decreased opioid consumption and earlier discharge to home compared with ISNB. These findings have important implications for pain control after TSA because pain represents a major concern for patients and providers after surgery. In addition to clinical improvements, use of liposomal bupivacaine may save time and eliminate costs associated with administering nerve blocks. Local injection may also be used in patients who are contraindicated for ISNB such as those with obesity, pulmonary disease, or peripheral neuropathy. Although we cannot definitively suggest that liposomal bupivacaine is superior to the current gold standard ISNB for pain control after shoulder arthroplasty, our results suggest a relative clinical equipoise between these modalities. Larger analytical studies, including randomized trials, should be performed to explore the potential benefits of liposomal bupivacaine injections for pain control after shoulder arthroplasty.

Am J Orthop. 2016;45(7):424-430. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

To the Editor:

Prior studies have assessed the quality of text-based dermatology information on the Internet using traditional search engine queries.¹ However, little is understood about the sources, accuracy, and quality of online dermatology images derived from direct image searches. Previous work has shown that direct search engine image queries were largely accurate for 3 pediatric dermatology diagnosis searches: atopic dermatitis, lichen striatus, and subcutaneous fat necrosis.² We assessed images obtained for common dermatologic conditions from a Google image search (GIS) compared to a traditional text-based Google web search (GWS).

Image results for 32 unique dermatologic search terms were analyzed (Table 1). These search terms were selected using the results of a prior study that identified the most common dermatologic diagnoses that led users to the 2 most popular dermatology-specific websites worldwide: the American Academy of Dermatology (www.aad.org) and DermNet New Zealand (www.dermnetnz.org).³ The Alexa directory (www.alexa.com), a large publicly available Internet analytics resource, was used to determine the most common dermatology search terms that led a user to either www.dermnetnz.org or www.aad.org. In addition, searches for the 3 most common types of skin cancer—melanoma, squamous cell carcinoma, and basal cell carcinoma—were included. Each term was entered into a GIS and a GWS. The first 10 results, which represent 92% of the websites ultimately visited by users,⁴ were analyzed. The source, diagnostic accuracy, and Fitzpatrick skin type of the images was determined. Website sources were organized into 11 categories. All data collection occurred within a 1-week period in August 2015.

A total of 320 images were analyzed. In the GIS, private websites (36%), dermatology association websites (28%), and general health information websites (10%) were the 3 most common sources. In the GWS, health information websites (35%), private websites (21%), and dermatology association websites (20%) accounted for the most common sources (Table 2). The majority of images were of Fitzpatrick skin types I and II (89%) and nearly all images were diagnostically accurate (98%). There was no statistically significant difference in accuracy of diagnosis between physician-associated websites (100% accuracy) versus nonphysician-associated sites (98% accuracy, P=.25).

Our results showed high diagnostic accuracy among the top GIS results for common dermatology search terms. Diagnostic accuracy did not vary between websites that were physician associated versus those that were not. Our results are comparable to the reported accuracy of online dermatologic health information.¹ In GIS results, the majority of images were provided by private websites, whereas the top websites in GWS results were health information websites.

Only 1% of images were of Fitzpatrick skin types VI and VII. Presentation of skin diseases is remarkably different based on the patient’s skin type.⁵ The shortage of readily accessible images of skin of color is in line with the lack of familiarity physicians and trainees have with dermatologic conditions in ethnic skin.⁶

Based on the results from this analysis, providers and patients searching for dermatologic conditions via a direct GIS should be cognizant of several considerations. Although our results showed that GIS was accurate, the searcher should note that image-based searches are not accompanied by relevant text that can help confirm relevancy and accuracy. Image searches depend on textual tags added by the source website. Websites that represent dermatological associations and academic centers can add an additional layer of confidence for users. Patients and clinicians also should be aware that the consideration of a patient’s Fitzpatrick skin type is critical when assessing the relevancy of a GIS result. In conclusion, search results via GIS queries are accurate for the dermatological diagnoses tested but may be lacking in skin of color variations, suggesting a potential unmet need based on our growing ethnic skin population.

To the Editor:

Prior studies have assessed the quality of text-based dermatology information on the Internet using traditional search engine queries.¹ However, little is understood about the sources, accuracy, and quality of online dermatology images derived from direct image searches. Previous work has shown that direct search engine image queries were largely accurate for 3 pediatric dermatology diagnosis searches: atopic dermatitis, lichen striatus, and subcutaneous fat necrosis.² We assessed images obtained for common dermatologic conditions from a Google image search (GIS) compared to a traditional text-based Google web search (GWS).

Image results for 32 unique dermatologic search terms were analyzed (Table 1). These search terms were selected using the results of a prior study that identified the most common dermatologic diagnoses that led users to the 2 most popular dermatology-specific websites worldwide: the American Academy of Dermatology (www.aad.org) and DermNet New Zealand (www.dermnetnz.org).³ The Alexa directory (www.alexa.com), a large publicly available Internet analytics resource, was used to determine the most common dermatology search terms that led a user to either www.dermnetnz.org or www.aad.org. In addition, searches for the 3 most common types of skin cancer—melanoma, squamous cell carcinoma, and basal cell carcinoma—were included. Each term was entered into a GIS and a GWS. The first 10 results, which represent 92% of the websites ultimately visited by users,⁴ were analyzed. The source, diagnostic accuracy, and Fitzpatrick skin type of the images was determined. Website sources were organized into 11 categories. All data collection occurred within a 1-week period in August 2015.

A total of 320 images were analyzed. In the GIS, private websites (36%), dermatology association websites (28%), and general health information websites (10%) were the 3 most common sources. In the GWS, health information websites (35%), private websites (21%), and dermatology association websites (20%) accounted for the most common sources (Table 2). The majority of images were of Fitzpatrick skin types I and II (89%) and nearly all images were diagnostically accurate (98%). There was no statistically significant difference in accuracy of diagnosis between physician-associated websites (100% accuracy) versus nonphysician-associated sites (98% accuracy, P=.25).

Our results showed high diagnostic accuracy among the top GIS results for common dermatology search terms. Diagnostic accuracy did not vary between websites that were physician associated versus those that were not. Our results are comparable to the reported accuracy of online dermatologic health information.¹ In GIS results, the majority of images were provided by private websites, whereas the top websites in GWS results were health information websites.

Only 1% of images were of Fitzpatrick skin types VI and VII. Presentation of skin diseases is remarkably different based on the patient’s skin type.⁵ The shortage of readily accessible images of skin of color is in line with the lack of familiarity physicians and trainees have with dermatologic conditions in ethnic skin.⁶

Based on the results from this analysis, providers and patients searching for dermatologic conditions via a direct GIS should be cognizant of several considerations. Although our results showed that GIS was accurate, the searcher should note that image-based searches are not accompanied by relevant text that can help confirm relevancy and accuracy. Image searches depend on textual tags added by the source website. Websites that represent dermatological associations and academic centers can add an additional layer of confidence for users. Patients and clinicians also should be aware that the consideration of a patient’s Fitzpatrick skin type is critical when assessing the relevancy of a GIS result. In conclusion, search results via GIS queries are accurate for the dermatological diagnoses tested but may be lacking in skin of color variations, suggesting a potential unmet need based on our growing ethnic skin population.

To the Editor:

Prior studies have assessed the quality of text-based dermatology information on the Internet using traditional search engine queries.¹ However, little is understood about the sources, accuracy, and quality of online dermatology images derived from direct image searches. Previous work has shown that direct search engine image queries were largely accurate for 3 pediatric dermatology diagnosis searches: atopic dermatitis, lichen striatus, and subcutaneous fat necrosis.² We assessed images obtained for common dermatologic conditions from a Google image search (GIS) compared to a traditional text-based Google web search (GWS).

Image results for 32 unique dermatologic search terms were analyzed (Table 1). These search terms were selected using the results of a prior study that identified the most common dermatologic diagnoses that led users to the 2 most popular dermatology-specific websites worldwide: the American Academy of Dermatology (www.aad.org) and DermNet New Zealand (www.dermnetnz.org).³ The Alexa directory (www.alexa.com), a large publicly available Internet analytics resource, was used to determine the most common dermatology search terms that led a user to either www.dermnetnz.org or www.aad.org. In addition, searches for the 3 most common types of skin cancer—melanoma, squamous cell carcinoma, and basal cell carcinoma—were included. Each term was entered into a GIS and a GWS. The first 10 results, which represent 92% of the websites ultimately visited by users,⁴ were analyzed. The source, diagnostic accuracy, and Fitzpatrick skin type of the images was determined. Website sources were organized into 11 categories. All data collection occurred within a 1-week period in August 2015.

A total of 320 images were analyzed. In the GIS, private websites (36%), dermatology association websites (28%), and general health information websites (10%) were the 3 most common sources. In the GWS, health information websites (35%), private websites (21%), and dermatology association websites (20%) accounted for the most common sources (Table 2). The majority of images were of Fitzpatrick skin types I and II (89%) and nearly all images were diagnostically accurate (98%). There was no statistically significant difference in accuracy of diagnosis between physician-associated websites (100% accuracy) versus nonphysician-associated sites (98% accuracy, P=.25).

Our results showed high diagnostic accuracy among the top GIS results for common dermatology search terms. Diagnostic accuracy did not vary between websites that were physician associated versus those that were not. Our results are comparable to the reported accuracy of online dermatologic health information.¹ In GIS results, the majority of images were provided by private websites, whereas the top websites in GWS results were health information websites.

Only 1% of images were of Fitzpatrick skin types VI and VII. Presentation of skin diseases is remarkably different based on the patient’s skin type.⁵ The shortage of readily accessible images of skin of color is in line with the lack of familiarity physicians and trainees have with dermatologic conditions in ethnic skin.⁶

Based on the results from this analysis, providers and patients searching for dermatologic conditions via a direct GIS should be cognizant of several considerations. Although our results showed that GIS was accurate, the searcher should note that image-based searches are not accompanied by relevant text that can help confirm relevancy and accuracy. Image searches depend on textual tags added by the source website. Websites that represent dermatological associations and academic centers can add an additional layer of confidence for users. Patients and clinicians also should be aware that the consideration of a patient’s Fitzpatrick skin type is critical when assessing the relevancy of a GIS result. In conclusion, search results via GIS queries are accurate for the dermatological diagnoses tested but may be lacking in skin of color variations, suggesting a potential unmet need based on our growing ethnic skin population.