Original Research

ABSTRACT

Revision shoulder arthroplasty is becoming more prevalent as the rate of primary shoulder arthroplasty in the US continues to increase. The management of proximal humeral bone loss in the revision setting presents a difficult problem without a clear solution. Different preoperative diagnoses often lead to distinctly different patterns of bone loss. Successful management of these cases requires a clear understanding of the normal anatomy of the proximal humerus, as well as structural limitations imposed by significant bone loss and the effect this loss has on component fixation. Our preferred technique differs depending on the pattern of bone loss encountered. The use of allograft-prosthetic composites, the cement-within-cement technique, and combinations of these strategies comprise the mainstay of our treatment algorithm. This article focuses on indications, surgical techniques, and some of the published outcomes using these strategies in the management of proximal humeral bone loss.

Continue to: The demand for shoulder arthroplasty...

The demand for shoulder arthroplasty (SA) has increased significantly over the past decade, with a 200% increase witnessed from 2011 to 2015.¹ SA performed in patients younger than 55 years is expected to increase 333% between 2011 to 2030.² With increasing rates of SA being performed in younger patient populations, rates of revision SA also can be expected to climb. Revision to reverse shoulder arthroplasty (RSA) has arisen as a viable option in these patients, and multiple studies demonstrate excellent outcomes that can be obtained with RSA.^3-11

Despite significant improvements obtained in revision SA since the mainstream acceptance of RSA, bone loss remains a problematic issue. Loss of humeral bone stock, in particular, can be a challenging problem to solve with multiple clinical implications. Biomechanical studies have demonstrated that if bone loss is left unaddressed, increased bending and torsional forces on the prosthesis result, which ultimately contribute to increased micromotion and eventual component failure.¹² In addition, existing challenges are associated with the lack of attachment sites for both multiple muscles and tendons. Also, there is a loss of the normal lateralized pull of the deltoid, which results in a decreased amount of force generated by this muscle.^13,14 Ultimately, the increased loss of bone can lead to a devastating situation where there is not enough bone to provide adequate fixation while maintaining the appropriate humeral length necessary to achieve stability of the articulation, which will inevitably lead to instability.^4,15 Therefore, techniques are needed to address proximal humeral bone loss while maintaining as much native humeral bone as possible.

PROXIMAL HUMERUS: ANATOMICAL CONSIDERATIONS

The anatomy of the proximal humerus has been studied in great detail and reported in a number of different studies.^16-23 The average humeral head thickness (24 mm in men and 19 mm in women) and offset relative to the humeral shaft (2.1 mm posterior and 6.6 mm medial) act to tension the rotator cuff musculature appropriately and contribute to a wrapping effect that allows the deltoid to function more effectively.^13,14 Knowledge regarding the rotator cuff footprint has advanced over the past 10 years, specifically with regard to the supraspinatus and infraspinatus.²⁴ The current belief is that the supraspinatus has a triangular insertion onto the most anterior aspect of the greater tuberosity, with a maximum medial-to-lateral length of 6.9 mm and a maximum anterior-to-posterior width of 12.6 mm. The infraspinatus insertion has a trapezoidal insertion, with a maximum medial-to-lateral length of 10.2 mm and anterior-to-posterior width of 32.7 mm. The subscapularis, by far the largest of all the rotator cuff muscles, has a complex geometry with regard to its insertion on the lesser tuberosity, with 4 different insertion points and an overall lateral footprint measuring 37.6 mm and a medial footprint measuring 40.7 mm.²⁵ Finally, the teres minor, with the smallest volume of all the rotator cuff muscles, inserts immediately inferior to the infraspinatus along the inferior facet of the greater tuberosity.²⁶

Aside from the rotator cuff, there are various other muscles and tendons that insert about the proximal humerus and are essential for normal function. The deltoid, which inserts at a point approximately 6 cm from the greater tuberosity along the length of the humerus, with an insertion length between 5 cm to 7 cm,^13,27 is the primary mover of the shoulder and essential for proper function after RSA.^28,29 The pectoralis major tendon, which begins inserting at a point approximately 5.6 cm from the humeral head and spans a distance of 7.7 cm along the length of the humerus,^30-32 is important not only for function but as an anatomical landmark in reconstruction. Lastly, the latissimus dorsi and teres major, which share a role in extension, adduction, and internal rotation of the glenohumeral joint, insert along the floor and medial lip of the intertubercular groove of the humerus, respectively.^33,34 In addition to their role in tendon transfer procedures because of treating irreparable posterosuperior cuff and subscapularis tears,^35,36 it has been suggested that these tendons may play some role in glenohumeral joint stability.³⁷

            In addition to the loss of muscular attachments, the absence of proximal humeral bone stock, in and of itself, can have deleterious effects on fixation of the humeral component. RSA is a semiconstrained device, which results in increased transmission of forces to the interface between the humeral implant and its surrounding structures, including cement (when present) and the bone itself. When there is the absence of significant amounts of bone, the remaining bone must now account for an even higher proportion of these forces. A previous biomechanical study showed that cemented humeral stems demonstrated significantly increased micromotion in the presence of proximal humeral bone loss, particularly when a modular humeral component was used.¹²

Continue to: TYPES OF BONE LOSS

There are a variety of different etiologies of proximal humeral bone loss that result in distinctly different clinical presentations. These can be fairly mild, as is the case of isolated resorption of the greater tuberosity in a non-united proximal humerus fracture (Figure 1). Alternatively, they can be severe, as seen in a grossly loose cemented long-stemmed component that is freely mobile, creating a windshield-wiper effect throughout the length of the humerus (Figure 2). This can be somewhat deceiving, however, as the amount of bone loss, as well as the pathophysiologic process that led to the bone loss, are important factors to determine ideal reconstructive methods. In the case of a failed open reduction internal fixation, where the tuberosity has failed to unite or has been resected, there is much less of a biologic response in comparison with implant loosening associated with osteolysis. This latter condition will be associated with a much more destructive inflammatory response resulting in poor tissue quality and often dramatic thinning of the cortex. If one simply measured the distance from the most proximal remaining bone stock to the area where the greater tuberosity should be, a loose stem with subsidence and ballooning of the cortices may appear to have a similar amount of bone loss as a failed hemiarthroplasty for fracture with a well-fixed stem. However, intraoperatively, one will find that the bone that appeared to be present radiographically in the case of the loose stem is of such poor quality that it cannot reasonably provide any beneficial fixation. In light of this, different treatment modalities are recommended for different types of bone loss, and the revision surgeon must be able to anticipate this and possess a full armamentarium of options to treat these challenging cases successfully.

INDICATIONS

Our technique to manage proximal humeral bone loss is dependent on both the quantity of bone loss, which can be measured radiographically, as well as the anticipated inflammatory response described above. As both the destructive process and the amount of bone loss increase, the importance of more advanced reconstructive procedures that will sustain implant security and soft-tissue management becomes apparent. In the least destructive cases with <5 cm of bone loss, successful revision can typically be accomplished with stem removal and placement of a new monoblock humeral stem. In cases where more advanced destructive pathology is present, and bone loss is >5 cm, an allograft-prosthetic composite (APC) is typically used. In both scenarios, if the stem being revised is cemented and the cement mantle remains intact, and of reasonable length, consideration is given to the cement-within-cement technique. Finally, in the most destructive cases where bone loss exceeds 10 cm and a large biological response is anticipated (eg, periprosthetic fractures with humeral loosening), the use of a longer diaphyseal-incorporating APC is often necessary. This prosthetic composite can be combined with a cement-within-cement technique as well.

It is important to comment on the implications of using modular stems in this setting. With advanced bone loss, a situation is often encountered where the newly implanted stem geometry and working length may be insufficient to acquire adequate rotational stability. In this setting, if a modular junction is positioned close to the stem and cement/bone interface, it will be exposed to very high stress concentrations which can lead to component fracture³⁸ as well as taper corrosion, also referred to as trunnionosis. This latter phenomenon, which has been well studied in the total hip arthroplasty literature with the use of modular components,³⁹ is especially relevant given the high torsional loads imparted at the modular junction. Ultimately, high torsional loads lead to micromotion and electrochemical ion release via degradation of the passivation layer, initiating the process of mechanically assisted crevice corrosion.⁴⁰ For these reasons, when a modular stem must be used in the presence of mild to moderate bone loss, using a proximal humeral allograft to protect the junction or to provide additional fixation may be implemented with a lower threshold than when using a monoblock stem.

SURGICAL TECHNIQUE: ALLOGRAFT-PROSTHETIC COMPOSITES

A standard deltopectoral approach is used, taking care to preserve all viable muscular attachments to the proximal humerus. After removal of the prosthetic humeral head, the decision to proceed with removal of the stem at this juncture is based on several factors. If the remaining proximal humeral bone is so compromised that it might not be able to withstand the forces exerted upon it during retraction for glenoid exposure, the component is left in place. Additionally, if there is consideration that the glenoid-sided bone loss may be so severe that a glenoid baseplate cannot be implanted, and the stem remains well fixed, it is retained so that it can be converted to a hemiarthroplasty.

If neither of the above issues is present, the humeral stem is removed. If a well-fixed press-fit stem is in place, it is typically removed using a combination of burrs and osteotomes to disrupt the bone-implant interface, and the stem is then carefully removed using an impactor and mallet. If a cemented stem is present, the stem is removed in a similar manner, and the cement mantle is left in place if stable, in anticipation of a cement-within-cement technique. If the mantle is disrupted, standard cement removal instruments are used to remove all cement from the canal meticulously.

Continue to: Management of the glenoid...

Management of the glenoid can have significant implications with regard to the humerus. Most notably, the size of the glenosphere has direct implications on the fixation of the humeral component. Use of larger diameter glenospheres result in increased contact area between the glenosphere and humerosocket, adding constraint to the articulation and further increasing the stresses at the implant-bone interface. As such, the use of larger glenospheres to prevent instability must be balanced with the resulting implications on humeral component fixation, especially in cases of severe bone loss.

After implanting the appropriate glenosphere, attention is then turned back to the humerus. Trial implants are sequentially used to obtain adequate humeral length and stability. Once this is accomplished, the amount of humeral bone loss is quantified by measuring the distance from the superior aspect of the medial humeral tray to the medial humeral shaft. If this number is >5 cm (Figure 3), the decision is made to proceed with an APC. The allograft humeral head is cut, cancellous bone is removed, and a step-cut is performed, with the medial portion of the allograft measuring the same length as that of bone loss and the lateral plate extending an additional several centimeters distally (Figure 4). Additional soft tissue is removed from the allograft, leaving the subscapularis stump intact for later repair with the patient’s native tissue. The allograft is secured to the patient’s proximal humerus using multiple cerclage wires, and the humeral stem is cemented into place. The final construct is shown in Figure 5.

ADDITIONAL CONSIDERATIONS: CASES OF ADVANCED BONE LOSS

In cases of advanced humeral bone loss, as is often seen when revising loose humeral stems, larger allografts that span a significant length of the diaphysis are often required. This type of bone loss has implications with regard to how the deltoid insertion is managed. Interestingly, even in situations when the vast majority of the remaining diaphysis consists of ectatic egg-shell bone, the deltoid tuberosity remains of fairly substantial quality due to the continued pull of the muscular insertion on this area. This fragment is isolated, carefully mobilized, and subsequently repaired back on top of the allograft using cables.

POSTOPERATIVE CARE

Patients are kept in a shoulder immobilizer for 6 weeks after surgery to facilitate allograft incorporation and subscapularis tendon healing. During this time, pendulum exercises are initiated. Active assisted range of motion (ROM) exercises begin after 6 weeks, consisting of supine forward elevation. A sling is given to be used in public. Light strengthening exercises begin at 3 months postoperatively.

DISCUSSION

In cases of mild to moderate proximal humeral bone loss, RSA using a long-stem humeral component without allograft augmentation is a viable option. Budge and colleagues³⁸ demonstrated excellent results in a population of 15 patients with an average of 38 mm of proximal humeral bone loss without use of allografts. Interestingly, they noted 1 case of component fracture in a modular prosthesis and therefore concluded that monoblock humeral stems should be used in the absence of allograft augmentation.

Continue to: In more advanced cases of bone loss...

In more advanced cases of bone loss, our data shows that use of APCs can result in equally satisfactory results. In a series of 25 patients with an average bone loss of 54 mm, patients were able to achieve statistically significant improvements in pain, ROM, and function with high rates of allograft incorporation.⁹ Overall, a low rate of complications was noted, including 1 infection. This finding is consistent with an additional study looking specifically at factors associated with infection in revision SA, which found that the use of allografts was not associated with increased risk of infection.⁴¹

As stated previously, the size of allograft needed for the APC construct is related to the distinct pathology encountered. In our experience, we have noted that well-fixed stems can be treated with short metaphyseal APCs in 85% of cases. On the other hand, loose stems require long allografts measuring >10 cm in 90% of cases. As such, these cases typically require mobilization of the deltoid insertion as described above, and therefore it is important that the surgeon is prepared for this aspect of the procedure preoperatively.

Finally, the cement-within-cement technique, originally popularized for use in revision total hip arthroplasty, has demonstrated reliable results when utilized in revision SA.⁴² To date, there are no recommendations regarding the minimal length of existing cement mantle that is needed to perform this technique. In situations in which the length of the cement mantle is questionable, our preference is to combine the cement-within-cement technique with an APC when possible.

ABSTRACT

Revision shoulder arthroplasty is becoming more prevalent as the rate of primary shoulder arthroplasty in the US continues to increase. The management of proximal humeral bone loss in the revision setting presents a difficult problem without a clear solution. Different preoperative diagnoses often lead to distinctly different patterns of bone loss. Successful management of these cases requires a clear understanding of the normal anatomy of the proximal humerus, as well as structural limitations imposed by significant bone loss and the effect this loss has on component fixation. Our preferred technique differs depending on the pattern of bone loss encountered. The use of allograft-prosthetic composites, the cement-within-cement technique, and combinations of these strategies comprise the mainstay of our treatment algorithm. This article focuses on indications, surgical techniques, and some of the published outcomes using these strategies in the management of proximal humeral bone loss.

Continue to: The demand for shoulder arthroplasty...

The demand for shoulder arthroplasty (SA) has increased significantly over the past decade, with a 200% increase witnessed from 2011 to 2015.¹ SA performed in patients younger than 55 years is expected to increase 333% between 2011 to 2030.² With increasing rates of SA being performed in younger patient populations, rates of revision SA also can be expected to climb. Revision to reverse shoulder arthroplasty (RSA) has arisen as a viable option in these patients, and multiple studies demonstrate excellent outcomes that can be obtained with RSA.^3-11

Despite significant improvements obtained in revision SA since the mainstream acceptance of RSA, bone loss remains a problematic issue. Loss of humeral bone stock, in particular, can be a challenging problem to solve with multiple clinical implications. Biomechanical studies have demonstrated that if bone loss is left unaddressed, increased bending and torsional forces on the prosthesis result, which ultimately contribute to increased micromotion and eventual component failure.¹² In addition, existing challenges are associated with the lack of attachment sites for both multiple muscles and tendons. Also, there is a loss of the normal lateralized pull of the deltoid, which results in a decreased amount of force generated by this muscle.^13,14 Ultimately, the increased loss of bone can lead to a devastating situation where there is not enough bone to provide adequate fixation while maintaining the appropriate humeral length necessary to achieve stability of the articulation, which will inevitably lead to instability.^4,15 Therefore, techniques are needed to address proximal humeral bone loss while maintaining as much native humeral bone as possible.

PROXIMAL HUMERUS: ANATOMICAL CONSIDERATIONS

The anatomy of the proximal humerus has been studied in great detail and reported in a number of different studies.^16-23 The average humeral head thickness (24 mm in men and 19 mm in women) and offset relative to the humeral shaft (2.1 mm posterior and 6.6 mm medial) act to tension the rotator cuff musculature appropriately and contribute to a wrapping effect that allows the deltoid to function more effectively.^13,14 Knowledge regarding the rotator cuff footprint has advanced over the past 10 years, specifically with regard to the supraspinatus and infraspinatus.²⁴ The current belief is that the supraspinatus has a triangular insertion onto the most anterior aspect of the greater tuberosity, with a maximum medial-to-lateral length of 6.9 mm and a maximum anterior-to-posterior width of 12.6 mm. The infraspinatus insertion has a trapezoidal insertion, with a maximum medial-to-lateral length of 10.2 mm and anterior-to-posterior width of 32.7 mm. The subscapularis, by far the largest of all the rotator cuff muscles, has a complex geometry with regard to its insertion on the lesser tuberosity, with 4 different insertion points and an overall lateral footprint measuring 37.6 mm and a medial footprint measuring 40.7 mm.²⁵ Finally, the teres minor, with the smallest volume of all the rotator cuff muscles, inserts immediately inferior to the infraspinatus along the inferior facet of the greater tuberosity.²⁶

Aside from the rotator cuff, there are various other muscles and tendons that insert about the proximal humerus and are essential for normal function. The deltoid, which inserts at a point approximately 6 cm from the greater tuberosity along the length of the humerus, with an insertion length between 5 cm to 7 cm,^13,27 is the primary mover of the shoulder and essential for proper function after RSA.^28,29 The pectoralis major tendon, which begins inserting at a point approximately 5.6 cm from the humeral head and spans a distance of 7.7 cm along the length of the humerus,^30-32 is important not only for function but as an anatomical landmark in reconstruction. Lastly, the latissimus dorsi and teres major, which share a role in extension, adduction, and internal rotation of the glenohumeral joint, insert along the floor and medial lip of the intertubercular groove of the humerus, respectively.^33,34 In addition to their role in tendon transfer procedures because of treating irreparable posterosuperior cuff and subscapularis tears,^35,36 it has been suggested that these tendons may play some role in glenohumeral joint stability.³⁷

            In addition to the loss of muscular attachments, the absence of proximal humeral bone stock, in and of itself, can have deleterious effects on fixation of the humeral component. RSA is a semiconstrained device, which results in increased transmission of forces to the interface between the humeral implant and its surrounding structures, including cement (when present) and the bone itself. When there is the absence of significant amounts of bone, the remaining bone must now account for an even higher proportion of these forces. A previous biomechanical study showed that cemented humeral stems demonstrated significantly increased micromotion in the presence of proximal humeral bone loss, particularly when a modular humeral component was used.¹²

Continue to: TYPES OF BONE LOSS

There are a variety of different etiologies of proximal humeral bone loss that result in distinctly different clinical presentations. These can be fairly mild, as is the case of isolated resorption of the greater tuberosity in a non-united proximal humerus fracture (Figure 1). Alternatively, they can be severe, as seen in a grossly loose cemented long-stemmed component that is freely mobile, creating a windshield-wiper effect throughout the length of the humerus (Figure 2). This can be somewhat deceiving, however, as the amount of bone loss, as well as the pathophysiologic process that led to the bone loss, are important factors to determine ideal reconstructive methods. In the case of a failed open reduction internal fixation, where the tuberosity has failed to unite or has been resected, there is much less of a biologic response in comparison with implant loosening associated with osteolysis. This latter condition will be associated with a much more destructive inflammatory response resulting in poor tissue quality and often dramatic thinning of the cortex. If one simply measured the distance from the most proximal remaining bone stock to the area where the greater tuberosity should be, a loose stem with subsidence and ballooning of the cortices may appear to have a similar amount of bone loss as a failed hemiarthroplasty for fracture with a well-fixed stem. However, intraoperatively, one will find that the bone that appeared to be present radiographically in the case of the loose stem is of such poor quality that it cannot reasonably provide any beneficial fixation. In light of this, different treatment modalities are recommended for different types of bone loss, and the revision surgeon must be able to anticipate this and possess a full armamentarium of options to treat these challenging cases successfully.

INDICATIONS

Our technique to manage proximal humeral bone loss is dependent on both the quantity of bone loss, which can be measured radiographically, as well as the anticipated inflammatory response described above. As both the destructive process and the amount of bone loss increase, the importance of more advanced reconstructive procedures that will sustain implant security and soft-tissue management becomes apparent. In the least destructive cases with <5 cm of bone loss, successful revision can typically be accomplished with stem removal and placement of a new monoblock humeral stem. In cases where more advanced destructive pathology is present, and bone loss is >5 cm, an allograft-prosthetic composite (APC) is typically used. In both scenarios, if the stem being revised is cemented and the cement mantle remains intact, and of reasonable length, consideration is given to the cement-within-cement technique. Finally, in the most destructive cases where bone loss exceeds 10 cm and a large biological response is anticipated (eg, periprosthetic fractures with humeral loosening), the use of a longer diaphyseal-incorporating APC is often necessary. This prosthetic composite can be combined with a cement-within-cement technique as well.

It is important to comment on the implications of using modular stems in this setting. With advanced bone loss, a situation is often encountered where the newly implanted stem geometry and working length may be insufficient to acquire adequate rotational stability. In this setting, if a modular junction is positioned close to the stem and cement/bone interface, it will be exposed to very high stress concentrations which can lead to component fracture³⁸ as well as taper corrosion, also referred to as trunnionosis. This latter phenomenon, which has been well studied in the total hip arthroplasty literature with the use of modular components,³⁹ is especially relevant given the high torsional loads imparted at the modular junction. Ultimately, high torsional loads lead to micromotion and electrochemical ion release via degradation of the passivation layer, initiating the process of mechanically assisted crevice corrosion.⁴⁰ For these reasons, when a modular stem must be used in the presence of mild to moderate bone loss, using a proximal humeral allograft to protect the junction or to provide additional fixation may be implemented with a lower threshold than when using a monoblock stem.

SURGICAL TECHNIQUE: ALLOGRAFT-PROSTHETIC COMPOSITES

A standard deltopectoral approach is used, taking care to preserve all viable muscular attachments to the proximal humerus. After removal of the prosthetic humeral head, the decision to proceed with removal of the stem at this juncture is based on several factors. If the remaining proximal humeral bone is so compromised that it might not be able to withstand the forces exerted upon it during retraction for glenoid exposure, the component is left in place. Additionally, if there is consideration that the glenoid-sided bone loss may be so severe that a glenoid baseplate cannot be implanted, and the stem remains well fixed, it is retained so that it can be converted to a hemiarthroplasty.

If neither of the above issues is present, the humeral stem is removed. If a well-fixed press-fit stem is in place, it is typically removed using a combination of burrs and osteotomes to disrupt the bone-implant interface, and the stem is then carefully removed using an impactor and mallet. If a cemented stem is present, the stem is removed in a similar manner, and the cement mantle is left in place if stable, in anticipation of a cement-within-cement technique. If the mantle is disrupted, standard cement removal instruments are used to remove all cement from the canal meticulously.

Continue to: Management of the glenoid...

Management of the glenoid can have significant implications with regard to the humerus. Most notably, the size of the glenosphere has direct implications on the fixation of the humeral component. Use of larger diameter glenospheres result in increased contact area between the glenosphere and humerosocket, adding constraint to the articulation and further increasing the stresses at the implant-bone interface. As such, the use of larger glenospheres to prevent instability must be balanced with the resulting implications on humeral component fixation, especially in cases of severe bone loss.

After implanting the appropriate glenosphere, attention is then turned back to the humerus. Trial implants are sequentially used to obtain adequate humeral length and stability. Once this is accomplished, the amount of humeral bone loss is quantified by measuring the distance from the superior aspect of the medial humeral tray to the medial humeral shaft. If this number is >5 cm (Figure 3), the decision is made to proceed with an APC. The allograft humeral head is cut, cancellous bone is removed, and a step-cut is performed, with the medial portion of the allograft measuring the same length as that of bone loss and the lateral plate extending an additional several centimeters distally (Figure 4). Additional soft tissue is removed from the allograft, leaving the subscapularis stump intact for later repair with the patient’s native tissue. The allograft is secured to the patient’s proximal humerus using multiple cerclage wires, and the humeral stem is cemented into place. The final construct is shown in Figure 5.

ADDITIONAL CONSIDERATIONS: CASES OF ADVANCED BONE LOSS

In cases of advanced humeral bone loss, as is often seen when revising loose humeral stems, larger allografts that span a significant length of the diaphysis are often required. This type of bone loss has implications with regard to how the deltoid insertion is managed. Interestingly, even in situations when the vast majority of the remaining diaphysis consists of ectatic egg-shell bone, the deltoid tuberosity remains of fairly substantial quality due to the continued pull of the muscular insertion on this area. This fragment is isolated, carefully mobilized, and subsequently repaired back on top of the allograft using cables.

POSTOPERATIVE CARE

Patients are kept in a shoulder immobilizer for 6 weeks after surgery to facilitate allograft incorporation and subscapularis tendon healing. During this time, pendulum exercises are initiated. Active assisted range of motion (ROM) exercises begin after 6 weeks, consisting of supine forward elevation. A sling is given to be used in public. Light strengthening exercises begin at 3 months postoperatively.

DISCUSSION

In cases of mild to moderate proximal humeral bone loss, RSA using a long-stem humeral component without allograft augmentation is a viable option. Budge and colleagues³⁸ demonstrated excellent results in a population of 15 patients with an average of 38 mm of proximal humeral bone loss without use of allografts. Interestingly, they noted 1 case of component fracture in a modular prosthesis and therefore concluded that monoblock humeral stems should be used in the absence of allograft augmentation.

Continue to: In more advanced cases of bone loss...

In more advanced cases of bone loss, our data shows that use of APCs can result in equally satisfactory results. In a series of 25 patients with an average bone loss of 54 mm, patients were able to achieve statistically significant improvements in pain, ROM, and function with high rates of allograft incorporation.⁹ Overall, a low rate of complications was noted, including 1 infection. This finding is consistent with an additional study looking specifically at factors associated with infection in revision SA, which found that the use of allografts was not associated with increased risk of infection.⁴¹

As stated previously, the size of allograft needed for the APC construct is related to the distinct pathology encountered. In our experience, we have noted that well-fixed stems can be treated with short metaphyseal APCs in 85% of cases. On the other hand, loose stems require long allografts measuring >10 cm in 90% of cases. As such, these cases typically require mobilization of the deltoid insertion as described above, and therefore it is important that the surgeon is prepared for this aspect of the procedure preoperatively.

Finally, the cement-within-cement technique, originally popularized for use in revision total hip arthroplasty, has demonstrated reliable results when utilized in revision SA.⁴² To date, there are no recommendations regarding the minimal length of existing cement mantle that is needed to perform this technique. In situations in which the length of the cement mantle is questionable, our preference is to combine the cement-within-cement technique with an APC when possible.

ABSTRACT

Revision shoulder arthroplasty is becoming more prevalent as the rate of primary shoulder arthroplasty in the US continues to increase. The management of proximal humeral bone loss in the revision setting presents a difficult problem without a clear solution. Different preoperative diagnoses often lead to distinctly different patterns of bone loss. Successful management of these cases requires a clear understanding of the normal anatomy of the proximal humerus, as well as structural limitations imposed by significant bone loss and the effect this loss has on component fixation. Our preferred technique differs depending on the pattern of bone loss encountered. The use of allograft-prosthetic composites, the cement-within-cement technique, and combinations of these strategies comprise the mainstay of our treatment algorithm. This article focuses on indications, surgical techniques, and some of the published outcomes using these strategies in the management of proximal humeral bone loss.

Continue to: The demand for shoulder arthroplasty...

The demand for shoulder arthroplasty (SA) has increased significantly over the past decade, with a 200% increase witnessed from 2011 to 2015.¹ SA performed in patients younger than 55 years is expected to increase 333% between 2011 to 2030.² With increasing rates of SA being performed in younger patient populations, rates of revision SA also can be expected to climb. Revision to reverse shoulder arthroplasty (RSA) has arisen as a viable option in these patients, and multiple studies demonstrate excellent outcomes that can be obtained with RSA.^3-11

Despite significant improvements obtained in revision SA since the mainstream acceptance of RSA, bone loss remains a problematic issue. Loss of humeral bone stock, in particular, can be a challenging problem to solve with multiple clinical implications. Biomechanical studies have demonstrated that if bone loss is left unaddressed, increased bending and torsional forces on the prosthesis result, which ultimately contribute to increased micromotion and eventual component failure.¹² In addition, existing challenges are associated with the lack of attachment sites for both multiple muscles and tendons. Also, there is a loss of the normal lateralized pull of the deltoid, which results in a decreased amount of force generated by this muscle.^13,14 Ultimately, the increased loss of bone can lead to a devastating situation where there is not enough bone to provide adequate fixation while maintaining the appropriate humeral length necessary to achieve stability of the articulation, which will inevitably lead to instability.^4,15 Therefore, techniques are needed to address proximal humeral bone loss while maintaining as much native humeral bone as possible.

PROXIMAL HUMERUS: ANATOMICAL CONSIDERATIONS

The anatomy of the proximal humerus has been studied in great detail and reported in a number of different studies.^16-23 The average humeral head thickness (24 mm in men and 19 mm in women) and offset relative to the humeral shaft (2.1 mm posterior and 6.6 mm medial) act to tension the rotator cuff musculature appropriately and contribute to a wrapping effect that allows the deltoid to function more effectively.^13,14 Knowledge regarding the rotator cuff footprint has advanced over the past 10 years, specifically with regard to the supraspinatus and infraspinatus.²⁴ The current belief is that the supraspinatus has a triangular insertion onto the most anterior aspect of the greater tuberosity, with a maximum medial-to-lateral length of 6.9 mm and a maximum anterior-to-posterior width of 12.6 mm. The infraspinatus insertion has a trapezoidal insertion, with a maximum medial-to-lateral length of 10.2 mm and anterior-to-posterior width of 32.7 mm. The subscapularis, by far the largest of all the rotator cuff muscles, has a complex geometry with regard to its insertion on the lesser tuberosity, with 4 different insertion points and an overall lateral footprint measuring 37.6 mm and a medial footprint measuring 40.7 mm.²⁵ Finally, the teres minor, with the smallest volume of all the rotator cuff muscles, inserts immediately inferior to the infraspinatus along the inferior facet of the greater tuberosity.²⁶

Aside from the rotator cuff, there are various other muscles and tendons that insert about the proximal humerus and are essential for normal function. The deltoid, which inserts at a point approximately 6 cm from the greater tuberosity along the length of the humerus, with an insertion length between 5 cm to 7 cm,^13,27 is the primary mover of the shoulder and essential for proper function after RSA.^28,29 The pectoralis major tendon, which begins inserting at a point approximately 5.6 cm from the humeral head and spans a distance of 7.7 cm along the length of the humerus,^30-32 is important not only for function but as an anatomical landmark in reconstruction. Lastly, the latissimus dorsi and teres major, which share a role in extension, adduction, and internal rotation of the glenohumeral joint, insert along the floor and medial lip of the intertubercular groove of the humerus, respectively.^33,34 In addition to their role in tendon transfer procedures because of treating irreparable posterosuperior cuff and subscapularis tears,^35,36 it has been suggested that these tendons may play some role in glenohumeral joint stability.³⁷

            In addition to the loss of muscular attachments, the absence of proximal humeral bone stock, in and of itself, can have deleterious effects on fixation of the humeral component. RSA is a semiconstrained device, which results in increased transmission of forces to the interface between the humeral implant and its surrounding structures, including cement (when present) and the bone itself. When there is the absence of significant amounts of bone, the remaining bone must now account for an even higher proportion of these forces. A previous biomechanical study showed that cemented humeral stems demonstrated significantly increased micromotion in the presence of proximal humeral bone loss, particularly when a modular humeral component was used.¹²

Continue to: TYPES OF BONE LOSS

There are a variety of different etiologies of proximal humeral bone loss that result in distinctly different clinical presentations. These can be fairly mild, as is the case of isolated resorption of the greater tuberosity in a non-united proximal humerus fracture (Figure 1). Alternatively, they can be severe, as seen in a grossly loose cemented long-stemmed component that is freely mobile, creating a windshield-wiper effect throughout the length of the humerus (Figure 2). This can be somewhat deceiving, however, as the amount of bone loss, as well as the pathophysiologic process that led to the bone loss, are important factors to determine ideal reconstructive methods. In the case of a failed open reduction internal fixation, where the tuberosity has failed to unite or has been resected, there is much less of a biologic response in comparison with implant loosening associated with osteolysis. This latter condition will be associated with a much more destructive inflammatory response resulting in poor tissue quality and often dramatic thinning of the cortex. If one simply measured the distance from the most proximal remaining bone stock to the area where the greater tuberosity should be, a loose stem with subsidence and ballooning of the cortices may appear to have a similar amount of bone loss as a failed hemiarthroplasty for fracture with a well-fixed stem. However, intraoperatively, one will find that the bone that appeared to be present radiographically in the case of the loose stem is of such poor quality that it cannot reasonably provide any beneficial fixation. In light of this, different treatment modalities are recommended for different types of bone loss, and the revision surgeon must be able to anticipate this and possess a full armamentarium of options to treat these challenging cases successfully.

INDICATIONS

Our technique to manage proximal humeral bone loss is dependent on both the quantity of bone loss, which can be measured radiographically, as well as the anticipated inflammatory response described above. As both the destructive process and the amount of bone loss increase, the importance of more advanced reconstructive procedures that will sustain implant security and soft-tissue management becomes apparent. In the least destructive cases with <5 cm of bone loss, successful revision can typically be accomplished with stem removal and placement of a new monoblock humeral stem. In cases where more advanced destructive pathology is present, and bone loss is >5 cm, an allograft-prosthetic composite (APC) is typically used. In both scenarios, if the stem being revised is cemented and the cement mantle remains intact, and of reasonable length, consideration is given to the cement-within-cement technique. Finally, in the most destructive cases where bone loss exceeds 10 cm and a large biological response is anticipated (eg, periprosthetic fractures with humeral loosening), the use of a longer diaphyseal-incorporating APC is often necessary. This prosthetic composite can be combined with a cement-within-cement technique as well.

It is important to comment on the implications of using modular stems in this setting. With advanced bone loss, a situation is often encountered where the newly implanted stem geometry and working length may be insufficient to acquire adequate rotational stability. In this setting, if a modular junction is positioned close to the stem and cement/bone interface, it will be exposed to very high stress concentrations which can lead to component fracture³⁸ as well as taper corrosion, also referred to as trunnionosis. This latter phenomenon, which has been well studied in the total hip arthroplasty literature with the use of modular components,³⁹ is especially relevant given the high torsional loads imparted at the modular junction. Ultimately, high torsional loads lead to micromotion and electrochemical ion release via degradation of the passivation layer, initiating the process of mechanically assisted crevice corrosion.⁴⁰ For these reasons, when a modular stem must be used in the presence of mild to moderate bone loss, using a proximal humeral allograft to protect the junction or to provide additional fixation may be implemented with a lower threshold than when using a monoblock stem.

SURGICAL TECHNIQUE: ALLOGRAFT-PROSTHETIC COMPOSITES

A standard deltopectoral approach is used, taking care to preserve all viable muscular attachments to the proximal humerus. After removal of the prosthetic humeral head, the decision to proceed with removal of the stem at this juncture is based on several factors. If the remaining proximal humeral bone is so compromised that it might not be able to withstand the forces exerted upon it during retraction for glenoid exposure, the component is left in place. Additionally, if there is consideration that the glenoid-sided bone loss may be so severe that a glenoid baseplate cannot be implanted, and the stem remains well fixed, it is retained so that it can be converted to a hemiarthroplasty.

If neither of the above issues is present, the humeral stem is removed. If a well-fixed press-fit stem is in place, it is typically removed using a combination of burrs and osteotomes to disrupt the bone-implant interface, and the stem is then carefully removed using an impactor and mallet. If a cemented stem is present, the stem is removed in a similar manner, and the cement mantle is left in place if stable, in anticipation of a cement-within-cement technique. If the mantle is disrupted, standard cement removal instruments are used to remove all cement from the canal meticulously.

Continue to: Management of the glenoid...

Management of the glenoid can have significant implications with regard to the humerus. Most notably, the size of the glenosphere has direct implications on the fixation of the humeral component. Use of larger diameter glenospheres result in increased contact area between the glenosphere and humerosocket, adding constraint to the articulation and further increasing the stresses at the implant-bone interface. As such, the use of larger glenospheres to prevent instability must be balanced with the resulting implications on humeral component fixation, especially in cases of severe bone loss.

After implanting the appropriate glenosphere, attention is then turned back to the humerus. Trial implants are sequentially used to obtain adequate humeral length and stability. Once this is accomplished, the amount of humeral bone loss is quantified by measuring the distance from the superior aspect of the medial humeral tray to the medial humeral shaft. If this number is >5 cm (Figure 3), the decision is made to proceed with an APC. The allograft humeral head is cut, cancellous bone is removed, and a step-cut is performed, with the medial portion of the allograft measuring the same length as that of bone loss and the lateral plate extending an additional several centimeters distally (Figure 4). Additional soft tissue is removed from the allograft, leaving the subscapularis stump intact for later repair with the patient’s native tissue. The allograft is secured to the patient’s proximal humerus using multiple cerclage wires, and the humeral stem is cemented into place. The final construct is shown in Figure 5.

ADDITIONAL CONSIDERATIONS: CASES OF ADVANCED BONE LOSS

In cases of advanced humeral bone loss, as is often seen when revising loose humeral stems, larger allografts that span a significant length of the diaphysis are often required. This type of bone loss has implications with regard to how the deltoid insertion is managed. Interestingly, even in situations when the vast majority of the remaining diaphysis consists of ectatic egg-shell bone, the deltoid tuberosity remains of fairly substantial quality due to the continued pull of the muscular insertion on this area. This fragment is isolated, carefully mobilized, and subsequently repaired back on top of the allograft using cables.

POSTOPERATIVE CARE

Patients are kept in a shoulder immobilizer for 6 weeks after surgery to facilitate allograft incorporation and subscapularis tendon healing. During this time, pendulum exercises are initiated. Active assisted range of motion (ROM) exercises begin after 6 weeks, consisting of supine forward elevation. A sling is given to be used in public. Light strengthening exercises begin at 3 months postoperatively.

DISCUSSION

In cases of mild to moderate proximal humeral bone loss, RSA using a long-stem humeral component without allograft augmentation is a viable option. Budge and colleagues³⁸ demonstrated excellent results in a population of 15 patients with an average of 38 mm of proximal humeral bone loss without use of allografts. Interestingly, they noted 1 case of component fracture in a modular prosthesis and therefore concluded that monoblock humeral stems should be used in the absence of allograft augmentation.

Continue to: In more advanced cases of bone loss...

In more advanced cases of bone loss, our data shows that use of APCs can result in equally satisfactory results. In a series of 25 patients with an average bone loss of 54 mm, patients were able to achieve statistically significant improvements in pain, ROM, and function with high rates of allograft incorporation.⁹ Overall, a low rate of complications was noted, including 1 infection. This finding is consistent with an additional study looking specifically at factors associated with infection in revision SA, which found that the use of allografts was not associated with increased risk of infection.⁴¹

As stated previously, the size of allograft needed for the APC construct is related to the distinct pathology encountered. In our experience, we have noted that well-fixed stems can be treated with short metaphyseal APCs in 85% of cases. On the other hand, loose stems require long allografts measuring >10 cm in 90% of cases. As such, these cases typically require mobilization of the deltoid insertion as described above, and therefore it is important that the surgeon is prepared for this aspect of the procedure preoperatively.

Finally, the cement-within-cement technique, originally popularized for use in revision total hip arthroplasty, has demonstrated reliable results when utilized in revision SA.⁴² To date, there are no recommendations regarding the minimal length of existing cement mantle that is needed to perform this technique. In situations in which the length of the cement mantle is questionable, our preference is to combine the cement-within-cement technique with an APC when possible.

ABSTRACT

Reconstructing proximal humeral bone loss in the setting of shoulder arthroplasty can be a daunting task. Proposed techniques include long-stemmed humeral components, allograft-prosthesis composites (APCs), and modular endoprosthetic reconstruction. While unsupported long-stemmed components are at high risk for component loosening, APC reconstruction techniques have been reported with success. However, graft resorption and eventual failure are significant concerns. Modular endoprosthetic systems allow bone deficiencies to be reconstructed with metal, which may allow for a more durable reconstruction.

Continue to: Shoulder arthroplasty is an established procedure...

Shoulder arthroplasty is an established procedure with good results for restoring motion and decreasing pain for a variety of indications, including arthritis, fracture, posttraumatic sequelae, and tumor resection.^1-4 As the population ages, the incidence of these shoulder disorders increases, with the incidence of total shoulder arthroplasty (TSA) and reverse total shoulder arthroplasty (RTSA) increasing at faster rates than that of hemiarthroplasty.^5,6 These expanding indications will, in turn, result in more revisions that would present challenges for surgeons.^1,7,8

The glenoid component is much more commonly revised than the humeral component; however, the humeral component may also require revision or removal to allow exposure of the glenoid component.⁹ Revision of the humeral stem might be required in cases of infection, periprosthetic fracture, dislocation, or aseptic loosening.¹⁰ The survival rate of humeral stems is generally >90% at 10 years and >80% at 20-year follow-up.⁷ Despite these good survival rates, a revision setting the humeral component requires exchange in about half of all cases.¹¹

Humeral bone loss or deficiency is one of the challenges encountered in both primary and revision TSA. The amount of proximal bone loss can be determined by measuring the distance from the top of the prosthesis laterally to the intact lateral cortex.¹² Methods for treating bone loss may involve monoblock revision stems to bypass the deficiency, allografts to rebuild the bone stock, or modular components or endoprostheses to restore the length and stability of the extremity.

Proximal humeral bone loss may make component positioning difficult and may create problems with fixation of the humeral stem. Proper sizing and placement of components are important for improving postoperative function, decreasing component wear and instability, and restoring humeral height and offset. Determining the appropriate center of rotation is important for the function and avoidance of impingement on the acromion, as well as for the restoration of the lever arm of the deltoid without overtensioning. The selection of components with the correct size and the accurate intraoperative placement are important to restore humeral height and offset.^13,14 Components must be positioned <4 mm from the height of the greater tuberosity and <8 mm of offset to avoid compromising motion.¹⁵ De Wilde and Walch¹⁶ described about 3 patients who underwent revision reverse shoulder arthroplasty after failure of the humeral implant because of inadequate proximal humeral bone stock. They concluded that treatment of the bone loss was critical to achieve a successful outcome.

LONG-STEMMED HUMERAL COMPONENTS WITHOUT GRAFTING

There is some evidence indicating that humeral bone loss can be managed without allograft or augmentation. Owens and colleagues¹⁷ evaluated the use of intermediate- or long-stemmed humeral components for primary shoulder arthroplasty in 17 patients with severe proximal humeral bone loss and in 18 patients with large humeral canals. The stems were fully cemented, cemented distally only with proximal allografting, and uncemented. Indications for fully cemented stems were loss of proximal bone that could be filled with a proximal cement mantle to ensure a secure fit. Distal cement fixation was applied when there was significant proximal bone loss and was often supplemented with cancellous or structural allograft and/or cancellous autograft. Intraoperative complications included cortical perforation or cement extrusion in 16% of patients. Excellent or satisfactory results were obtained in 21 (60%) of the 35 shoulders, 14 (78%) of the 18 shoulders with large humeral canals, and 7 (41%) of the 17 shoulders with bone loss. All the 17 components implanted in patients with proximal humeral bone loss were stable with no gross loosening at an average 6-year follow-up.

Continue to: Budge and colleagues...

Budge and colleagues¹² prospectively enrolled 15 patients with substantial proximal humeral bone loss (38.4 mm) who had conversion to RTSA without allografting after a failed TSA. All patients showed improvements in terms of the American Shoulder and Elbow Surgeons (ASES) score, subjective shoulder value, Constant score, and Visual Analog Scale (VAS) pain score, as well as an improved active range of motion (ROM) and good radiographic outcomes at 2-year follow-up. Although the complication rate was high (7 of 15), most of the complications were minor, with only 2 requiring operative intervention. The only component fracture occurred in a patient with a modular prosthesis that was unsupported by bone proximally. Budge and colleagues¹² suggested that concerns about prosthetic fracture can be alleviated using a nonmodular monoblock design. No prosthesis-related complications occurred in their series, leading them to recommend monoblock humeral stems in patients with severe proximal humeral bone loss.

Stephens and colleagues¹⁸ reported revision to RTSA in 32 patients with hemiarthroplasties, half of whom had proximal humeral bone loss (average 36.3 mm). Of these 16 patients, 10 were treated with monoblock stems and 6 with modular components, with cement fixation of all implants. At an average 4-year follow-up, patients with proximal bone loss had improved motion and outcomes, and decreased pain compared to their preoperative condition; however, they had lower functional and pain ratings, as well as less ROM compared to those of patients with intact proximal bone stock. Complications occurred in 5 (31%) of those with bone loss and in 1 (0.6%) of those without bone loss. Three of the 16 patients with bone loss had humeral stem loosening, with 2 of the 3 having subsidence. Only 1 patient required return to the operating room for the treatment of a periprosthetic fracture sustained in a fall. Of the 16 patients with bone loss, 14 patients demonstrated scapular notching, which was severe in 5 of them. Because patients with altered humeral length and/or standard length stems had worse outcomes, the authors recommended longer stems to improve fixation and advocated the use of a long-stemmed monoblock prosthesis over an allograft-prosthesis composite (APC).¹⁸

However, Werner and colleagues¹⁹ reported high rates of loosening and distal migration with the use of long-stemmed humeral implants in 50 patients with revision RTSA. They noted periprosthetic lucency on radiographs in 48% of patients, with more than half of them requiring revision. In 6 patients with subsidence of the humeral shaft, revision was done using custom, modular implants, with the anatomic curve being further stabilized using distal screw and cable fixation to provide rotational stability.

Using a biomechanical model, Cuff and colleagues²⁰ compared 3 RTSA humeral designs, 2 modular designs, and 1 monoblock design in 12 intact models and in 12 models simulating 5 cm of proximal humeral bone loss. They observed that proximal humeral bone loss led to increased humeral component micromotion and rotational instability. The bone loss group had 5 failures compared to 2 in the control group. All failures occurred in those with modular components, whereas those with monoblock implants had no failures.

ALLOGRAFT-PROSTHESIS COMPOSITE

Composite treatment with a humeral stem and a metaphyseal allograft was described by Kassab and colleagues²¹ in 2005 and Levy and colleagues²² in 2007 (Figures 1A-1C) in patients with tumor resections²¹ or failed hemiarthroplasties.²² Allograft was used when there was insufficient metaphyseal bone to support the implant, and a graft was fashioned and fixed with cerclage wire before the component was cemented in place. In the 29 patients reported by Levy and colleagues,²² subjective and objective measurements trended toward better results in those with an APC than in those with RTSA alone, but this difference did not reach statistical significance. Several authors have identified a lack of proximal humeral bone support as 1 of the 4 possible causes of failure, and suggested that the allograft provides structural support, serves as an attachment for subscapularis repair, and maximizes deltoid function by increasing lateral offset and setting the moment arm of the deltoid.^21-23

Continue to: In a prospective study of RTSA...

In a prospective study of RTSA using structural allografts for failed hemiarthroplasty in 25 patients with an average bone loss of 5 cm, 19 patients (76%) reported good or excellent results, 5 reported satisfactory results, and 1 patient reported an unsatisfactory result.¹ Patients had significantly improved forward flexion, abduction, and external rotation and improved outcome scores (ASES and SST). Graft incorporation was good, with 88% and 79% incorporation in the metaphysis and diaphysis, respectively. This technique used a fresh-frozen proximal humeral allograft to fashion a custom proximal block with a lateral step-cut, which was fixed around the stem with cables. A long stem and cement were used. If there was no cement mantle remaining or if the medial portion of the graft was longer than 120 mm, the cement mantle was completely excised. The allograft stump of the subscapularis was used to repair the subscapularis tendon either end-to-end or pants-over-vest. The authors noted that the subscapularis repair provided increased stability; the only dislocation not caused by trauma did not have an identifiable tendon to repair. In this manner, APC reconstruction provided structural and rotational support to the humeral stem as well as bone stock for future revision.^1,20

One significant concern with APC reconstruction is the potential for graft resorption, which can lead to humeral stem loosening, loss of contour of the tuberosity, or weakening to the point of fracture.^24,25 This may be worsened by stress shielding of the allograft by distal stem cement fixation.²⁶ Other concerns include the cost of the allograft, increased risk of de novo infection, donor-to-host infection, increased operative time and complexity, and failure of allograft incorporation.

The use of a proximal femoral allograft has been described when there is a lack of a proximal humeral allograft.^1,27 Kelly and colleagues²⁷ described good results in 2 patients in whom proximal femoral allograft was used along with bone morphogenetic protein, cemented long-stemmed revision implants, and locking plate augmentation.

ENDOPROSTHETIC RECONSTRUCTION

Various forms of prosthetic augmentation have been described to compensate for proximal humeral bone loss, with the majority of reports involving the use of endoprosthetic replacement for tumor procedures.^28-31 Use of endoprostheses has also been described for revision procedures in patients with rheumatoid arthritis with massive bone loss, demonstrating modest improvements compared to severe preoperative functional limitations.³²

Tumor patients, as well as revision arthroplasty patients, may present difficulties with prosthetic fixation due to massive bone loss. Chao and colleagues²⁹ reported about the long-term outcomes after the use of implants with a porous ongrowth surface and extracortical bridging bone graft in multiple anatomic locations, including the proximal humerus, the proximal and distal femur, and the femoral diaphysis. In 3 patients with proximal humeral reconstruction, the measured ongrowth was only 30%. Given the small number of patients with a proximal humerus, no statistical significance was observed in the prosthesis location and the amount of bony ongrowth, but it was far less than that in the lower extremity.

Continue to: Endoprosthetic reconstruction...

Endoprosthetic reconstruction of the proximal humerus is commonly used for tumor resection that resulted in bone loss. Cannon and colleagues²⁸ reported a 97.6% survival rate at a mean follow-up of 30 months in 83 patients with modular and custom reconstruction with a unipolar head. The ROM was limited, but the prosthesis provided adequate stability to allow elbow and hand function. Proximal migration of the prosthetic head was noticed with increasing frequency as the length of follow-up increased.

Use of an endoprosthesis with compressive osteointegration (Zimmer Biomet) has been described in lower extremities and more recently with follow-up on several cases, including 2 proximal humeral replacements for oncology patients to treat severe bone loss. One case was for a primary sarcoma resection, and the other was for the revision of aseptic loosening of a previous endoprosthesis. Follow-up periods for these 2 patients were 54 and 141 months, respectively. Both these patients had complications, but both retained the endoprosthesis. The authors concluded that this is a salvage operation with high risk.³⁰ In another study, Guven and colleagues³¹ reported about reverse endoprosthetic reconstruction for tumor resection with bone loss. The ROM was improved, with a mean active forward elevation of 96° (range, 30°-160°), an abduction of 88° (range, 30-160°), and an external rotation of 13° (range, 0°-20°).

Modular endoprostheses have been evaluated as a method for improving bone fixation and restoring soft-tissue tension, while avoiding the complications associated with traditional endoprostheses or allografts (Figures 2A-2D). These systems allow precise adjustments of length using different trial lengths intraoperatively to obtain proper stability and deltoid tension. Of the 12 patients in a 2 center study, 11 had cementless components inserted using a press-fit technique (unpublished data, J. Feldman). At a minimum 2-year follow-up, the patients had an average improvement in forward elevation from 78° to 97°. Excluding 2 patients with loss of the deltoid tuberosity, the forward elevation averaged 109°. There were significant improvements in internal rotation (from 18° to 38°), as well as in the scores of Quick Disabilities of the Arm, Shoulder and Hand (DASH), forward elevation strength, ASES, and VAS pain. However, the overall complication rate was 41%. Therefore, despite these promising early results, longer-term studies are needed.

CONCLUSION

Proximal humeral bone loss remains a significant challenge for the shoulder arthroplasty surgeon. In the setting of a primary or a revision arthroplasty, the bone stock must be thoroughly evaluated during preoperative planning, and a surgical plan for addressing the deficits should be developed. Because proximal humeral bone loss may contribute to prosthetic failure, every effort should be made to reconstitute the bone stock.¹⁶ If the bone loss is less extensive, impaction grafting may be considered. Options to address massive proximal humeral bone loss include APCs and endoprosthetic reconstruction. The use of an allograft allows subscapularis repair, which may help stabilize the shoulder and restore the natural lever arm, as well as the tension of the deltoid.^1,21-23 In addition, it helps avoid rotational instability and micromotion and provides bone stock for future revisions. However, concern persists regarding allograft resorption over time. More recently, modular endoprosthetic reconstruction systems have been developed to address bone deficiency with metal augmentation. Early clinical results demonstrate a high complication rate in this complex cohort of patients, not unlike those in the series of APCs, but clinical outcomes were improved compared to those in historical series. Nevertheless, longer-term clinical studies are necessary to determine the role of these modular endoprosthetic implant systems.

ABSTRACT

Reconstructing proximal humeral bone loss in the setting of shoulder arthroplasty can be a daunting task. Proposed techniques include long-stemmed humeral components, allograft-prosthesis composites (APCs), and modular endoprosthetic reconstruction. While unsupported long-stemmed components are at high risk for component loosening, APC reconstruction techniques have been reported with success. However, graft resorption and eventual failure are significant concerns. Modular endoprosthetic systems allow bone deficiencies to be reconstructed with metal, which may allow for a more durable reconstruction.

Continue to: Shoulder arthroplasty is an established procedure...

Shoulder arthroplasty is an established procedure with good results for restoring motion and decreasing pain for a variety of indications, including arthritis, fracture, posttraumatic sequelae, and tumor resection.^1-4 As the population ages, the incidence of these shoulder disorders increases, with the incidence of total shoulder arthroplasty (TSA) and reverse total shoulder arthroplasty (RTSA) increasing at faster rates than that of hemiarthroplasty.^5,6 These expanding indications will, in turn, result in more revisions that would present challenges for surgeons.^1,7,8

The glenoid component is much more commonly revised than the humeral component; however, the humeral component may also require revision or removal to allow exposure of the glenoid component.⁹ Revision of the humeral stem might be required in cases of infection, periprosthetic fracture, dislocation, or aseptic loosening.¹⁰ The survival rate of humeral stems is generally >90% at 10 years and >80% at 20-year follow-up.⁷ Despite these good survival rates, a revision setting the humeral component requires exchange in about half of all cases.¹¹

Humeral bone loss or deficiency is one of the challenges encountered in both primary and revision TSA. The amount of proximal bone loss can be determined by measuring the distance from the top of the prosthesis laterally to the intact lateral cortex.¹² Methods for treating bone loss may involve monoblock revision stems to bypass the deficiency, allografts to rebuild the bone stock, or modular components or endoprostheses to restore the length and stability of the extremity.

Proximal humeral bone loss may make component positioning difficult and may create problems with fixation of the humeral stem. Proper sizing and placement of components are important for improving postoperative function, decreasing component wear and instability, and restoring humeral height and offset. Determining the appropriate center of rotation is important for the function and avoidance of impingement on the acromion, as well as for the restoration of the lever arm of the deltoid without overtensioning. The selection of components with the correct size and the accurate intraoperative placement are important to restore humeral height and offset.^13,14 Components must be positioned <4 mm from the height of the greater tuberosity and <8 mm of offset to avoid compromising motion.¹⁵ De Wilde and Walch¹⁶ described about 3 patients who underwent revision reverse shoulder arthroplasty after failure of the humeral implant because of inadequate proximal humeral bone stock. They concluded that treatment of the bone loss was critical to achieve a successful outcome.

LONG-STEMMED HUMERAL COMPONENTS WITHOUT GRAFTING

There is some evidence indicating that humeral bone loss can be managed without allograft or augmentation. Owens and colleagues¹⁷ evaluated the use of intermediate- or long-stemmed humeral components for primary shoulder arthroplasty in 17 patients with severe proximal humeral bone loss and in 18 patients with large humeral canals. The stems were fully cemented, cemented distally only with proximal allografting, and uncemented. Indications for fully cemented stems were loss of proximal bone that could be filled with a proximal cement mantle to ensure a secure fit. Distal cement fixation was applied when there was significant proximal bone loss and was often supplemented with cancellous or structural allograft and/or cancellous autograft. Intraoperative complications included cortical perforation or cement extrusion in 16% of patients. Excellent or satisfactory results were obtained in 21 (60%) of the 35 shoulders, 14 (78%) of the 18 shoulders with large humeral canals, and 7 (41%) of the 17 shoulders with bone loss. All the 17 components implanted in patients with proximal humeral bone loss were stable with no gross loosening at an average 6-year follow-up.

Continue to: Budge and colleagues...

Budge and colleagues¹² prospectively enrolled 15 patients with substantial proximal humeral bone loss (38.4 mm) who had conversion to RTSA without allografting after a failed TSA. All patients showed improvements in terms of the American Shoulder and Elbow Surgeons (ASES) score, subjective shoulder value, Constant score, and Visual Analog Scale (VAS) pain score, as well as an improved active range of motion (ROM) and good radiographic outcomes at 2-year follow-up. Although the complication rate was high (7 of 15), most of the complications were minor, with only 2 requiring operative intervention. The only component fracture occurred in a patient with a modular prosthesis that was unsupported by bone proximally. Budge and colleagues¹² suggested that concerns about prosthetic fracture can be alleviated using a nonmodular monoblock design. No prosthesis-related complications occurred in their series, leading them to recommend monoblock humeral stems in patients with severe proximal humeral bone loss.

Stephens and colleagues¹⁸ reported revision to RTSA in 32 patients with hemiarthroplasties, half of whom had proximal humeral bone loss (average 36.3 mm). Of these 16 patients, 10 were treated with monoblock stems and 6 with modular components, with cement fixation of all implants. At an average 4-year follow-up, patients with proximal bone loss had improved motion and outcomes, and decreased pain compared to their preoperative condition; however, they had lower functional and pain ratings, as well as less ROM compared to those of patients with intact proximal bone stock. Complications occurred in 5 (31%) of those with bone loss and in 1 (0.6%) of those without bone loss. Three of the 16 patients with bone loss had humeral stem loosening, with 2 of the 3 having subsidence. Only 1 patient required return to the operating room for the treatment of a periprosthetic fracture sustained in a fall. Of the 16 patients with bone loss, 14 patients demonstrated scapular notching, which was severe in 5 of them. Because patients with altered humeral length and/or standard length stems had worse outcomes, the authors recommended longer stems to improve fixation and advocated the use of a long-stemmed monoblock prosthesis over an allograft-prosthesis composite (APC).¹⁸

However, Werner and colleagues¹⁹ reported high rates of loosening and distal migration with the use of long-stemmed humeral implants in 50 patients with revision RTSA. They noted periprosthetic lucency on radiographs in 48% of patients, with more than half of them requiring revision. In 6 patients with subsidence of the humeral shaft, revision was done using custom, modular implants, with the anatomic curve being further stabilized using distal screw and cable fixation to provide rotational stability.

Using a biomechanical model, Cuff and colleagues²⁰ compared 3 RTSA humeral designs, 2 modular designs, and 1 monoblock design in 12 intact models and in 12 models simulating 5 cm of proximal humeral bone loss. They observed that proximal humeral bone loss led to increased humeral component micromotion and rotational instability. The bone loss group had 5 failures compared to 2 in the control group. All failures occurred in those with modular components, whereas those with monoblock implants had no failures.

ALLOGRAFT-PROSTHESIS COMPOSITE

Composite treatment with a humeral stem and a metaphyseal allograft was described by Kassab and colleagues²¹ in 2005 and Levy and colleagues²² in 2007 (Figures 1A-1C) in patients with tumor resections²¹ or failed hemiarthroplasties.²² Allograft was used when there was insufficient metaphyseal bone to support the implant, and a graft was fashioned and fixed with cerclage wire before the component was cemented in place. In the 29 patients reported by Levy and colleagues,²² subjective and objective measurements trended toward better results in those with an APC than in those with RTSA alone, but this difference did not reach statistical significance. Several authors have identified a lack of proximal humeral bone support as 1 of the 4 possible causes of failure, and suggested that the allograft provides structural support, serves as an attachment for subscapularis repair, and maximizes deltoid function by increasing lateral offset and setting the moment arm of the deltoid.^21-23

Continue to: In a prospective study of RTSA...

In a prospective study of RTSA using structural allografts for failed hemiarthroplasty in 25 patients with an average bone loss of 5 cm, 19 patients (76%) reported good or excellent results, 5 reported satisfactory results, and 1 patient reported an unsatisfactory result.¹ Patients had significantly improved forward flexion, abduction, and external rotation and improved outcome scores (ASES and SST). Graft incorporation was good, with 88% and 79% incorporation in the metaphysis and diaphysis, respectively. This technique used a fresh-frozen proximal humeral allograft to fashion a custom proximal block with a lateral step-cut, which was fixed around the stem with cables. A long stem and cement were used. If there was no cement mantle remaining or if the medial portion of the graft was longer than 120 mm, the cement mantle was completely excised. The allograft stump of the subscapularis was used to repair the subscapularis tendon either end-to-end or pants-over-vest. The authors noted that the subscapularis repair provided increased stability; the only dislocation not caused by trauma did not have an identifiable tendon to repair. In this manner, APC reconstruction provided structural and rotational support to the humeral stem as well as bone stock for future revision.^1,20

One significant concern with APC reconstruction is the potential for graft resorption, which can lead to humeral stem loosening, loss of contour of the tuberosity, or weakening to the point of fracture.^24,25 This may be worsened by stress shielding of the allograft by distal stem cement fixation.²⁶ Other concerns include the cost of the allograft, increased risk of de novo infection, donor-to-host infection, increased operative time and complexity, and failure of allograft incorporation.

The use of a proximal femoral allograft has been described when there is a lack of a proximal humeral allograft.^1,27 Kelly and colleagues²⁷ described good results in 2 patients in whom proximal femoral allograft was used along with bone morphogenetic protein, cemented long-stemmed revision implants, and locking plate augmentation.

ENDOPROSTHETIC RECONSTRUCTION

Various forms of prosthetic augmentation have been described to compensate for proximal humeral bone loss, with the majority of reports involving the use of endoprosthetic replacement for tumor procedures.^28-31 Use of endoprostheses has also been described for revision procedures in patients with rheumatoid arthritis with massive bone loss, demonstrating modest improvements compared to severe preoperative functional limitations.³²

Tumor patients, as well as revision arthroplasty patients, may present difficulties with prosthetic fixation due to massive bone loss. Chao and colleagues²⁹ reported about the long-term outcomes after the use of implants with a porous ongrowth surface and extracortical bridging bone graft in multiple anatomic locations, including the proximal humerus, the proximal and distal femur, and the femoral diaphysis. In 3 patients with proximal humeral reconstruction, the measured ongrowth was only 30%. Given the small number of patients with a proximal humerus, no statistical significance was observed in the prosthesis location and the amount of bony ongrowth, but it was far less than that in the lower extremity.

Continue to: Endoprosthetic reconstruction...

Endoprosthetic reconstruction of the proximal humerus is commonly used for tumor resection that resulted in bone loss. Cannon and colleagues²⁸ reported a 97.6% survival rate at a mean follow-up of 30 months in 83 patients with modular and custom reconstruction with a unipolar head. The ROM was limited, but the prosthesis provided adequate stability to allow elbow and hand function. Proximal migration of the prosthetic head was noticed with increasing frequency as the length of follow-up increased.

Use of an endoprosthesis with compressive osteointegration (Zimmer Biomet) has been described in lower extremities and more recently with follow-up on several cases, including 2 proximal humeral replacements for oncology patients to treat severe bone loss. One case was for a primary sarcoma resection, and the other was for the revision of aseptic loosening of a previous endoprosthesis. Follow-up periods for these 2 patients were 54 and 141 months, respectively. Both these patients had complications, but both retained the endoprosthesis. The authors concluded that this is a salvage operation with high risk.³⁰ In another study, Guven and colleagues³¹ reported about reverse endoprosthetic reconstruction for tumor resection with bone loss. The ROM was improved, with a mean active forward elevation of 96° (range, 30°-160°), an abduction of 88° (range, 30-160°), and an external rotation of 13° (range, 0°-20°).

Modular endoprostheses have been evaluated as a method for improving bone fixation and restoring soft-tissue tension, while avoiding the complications associated with traditional endoprostheses or allografts (Figures 2A-2D). These systems allow precise adjustments of length using different trial lengths intraoperatively to obtain proper stability and deltoid tension. Of the 12 patients in a 2 center study, 11 had cementless components inserted using a press-fit technique (unpublished data, J. Feldman). At a minimum 2-year follow-up, the patients had an average improvement in forward elevation from 78° to 97°. Excluding 2 patients with loss of the deltoid tuberosity, the forward elevation averaged 109°. There were significant improvements in internal rotation (from 18° to 38°), as well as in the scores of Quick Disabilities of the Arm, Shoulder and Hand (DASH), forward elevation strength, ASES, and VAS pain. However, the overall complication rate was 41%. Therefore, despite these promising early results, longer-term studies are needed.

CONCLUSION

Proximal humeral bone loss remains a significant challenge for the shoulder arthroplasty surgeon. In the setting of a primary or a revision arthroplasty, the bone stock must be thoroughly evaluated during preoperative planning, and a surgical plan for addressing the deficits should be developed. Because proximal humeral bone loss may contribute to prosthetic failure, every effort should be made to reconstitute the bone stock.¹⁶ If the bone loss is less extensive, impaction grafting may be considered. Options to address massive proximal humeral bone loss include APCs and endoprosthetic reconstruction. The use of an allograft allows subscapularis repair, which may help stabilize the shoulder and restore the natural lever arm, as well as the tension of the deltoid.^1,21-23 In addition, it helps avoid rotational instability and micromotion and provides bone stock for future revisions. However, concern persists regarding allograft resorption over time. More recently, modular endoprosthetic reconstruction systems have been developed to address bone deficiency with metal augmentation. Early clinical results demonstrate a high complication rate in this complex cohort of patients, not unlike those in the series of APCs, but clinical outcomes were improved compared to those in historical series. Nevertheless, longer-term clinical studies are necessary to determine the role of these modular endoprosthetic implant systems.

ABSTRACT

Reconstructing proximal humeral bone loss in the setting of shoulder arthroplasty can be a daunting task. Proposed techniques include long-stemmed humeral components, allograft-prosthesis composites (APCs), and modular endoprosthetic reconstruction. While unsupported long-stemmed components are at high risk for component loosening, APC reconstruction techniques have been reported with success. However, graft resorption and eventual failure are significant concerns. Modular endoprosthetic systems allow bone deficiencies to be reconstructed with metal, which may allow for a more durable reconstruction.

Continue to: Shoulder arthroplasty is an established procedure...

Shoulder arthroplasty is an established procedure with good results for restoring motion and decreasing pain for a variety of indications, including arthritis, fracture, posttraumatic sequelae, and tumor resection.^1-4 As the population ages, the incidence of these shoulder disorders increases, with the incidence of total shoulder arthroplasty (TSA) and reverse total shoulder arthroplasty (RTSA) increasing at faster rates than that of hemiarthroplasty.^5,6 These expanding indications will, in turn, result in more revisions that would present challenges for surgeons.^1,7,8

The glenoid component is much more commonly revised than the humeral component; however, the humeral component may also require revision or removal to allow exposure of the glenoid component.⁹ Revision of the humeral stem might be required in cases of infection, periprosthetic fracture, dislocation, or aseptic loosening.¹⁰ The survival rate of humeral stems is generally >90% at 10 years and >80% at 20-year follow-up.⁷ Despite these good survival rates, a revision setting the humeral component requires exchange in about half of all cases.¹¹

Humeral bone loss or deficiency is one of the challenges encountered in both primary and revision TSA. The amount of proximal bone loss can be determined by measuring the distance from the top of the prosthesis laterally to the intact lateral cortex.¹² Methods for treating bone loss may involve monoblock revision stems to bypass the deficiency, allografts to rebuild the bone stock, or modular components or endoprostheses to restore the length and stability of the extremity.

Proximal humeral bone loss may make component positioning difficult and may create problems with fixation of the humeral stem. Proper sizing and placement of components are important for improving postoperative function, decreasing component wear and instability, and restoring humeral height and offset. Determining the appropriate center of rotation is important for the function and avoidance of impingement on the acromion, as well as for the restoration of the lever arm of the deltoid without overtensioning. The selection of components with the correct size and the accurate intraoperative placement are important to restore humeral height and offset.^13,14 Components must be positioned <4 mm from the height of the greater tuberosity and <8 mm of offset to avoid compromising motion.¹⁵ De Wilde and Walch¹⁶ described about 3 patients who underwent revision reverse shoulder arthroplasty after failure of the humeral implant because of inadequate proximal humeral bone stock. They concluded that treatment of the bone loss was critical to achieve a successful outcome.

LONG-STEMMED HUMERAL COMPONENTS WITHOUT GRAFTING

There is some evidence indicating that humeral bone loss can be managed without allograft or augmentation. Owens and colleagues¹⁷ evaluated the use of intermediate- or long-stemmed humeral components for primary shoulder arthroplasty in 17 patients with severe proximal humeral bone loss and in 18 patients with large humeral canals. The stems were fully cemented, cemented distally only with proximal allografting, and uncemented. Indications for fully cemented stems were loss of proximal bone that could be filled with a proximal cement mantle to ensure a secure fit. Distal cement fixation was applied when there was significant proximal bone loss and was often supplemented with cancellous or structural allograft and/or cancellous autograft. Intraoperative complications included cortical perforation or cement extrusion in 16% of patients. Excellent or satisfactory results were obtained in 21 (60%) of the 35 shoulders, 14 (78%) of the 18 shoulders with large humeral canals, and 7 (41%) of the 17 shoulders with bone loss. All the 17 components implanted in patients with proximal humeral bone loss were stable with no gross loosening at an average 6-year follow-up.

Continue to: Budge and colleagues...

Budge and colleagues¹² prospectively enrolled 15 patients with substantial proximal humeral bone loss (38.4 mm) who had conversion to RTSA without allografting after a failed TSA. All patients showed improvements in terms of the American Shoulder and Elbow Surgeons (ASES) score, subjective shoulder value, Constant score, and Visual Analog Scale (VAS) pain score, as well as an improved active range of motion (ROM) and good radiographic outcomes at 2-year follow-up. Although the complication rate was high (7 of 15), most of the complications were minor, with only 2 requiring operative intervention. The only component fracture occurred in a patient with a modular prosthesis that was unsupported by bone proximally. Budge and colleagues¹² suggested that concerns about prosthetic fracture can be alleviated using a nonmodular monoblock design. No prosthesis-related complications occurred in their series, leading them to recommend monoblock humeral stems in patients with severe proximal humeral bone loss.

Stephens and colleagues¹⁸ reported revision to RTSA in 32 patients with hemiarthroplasties, half of whom had proximal humeral bone loss (average 36.3 mm). Of these 16 patients, 10 were treated with monoblock stems and 6 with modular components, with cement fixation of all implants. At an average 4-year follow-up, patients with proximal bone loss had improved motion and outcomes, and decreased pain compared to their preoperative condition; however, they had lower functional and pain ratings, as well as less ROM compared to those of patients with intact proximal bone stock. Complications occurred in 5 (31%) of those with bone loss and in 1 (0.6%) of those without bone loss. Three of the 16 patients with bone loss had humeral stem loosening, with 2 of the 3 having subsidence. Only 1 patient required return to the operating room for the treatment of a periprosthetic fracture sustained in a fall. Of the 16 patients with bone loss, 14 patients demonstrated scapular notching, which was severe in 5 of them. Because patients with altered humeral length and/or standard length stems had worse outcomes, the authors recommended longer stems to improve fixation and advocated the use of a long-stemmed monoblock prosthesis over an allograft-prosthesis composite (APC).¹⁸

However, Werner and colleagues¹⁹ reported high rates of loosening and distal migration with the use of long-stemmed humeral implants in 50 patients with revision RTSA. They noted periprosthetic lucency on radiographs in 48% of patients, with more than half of them requiring revision. In 6 patients with subsidence of the humeral shaft, revision was done using custom, modular implants, with the anatomic curve being further stabilized using distal screw and cable fixation to provide rotational stability.

Using a biomechanical model, Cuff and colleagues²⁰ compared 3 RTSA humeral designs, 2 modular designs, and 1 monoblock design in 12 intact models and in 12 models simulating 5 cm of proximal humeral bone loss. They observed that proximal humeral bone loss led to increased humeral component micromotion and rotational instability. The bone loss group had 5 failures compared to 2 in the control group. All failures occurred in those with modular components, whereas those with monoblock implants had no failures.

ALLOGRAFT-PROSTHESIS COMPOSITE

Composite treatment with a humeral stem and a metaphyseal allograft was described by Kassab and colleagues²¹ in 2005 and Levy and colleagues²² in 2007 (Figures 1A-1C) in patients with tumor resections²¹ or failed hemiarthroplasties.²² Allograft was used when there was insufficient metaphyseal bone to support the implant, and a graft was fashioned and fixed with cerclage wire before the component was cemented in place. In the 29 patients reported by Levy and colleagues,²² subjective and objective measurements trended toward better results in those with an APC than in those with RTSA alone, but this difference did not reach statistical significance. Several authors have identified a lack of proximal humeral bone support as 1 of the 4 possible causes of failure, and suggested that the allograft provides structural support, serves as an attachment for subscapularis repair, and maximizes deltoid function by increasing lateral offset and setting the moment arm of the deltoid.^21-23

Continue to: In a prospective study of RTSA...

In a prospective study of RTSA using structural allografts for failed hemiarthroplasty in 25 patients with an average bone loss of 5 cm, 19 patients (76%) reported good or excellent results, 5 reported satisfactory results, and 1 patient reported an unsatisfactory result.¹ Patients had significantly improved forward flexion, abduction, and external rotation and improved outcome scores (ASES and SST). Graft incorporation was good, with 88% and 79% incorporation in the metaphysis and diaphysis, respectively. This technique used a fresh-frozen proximal humeral allograft to fashion a custom proximal block with a lateral step-cut, which was fixed around the stem with cables. A long stem and cement were used. If there was no cement mantle remaining or if the medial portion of the graft was longer than 120 mm, the cement mantle was completely excised. The allograft stump of the subscapularis was used to repair the subscapularis tendon either end-to-end or pants-over-vest. The authors noted that the subscapularis repair provided increased stability; the only dislocation not caused by trauma did not have an identifiable tendon to repair. In this manner, APC reconstruction provided structural and rotational support to the humeral stem as well as bone stock for future revision.^1,20

One significant concern with APC reconstruction is the potential for graft resorption, which can lead to humeral stem loosening, loss of contour of the tuberosity, or weakening to the point of fracture.^24,25 This may be worsened by stress shielding of the allograft by distal stem cement fixation.²⁶ Other concerns include the cost of the allograft, increased risk of de novo infection, donor-to-host infection, increased operative time and complexity, and failure of allograft incorporation.

The use of a proximal femoral allograft has been described when there is a lack of a proximal humeral allograft.^1,27 Kelly and colleagues²⁷ described good results in 2 patients in whom proximal femoral allograft was used along with bone morphogenetic protein, cemented long-stemmed revision implants, and locking plate augmentation.

ENDOPROSTHETIC RECONSTRUCTION

Various forms of prosthetic augmentation have been described to compensate for proximal humeral bone loss, with the majority of reports involving the use of endoprosthetic replacement for tumor procedures.^28-31 Use of endoprostheses has also been described for revision procedures in patients with rheumatoid arthritis with massive bone loss, demonstrating modest improvements compared to severe preoperative functional limitations.³²

Tumor patients, as well as revision arthroplasty patients, may present difficulties with prosthetic fixation due to massive bone loss. Chao and colleagues²⁹ reported about the long-term outcomes after the use of implants with a porous ongrowth surface and extracortical bridging bone graft in multiple anatomic locations, including the proximal humerus, the proximal and distal femur, and the femoral diaphysis. In 3 patients with proximal humeral reconstruction, the measured ongrowth was only 30%. Given the small number of patients with a proximal humerus, no statistical significance was observed in the prosthesis location and the amount of bony ongrowth, but it was far less than that in the lower extremity.

Continue to: Endoprosthetic reconstruction...

Endoprosthetic reconstruction of the proximal humerus is commonly used for tumor resection that resulted in bone loss. Cannon and colleagues²⁸ reported a 97.6% survival rate at a mean follow-up of 30 months in 83 patients with modular and custom reconstruction with a unipolar head. The ROM was limited, but the prosthesis provided adequate stability to allow elbow and hand function. Proximal migration of the prosthetic head was noticed with increasing frequency as the length of follow-up increased.

Use of an endoprosthesis with compressive osteointegration (Zimmer Biomet) has been described in lower extremities and more recently with follow-up on several cases, including 2 proximal humeral replacements for oncology patients to treat severe bone loss. One case was for a primary sarcoma resection, and the other was for the revision of aseptic loosening of a previous endoprosthesis. Follow-up periods for these 2 patients were 54 and 141 months, respectively. Both these patients had complications, but both retained the endoprosthesis. The authors concluded that this is a salvage operation with high risk.³⁰ In another study, Guven and colleagues³¹ reported about reverse endoprosthetic reconstruction for tumor resection with bone loss. The ROM was improved, with a mean active forward elevation of 96° (range, 30°-160°), an abduction of 88° (range, 30-160°), and an external rotation of 13° (range, 0°-20°).

Modular endoprostheses have been evaluated as a method for improving bone fixation and restoring soft-tissue tension, while avoiding the complications associated with traditional endoprostheses or allografts (Figures 2A-2D). These systems allow precise adjustments of length using different trial lengths intraoperatively to obtain proper stability and deltoid tension. Of the 12 patients in a 2 center study, 11 had cementless components inserted using a press-fit technique (unpublished data, J. Feldman). At a minimum 2-year follow-up, the patients had an average improvement in forward elevation from 78° to 97°. Excluding 2 patients with loss of the deltoid tuberosity, the forward elevation averaged 109°. There were significant improvements in internal rotation (from 18° to 38°), as well as in the scores of Quick Disabilities of the Arm, Shoulder and Hand (DASH), forward elevation strength, ASES, and VAS pain. However, the overall complication rate was 41%. Therefore, despite these promising early results, longer-term studies are needed.

CONCLUSION

Proximal humeral bone loss remains a significant challenge for the shoulder arthroplasty surgeon. In the setting of a primary or a revision arthroplasty, the bone stock must be thoroughly evaluated during preoperative planning, and a surgical plan for addressing the deficits should be developed. Because proximal humeral bone loss may contribute to prosthetic failure, every effort should be made to reconstitute the bone stock.¹⁶ If the bone loss is less extensive, impaction grafting may be considered. Options to address massive proximal humeral bone loss include APCs and endoprosthetic reconstruction. The use of an allograft allows subscapularis repair, which may help stabilize the shoulder and restore the natural lever arm, as well as the tension of the deltoid.^1,21-23 In addition, it helps avoid rotational instability and micromotion and provides bone stock for future revisions. However, concern persists regarding allograft resorption over time. More recently, modular endoprosthetic reconstruction systems have been developed to address bone deficiency with metal augmentation. Early clinical results demonstrate a high complication rate in this complex cohort of patients, not unlike those in the series of APCs, but clinical outcomes were improved compared to those in historical series. Nevertheless, longer-term clinical studies are necessary to determine the role of these modular endoprosthetic implant systems.

ABSTRACT

The aim of this study was to assess the efficacy and safety of a novel magnesium-based resorbable bone cement (OsteoCrete, Bone Solutions Incorporated) for anchor and tendon fixation.

Cadaveric humeral testing involved straight pull-to-failure of rotator cuff suture anchors; OsteoCrete was injected through one anchor, and a second anchor served as the uninjected control. Testing was conducted 15 minutes post-injection. A canine preclinical model was used to evaluate the safety of the following parameters: Rotator cuff repair: A double-row technique was used to repair transected infraspinatus tendons; OsteoCrete was injected through both anchors in one limb, and the contralateral limb served as the uninjected control. Biceps tenodesis: The transected biceps tendon was implanted into a proximal humeral socket with a transcortical button; OsteoCrete was injected into the socket of one limb, and a screw was used for final fixation in the contralateral control limb. Nondestructive biomechanical testing and histologic assessment were performed after 12 weeks.

OsteoCrete-augmented anchors showed significantly higher load-to-failure compared to that with uninjected controls. In cadaveric humeri with reduced bone quality, OsteoCrete increased the mean load-to-failure by 99%. Within the preclinical model, there were no complications or statistically significant biomechanical/histologic differences between the techniques.

OsteoCrete has the potential for safely providing improved suture anchor and tissue fixation in patients with poor bone or tissue quality.

Continue to: Calcium phosphate bone void fillers...

Calcium phosphate bone void fillers have been commonly used in orthopedic surgery for several applications, including, but not limited to, a variety of fracture fixation or augmentation procedures.^1-8 Continuing research on calcium phosphates has evidenced that the addition of magnesium phosphate to the formulation results in improved reactivity of the bone void filler. An in vitro study demonstrated enhanced attachment and proliferation of MG₆₃ osteoblast-like cells on calcium magnesium phosphate cement (CMPC), in comparison with calcium phosphate cement (CPC), along with increased cellular alkaline phosphatase activity.⁹ The authors further explored the proliferation rates of MG₆₃ cells by comparing CMPC with CPC and magnesium phosphate cement (MPC), and observed significantly increased proliferation of cells on CMPC. They also compared CMPC and CPC using a rabbit bone void model and observed substantial CMPC resorption with new bone formation at the 3-month time point and further reported that the majority of the defect had filled with new bone at 6 months, whereas CPC resulted in <10% new bone formation after 6 months.¹⁰ The authors continued to study the differences between CPC, MPC, and CMPC and identified increased proliferation of bone marrow stromal cells (bMSCs), when the cells were associated with CMPC and MPC, and when compared to that with CPC. The osteogenic differentiation of bMSCs was highest in the CMPC and CPC groups, when compared to that in the MPC group, with no significant difference between the CMPC and CPC groups. The authors also compared these 3 different formulations using a rabbit maxillary sinus floor elevation model, in which CMPC resulted in increased new bone formation and mineralization compared to that with CPC and MPC, which was further enhanced with the addition of bMSCs.¹¹

These studies highlight the importance of having both a magnesium phosphate and a calcium phosphate component for a resorbable cement intended for use as a bone void filler. The rationale behind this strategy is related to the release of magnesium ions from the magnesium phosphate component. Magnesium has been shown to increase the proliferation of bMSCs, improve the attachment and growth of osteoblasts, stimulate the proteins involved in bone regeneration, enhance new bone formation, and boost bone mineralization.^12,13

OsteoCrete (Bone Solutions Incorporation) is a novel CMPC composed of magnesium oxide, monopotassium phosphate, monosodium phosphate, hydroxyapatite, and sucrose. OsteoCrete has been demonstrated to significantly increase peak torque-to-failure of stainless-steel cortical bone screw fixation, when compared with screw fixation without augmentation and screw fixation with calcium phosphate augmentation using an in vivo equine model. In the same study, the authors showed that OsteoCrete resulted in an interface toughness that was significantly increased compared to that with no treatment, CPC augmentation, and polymethylmethacrylate (PMMA) augmentation. At 6 months after implantation, woven bone had replaced 69% of the OsteoCrete at the screw interface, compared to 44% of that with CPC.¹⁴ An equine study examined the effects of OsteoCrete on bone stability and healing using a metatarsal osteotomy model; the study reported significantly improved radiographic callus formation and a greater amount of new bone formation within the fracture gap when compared to that with CPC augmentation or no augmentation. OsteoCrete also secured the fragment significantly better than the CPC and control groups based on a decreased fracture gap over time.¹⁵ Another study using a preclinical anterior cruciate ligament (ACL) reconstruction model reported that OsteoCrete resulted in significantly better new bone formation in the tibial tunnel, a smaller amount of fibrous tissue, more cartilage formation at the tendon-bone interface, and a higher ultimate load-to-failure compared to that with standard ACL reconstruction in the contralateral limb after 6 weeks.¹⁶ OsteoCrete and PMMA were evaluated in terms of biomechanical fixation of a stemless humeral prosthesis, with data showing that both groups have higher failure loads, failure displacements, and failure cycles when compared to those with the control, nonaugmented group.¹⁷ Another preclinical model evaluated cranial bone flap augmentation with 2 resorbable cements and highlighted faster cement resorption and replacement with bone, along with superior stability within the OsteoCrete group compared to that with CPC.¹⁸ In a preclinical bone void study conducted for obtaining US Food and Drug Administration 510(k) clearance, OsteoCrete resulted in 83% greater resorption than that with CPC after 12 weeks and 35% greater resorption at 26 weeks, with 84% of OsteoCrete being resorbed and replaced with woven or lamellar mineralized bone of normal morphology at the 26-week time point (unpublished data provided by Bone Solutions Incorporated [BSI]).

These data indicate that CMPCs such as OsteoCrete appear to have potential benefits for augmenting the healing of bone implants and bone soft tissue. Therefore, the objective of this study was to assess the safety and efficacy of OsteoCrete in applications for the augmentation of anchor and tendon fixation in rotator cuff repair and biceps tenodesis procedures, respectively. Improving healing for these 2 commonly performed procedures would be of great benefit in improving the functional outcomes and mitigating the complications and morbidity.

MATERIALS AND METHODS

IN VITRO STUDY METHODS

Cadaveric humeri (N = 12, six matched pairs) of females (age, 70-75 years) were warmed to 37°C prior to testing. Two 4.75-mm vented anchors (SwiveLock, Arthrex) with FiberTape were implanted into a lateral row position (anterior and posterior anchor positioning) of a double-row rotator cuff repair within the greater tuberosity. One anchor was injected with 1 ml of OsteoCrete–after preparation according to the manufacturer’s instructions–through the cannulation channel after placement, and the other anchor served as the uninjected control for each humerus. For the six matched pairs, the OsteoCrete group and the control group were rotated with respect to anterior vs posterior location within the lateral row position. After 15 minutes of the injection, straight pull-to-failure (12 in/min) was performed. Data were compared between the groups for significant (P < .05) differences using t-tests and Pearson correlation.

Continue to: IN VIVO STUDY METHODS

With Institutional Animal Care and Use Committee approval, adult (age, 2-4 years) purpose-bred dogs (N = 8) underwent aseptic surgery of both forelimbs for rotator cuff (infraspinatus) tendon repair (Figure 1) and biceps tenodesis (Figure 2). For the rotator cuff repair, two 4.75-mm vented anchors (1 medial and 1 lateral) with FiberTape were used in a modified double-row technique to repair the acutely transected infraspinatus tendon. In one limb, 1 ml of OsteoCrete was injected through both anchors; the other limb served as the uninjected control. For the biceps tenodesis procedure, the long head of the biceps tendon was transected at its origin and whip-stitched. The tendon was transposed and inserted into a 7-mm diameter socket drilled into the proximal humerus using a tension-slide technique with a transcortical button for fixation. In one limb, 1 ml of OsteoCrete was injected into the socket prior to final tensioning and tying. In the contralateral limb, a 7-mm interference screw (Bio-Tenodesis™ Screw, Arthrex) was inserted into the socket after tensioning and tying. The dogs were allowed to perform out-of-kennel monitored exercise daily for a period of 12 weeks after surgery and were then sacrificed.

The infraspinatus and biceps bone-tendon-muscle units were excised en bloc. Custom-designed jigs were used for biomechanical testing of the bone-tendon-muscle units along the anatomical vector of muscle contraction. Optical markers were mounted at standardized anatomical locations. Elongation of the repair site was defined as the change in distance between markers and was measured to 0.01-mm resolution using an optical tracking system (Optotrak Certus, NDI), synchronized with measurement of the applied tension load. The bone-tendon-muscle units were loaded in tension to 3-mm elongation at a displacement controlled rate of 0.01 mm/s. Load at 1-mm, 2-mm, and 3-mm displacement of the tendon-bone junction was extracted from the load vs the displacement curve of each sample. Stiffness was calculated as the slope of the linear portion of the load vs the displacement curve.^19,20

For histologic assessments, sections of each treatment site were obtained using a microsaw and alternated between decalcified and non-decalcified processing. For decalcified bone processing, formalin-fixed tissues were placed in 10% ethylenediaminetetraacetic acid with phosphate-buffered saline for 39 days and then processed routinely for the assessment of sections stained with hematoxylin and eosin (H&E), toluidine blue, and picrosirius red. For non-decalcified bone processing, the tissues were dehydrated through a series of graded ethyl alcohol solutions, embedded in PMMA, sectioned, and stained with toluidine blue and Goldner’s trichrome. Two pathologists who were blinded to the clinical application and the differences between techniques assessed the histologic sections and scored each section using the modified Bonar score that assesses cell morphology, collagen arrangement, cellularity, vascularity, and extracellular matrix using a 15-point scale, where a higher score indicates more pathology.²¹

Categorical data were compared for detecting statistically significant differences using the rank sum test. Continuous data were compared for identifying statistically significant differences using the t-test or one-way ANOVA. Significance was set at P < .05.

RESULTS

IN VITRO RESULTS

OsteoCrete-augmented anchors (mean = 225 N; range, 158-287 N) had significantly (P < .001) higher pull-out load-to-failure compared to that in the uninjected controls (mean = 161 N; range, 68-202 N), which translated to a 50% mean increase (range, 3%-134%) in load-to-failure (Table 1). For humeri with reduced bone quality (control anchors that failed at <160 N, 4 humeri), the mean increase in load-to-failure for OsteoCrete-augmented anchors was 99% (range, 58%-135%), with the difference between mean values being again significantly different (OsteoCrete mean = 205 N; control mean = 110 N, P < .001). When the control and OsteoCrete load-to-failure values were compared using Pearson correlation, a significantly strong positive correlation (r = 0.66, P = 0.02) was detected. When the control load-to-failure values were compared with its percent increase value when OsteoCrete was used, there was a significantly very strong negative correlation (r = −0.90, P < .001).

Table 1. Cadaveric Lateral Row Rotator Cuff Anchor Pull-To-Failure; Testing Occurred 15 Minutes Post-Injection

^aOsteoCrete (Bone Solutions Incorporated) resulted in significantly increased (P < 0.001) pull-to-failure. Abbreviations: AP, control anchor located in anterior position, OsteoCrete anchor located in posterior position; PA, control anchor located in posterior position, OsteoCrete anchor located in anterior position.

Continue to: IN VIVO RESULTS

No intraoperative or postoperative complications were noted. All repairs were found to be intact based on the gross assessment and the completed biomechanical testing without failure. No statistically significant (P > 0.3) biomechanical differences were found between the techniques (Table 2). Histologic assessments showed low-to-mild pathology scores for all sites with no statistically significant (P > 0.3) differences between the techniques (Table 2). Both control and OsteoCrete rotator cuff repairs demonstrated tendon-to-bone integration via fibrous connective tissue attachment to bone. All anchors were in place with no evidence for loosening, tunnel expansion, or cyst formation. OsteoCrete-augmented anchor repairs were associated with cement remaining within their lumens along with a thin layer of cement interposed between the anchor and the bone interface around their entire periphery. The cement-bone interface was discrete with typical inflammatory cell infiltrate without evidence for infection, membrane or cyst formation, or other untoward pathologic responses. In the OsteoCrete biceps tenodesis group, the tendons filled the tunnels with a thin layer of cement remaining interposed between the tendon and the bone interface around the entire periphery. The tendon-cement-bone interface was discrete with typical inflammatory cell infiltrates and without evidence for infection, membrane or cyst formation, or other untoward pathologic responses. Tendon-to-bone integration was not observed in the control or OsteoCrete biceps tenodesis groups at the 12-week study endpoint. Representative histologic images of the rotator cuff tendon repairs and biceps tenodesis procedures are shown in Figures 3A, 3B and Figures 4A, 4B, respectively.

Table 2. Biomechanical Testing And Histologic Scoring Of Rotator Cuff And Biceps Tendon Repairs In A Preclinical Model

There were no significant differences (P < 0.05) between groups. Histologic scoring based on a 15-point scale with higher scores indicating more pathology.

DISCUSSION

The results of this study highlight the safety and efficacy of OsteoCrete in applications for the augmentation of anchor and tendon fixation in rotator cuff repair and biceps tenodesis procedures, respectively. Anchors augmented with OsteoCrete resulted in significantly increased load-to-failure pull-out strength 15 minutes after insertion. In addition, a very strong negative correlation was found between the percentage of improved load-to-failure after OsteoCrete injection and the bone quality of the humerus, which was based on the control load-to-failure values. In the validated preclinical model used in this study, OsteoCrete-based fixation was found to be noninferior to current standard-of-care techniques and was not associated with any untoward pathologic responses of humeral bone, rotator cuff tendon, or biceps tendon based on the biomechanical and histologic analyses. These data highlight the functional efficacy and biocompatibility of OsteoCrete when used for these common indications.

More than 270,000 rotator cuff procedures have been reported to be performed in the US annually (average patient age: 61 years for women, 56 years for men).²² Rotator cuff repair procedures have been associated with a 20% failure rate, with one of the causes being related to an inability for the tendon to heal, even with strong initial fixation.²³ Rotator cuff repair techniques are being continuously optimized with the goal of improving patient outcomes. This goal is being realized, primarily with respect to re-tear rates.^24,25 However, even with advanced techniques, there are still relatively high rates of failure reported, with increasing patient age serving as one of the primary negative prognostic factors.²⁶ An older patient population is associated with decreased bone mass and strength, and postmenopausal females have decreased bone quality; these factors are associated with higher rotator cuff failure rates due to poor tendon healing, with anchor fixation failure also playing a role.^27-29 Therefore, it is critically important to develop methods for augmenting implant and tendon fixation to bone to achieve functional healing. The results of this study suggest that OsteoCrete provides a valid method for accomplishing this goal based on the observation that proximal humeral anchor fixation was improved by 50% in load-to-failure 15 minutes post-injection with an even more profound impact on the anchors placed in poor-quality bone (99% increased load-to-failure 15 minutes post-injection). It is probable that the degree of improvement in fixation strength would be even greater 1 day after fixation, since the strength of OsteoCrete continues to increase over the first 30 hours of curing.

Based on the preclinical animal model data of this study, OsteoCrete augmentation of rotator cuff anchor fixation had no untoward effects on tendon healing or function and can be considered as safe for use. Previously published data also suggest that OsteoCrete may improve osseous replacement of anchors as a result of magnesium ion release, which can drive adjacent attachment and growth of osteoblasts, leading to enhanced new bone formation.^9-16,18 As such, surgeons may consider this means of anchor augmentation in situations of questionable or poor-quality bone and/or when accelerated postoperative rehabilitation protocols are desired.

A very low early incidence failure rate (1.2%) has been reported when a distal biceps tendon rupture is repaired using cortical suspensory fixation in conjunction with an interference screw.³⁰ When an early re-rupture does occur, the most common explanation for failure tends to be a lack of patient compliance, with excessive force being placed on the repair.³¹ This study was not meant to investigate the methods to increase the strength of a biceps tendon repair using OsteoCrete but instead to replace the interference screw with OsteoCrete in a safe and noninferior manner. Primary fixation was still dependent on cortical suspensory fixation; however, OsteoCrete was used to help aid in stabilization of the tendon without the need for interference screw fixation. Although rare, osteolysis and perianchor cyst formation have been reported adjacent to nonbiodegradable anchors (PEEK), along with several types of biodegradable anchors (PLLA, hydroxyapatite plus PLLA, β-tricalcium phosphate plus PLLA, and polyglycolic acid; the latter of the 3 resulted in the lowest incidence of perianchor cyst formation) in the shoulder and elbow.^32-34 Whenever osteolysis or cyst formation occurs around an anchor, it leads to decreased bone volume and potential adjacent bone weakness, which may act as a stress riser, thus increasing the risk for fracture. This potential is probably more of a concern within the proximal radius where there is a decreased amount of bone stock around the anchor.³⁴

Continue to: In this study...

In this study, a short-term 12-week analysis revealed no significant differences in the nondestructive biomechanical testing and histologic analysis results between the use of OsteoCrete and the use of a tenodesis anchor. These results indicate the potential for using OsteoCrete as an anchor replacement. The biceps tendon did not react negatively to the OsteoCrete material, which indicated that OsteoCrete can be used adjacent to tendons without the concern of weakening the tendon due to an inflammatory reaction. This being said, tendon-to-bone integration was not evident at this early time point. It would be helpful to further explore the potential of this technique with a longer-term study investigating tendon-to-bone integration in more detail. Ideally, a long-term study would reveal an increased amount of new bone formation within the socket when compared to that with the anchor comparison, similar to the results reported by Gulotta and colleagues¹⁶ when using a tendon for ACL reconstruction with OsteoCrete.

We do note several limitations in this study. The dogs used in this study were healthy with normal bone and tendon morphology, the tendons were transected and repaired during the course of the same surgery, and only 1 early time point was evaluated. Additional investigations continuing the characterization of these clinical applications using an osteopenic or osteoporotic preclinical model with chronic tendon pathology and longer-term evaluation are now warranted based on the positive findings of this initial work.

CONCLUSION

OsteoCrete augmentation significantly improved initial rotator cuff anchor fixation (human in vitro) and was safe and effective for anchor and tendon fixation in rotator cuff tendon repair and biceps tenodesis procedures (canine in vivo), respectively, when compared with the current standard-of-care. Of note, the significant improvements associated with OsteoCrete were the greatest in poor-quality bone. Based on these results and considering the previously discussed limitations, it can be concluded that OsteoCrete has the potential for safely providing improved suture anchor and tissue fixation in patients with poor bone or tissue quality. Further in vivo study toward potential clinical applications is warranted.

ABSTRACT

The aim of this study was to assess the efficacy and safety of a novel magnesium-based resorbable bone cement (OsteoCrete, Bone Solutions Incorporated) for anchor and tendon fixation.

Cadaveric humeral testing involved straight pull-to-failure of rotator cuff suture anchors; OsteoCrete was injected through one anchor, and a second anchor served as the uninjected control. Testing was conducted 15 minutes post-injection. A canine preclinical model was used to evaluate the safety of the following parameters: Rotator cuff repair: A double-row technique was used to repair transected infraspinatus tendons; OsteoCrete was injected through both anchors in one limb, and the contralateral limb served as the uninjected control. Biceps tenodesis: The transected biceps tendon was implanted into a proximal humeral socket with a transcortical button; OsteoCrete was injected into the socket of one limb, and a screw was used for final fixation in the contralateral control limb. Nondestructive biomechanical testing and histologic assessment were performed after 12 weeks.

OsteoCrete-augmented anchors showed significantly higher load-to-failure compared to that with uninjected controls. In cadaveric humeri with reduced bone quality, OsteoCrete increased the mean load-to-failure by 99%. Within the preclinical model, there were no complications or statistically significant biomechanical/histologic differences between the techniques.

OsteoCrete has the potential for safely providing improved suture anchor and tissue fixation in patients with poor bone or tissue quality.

Continue to: Calcium phosphate bone void fillers...

Calcium phosphate bone void fillers have been commonly used in orthopedic surgery for several applications, including, but not limited to, a variety of fracture fixation or augmentation procedures.^1-8 Continuing research on calcium phosphates has evidenced that the addition of magnesium phosphate to the formulation results in improved reactivity of the bone void filler. An in vitro study demonstrated enhanced attachment and proliferation of MG₆₃ osteoblast-like cells on calcium magnesium phosphate cement (CMPC), in comparison with calcium phosphate cement (CPC), along with increased cellular alkaline phosphatase activity.⁹ The authors further explored the proliferation rates of MG₆₃ cells by comparing CMPC with CPC and magnesium phosphate cement (MPC), and observed significantly increased proliferation of cells on CMPC. They also compared CMPC and CPC using a rabbit bone void model and observed substantial CMPC resorption with new bone formation at the 3-month time point and further reported that the majority of the defect had filled with new bone at 6 months, whereas CPC resulted in <10% new bone formation after 6 months.¹⁰ The authors continued to study the differences between CPC, MPC, and CMPC and identified increased proliferation of bone marrow stromal cells (bMSCs), when the cells were associated with CMPC and MPC, and when compared to that with CPC. The osteogenic differentiation of bMSCs was highest in the CMPC and CPC groups, when compared to that in the MPC group, with no significant difference between the CMPC and CPC groups. The authors also compared these 3 different formulations using a rabbit maxillary sinus floor elevation model, in which CMPC resulted in increased new bone formation and mineralization compared to that with CPC and MPC, which was further enhanced with the addition of bMSCs.¹¹

These studies highlight the importance of having both a magnesium phosphate and a calcium phosphate component for a resorbable cement intended for use as a bone void filler. The rationale behind this strategy is related to the release of magnesium ions from the magnesium phosphate component. Magnesium has been shown to increase the proliferation of bMSCs, improve the attachment and growth of osteoblasts, stimulate the proteins involved in bone regeneration, enhance new bone formation, and boost bone mineralization.^12,13

OsteoCrete (Bone Solutions Incorporation) is a novel CMPC composed of magnesium oxide, monopotassium phosphate, monosodium phosphate, hydroxyapatite, and sucrose. OsteoCrete has been demonstrated to significantly increase peak torque-to-failure of stainless-steel cortical bone screw fixation, when compared with screw fixation without augmentation and screw fixation with calcium phosphate augmentation using an in vivo equine model. In the same study, the authors showed that OsteoCrete resulted in an interface toughness that was significantly increased compared to that with no treatment, CPC augmentation, and polymethylmethacrylate (PMMA) augmentation. At 6 months after implantation, woven bone had replaced 69% of the OsteoCrete at the screw interface, compared to 44% of that with CPC.¹⁴ An equine study examined the effects of OsteoCrete on bone stability and healing using a metatarsal osteotomy model; the study reported significantly improved radiographic callus formation and a greater amount of new bone formation within the fracture gap when compared to that with CPC augmentation or no augmentation. OsteoCrete also secured the fragment significantly better than the CPC and control groups based on a decreased fracture gap over time.¹⁵ Another study using a preclinical anterior cruciate ligament (ACL) reconstruction model reported that OsteoCrete resulted in significantly better new bone formation in the tibial tunnel, a smaller amount of fibrous tissue, more cartilage formation at the tendon-bone interface, and a higher ultimate load-to-failure compared to that with standard ACL reconstruction in the contralateral limb after 6 weeks.¹⁶ OsteoCrete and PMMA were evaluated in terms of biomechanical fixation of a stemless humeral prosthesis, with data showing that both groups have higher failure loads, failure displacements, and failure cycles when compared to those with the control, nonaugmented group.¹⁷ Another preclinical model evaluated cranial bone flap augmentation with 2 resorbable cements and highlighted faster cement resorption and replacement with bone, along with superior stability within the OsteoCrete group compared to that with CPC.¹⁸ In a preclinical bone void study conducted for obtaining US Food and Drug Administration 510(k) clearance, OsteoCrete resulted in 83% greater resorption than that with CPC after 12 weeks and 35% greater resorption at 26 weeks, with 84% of OsteoCrete being resorbed and replaced with woven or lamellar mineralized bone of normal morphology at the 26-week time point (unpublished data provided by Bone Solutions Incorporated [BSI]).

These data indicate that CMPCs such as OsteoCrete appear to have potential benefits for augmenting the healing of bone implants and bone soft tissue. Therefore, the objective of this study was to assess the safety and efficacy of OsteoCrete in applications for the augmentation of anchor and tendon fixation in rotator cuff repair and biceps tenodesis procedures, respectively. Improving healing for these 2 commonly performed procedures would be of great benefit in improving the functional outcomes and mitigating the complications and morbidity.

MATERIALS AND METHODS

IN VITRO STUDY METHODS

Cadaveric humeri (N = 12, six matched pairs) of females (age, 70-75 years) were warmed to 37°C prior to testing. Two 4.75-mm vented anchors (SwiveLock, Arthrex) with FiberTape were implanted into a lateral row position (anterior and posterior anchor positioning) of a double-row rotator cuff repair within the greater tuberosity. One anchor was injected with 1 ml of OsteoCrete–after preparation according to the manufacturer’s instructions–through the cannulation channel after placement, and the other anchor served as the uninjected control for each humerus. For the six matched pairs, the OsteoCrete group and the control group were rotated with respect to anterior vs posterior location within the lateral row position. After 15 minutes of the injection, straight pull-to-failure (12 in/min) was performed. Data were compared between the groups for significant (P < .05) differences using t-tests and Pearson correlation.

Continue to: IN VIVO STUDY METHODS

With Institutional Animal Care and Use Committee approval, adult (age, 2-4 years) purpose-bred dogs (N = 8) underwent aseptic surgery of both forelimbs for rotator cuff (infraspinatus) tendon repair (Figure 1) and biceps tenodesis (Figure 2). For the rotator cuff repair, two 4.75-mm vented anchors (1 medial and 1 lateral) with FiberTape were used in a modified double-row technique to repair the acutely transected infraspinatus tendon. In one limb, 1 ml of OsteoCrete was injected through both anchors; the other limb served as the uninjected control. For the biceps tenodesis procedure, the long head of the biceps tendon was transected at its origin and whip-stitched. The tendon was transposed and inserted into a 7-mm diameter socket drilled into the proximal humerus using a tension-slide technique with a transcortical button for fixation. In one limb, 1 ml of OsteoCrete was injected into the socket prior to final tensioning and tying. In the contralateral limb, a 7-mm interference screw (Bio-Tenodesis™ Screw, Arthrex) was inserted into the socket after tensioning and tying. The dogs were allowed to perform out-of-kennel monitored exercise daily for a period of 12 weeks after surgery and were then sacrificed.

The infraspinatus and biceps bone-tendon-muscle units were excised en bloc. Custom-designed jigs were used for biomechanical testing of the bone-tendon-muscle units along the anatomical vector of muscle contraction. Optical markers were mounted at standardized anatomical locations. Elongation of the repair site was defined as the change in distance between markers and was measured to 0.01-mm resolution using an optical tracking system (Optotrak Certus, NDI), synchronized with measurement of the applied tension load. The bone-tendon-muscle units were loaded in tension to 3-mm elongation at a displacement controlled rate of 0.01 mm/s. Load at 1-mm, 2-mm, and 3-mm displacement of the tendon-bone junction was extracted from the load vs the displacement curve of each sample. Stiffness was calculated as the slope of the linear portion of the load vs the displacement curve.^19,20

For histologic assessments, sections of each treatment site were obtained using a microsaw and alternated between decalcified and non-decalcified processing. For decalcified bone processing, formalin-fixed tissues were placed in 10% ethylenediaminetetraacetic acid with phosphate-buffered saline for 39 days and then processed routinely for the assessment of sections stained with hematoxylin and eosin (H&E), toluidine blue, and picrosirius red. For non-decalcified bone processing, the tissues were dehydrated through a series of graded ethyl alcohol solutions, embedded in PMMA, sectioned, and stained with toluidine blue and Goldner’s trichrome. Two pathologists who were blinded to the clinical application and the differences between techniques assessed the histologic sections and scored each section using the modified Bonar score that assesses cell morphology, collagen arrangement, cellularity, vascularity, and extracellular matrix using a 15-point scale, where a higher score indicates more pathology.²¹

Categorical data were compared for detecting statistically significant differences using the rank sum test. Continuous data were compared for identifying statistically significant differences using the t-test or one-way ANOVA. Significance was set at P < .05.

RESULTS

IN VITRO RESULTS

OsteoCrete-augmented anchors (mean = 225 N; range, 158-287 N) had significantly (P < .001) higher pull-out load-to-failure compared to that in the uninjected controls (mean = 161 N; range, 68-202 N), which translated to a 50% mean increase (range, 3%-134%) in load-to-failure (Table 1). For humeri with reduced bone quality (control anchors that failed at <160 N, 4 humeri), the mean increase in load-to-failure for OsteoCrete-augmented anchors was 99% (range, 58%-135%), with the difference between mean values being again significantly different (OsteoCrete mean = 205 N; control mean = 110 N, P < .001). When the control and OsteoCrete load-to-failure values were compared using Pearson correlation, a significantly strong positive correlation (r = 0.66, P = 0.02) was detected. When the control load-to-failure values were compared with its percent increase value when OsteoCrete was used, there was a significantly very strong negative correlation (r = −0.90, P < .001).

Table 1. Cadaveric Lateral Row Rotator Cuff Anchor Pull-To-Failure; Testing Occurred 15 Minutes Post-Injection

^aOsteoCrete (Bone Solutions Incorporated) resulted in significantly increased (P < 0.001) pull-to-failure. Abbreviations: AP, control anchor located in anterior position, OsteoCrete anchor located in posterior position; PA, control anchor located in posterior position, OsteoCrete anchor located in anterior position.

Continue to: IN VIVO RESULTS

No intraoperative or postoperative complications were noted. All repairs were found to be intact based on the gross assessment and the completed biomechanical testing without failure. No statistically significant (P > 0.3) biomechanical differences were found between the techniques (Table 2). Histologic assessments showed low-to-mild pathology scores for all sites with no statistically significant (P > 0.3) differences between the techniques (Table 2). Both control and OsteoCrete rotator cuff repairs demonstrated tendon-to-bone integration via fibrous connective tissue attachment to bone. All anchors were in place with no evidence for loosening, tunnel expansion, or cyst formation. OsteoCrete-augmented anchor repairs were associated with cement remaining within their lumens along with a thin layer of cement interposed between the anchor and the bone interface around their entire periphery. The cement-bone interface was discrete with typical inflammatory cell infiltrate without evidence for infection, membrane or cyst formation, or other untoward pathologic responses. In the OsteoCrete biceps tenodesis group, the tendons filled the tunnels with a thin layer of cement remaining interposed between the tendon and the bone interface around the entire periphery. The tendon-cement-bone interface was discrete with typical inflammatory cell infiltrates and without evidence for infection, membrane or cyst formation, or other untoward pathologic responses. Tendon-to-bone integration was not observed in the control or OsteoCrete biceps tenodesis groups at the 12-week study endpoint. Representative histologic images of the rotator cuff tendon repairs and biceps tenodesis procedures are shown in Figures 3A, 3B and Figures 4A, 4B, respectively.

Table 2. Biomechanical Testing And Histologic Scoring Of Rotator Cuff And Biceps Tendon Repairs In A Preclinical Model

There were no significant differences (P < 0.05) between groups. Histologic scoring based on a 15-point scale with higher scores indicating more pathology.

DISCUSSION

The results of this study highlight the safety and efficacy of OsteoCrete in applications for the augmentation of anchor and tendon fixation in rotator cuff repair and biceps tenodesis procedures, respectively. Anchors augmented with OsteoCrete resulted in significantly increased load-to-failure pull-out strength 15 minutes after insertion. In addition, a very strong negative correlation was found between the percentage of improved load-to-failure after OsteoCrete injection and the bone quality of the humerus, which was based on the control load-to-failure values. In the validated preclinical model used in this study, OsteoCrete-based fixation was found to be noninferior to current standard-of-care techniques and was not associated with any untoward pathologic responses of humeral bone, rotator cuff tendon, or biceps tendon based on the biomechanical and histologic analyses. These data highlight the functional efficacy and biocompatibility of OsteoCrete when used for these common indications.

More than 270,000 rotator cuff procedures have been reported to be performed in the US annually (average patient age: 61 years for women, 56 years for men).²² Rotator cuff repair procedures have been associated with a 20% failure rate, with one of the causes being related to an inability for the tendon to heal, even with strong initial fixation.²³ Rotator cuff repair techniques are being continuously optimized with the goal of improving patient outcomes. This goal is being realized, primarily with respect to re-tear rates.^24,25 However, even with advanced techniques, there are still relatively high rates of failure reported, with increasing patient age serving as one of the primary negative prognostic factors.²⁶ An older patient population is associated with decreased bone mass and strength, and postmenopausal females have decreased bone quality; these factors are associated with higher rotator cuff failure rates due to poor tendon healing, with anchor fixation failure also playing a role.^27-29 Therefore, it is critically important to develop methods for augmenting implant and tendon fixation to bone to achieve functional healing. The results of this study suggest that OsteoCrete provides a valid method for accomplishing this goal based on the observation that proximal humeral anchor fixation was improved by 50% in load-to-failure 15 minutes post-injection with an even more profound impact on the anchors placed in poor-quality bone (99% increased load-to-failure 15 minutes post-injection). It is probable that the degree of improvement in fixation strength would be even greater 1 day after fixation, since the strength of OsteoCrete continues to increase over the first 30 hours of curing.

Based on the preclinical animal model data of this study, OsteoCrete augmentation of rotator cuff anchor fixation had no untoward effects on tendon healing or function and can be considered as safe for use. Previously published data also suggest that OsteoCrete may improve osseous replacement of anchors as a result of magnesium ion release, which can drive adjacent attachment and growth of osteoblasts, leading to enhanced new bone formation.^9-16,18 As such, surgeons may consider this means of anchor augmentation in situations of questionable or poor-quality bone and/or when accelerated postoperative rehabilitation protocols are desired.

A very low early incidence failure rate (1.2%) has been reported when a distal biceps tendon rupture is repaired using cortical suspensory fixation in conjunction with an interference screw.³⁰ When an early re-rupture does occur, the most common explanation for failure tends to be a lack of patient compliance, with excessive force being placed on the repair.³¹ This study was not meant to investigate the methods to increase the strength of a biceps tendon repair using OsteoCrete but instead to replace the interference screw with OsteoCrete in a safe and noninferior manner. Primary fixation was still dependent on cortical suspensory fixation; however, OsteoCrete was used to help aid in stabilization of the tendon without the need for interference screw fixation. Although rare, osteolysis and perianchor cyst formation have been reported adjacent to nonbiodegradable anchors (PEEK), along with several types of biodegradable anchors (PLLA, hydroxyapatite plus PLLA, β-tricalcium phosphate plus PLLA, and polyglycolic acid; the latter of the 3 resulted in the lowest incidence of perianchor cyst formation) in the shoulder and elbow.^32-34 Whenever osteolysis or cyst formation occurs around an anchor, it leads to decreased bone volume and potential adjacent bone weakness, which may act as a stress riser, thus increasing the risk for fracture. This potential is probably more of a concern within the proximal radius where there is a decreased amount of bone stock around the anchor.³⁴

Continue to: In this study...

In this study, a short-term 12-week analysis revealed no significant differences in the nondestructive biomechanical testing and histologic analysis results between the use of OsteoCrete and the use of a tenodesis anchor. These results indicate the potential for using OsteoCrete as an anchor replacement. The biceps tendon did not react negatively to the OsteoCrete material, which indicated that OsteoCrete can be used adjacent to tendons without the concern of weakening the tendon due to an inflammatory reaction. This being said, tendon-to-bone integration was not evident at this early time point. It would be helpful to further explore the potential of this technique with a longer-term study investigating tendon-to-bone integration in more detail. Ideally, a long-term study would reveal an increased amount of new bone formation within the socket when compared to that with the anchor comparison, similar to the results reported by Gulotta and colleagues¹⁶ when using a tendon for ACL reconstruction with OsteoCrete.

We do note several limitations in this study. The dogs used in this study were healthy with normal bone and tendon morphology, the tendons were transected and repaired during the course of the same surgery, and only 1 early time point was evaluated. Additional investigations continuing the characterization of these clinical applications using an osteopenic or osteoporotic preclinical model with chronic tendon pathology and longer-term evaluation are now warranted based on the positive findings of this initial work.

CONCLUSION

OsteoCrete augmentation significantly improved initial rotator cuff anchor fixation (human in vitro) and was safe and effective for anchor and tendon fixation in rotator cuff tendon repair and biceps tenodesis procedures (canine in vivo), respectively, when compared with the current standard-of-care. Of note, the significant improvements associated with OsteoCrete were the greatest in poor-quality bone. Based on these results and considering the previously discussed limitations, it can be concluded that OsteoCrete has the potential for safely providing improved suture anchor and tissue fixation in patients with poor bone or tissue quality. Further in vivo study toward potential clinical applications is warranted.

ABSTRACT

The aim of this study was to assess the efficacy and safety of a novel magnesium-based resorbable bone cement (OsteoCrete, Bone Solutions Incorporated) for anchor and tendon fixation.

Cadaveric humeral testing involved straight pull-to-failure of rotator cuff suture anchors; OsteoCrete was injected through one anchor, and a second anchor served as the uninjected control. Testing was conducted 15 minutes post-injection. A canine preclinical model was used to evaluate the safety of the following parameters: Rotator cuff repair: A double-row technique was used to repair transected infraspinatus tendons; OsteoCrete was injected through both anchors in one limb, and the contralateral limb served as the uninjected control. Biceps tenodesis: The transected biceps tendon was implanted into a proximal humeral socket with a transcortical button; OsteoCrete was injected into the socket of one limb, and a screw was used for final fixation in the contralateral control limb. Nondestructive biomechanical testing and histologic assessment were performed after 12 weeks.

OsteoCrete-augmented anchors showed significantly higher load-to-failure compared to that with uninjected controls. In cadaveric humeri with reduced bone quality, OsteoCrete increased the mean load-to-failure by 99%. Within the preclinical model, there were no complications or statistically significant biomechanical/histologic differences between the techniques.

OsteoCrete has the potential for safely providing improved suture anchor and tissue fixation in patients with poor bone or tissue quality.

Continue to: Calcium phosphate bone void fillers...

Calcium phosphate bone void fillers have been commonly used in orthopedic surgery for several applications, including, but not limited to, a variety of fracture fixation or augmentation procedures.^1-8 Continuing research on calcium phosphates has evidenced that the addition of magnesium phosphate to the formulation results in improved reactivity of the bone void filler. An in vitro study demonstrated enhanced attachment and proliferation of MG₆₃ osteoblast-like cells on calcium magnesium phosphate cement (CMPC), in comparison with calcium phosphate cement (CPC), along with increased cellular alkaline phosphatase activity.⁹ The authors further explored the proliferation rates of MG₆₃ cells by comparing CMPC with CPC and magnesium phosphate cement (MPC), and observed significantly increased proliferation of cells on CMPC. They also compared CMPC and CPC using a rabbit bone void model and observed substantial CMPC resorption with new bone formation at the 3-month time point and further reported that the majority of the defect had filled with new bone at 6 months, whereas CPC resulted in <10% new bone formation after 6 months.¹⁰ The authors continued to study the differences between CPC, MPC, and CMPC and identified increased proliferation of bone marrow stromal cells (bMSCs), when the cells were associated with CMPC and MPC, and when compared to that with CPC. The osteogenic differentiation of bMSCs was highest in the CMPC and CPC groups, when compared to that in the MPC group, with no significant difference between the CMPC and CPC groups. The authors also compared these 3 different formulations using a rabbit maxillary sinus floor elevation model, in which CMPC resulted in increased new bone formation and mineralization compared to that with CPC and MPC, which was further enhanced with the addition of bMSCs.¹¹

These studies highlight the importance of having both a magnesium phosphate and a calcium phosphate component for a resorbable cement intended for use as a bone void filler. The rationale behind this strategy is related to the release of magnesium ions from the magnesium phosphate component. Magnesium has been shown to increase the proliferation of bMSCs, improve the attachment and growth of osteoblasts, stimulate the proteins involved in bone regeneration, enhance new bone formation, and boost bone mineralization.^12,13

OsteoCrete (Bone Solutions Incorporation) is a novel CMPC composed of magnesium oxide, monopotassium phosphate, monosodium phosphate, hydroxyapatite, and sucrose. OsteoCrete has been demonstrated to significantly increase peak torque-to-failure of stainless-steel cortical bone screw fixation, when compared with screw fixation without augmentation and screw fixation with calcium phosphate augmentation using an in vivo equine model. In the same study, the authors showed that OsteoCrete resulted in an interface toughness that was significantly increased compared to that with no treatment, CPC augmentation, and polymethylmethacrylate (PMMA) augmentation. At 6 months after implantation, woven bone had replaced 69% of the OsteoCrete at the screw interface, compared to 44% of that with CPC.¹⁴ An equine study examined the effects of OsteoCrete on bone stability and healing using a metatarsal osteotomy model; the study reported significantly improved radiographic callus formation and a greater amount of new bone formation within the fracture gap when compared to that with CPC augmentation or no augmentation. OsteoCrete also secured the fragment significantly better than the CPC and control groups based on a decreased fracture gap over time.¹⁵ Another study using a preclinical anterior cruciate ligament (ACL) reconstruction model reported that OsteoCrete resulted in significantly better new bone formation in the tibial tunnel, a smaller amount of fibrous tissue, more cartilage formation at the tendon-bone interface, and a higher ultimate load-to-failure compared to that with standard ACL reconstruction in the contralateral limb after 6 weeks.¹⁶ OsteoCrete and PMMA were evaluated in terms of biomechanical fixation of a stemless humeral prosthesis, with data showing that both groups have higher failure loads, failure displacements, and failure cycles when compared to those with the control, nonaugmented group.¹⁷ Another preclinical model evaluated cranial bone flap augmentation with 2 resorbable cements and highlighted faster cement resorption and replacement with bone, along with superior stability within the OsteoCrete group compared to that with CPC.¹⁸ In a preclinical bone void study conducted for obtaining US Food and Drug Administration 510(k) clearance, OsteoCrete resulted in 83% greater resorption than that with CPC after 12 weeks and 35% greater resorption at 26 weeks, with 84% of OsteoCrete being resorbed and replaced with woven or lamellar mineralized bone of normal morphology at the 26-week time point (unpublished data provided by Bone Solutions Incorporated [BSI]).

These data indicate that CMPCs such as OsteoCrete appear to have potential benefits for augmenting the healing of bone implants and bone soft tissue. Therefore, the objective of this study was to assess the safety and efficacy of OsteoCrete in applications for the augmentation of anchor and tendon fixation in rotator cuff repair and biceps tenodesis procedures, respectively. Improving healing for these 2 commonly performed procedures would be of great benefit in improving the functional outcomes and mitigating the complications and morbidity.

MATERIALS AND METHODS

IN VITRO STUDY METHODS

Cadaveric humeri (N = 12, six matched pairs) of females (age, 70-75 years) were warmed to 37°C prior to testing. Two 4.75-mm vented anchors (SwiveLock, Arthrex) with FiberTape were implanted into a lateral row position (anterior and posterior anchor positioning) of a double-row rotator cuff repair within the greater tuberosity. One anchor was injected with 1 ml of OsteoCrete–after preparation according to the manufacturer’s instructions–through the cannulation channel after placement, and the other anchor served as the uninjected control for each humerus. For the six matched pairs, the OsteoCrete group and the control group were rotated with respect to anterior vs posterior location within the lateral row position. After 15 minutes of the injection, straight pull-to-failure (12 in/min) was performed. Data were compared between the groups for significant (P < .05) differences using t-tests and Pearson correlation.

Continue to: IN VIVO STUDY METHODS

With Institutional Animal Care and Use Committee approval, adult (age, 2-4 years) purpose-bred dogs (N = 8) underwent aseptic surgery of both forelimbs for rotator cuff (infraspinatus) tendon repair (Figure 1) and biceps tenodesis (Figure 2). For the rotator cuff repair, two 4.75-mm vented anchors (1 medial and 1 lateral) with FiberTape were used in a modified double-row technique to repair the acutely transected infraspinatus tendon. In one limb, 1 ml of OsteoCrete was injected through both anchors; the other limb served as the uninjected control. For the biceps tenodesis procedure, the long head of the biceps tendon was transected at its origin and whip-stitched. The tendon was transposed and inserted into a 7-mm diameter socket drilled into the proximal humerus using a tension-slide technique with a transcortical button for fixation. In one limb, 1 ml of OsteoCrete was injected into the socket prior to final tensioning and tying. In the contralateral limb, a 7-mm interference screw (Bio-Tenodesis™ Screw, Arthrex) was inserted into the socket after tensioning and tying. The dogs were allowed to perform out-of-kennel monitored exercise daily for a period of 12 weeks after surgery and were then sacrificed.

The infraspinatus and biceps bone-tendon-muscle units were excised en bloc. Custom-designed jigs were used for biomechanical testing of the bone-tendon-muscle units along the anatomical vector of muscle contraction. Optical markers were mounted at standardized anatomical locations. Elongation of the repair site was defined as the change in distance between markers and was measured to 0.01-mm resolution using an optical tracking system (Optotrak Certus, NDI), synchronized with measurement of the applied tension load. The bone-tendon-muscle units were loaded in tension to 3-mm elongation at a displacement controlled rate of 0.01 mm/s. Load at 1-mm, 2-mm, and 3-mm displacement of the tendon-bone junction was extracted from the load vs the displacement curve of each sample. Stiffness was calculated as the slope of the linear portion of the load vs the displacement curve.^19,20

For histologic assessments, sections of each treatment site were obtained using a microsaw and alternated between decalcified and non-decalcified processing. For decalcified bone processing, formalin-fixed tissues were placed in 10% ethylenediaminetetraacetic acid with phosphate-buffered saline for 39 days and then processed routinely for the assessment of sections stained with hematoxylin and eosin (H&E), toluidine blue, and picrosirius red. For non-decalcified bone processing, the tissues were dehydrated through a series of graded ethyl alcohol solutions, embedded in PMMA, sectioned, and stained with toluidine blue and Goldner’s trichrome. Two pathologists who were blinded to the clinical application and the differences between techniques assessed the histologic sections and scored each section using the modified Bonar score that assesses cell morphology, collagen arrangement, cellularity, vascularity, and extracellular matrix using a 15-point scale, where a higher score indicates more pathology.²¹

Categorical data were compared for detecting statistically significant differences using the rank sum test. Continuous data were compared for identifying statistically significant differences using the t-test or one-way ANOVA. Significance was set at P < .05.

RESULTS

IN VITRO RESULTS

OsteoCrete-augmented anchors (mean = 225 N; range, 158-287 N) had significantly (P < .001) higher pull-out load-to-failure compared to that in the uninjected controls (mean = 161 N; range, 68-202 N), which translated to a 50% mean increase (range, 3%-134%) in load-to-failure (Table 1). For humeri with reduced bone quality (control anchors that failed at <160 N, 4 humeri), the mean increase in load-to-failure for OsteoCrete-augmented anchors was 99% (range, 58%-135%), with the difference between mean values being again significantly different (OsteoCrete mean = 205 N; control mean = 110 N, P < .001). When the control and OsteoCrete load-to-failure values were compared using Pearson correlation, a significantly strong positive correlation (r = 0.66, P = 0.02) was detected. When the control load-to-failure values were compared with its percent increase value when OsteoCrete was used, there was a significantly very strong negative correlation (r = −0.90, P < .001).

Table 1. Cadaveric Lateral Row Rotator Cuff Anchor Pull-To-Failure; Testing Occurred 15 Minutes Post-Injection

^aOsteoCrete (Bone Solutions Incorporated) resulted in significantly increased (P < 0.001) pull-to-failure. Abbreviations: AP, control anchor located in anterior position, OsteoCrete anchor located in posterior position; PA, control anchor located in posterior position, OsteoCrete anchor located in anterior position.

Continue to: IN VIVO RESULTS

No intraoperative or postoperative complications were noted. All repairs were found to be intact based on the gross assessment and the completed biomechanical testing without failure. No statistically significant (P > 0.3) biomechanical differences were found between the techniques (Table 2). Histologic assessments showed low-to-mild pathology scores for all sites with no statistically significant (P > 0.3) differences between the techniques (Table 2). Both control and OsteoCrete rotator cuff repairs demonstrated tendon-to-bone integration via fibrous connective tissue attachment to bone. All anchors were in place with no evidence for loosening, tunnel expansion, or cyst formation. OsteoCrete-augmented anchor repairs were associated with cement remaining within their lumens along with a thin layer of cement interposed between the anchor and the bone interface around their entire periphery. The cement-bone interface was discrete with typical inflammatory cell infiltrate without evidence for infection, membrane or cyst formation, or other untoward pathologic responses. In the OsteoCrete biceps tenodesis group, the tendons filled the tunnels with a thin layer of cement remaining interposed between the tendon and the bone interface around the entire periphery. The tendon-cement-bone interface was discrete with typical inflammatory cell infiltrates and without evidence for infection, membrane or cyst formation, or other untoward pathologic responses. Tendon-to-bone integration was not observed in the control or OsteoCrete biceps tenodesis groups at the 12-week study endpoint. Representative histologic images of the rotator cuff tendon repairs and biceps tenodesis procedures are shown in Figures 3A, 3B and Figures 4A, 4B, respectively.

Table 2. Biomechanical Testing And Histologic Scoring Of Rotator Cuff And Biceps Tendon Repairs In A Preclinical Model

There were no significant differences (P < 0.05) between groups. Histologic scoring based on a 15-point scale with higher scores indicating more pathology.

DISCUSSION

The results of this study highlight the safety and efficacy of OsteoCrete in applications for the augmentation of anchor and tendon fixation in rotator cuff repair and biceps tenodesis procedures, respectively. Anchors augmented with OsteoCrete resulted in significantly increased load-to-failure pull-out strength 15 minutes after insertion. In addition, a very strong negative correlation was found between the percentage of improved load-to-failure after OsteoCrete injection and the bone quality of the humerus, which was based on the control load-to-failure values. In the validated preclinical model used in this study, OsteoCrete-based fixation was found to be noninferior to current standard-of-care techniques and was not associated with any untoward pathologic responses of humeral bone, rotator cuff tendon, or biceps tendon based on the biomechanical and histologic analyses. These data highlight the functional efficacy and biocompatibility of OsteoCrete when used for these common indications.

More than 270,000 rotator cuff procedures have been reported to be performed in the US annually (average patient age: 61 years for women, 56 years for men).²² Rotator cuff repair procedures have been associated with a 20% failure rate, with one of the causes being related to an inability for the tendon to heal, even with strong initial fixation.²³ Rotator cuff repair techniques are being continuously optimized with the goal of improving patient outcomes. This goal is being realized, primarily with respect to re-tear rates.^24,25 However, even with advanced techniques, there are still relatively high rates of failure reported, with increasing patient age serving as one of the primary negative prognostic factors.²⁶ An older patient population is associated with decreased bone mass and strength, and postmenopausal females have decreased bone quality; these factors are associated with higher rotator cuff failure rates due to poor tendon healing, with anchor fixation failure also playing a role.^27-29 Therefore, it is critically important to develop methods for augmenting implant and tendon fixation to bone to achieve functional healing. The results of this study suggest that OsteoCrete provides a valid method for accomplishing this goal based on the observation that proximal humeral anchor fixation was improved by 50% in load-to-failure 15 minutes post-injection with an even more profound impact on the anchors placed in poor-quality bone (99% increased load-to-failure 15 minutes post-injection). It is probable that the degree of improvement in fixation strength would be even greater 1 day after fixation, since the strength of OsteoCrete continues to increase over the first 30 hours of curing.

Based on the preclinical animal model data of this study, OsteoCrete augmentation of rotator cuff anchor fixation had no untoward effects on tendon healing or function and can be considered as safe for use. Previously published data also suggest that OsteoCrete may improve osseous replacement of anchors as a result of magnesium ion release, which can drive adjacent attachment and growth of osteoblasts, leading to enhanced new bone formation.^9-16,18 As such, surgeons may consider this means of anchor augmentation in situations of questionable or poor-quality bone and/or when accelerated postoperative rehabilitation protocols are desired.

A very low early incidence failure rate (1.2%) has been reported when a distal biceps tendon rupture is repaired using cortical suspensory fixation in conjunction with an interference screw.³⁰ When an early re-rupture does occur, the most common explanation for failure tends to be a lack of patient compliance, with excessive force being placed on the repair.³¹ This study was not meant to investigate the methods to increase the strength of a biceps tendon repair using OsteoCrete but instead to replace the interference screw with OsteoCrete in a safe and noninferior manner. Primary fixation was still dependent on cortical suspensory fixation; however, OsteoCrete was used to help aid in stabilization of the tendon without the need for interference screw fixation. Although rare, osteolysis and perianchor cyst formation have been reported adjacent to nonbiodegradable anchors (PEEK), along with several types of biodegradable anchors (PLLA, hydroxyapatite plus PLLA, β-tricalcium phosphate plus PLLA, and polyglycolic acid; the latter of the 3 resulted in the lowest incidence of perianchor cyst formation) in the shoulder and elbow.^32-34 Whenever osteolysis or cyst formation occurs around an anchor, it leads to decreased bone volume and potential adjacent bone weakness, which may act as a stress riser, thus increasing the risk for fracture. This potential is probably more of a concern within the proximal radius where there is a decreased amount of bone stock around the anchor.³⁴

Continue to: In this study...

In this study, a short-term 12-week analysis revealed no significant differences in the nondestructive biomechanical testing and histologic analysis results between the use of OsteoCrete and the use of a tenodesis anchor. These results indicate the potential for using OsteoCrete as an anchor replacement. The biceps tendon did not react negatively to the OsteoCrete material, which indicated that OsteoCrete can be used adjacent to tendons without the concern of weakening the tendon due to an inflammatory reaction. This being said, tendon-to-bone integration was not evident at this early time point. It would be helpful to further explore the potential of this technique with a longer-term study investigating tendon-to-bone integration in more detail. Ideally, a long-term study would reveal an increased amount of new bone formation within the socket when compared to that with the anchor comparison, similar to the results reported by Gulotta and colleagues¹⁶ when using a tendon for ACL reconstruction with OsteoCrete.

We do note several limitations in this study. The dogs used in this study were healthy with normal bone and tendon morphology, the tendons were transected and repaired during the course of the same surgery, and only 1 early time point was evaluated. Additional investigations continuing the characterization of these clinical applications using an osteopenic or osteoporotic preclinical model with chronic tendon pathology and longer-term evaluation are now warranted based on the positive findings of this initial work.

CONCLUSION

OsteoCrete augmentation significantly improved initial rotator cuff anchor fixation (human in vitro) and was safe and effective for anchor and tendon fixation in rotator cuff tendon repair and biceps tenodesis procedures (canine in vivo), respectively, when compared with the current standard-of-care. Of note, the significant improvements associated with OsteoCrete were the greatest in poor-quality bone. Based on these results and considering the previously discussed limitations, it can be concluded that OsteoCrete has the potential for safely providing improved suture anchor and tissue fixation in patients with poor bone or tissue quality. Further in vivo study toward potential clinical applications is warranted.

From the Mayo Clinic, Rochester, MN.

Abstract

• Objective: To elicit patient perceptions of a computer tablet (“e-Board”) used to display information relevant to hospital discharge and to gather patients’ expectations and perceptions regarding hospital discharge.
• Methods: Adult patients discharged from 1 of 3 medical-surgical, noncardiac monitored units of a 1265-bed, academic, tertiary care hospital were interviewed during patient focus groups. Reviewer pairs performed qualitative analysis of focus group transcripts and identified key themes, which were grouped into categories.
• Results: Patients felt a novel e-Board could help with the discharge process. They identified coordination of discharge, communication about discharge, ramifications of unexpected admissions, and interpersonal interactions during admission as the most significant issues around discharge.
• Conclusions: Focus groups elicit actionable information from patients about hospital discharge. Using this information, e-tools may help to design a patient-centered discharge process.

Key words: hospitals; patient satisfaction; focus groups; acute inpatient care.

Transition from the hospital to home represents a critical time for patients after acute illness, and support of patients and their care partners can help decrease consequences of poor care transitions, such as readmissions [1]. Focused discharge planning may improve outcomes and increase patient satisfaction [2], which is a key metric in hospital value-based purchasing programs, which tie Hospital Consumer Assessment of Healthcare Providers and Services (HCAHPS) survey scores to reimbursement. Although patient experience surveys explore several categories of patient satisfaction, HCAHPS may not reveal readily actionable opportunities that would allow clinicians to improve patient experience. Conducting focus groups and interviews can help discern patients’ perceptions and provide patient-centered opportunities to improve hospital discharge processes. Recent studies using these methodologies have revealed patients’ perceptions of barriers to inter-professional collaboration during discharge [3] and their desires and expectations of, as well as suggestions for improvement of, hospitalization [4].

Care transition bundles have been developed to facilitate the process of transitioning home [1,5], but none include e-health tools to help facilitate the discharge process. A study group leveraged available software at our institution to create a bedside “e-Board,” addressing opportunities that surfaced during previous patient focus groups regarding our institution’s discharge process. The software tools were loaded onto a tablet computer (Apple iPad; Cupertino, CA) and included displays of the patient’s physician and nurse, with estimated time of team bedside rounds; day and time of anticipated discharge; display of discharge medications; and a screening tool, I-MOVE, to assess mobility prior to return to independent living [6].

We conducted focus groups to gather patients’ insights for incorporation into a bedside e-health tool for discharge and into our hospital’s current discharge process. The primary objective of the current study was to elicit patient and family perceptions of a bedside e-Board, created to display information regarding discharge. Our secondary objective was to learn about patient expectations and perceptions regarding the hospital discharge process.

Methods

Setting

The study setting was 3 medical-surgical, non-cardiac monitored units of a 1265-bed, academic, tertiary care hospital in Rochester, MN. The study was considered a minimal risk study by the center’s institutional review board.

Participants

Patients aged 18 years or older discharged from 1 of the 3 study units during 2012–2013 were eligible to participate. Patients were excluded if they were not discharged home or to assisted living, were clinic employees, retirees or dependents of clinic employees, were hospitalized longer than 6 months prior to study entry, lived further than 60 miles from the town of Rochester, could not travel, or did not sign research consent.

There were 975 patients who met inclusion criteria. The institution’s survey research center randomly selected 300 eligible patients and contacted them by letter after discharge. The letter was followed up with a telephone call and verbal consent was obtained if the patient expressed interest in participation. Of the 17 patients who gave consent, 12 patients participated in focus group interviews.

E-Board Development

Prior focus group discussions facilitated by our institution’s marketing department (Mr. Kent Seltman, personal communication) explored patients’ perceptions of the discharge process from the institution’s primary hospital. The opportunities for improvement that surfaced during these focus groups included identifying the date of discharge, communication about the time of discharge, and discharging the patient at the identified time, not several hours later. The study group leveraged software available at our institution to create a bedside e-Board that could possibly mitigate these issues by improving communication about discharge. The software tools were loaded onto a tablet computer for patients to use as a resource during their admission. These tools included:

1. A photo display of the patient’s nurse and physician, with estimated time of bedside rounds
2. A display of the day and time of anticipated discharge. Providing anticipated day and time of discharge has been found to be an achievable goal for internal medicine and surgical services [7].
3. A medication display, named the “Durable Display at Discharge,” previously found to improve patient understanding of prescribed medications [8]
4. A display of a mobility tool, I-MOVE, designed to screen for debility that could prevent patients’ return to independent living [6].

Focus Groups

Facilitated interviews were conducted on 2 consecutive days in March 2014. Participants were divided into a focus group of 5 to 6 participants if they were functionally independent, or dyads of patient and care partner if they were functionally dependent. Interviews were both video- and audiotaped.

A trained facilitator led 1.5-hour sessions with each focus group. The sessions began with introductions and guidelines by which the focus groups were conducted, including explanations of the video and audio recording equipment, and a request for participants to speak one person at a time to facilitate recording. Discussions were carried out in 2 parts, guided by a facilitator script ( available from the authors). First, participants were asked to share their experiences regarding planning for discharge and the information they received leading up to their planned day and time of hospital discharge. Second, participants were shown a prototype of the e-Board. Participants were asked to reflect as to whether they had received similar information when they had been hospitalized, whether that information was helpful or useful, what information they did not receive that would have been helpful, how information was given, and whether information displayed via an e-Board would be better or worse than the ways they received information while in the hospital.

Data Analysis

Three teams, each comprised of 2 reviewers, met to analyze the video and audio recordings of each focus group. Unfortunately, the video files from the dyad interviews were not recoverable after the recorded sessions, and thus those groups were excluded from the study. Reviewers met prior to analyzing the focus group video and audio recordings to review the qualitative analysis protocol developed by the research team [9] (protocol available froom the authors). The teams then independently reviewed the video recordings and transcripts of the focus groups. The reviewer teams observed the focus group recordings and identified (1) themes regarding perceptions of the bedside e-Board and (2) experiences and perceptions around discharge. The protocol helped reviewer teams create a classification structure by identifying the key themes, which were then combined to create categories. The reviewer teams then compared their classification structures and by incorporating the most frequently identified categories, built a relational model of discharge perceptions.

Results

Eleven patients participated in 2 focus groups, one group of 5 patients and the other of 6 patients. Patient participants included 6 females and 5 males ranging in age from 22 to 84 years.

Using the qualitative analysis protocol, review teams grouped key themes from the focus group discussions about discharge into 4 categories. The categories, with themes listed below and representative patient comments in the Table, were

1.  Coordination and timing of discharge

• Giving patients the opportunity to prepare for discussion with clinician teams
•  Communicating the specific time of discharge
• Internal collaboration of inter-professional teams
• Preparing for transition out of the hospital

  2.  Communication

• Patient inclusion in care discussions
• Discharge summary delay and/or completeness
• Education at the time of discharge

  3. Ramifications of the unexpected and unknown

• Increased stress and frustration due to inability to plan, fear of the unknown, and lack of information

  4. Interpersonal interactions

• Both favorable and unfavorable interactions caused an emotional response that impacts perceptions of hospitalization and discharge

The reviewers also analyzed patients’ comments regarding the bedside e-Board. The medication display (“Durable Display at Discharge,” Figure 1) was universally considered to be the most relevant and best-liked of the 4 elements tested. The visual display of medications and their purpose were commonly referenced as the most positive aspects of the display, and patients and caregivers were readily able to generate multiple potential uses for the display. Several mentioned that the information on the medication display were so desirable and necessary that if not supplied by the hospital, they hand-crafted such reminder displays at home.

It was difficult for patients to see how the I-MOVE assessment (Figure 2) would apply to their discharge planning. They perceived I-MOVE as a tool for clinicians. One exception was a patient who had on a previous admission undergone heart surgery. She explained to the other patients that in such debilitated conditions, mobility independence assessments were important and commonly done.

Patients voiced some skepticism and concerns regarding the e-Board, including expense, privacy, security, and cleanliness. One patient observed the tablet was “more current than a printed piece of paper. It’s more up to date.” Other patients, however, questioned the process required to update information and wondered how much electronic displays added compared to the dry-erase board already in each patient’s room with which they were more familiar. They also voiced concern that the tablet would replace face-to-face interactions with their care teams. A patient shared that, “if we don’t have the conversation and we just get it through this, then I would hate that…you want to be able to give your input.”

Discussion

In this study, we used available software to create a bedside e-Board that addressed opportunities for patient-centered improvement in our institution’s discharge process. Patients felt that 3 of 4 software tools on the tablet could enhance the discharge experience. Additionally, we explored patients’ expectations and perceptions of our hospital discharge process.

Key information to inform our current discharge process was divulged by our patients during focus groups. Patients conveyed that the only time that matters to them is the time they get to walk out the door of the hospital, and that general statements (eg, “You’ll probably be going home today.”) create anxiety and dissatisfaction. Since family and care partners need to manage hospital discharge in combination with regular activities of daily life (eg, work schedules, child care), un-communicated changes to the discharge time are very difficult to accommodate and should be discussed in advance. Further, acknowledging the disruption of hospital admission to patients’, their families’, and care partners’ daily lives, as well as being mindful of the impact of interpersonal interactions with patients, remind clinicians of the impact hospitalization has on patients.

Focus group discussions revealed that an ideal patient-centered discharge process would include active patient participation, clear communication regarding the discharge process, especially changes in the specific discharge date and time, and education regarding discharge summary instructions. Further, patients voiced that the unexpected nature of admissions can be very disruptive to patients’ lives and that interpersonal interactions during admission cause emotional responses in patients that influence their perceptions of hospitalization.

Comments regarding poor coordination and communication of internal processes, opportunities to improve collaboration within and across care teams, and need to improve communication with patients regarding timing of discharge and plan of care are consistent with recent studies that used focus groups to explore patient perceptions and expectations around discharge [3,4]. The ramifications of unexpected admissions and the emotional responses patients expressed regarding interpersonal interactions during admission have not been reported by others conducting patient focus groups.

The unexpected nature of many admissions, and the uncertainty of the day-to-day activities during hospitalization, caused patients anxiety and stress. These emotions perhaps heightened their response and memories of both favorable and unfavorable interpersonal interactions. These memories left lasting impressions on patients and care teams may help alleviate anxiety and stress by providing consistency and routine such as rounding at the same time daily, and communicating this time with patients. In this regard, the e-Board was helpful in communicating the patients’ care team and their planned rounding time.

Regarding the ability of e-tools to facilitate information sharing and planning for discharge, patients felt that the display of medications would have been most beneficial when thinking about post-discharge care. They perceived a display of discharge date and time estimate display as very useful to coordinate the activities around physically leaving the hospital, but based on their experiences did not find anticipated discharge times to be believable.

Patients’ perceptions of the tool were assessed after a recent hospitalization, and our data would have been strengthened had patients and their care partners used the e-Board during the actual admission. On the other hand, post-discharge, patients had time to reflect on opportunities for improving their recent admission and had insight into gaps in their discharge that the tool could potentially fill. Because we were unable to access video recordings from our dyad groups, which led us to exclude these participants, we lost care partners’ perceptions of the e-Board and discharge process. Care partners likely have different perceptions of discharge processes compared to patients, and their insight would have augmented our findings.

Several patients observed that the e-Board presented much of the same information that was filled out by care teams on the in-room dry erase boards and questioned whether the tablet was needed. These observations provide future opportunity for studies comparing display of discharge information on in-room dry-erase boards to an electronic tablet display. E-tools have shown some benefit when used for patient self-monitoring [10], to increase patient engagement [11,12], or to improve patient education [12]. Computer tablets may be most useful when used in these manners, compared to information display.

Focus groups provide patient-provided information that is readily actionable, and this work presents patient insight into discharge processes elicited through focus groups. Patients discussed their perceptions of an e-tool that might address patient-identified opportunities to improve the discharge process. Future work in this area will explore e-tools, and how best to leverage their functionality to design a patient-centered discharge process.

Acknowledgments: Our thanks to Mr. Thomas J. (Tripp) Welch for the original suggestion of this study design, and to Ms. Heidi Miller and Ms. Lizann Williams for their invaluable contributions to this work. A special thanks to our exceptional colleagues of the Mayo Clinic Department of Medicine Clinical Research Office Clinical Trials Unit for their efforts in executing this study, and to the study participants who participated in this research, without whom this project would not have been possible.

Corresponding author: Deanne Kashiwagi, MD, MS, 200 First Street SW, Rochester, MN 55902, [email protected].

Financial disclosures: None.

From the Mayo Clinic, Rochester, MN.

Abstract

• Objective: To elicit patient perceptions of a computer tablet (“e-Board”) used to display information relevant to hospital discharge and to gather patients’ expectations and perceptions regarding hospital discharge.
• Methods: Adult patients discharged from 1 of 3 medical-surgical, noncardiac monitored units of a 1265-bed, academic, tertiary care hospital were interviewed during patient focus groups. Reviewer pairs performed qualitative analysis of focus group transcripts and identified key themes, which were grouped into categories.
• Results: Patients felt a novel e-Board could help with the discharge process. They identified coordination of discharge, communication about discharge, ramifications of unexpected admissions, and interpersonal interactions during admission as the most significant issues around discharge.
• Conclusions: Focus groups elicit actionable information from patients about hospital discharge. Using this information, e-tools may help to design a patient-centered discharge process.

Key words: hospitals; patient satisfaction; focus groups; acute inpatient care.

Transition from the hospital to home represents a critical time for patients after acute illness, and support of patients and their care partners can help decrease consequences of poor care transitions, such as readmissions [1]. Focused discharge planning may improve outcomes and increase patient satisfaction [2], which is a key metric in hospital value-based purchasing programs, which tie Hospital Consumer Assessment of Healthcare Providers and Services (HCAHPS) survey scores to reimbursement. Although patient experience surveys explore several categories of patient satisfaction, HCAHPS may not reveal readily actionable opportunities that would allow clinicians to improve patient experience. Conducting focus groups and interviews can help discern patients’ perceptions and provide patient-centered opportunities to improve hospital discharge processes. Recent studies using these methodologies have revealed patients’ perceptions of barriers to inter-professional collaboration during discharge [3] and their desires and expectations of, as well as suggestions for improvement of, hospitalization [4].

Care transition bundles have been developed to facilitate the process of transitioning home [1,5], but none include e-health tools to help facilitate the discharge process. A study group leveraged available software at our institution to create a bedside “e-Board,” addressing opportunities that surfaced during previous patient focus groups regarding our institution’s discharge process. The software tools were loaded onto a tablet computer (Apple iPad; Cupertino, CA) and included displays of the patient’s physician and nurse, with estimated time of team bedside rounds; day and time of anticipated discharge; display of discharge medications; and a screening tool, I-MOVE, to assess mobility prior to return to independent living [6].

We conducted focus groups to gather patients’ insights for incorporation into a bedside e-health tool for discharge and into our hospital’s current discharge process. The primary objective of the current study was to elicit patient and family perceptions of a bedside e-Board, created to display information regarding discharge. Our secondary objective was to learn about patient expectations and perceptions regarding the hospital discharge process.

Methods

Setting

The study setting was 3 medical-surgical, non-cardiac monitored units of a 1265-bed, academic, tertiary care hospital in Rochester, MN. The study was considered a minimal risk study by the center’s institutional review board.

Participants

Patients aged 18 years or older discharged from 1 of the 3 study units during 2012–2013 were eligible to participate. Patients were excluded if they were not discharged home or to assisted living, were clinic employees, retirees or dependents of clinic employees, were hospitalized longer than 6 months prior to study entry, lived further than 60 miles from the town of Rochester, could not travel, or did not sign research consent.

There were 975 patients who met inclusion criteria. The institution’s survey research center randomly selected 300 eligible patients and contacted them by letter after discharge. The letter was followed up with a telephone call and verbal consent was obtained if the patient expressed interest in participation. Of the 17 patients who gave consent, 12 patients participated in focus group interviews.

E-Board Development

Prior focus group discussions facilitated by our institution’s marketing department (Mr. Kent Seltman, personal communication) explored patients’ perceptions of the discharge process from the institution’s primary hospital. The opportunities for improvement that surfaced during these focus groups included identifying the date of discharge, communication about the time of discharge, and discharging the patient at the identified time, not several hours later. The study group leveraged software available at our institution to create a bedside e-Board that could possibly mitigate these issues by improving communication about discharge. The software tools were loaded onto a tablet computer for patients to use as a resource during their admission. These tools included:

1. A photo display of the patient’s nurse and physician, with estimated time of bedside rounds
2. A display of the day and time of anticipated discharge. Providing anticipated day and time of discharge has been found to be an achievable goal for internal medicine and surgical services [7].
3. A medication display, named the “Durable Display at Discharge,” previously found to improve patient understanding of prescribed medications [8]
4. A display of a mobility tool, I-MOVE, designed to screen for debility that could prevent patients’ return to independent living [6].

Focus Groups

Facilitated interviews were conducted on 2 consecutive days in March 2014. Participants were divided into a focus group of 5 to 6 participants if they were functionally independent, or dyads of patient and care partner if they were functionally dependent. Interviews were both video- and audiotaped.

A trained facilitator led 1.5-hour sessions with each focus group. The sessions began with introductions and guidelines by which the focus groups were conducted, including explanations of the video and audio recording equipment, and a request for participants to speak one person at a time to facilitate recording. Discussions were carried out in 2 parts, guided by a facilitator script ( available from the authors). First, participants were asked to share their experiences regarding planning for discharge and the information they received leading up to their planned day and time of hospital discharge. Second, participants were shown a prototype of the e-Board. Participants were asked to reflect as to whether they had received similar information when they had been hospitalized, whether that information was helpful or useful, what information they did not receive that would have been helpful, how information was given, and whether information displayed via an e-Board would be better or worse than the ways they received information while in the hospital.

Data Analysis

Three teams, each comprised of 2 reviewers, met to analyze the video and audio recordings of each focus group. Unfortunately, the video files from the dyad interviews were not recoverable after the recorded sessions, and thus those groups were excluded from the study. Reviewers met prior to analyzing the focus group video and audio recordings to review the qualitative analysis protocol developed by the research team [9] (protocol available froom the authors). The teams then independently reviewed the video recordings and transcripts of the focus groups. The reviewer teams observed the focus group recordings and identified (1) themes regarding perceptions of the bedside e-Board and (2) experiences and perceptions around discharge. The protocol helped reviewer teams create a classification structure by identifying the key themes, which were then combined to create categories. The reviewer teams then compared their classification structures and by incorporating the most frequently identified categories, built a relational model of discharge perceptions.

Results

Eleven patients participated in 2 focus groups, one group of 5 patients and the other of 6 patients. Patient participants included 6 females and 5 males ranging in age from 22 to 84 years.

Using the qualitative analysis protocol, review teams grouped key themes from the focus group discussions about discharge into 4 categories. The categories, with themes listed below and representative patient comments in the Table, were

1.  Coordination and timing of discharge

• Giving patients the opportunity to prepare for discussion with clinician teams
•  Communicating the specific time of discharge
• Internal collaboration of inter-professional teams
• Preparing for transition out of the hospital

  2.  Communication

• Patient inclusion in care discussions
• Discharge summary delay and/or completeness
• Education at the time of discharge

  3. Ramifications of the unexpected and unknown

• Increased stress and frustration due to inability to plan, fear of the unknown, and lack of information

  4. Interpersonal interactions

• Both favorable and unfavorable interactions caused an emotional response that impacts perceptions of hospitalization and discharge

The reviewers also analyzed patients’ comments regarding the bedside e-Board. The medication display (“Durable Display at Discharge,” Figure 1) was universally considered to be the most relevant and best-liked of the 4 elements tested. The visual display of medications and their purpose were commonly referenced as the most positive aspects of the display, and patients and caregivers were readily able to generate multiple potential uses for the display. Several mentioned that the information on the medication display were so desirable and necessary that if not supplied by the hospital, they hand-crafted such reminder displays at home.

It was difficult for patients to see how the I-MOVE assessment (Figure 2) would apply to their discharge planning. They perceived I-MOVE as a tool for clinicians. One exception was a patient who had on a previous admission undergone heart surgery. She explained to the other patients that in such debilitated conditions, mobility independence assessments were important and commonly done.

Patients voiced some skepticism and concerns regarding the e-Board, including expense, privacy, security, and cleanliness. One patient observed the tablet was “more current than a printed piece of paper. It’s more up to date.” Other patients, however, questioned the process required to update information and wondered how much electronic displays added compared to the dry-erase board already in each patient’s room with which they were more familiar. They also voiced concern that the tablet would replace face-to-face interactions with their care teams. A patient shared that, “if we don’t have the conversation and we just get it through this, then I would hate that…you want to be able to give your input.”

Discussion

In this study, we used available software to create a bedside e-Board that addressed opportunities for patient-centered improvement in our institution’s discharge process. Patients felt that 3 of 4 software tools on the tablet could enhance the discharge experience. Additionally, we explored patients’ expectations and perceptions of our hospital discharge process.

Key information to inform our current discharge process was divulged by our patients during focus groups. Patients conveyed that the only time that matters to them is the time they get to walk out the door of the hospital, and that general statements (eg, “You’ll probably be going home today.”) create anxiety and dissatisfaction. Since family and care partners need to manage hospital discharge in combination with regular activities of daily life (eg, work schedules, child care), un-communicated changes to the discharge time are very difficult to accommodate and should be discussed in advance. Further, acknowledging the disruption of hospital admission to patients’, their families’, and care partners’ daily lives, as well as being mindful of the impact of interpersonal interactions with patients, remind clinicians of the impact hospitalization has on patients.

Focus group discussions revealed that an ideal patient-centered discharge process would include active patient participation, clear communication regarding the discharge process, especially changes in the specific discharge date and time, and education regarding discharge summary instructions. Further, patients voiced that the unexpected nature of admissions can be very disruptive to patients’ lives and that interpersonal interactions during admission cause emotional responses in patients that influence their perceptions of hospitalization.

Comments regarding poor coordination and communication of internal processes, opportunities to improve collaboration within and across care teams, and need to improve communication with patients regarding timing of discharge and plan of care are consistent with recent studies that used focus groups to explore patient perceptions and expectations around discharge [3,4]. The ramifications of unexpected admissions and the emotional responses patients expressed regarding interpersonal interactions during admission have not been reported by others conducting patient focus groups.

The unexpected nature of many admissions, and the uncertainty of the day-to-day activities during hospitalization, caused patients anxiety and stress. These emotions perhaps heightened their response and memories of both favorable and unfavorable interpersonal interactions. These memories left lasting impressions on patients and care teams may help alleviate anxiety and stress by providing consistency and routine such as rounding at the same time daily, and communicating this time with patients. In this regard, the e-Board was helpful in communicating the patients’ care team and their planned rounding time.

Regarding the ability of e-tools to facilitate information sharing and planning for discharge, patients felt that the display of medications would have been most beneficial when thinking about post-discharge care. They perceived a display of discharge date and time estimate display as very useful to coordinate the activities around physically leaving the hospital, but based on their experiences did not find anticipated discharge times to be believable.

Patients’ perceptions of the tool were assessed after a recent hospitalization, and our data would have been strengthened had patients and their care partners used the e-Board during the actual admission. On the other hand, post-discharge, patients had time to reflect on opportunities for improving their recent admission and had insight into gaps in their discharge that the tool could potentially fill. Because we were unable to access video recordings from our dyad groups, which led us to exclude these participants, we lost care partners’ perceptions of the e-Board and discharge process. Care partners likely have different perceptions of discharge processes compared to patients, and their insight would have augmented our findings.

Several patients observed that the e-Board presented much of the same information that was filled out by care teams on the in-room dry erase boards and questioned whether the tablet was needed. These observations provide future opportunity for studies comparing display of discharge information on in-room dry-erase boards to an electronic tablet display. E-tools have shown some benefit when used for patient self-monitoring [10], to increase patient engagement [11,12], or to improve patient education [12]. Computer tablets may be most useful when used in these manners, compared to information display.

Focus groups provide patient-provided information that is readily actionable, and this work presents patient insight into discharge processes elicited through focus groups. Patients discussed their perceptions of an e-tool that might address patient-identified opportunities to improve the discharge process. Future work in this area will explore e-tools, and how best to leverage their functionality to design a patient-centered discharge process.

Acknowledgments: Our thanks to Mr. Thomas J. (Tripp) Welch for the original suggestion of this study design, and to Ms. Heidi Miller and Ms. Lizann Williams for their invaluable contributions to this work. A special thanks to our exceptional colleagues of the Mayo Clinic Department of Medicine Clinical Research Office Clinical Trials Unit for their efforts in executing this study, and to the study participants who participated in this research, without whom this project would not have been possible.

Corresponding author: Deanne Kashiwagi, MD, MS, 200 First Street SW, Rochester, MN 55902, [email protected].

Financial disclosures: None.

From the Mayo Clinic, Rochester, MN.

Abstract

• Objective: To elicit patient perceptions of a computer tablet (“e-Board”) used to display information relevant to hospital discharge and to gather patients’ expectations and perceptions regarding hospital discharge.
• Methods: Adult patients discharged from 1 of 3 medical-surgical, noncardiac monitored units of a 1265-bed, academic, tertiary care hospital were interviewed during patient focus groups. Reviewer pairs performed qualitative analysis of focus group transcripts and identified key themes, which were grouped into categories.
• Results: Patients felt a novel e-Board could help with the discharge process. They identified coordination of discharge, communication about discharge, ramifications of unexpected admissions, and interpersonal interactions during admission as the most significant issues around discharge.
• Conclusions: Focus groups elicit actionable information from patients about hospital discharge. Using this information, e-tools may help to design a patient-centered discharge process.

Key words: hospitals; patient satisfaction; focus groups; acute inpatient care.

Transition from the hospital to home represents a critical time for patients after acute illness, and support of patients and their care partners can help decrease consequences of poor care transitions, such as readmissions [1]. Focused discharge planning may improve outcomes and increase patient satisfaction [2], which is a key metric in hospital value-based purchasing programs, which tie Hospital Consumer Assessment of Healthcare Providers and Services (HCAHPS) survey scores to reimbursement. Although patient experience surveys explore several categories of patient satisfaction, HCAHPS may not reveal readily actionable opportunities that would allow clinicians to improve patient experience. Conducting focus groups and interviews can help discern patients’ perceptions and provide patient-centered opportunities to improve hospital discharge processes. Recent studies using these methodologies have revealed patients’ perceptions of barriers to inter-professional collaboration during discharge [3] and their desires and expectations of, as well as suggestions for improvement of, hospitalization [4].

Care transition bundles have been developed to facilitate the process of transitioning home [1,5], but none include e-health tools to help facilitate the discharge process. A study group leveraged available software at our institution to create a bedside “e-Board,” addressing opportunities that surfaced during previous patient focus groups regarding our institution’s discharge process. The software tools were loaded onto a tablet computer (Apple iPad; Cupertino, CA) and included displays of the patient’s physician and nurse, with estimated time of team bedside rounds; day and time of anticipated discharge; display of discharge medications; and a screening tool, I-MOVE, to assess mobility prior to return to independent living [6].

We conducted focus groups to gather patients’ insights for incorporation into a bedside e-health tool for discharge and into our hospital’s current discharge process. The primary objective of the current study was to elicit patient and family perceptions of a bedside e-Board, created to display information regarding discharge. Our secondary objective was to learn about patient expectations and perceptions regarding the hospital discharge process.

Methods

Setting

The study setting was 3 medical-surgical, non-cardiac monitored units of a 1265-bed, academic, tertiary care hospital in Rochester, MN. The study was considered a minimal risk study by the center’s institutional review board.

Participants

Patients aged 18 years or older discharged from 1 of the 3 study units during 2012–2013 were eligible to participate. Patients were excluded if they were not discharged home or to assisted living, were clinic employees, retirees or dependents of clinic employees, were hospitalized longer than 6 months prior to study entry, lived further than 60 miles from the town of Rochester, could not travel, or did not sign research consent.

There were 975 patients who met inclusion criteria. The institution’s survey research center randomly selected 300 eligible patients and contacted them by letter after discharge. The letter was followed up with a telephone call and verbal consent was obtained if the patient expressed interest in participation. Of the 17 patients who gave consent, 12 patients participated in focus group interviews.

E-Board Development

Prior focus group discussions facilitated by our institution’s marketing department (Mr. Kent Seltman, personal communication) explored patients’ perceptions of the discharge process from the institution’s primary hospital. The opportunities for improvement that surfaced during these focus groups included identifying the date of discharge, communication about the time of discharge, and discharging the patient at the identified time, not several hours later. The study group leveraged software available at our institution to create a bedside e-Board that could possibly mitigate these issues by improving communication about discharge. The software tools were loaded onto a tablet computer for patients to use as a resource during their admission. These tools included:

1. A photo display of the patient’s nurse and physician, with estimated time of bedside rounds
2. A display of the day and time of anticipated discharge. Providing anticipated day and time of discharge has been found to be an achievable goal for internal medicine and surgical services [7].
3. A medication display, named the “Durable Display at Discharge,” previously found to improve patient understanding of prescribed medications [8]
4. A display of a mobility tool, I-MOVE, designed to screen for debility that could prevent patients’ return to independent living [6].

Focus Groups

Facilitated interviews were conducted on 2 consecutive days in March 2014. Participants were divided into a focus group of 5 to 6 participants if they were functionally independent, or dyads of patient and care partner if they were functionally dependent. Interviews were both video- and audiotaped.

A trained facilitator led 1.5-hour sessions with each focus group. The sessions began with introductions and guidelines by which the focus groups were conducted, including explanations of the video and audio recording equipment, and a request for participants to speak one person at a time to facilitate recording. Discussions were carried out in 2 parts, guided by a facilitator script ( available from the authors). First, participants were asked to share their experiences regarding planning for discharge and the information they received leading up to their planned day and time of hospital discharge. Second, participants were shown a prototype of the e-Board. Participants were asked to reflect as to whether they had received similar information when they had been hospitalized, whether that information was helpful or useful, what information they did not receive that would have been helpful, how information was given, and whether information displayed via an e-Board would be better or worse than the ways they received information while in the hospital.

Data Analysis

Three teams, each comprised of 2 reviewers, met to analyze the video and audio recordings of each focus group. Unfortunately, the video files from the dyad interviews were not recoverable after the recorded sessions, and thus those groups were excluded from the study. Reviewers met prior to analyzing the focus group video and audio recordings to review the qualitative analysis protocol developed by the research team [9] (protocol available froom the authors). The teams then independently reviewed the video recordings and transcripts of the focus groups. The reviewer teams observed the focus group recordings and identified (1) themes regarding perceptions of the bedside e-Board and (2) experiences and perceptions around discharge. The protocol helped reviewer teams create a classification structure by identifying the key themes, which were then combined to create categories. The reviewer teams then compared their classification structures and by incorporating the most frequently identified categories, built a relational model of discharge perceptions.

Results

Eleven patients participated in 2 focus groups, one group of 5 patients and the other of 6 patients. Patient participants included 6 females and 5 males ranging in age from 22 to 84 years.

Using the qualitative analysis protocol, review teams grouped key themes from the focus group discussions about discharge into 4 categories. The categories, with themes listed below and representative patient comments in the Table, were

1.  Coordination and timing of discharge

• Giving patients the opportunity to prepare for discussion with clinician teams
•  Communicating the specific time of discharge
• Internal collaboration of inter-professional teams
• Preparing for transition out of the hospital

  2.  Communication

• Patient inclusion in care discussions
• Discharge summary delay and/or completeness
• Education at the time of discharge

  3. Ramifications of the unexpected and unknown

• Increased stress and frustration due to inability to plan, fear of the unknown, and lack of information

  4. Interpersonal interactions

• Both favorable and unfavorable interactions caused an emotional response that impacts perceptions of hospitalization and discharge

The reviewers also analyzed patients’ comments regarding the bedside e-Board. The medication display (“Durable Display at Discharge,” Figure 1) was universally considered to be the most relevant and best-liked of the 4 elements tested. The visual display of medications and their purpose were commonly referenced as the most positive aspects of the display, and patients and caregivers were readily able to generate multiple potential uses for the display. Several mentioned that the information on the medication display were so desirable and necessary that if not supplied by the hospital, they hand-crafted such reminder displays at home.

It was difficult for patients to see how the I-MOVE assessment (Figure 2) would apply to their discharge planning. They perceived I-MOVE as a tool for clinicians. One exception was a patient who had on a previous admission undergone heart surgery. She explained to the other patients that in such debilitated conditions, mobility independence assessments were important and commonly done.

Patients voiced some skepticism and concerns regarding the e-Board, including expense, privacy, security, and cleanliness. One patient observed the tablet was “more current than a printed piece of paper. It’s more up to date.” Other patients, however, questioned the process required to update information and wondered how much electronic displays added compared to the dry-erase board already in each patient’s room with which they were more familiar. They also voiced concern that the tablet would replace face-to-face interactions with their care teams. A patient shared that, “if we don’t have the conversation and we just get it through this, then I would hate that…you want to be able to give your input.”

Discussion

In this study, we used available software to create a bedside e-Board that addressed opportunities for patient-centered improvement in our institution’s discharge process. Patients felt that 3 of 4 software tools on the tablet could enhance the discharge experience. Additionally, we explored patients’ expectations and perceptions of our hospital discharge process.

Key information to inform our current discharge process was divulged by our patients during focus groups. Patients conveyed that the only time that matters to them is the time they get to walk out the door of the hospital, and that general statements (eg, “You’ll probably be going home today.”) create anxiety and dissatisfaction. Since family and care partners need to manage hospital discharge in combination with regular activities of daily life (eg, work schedules, child care), un-communicated changes to the discharge time are very difficult to accommodate and should be discussed in advance. Further, acknowledging the disruption of hospital admission to patients’, their families’, and care partners’ daily lives, as well as being mindful of the impact of interpersonal interactions with patients, remind clinicians of the impact hospitalization has on patients.

Focus group discussions revealed that an ideal patient-centered discharge process would include active patient participation, clear communication regarding the discharge process, especially changes in the specific discharge date and time, and education regarding discharge summary instructions. Further, patients voiced that the unexpected nature of admissions can be very disruptive to patients’ lives and that interpersonal interactions during admission cause emotional responses in patients that influence their perceptions of hospitalization.

Comments regarding poor coordination and communication of internal processes, opportunities to improve collaboration within and across care teams, and need to improve communication with patients regarding timing of discharge and plan of care are consistent with recent studies that used focus groups to explore patient perceptions and expectations around discharge [3,4]. The ramifications of unexpected admissions and the emotional responses patients expressed regarding interpersonal interactions during admission have not been reported by others conducting patient focus groups.

The unexpected nature of many admissions, and the uncertainty of the day-to-day activities during hospitalization, caused patients anxiety and stress. These emotions perhaps heightened their response and memories of both favorable and unfavorable interpersonal interactions. These memories left lasting impressions on patients and care teams may help alleviate anxiety and stress by providing consistency and routine such as rounding at the same time daily, and communicating this time with patients. In this regard, the e-Board was helpful in communicating the patients’ care team and their planned rounding time.

Regarding the ability of e-tools to facilitate information sharing and planning for discharge, patients felt that the display of medications would have been most beneficial when thinking about post-discharge care. They perceived a display of discharge date and time estimate display as very useful to coordinate the activities around physically leaving the hospital, but based on their experiences did not find anticipated discharge times to be believable.

Patients’ perceptions of the tool were assessed after a recent hospitalization, and our data would have been strengthened had patients and their care partners used the e-Board during the actual admission. On the other hand, post-discharge, patients had time to reflect on opportunities for improving their recent admission and had insight into gaps in their discharge that the tool could potentially fill. Because we were unable to access video recordings from our dyad groups, which led us to exclude these participants, we lost care partners’ perceptions of the e-Board and discharge process. Care partners likely have different perceptions of discharge processes compared to patients, and their insight would have augmented our findings.

Several patients observed that the e-Board presented much of the same information that was filled out by care teams on the in-room dry erase boards and questioned whether the tablet was needed. These observations provide future opportunity for studies comparing display of discharge information on in-room dry-erase boards to an electronic tablet display. E-tools have shown some benefit when used for patient self-monitoring [10], to increase patient engagement [11,12], or to improve patient education [12]. Computer tablets may be most useful when used in these manners, compared to information display.

Focus groups provide patient-provided information that is readily actionable, and this work presents patient insight into discharge processes elicited through focus groups. Patients discussed their perceptions of an e-tool that might address patient-identified opportunities to improve the discharge process. Future work in this area will explore e-tools, and how best to leverage their functionality to design a patient-centered discharge process.

Acknowledgments: Our thanks to Mr. Thomas J. (Tripp) Welch for the original suggestion of this study design, and to Ms. Heidi Miller and Ms. Lizann Williams for their invaluable contributions to this work. A special thanks to our exceptional colleagues of the Mayo Clinic Department of Medicine Clinical Research Office Clinical Trials Unit for their efforts in executing this study, and to the study participants who participated in this research, without whom this project would not have been possible.

Corresponding author: Deanne Kashiwagi, MD, MS, 200 First Street SW, Rochester, MN 55902, [email protected].

Financial disclosures: None.

ABSTRACT

Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. The purpose of this study was to demonstrate the feasibility of revisions with a completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

Between 2003 and 2011, 104 primary total shoulder arthroplasties (TSAs) were performed with an uncemented glenoid component in our group. Of these patients, 13 (average age, 64 years) were revised to reverse shoulder arthroplasty (RSA) using a modular convertible platform system and were included in this study. Average follow-up after revision was 22 months. Outcome measures included pain, range of motion, Constant-Murley scores, Simple Shoulder Tests, and subjective shoulder values. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021), and active external rotation increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°). Mean pain scores significantly improved from 4.2 to 13.3 points. The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90). Subjectively, 12 patients rated their shoulder as better or much better than preoperatively. This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function.

Continue to: Polyethylene glenoid components...

Polyethylene glenoid components are the gold standard in anatomic total shoulder arthroplasty (TSA). However, even though TSA survivorship exceeds 95% at 10-year follow-up,¹ glenoid component loosening remains the main complication and the weak link in these implants. This complication accounts for 25% of all complications related to TSA in the literature.² In most cases, glenoid component loosening is not isolated but combined with a rotator cuff tear, glenohumeral instability, or component malposition.^3-5 Therefore, revision of TSA to reverse shoulder arthroplasty (RSA) often requires the removal of both the humeral stem and glenoid component. Removal of the humeral stem can be challenging and can necessitate removal of the cement and osteotomy of the diaphysis, risking fracture and extensive damage to the soft tissue (Figures 1A, 1B).^6-8 Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. Allografts and specific designs with a longer post can be mandatory to obtain a stable fixation of the new baseplate.^9-12

We hypothesized that a completely convertible platform system on both the humeral and the glenoid side could facilitate the revision of a failed TSA to a RSA. This would enable the surgeon to leave the humeral stem and the glenoid baseplate in place, avoiding the difficulty of stem removal and the reimplantation of a glenoid component, especially in osteoporotic glenoid bone and elderly patients. The revision procedure would then only consist of replacing the humeral head by a metallic tray and polyethylene bearing on the humeral side and by impacting a glenosphere on the glenoid baseplate (Figures 2A, 2B).

The purpose of this study was to demonstrate the feasibility of revisions with this completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

MATERIALS AND METHODS

PATIENT SELECTION

Between 2003 and 2011, 104 primary TSAs were performed with an uncemented glenoid component in our group. Of these patients, 18 underwent revision (17.3%). Among these 18 patients, 13 were revised to RSA using a modular convertible platform system and were included in this study, while 5 patients were revised to another TSA (2 dissociations of the polyethylene glenoid implant, 2 excessively low implantations of the glenoid baseplate, and 1 glenoid loosening). The mean age of the 13 patients (9 women, 4 men) included in this retrospective study at the time of revision was 64 years (range, 50-75 years). The reasons for revision surgery were rotator cuff tear (5, among which 2 were posterosuperior tears, and 3 were tears of the subscapularis), dislocations (5 posterior and 1 anterior, among which 4 had a B2 or C glenoid), suprascapular nerve paralysis (1), and dissociation of the polyethylene (1). The initial TSA was indicated for primary osteoarthritis with a normal cuff (9), primary osteoarthritis with a reparable cuff tear (2), posttraumatic osteoarthritis (1), and chronic dislocation (1). The right dominant shoulder was involved in 10 cases. The mean time interval between the primary TSA and the revision was 15 months (range, 1-61 months).

OPERATIVE TECHNIQUE

PREOPERATIVE PLANNING

Revision of a failed TSA is always a difficult challenge, and evaluation of bone loss on both the humeral and the glenoid sides, as well as the status of the cuff, is mandatory, even with a completely convertible arthroplasty system. The surgeon must be prepared to remove the humeral stem in case reduction of the joint is impossible. We systematically performed standard radiographs (anteroposterior, axillary, and outlet views) and computed tomography (CT) scans in order to assess both the version and positioning, as well as potential signs of loosening of the implants and the status of the cuff (continuity, degree of muscle trophicity, and fatty infiltration). A preoperative leucocyte count, sedimentation rate, and C-reactive protein rates were requested in every revision case, even if a mechanical etiology was strongly suspected.

Continue to: REVISION PROCEDURE

All the implants that had been used in the primary TSAs were Arrow Universal Shoulder Prostheses (FH Orthopedics). All revisions were performed through the previous deltopectoral approach in the beach chair position under general anesthesia with an interscalene block. Adhesions of the deep part of the deltoid were carefully released. The conjoint tendon was released, and the location of the musculocutaneous and axillary nerves was identified before any retractor was placed. In the 10 cases where the subscapularis was intact, it was peeled off the medial border of the bicipital groove to obtain sufficient length for a tension-free reinsertion.

The anatomical head of the humeral implant was disconnected from the stem and removed. All stems were found to be well fixed; there were no cases of loosening or evidence of infection. A circumferential capsular release was systematically carried out. The polyethylene glenoid onlay was then unlocked from the baseplate.

The quality of the fixation of the glenoid baseplate was systematically evaluated; no screw was found to be loose, and the fixation of all baseplates was stable. Therefore, there was no need to revise the glenoid baseplate, even when its position was considered excessively retroverted (Glenoid B2) or high. A glenosphere was impacted on the baseplate, and a polyethylene humeral bearing was then implanted on the humeral stem. The thinnest polyethylene bearing available (number 0) was chosen in all cases, and a size 36 glenosphere was chosen in 12 out of 13 cases. Intraoperative stability of the implant was satisfactory, and no impingement was found posteriorly, anteriorly, or inferiorly.

In one case, the humeral stem was a first-generation humeral implant which was not compatible with the new-generation humeral bearing, and the humeral stem had to be replaced.

In 2 cases, reduction of the RSA was either impossible or felt to be too tight, even after extensive soft-tissue release and resection of the remaining supraspinatus. The main reason for this was an excessively proud humeral stem because of an onlay polyethylene humeral bearing instead of an inlay design. However, removal of the uncemented humeral stem was always possible with no osteotomy or cortical window of the humeral shaft as the humeral stem has been designed with a bone ingrowth surface only on the metaphyseal part with a smooth surface on diaphyseal part. After removal of the stem, a small amount of humeral metaphysis was cut, and a new humeral stem was press-fit in a lower position. This allowed restoration of an appropriate tension of the soft tissue and, therefore, an easier reduction. The subscapularis was medialized and reinserted transosseously when possible with a double-row repair. In 3 cases, the subscapularis was torn and retracted at the level of the glenoid, or impossible to identify to allow its reinsertion.

Continue to: According to our infectious disease department...

According to our infectious disease department, we made a minimum of 5 cultures for each revision case looking for a possible low-grade infection. All cultures in our group are held for 14 days to assess for Propionibacterium acnes.

POSTOPERATIVE MANAGEMENT

A shoulder splint in neutral rotation was used for the first 4 weeks. Passive range of motion (ROM) was started immediately with pendulum exercises and passive anterior elevation. Active assisted and active ROM were allowed after 4 weeks, and physiotherapy was continued for 6 months. Elderly patients were referred to a center of rehabilitation. We found only 1 or 2 positive cultures (Propionibacterium acnes) for 4 patients, and we decided to consider them as a contamination. None of the patients were treated with antibiotics.

CLINICAL AND RADIOLOGICAL ASSESSMENT

Clinical evaluation included pre- and postoperative pain scores (visual analog scale [VAS]), ROM, the Constant-Murley¹³ score, the Simple Shoulder Test (SST),¹⁴ and the subjective shoulder value.¹⁵ Subjective satisfaction was assessed by asking the patients at follow-up how they felt compared with before surgery and was graded using a 4-point scale: 1, much better; 2, better; 3, the same; and 4, worse. Radiographic evaluation was performed on pre- and postoperative standard anteroposterior, outlet, and axillary views. Radiographs were reviewed to determine the presence of glenohumeral subluxation, periprosthetic lucency, component shift in position, and scapular notching.

STATISTICAL ANALYSIS

Descriptive statistics are reported as mean (range) for continuous measures and number (percentage) for discrete variables. The Wilcoxon signed-rank test was used for preoperative vs postoperative changes. The alpha level for all tests was set at 0.05 for statistical significance.

RESULTS

CLINICAL OUTCOME

At a mean of 22 months (range, 7-38 months) follow-up after revision, active ROM was significantly improved. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021). Active external rotation with the elbow on the side increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°) (P = 0.034), and increased with the arm held at 90° abduction from 13° (range, 0°-20°) to 49° (range, 0°-80°) (P = 0.025). Mean pain scores improved from 4.2 to 13.3 points (P < 0.001). VAS improved significantly from 9 to 1 (P < 0.0001). The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90) (P = 0.006). The final SST was 7 per 12. Subjectively, 4 patients rated their shoulder as much better, 8 as better, and 1 as the same as preoperatively. No intra- or postoperative complications, including infections, were observed. The mean duration of the procedure was 60 minutes (range, 30-75 minutes).

Continue to: RADIOLOGICAL OUTCOME

No periprosthetic lucency or shift in component was observed at the last follow-up. There was no scapular notching. No resorption of the tuberosities, and no fractures of the acromion or the scapular spine were observed.

DISCUSSION

In this retrospective study, failure of TSA with a metal-backed glenoid implant was successfully revised to RSA. In 10 patients, the use of a universal platform system allowed an easier conversion without removal of the humeral stem or the glenoid component (Figures 3A-3D). Twelve of the 13 patients were satisfied or very satisfied at the last follow-up. None of the patients were in pain, and the mean Constant score was 63. In all the cases, the glenoid baseplate was not changed. In 3 cases the humeral stem was changed without any fracture of the tuberosities of need for an osteotomy. This greatly simplified the revision procedure, as glenoid revisions can be very challenging. Indeed, it is often difficult to assess precisely preoperatively the remaining glenoid bone stock after removal of the glenoid component and the cement. Many therapeutic options to deal with glenoid loosening have been reported in the literature: glenoid bone reconstruction after glenoid component removal and revision to a hemiarthroplasty (HA),^10,16-18 glenoid bone reconstruction after glenoid component removal and revision to a new TSA with a cemented glenoid implant,^16,17,19,20 and glenoid reconstruction after glenoid component removal and revision to a RSA.^12,21 These authors reported that glenoid reconstruction frequently necessitates an iliac bone graft associated with a special design of the baseplate with a long post fixed into the native glenoid bone. However, sometimes implantation of an uncemented glenoid component can be unstable with a high risk of early mobilization of the implant, and 2 steps may be necessary. Conversion to a HA,^10,16-18 or a TSA^16,17,19,20 with a new cemented implant have both been associated with poor clinical outcome, with a high rate of recurrent glenoid loosening for the TSAs.

In our retrospective study, we reported no intra- or postoperative complications. Flury and colleagues²² reported a complication rate of 38% in 21 patients after conversion from a TSA to a RSA with a mean follow-up of 46 months. They removed all the components of the prosthesis with a crack or fracture of the humerus and/or the glenoid. Ortmaier and colleagues²³ reported a rate of complication of 22.7% during the conversion of TSA to RSA. They did an osteotomy of the humeral diaphysis to extract the stem in 40% of cases and had to remove the glenoid cement in 86% of cases with severe damage of the glenoid bone in 10% of cases. Fewer complications were found in our study, as we did not need any procedure such as humeral osteotomy, cerclage, bone grafting, and/or reconstruction of the glenoid. The short operative time and the absence of extensive soft-tissue dissection, thanks to a standard deltopectoral approach, could explain the absence of infection in our series.

Other authors shared our strategy of a universal convertible system and reported their results in the literature. Castagna and colleagues²⁴ in 2013 reported the clinical and radiological results of conversions of HA or TSA to RSA using a modular, convertible system (SMR Shoulder System, Lima Corporate). In their series, only 8 cases of TSAs were converted to RSA. They preserved, in each case, the humeral stem and the glenoid baseplate. There were no intra- or postoperative complications. The mean VAS score decreased from 8 to 2. Weber-Spickschen and colleague²⁵ reported recently in 2015 the same experience with the same system (SMR Shoulder System). They reviewed 15 conversions of TSAs to RSAs without any removal of the implants at a mean 43-month follow-up. They reported excellent pain relief (VAS decreased from 8 to 1) and improvement in shoulder function with a low rate of complications.

Kany and colleagues²⁶ in 2015 had already reported the advantages of a shoulder platform system for revisions. In their series, the authors included cases of failure of HAs and TSAs with loose cemented glenoids and metal-backed glenoids. The clinical and radiological results were similar, with a final Constant score of 60 (range, 42-85) and a similar rate of humeral stems which had to be changed (24%). These stems were replaced either because they were too proud or because there was not enough space to add an onlay polyethylene socket.

Continue to: Despite the encouraging results...

Despite the encouraging results reported in this study, there are some limitations. Firstly, no control group was used. Attempting to address this issue, we compared our results with the literature. Secondly, the number of patients in our study was small. Finally, the follow-up duration (mean 22 months) did not provide long-term outcomes.

CONCLUSION

This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function. A platform system on both the humeral and the glenoid side reduces the operative time of the conversion with a low risk of complications.

ABSTRACT

Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. The purpose of this study was to demonstrate the feasibility of revisions with a completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

Between 2003 and 2011, 104 primary total shoulder arthroplasties (TSAs) were performed with an uncemented glenoid component in our group. Of these patients, 13 (average age, 64 years) were revised to reverse shoulder arthroplasty (RSA) using a modular convertible platform system and were included in this study. Average follow-up after revision was 22 months. Outcome measures included pain, range of motion, Constant-Murley scores, Simple Shoulder Tests, and subjective shoulder values. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021), and active external rotation increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°). Mean pain scores significantly improved from 4.2 to 13.3 points. The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90). Subjectively, 12 patients rated their shoulder as better or much better than preoperatively. This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function.

Continue to: Polyethylene glenoid components...

Polyethylene glenoid components are the gold standard in anatomic total shoulder arthroplasty (TSA). However, even though TSA survivorship exceeds 95% at 10-year follow-up,¹ glenoid component loosening remains the main complication and the weak link in these implants. This complication accounts for 25% of all complications related to TSA in the literature.² In most cases, glenoid component loosening is not isolated but combined with a rotator cuff tear, glenohumeral instability, or component malposition.^3-5 Therefore, revision of TSA to reverse shoulder arthroplasty (RSA) often requires the removal of both the humeral stem and glenoid component. Removal of the humeral stem can be challenging and can necessitate removal of the cement and osteotomy of the diaphysis, risking fracture and extensive damage to the soft tissue (Figures 1A, 1B).^6-8 Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. Allografts and specific designs with a longer post can be mandatory to obtain a stable fixation of the new baseplate.^9-12

We hypothesized that a completely convertible platform system on both the humeral and the glenoid side could facilitate the revision of a failed TSA to a RSA. This would enable the surgeon to leave the humeral stem and the glenoid baseplate in place, avoiding the difficulty of stem removal and the reimplantation of a glenoid component, especially in osteoporotic glenoid bone and elderly patients. The revision procedure would then only consist of replacing the humeral head by a metallic tray and polyethylene bearing on the humeral side and by impacting a glenosphere on the glenoid baseplate (Figures 2A, 2B).

The purpose of this study was to demonstrate the feasibility of revisions with this completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

MATERIALS AND METHODS

PATIENT SELECTION

Between 2003 and 2011, 104 primary TSAs were performed with an uncemented glenoid component in our group. Of these patients, 18 underwent revision (17.3%). Among these 18 patients, 13 were revised to RSA using a modular convertible platform system and were included in this study, while 5 patients were revised to another TSA (2 dissociations of the polyethylene glenoid implant, 2 excessively low implantations of the glenoid baseplate, and 1 glenoid loosening). The mean age of the 13 patients (9 women, 4 men) included in this retrospective study at the time of revision was 64 years (range, 50-75 years). The reasons for revision surgery were rotator cuff tear (5, among which 2 were posterosuperior tears, and 3 were tears of the subscapularis), dislocations (5 posterior and 1 anterior, among which 4 had a B2 or C glenoid), suprascapular nerve paralysis (1), and dissociation of the polyethylene (1). The initial TSA was indicated for primary osteoarthritis with a normal cuff (9), primary osteoarthritis with a reparable cuff tear (2), posttraumatic osteoarthritis (1), and chronic dislocation (1). The right dominant shoulder was involved in 10 cases. The mean time interval between the primary TSA and the revision was 15 months (range, 1-61 months).

OPERATIVE TECHNIQUE

PREOPERATIVE PLANNING

Revision of a failed TSA is always a difficult challenge, and evaluation of bone loss on both the humeral and the glenoid sides, as well as the status of the cuff, is mandatory, even with a completely convertible arthroplasty system. The surgeon must be prepared to remove the humeral stem in case reduction of the joint is impossible. We systematically performed standard radiographs (anteroposterior, axillary, and outlet views) and computed tomography (CT) scans in order to assess both the version and positioning, as well as potential signs of loosening of the implants and the status of the cuff (continuity, degree of muscle trophicity, and fatty infiltration). A preoperative leucocyte count, sedimentation rate, and C-reactive protein rates were requested in every revision case, even if a mechanical etiology was strongly suspected.

Continue to: REVISION PROCEDURE

All the implants that had been used in the primary TSAs were Arrow Universal Shoulder Prostheses (FH Orthopedics). All revisions were performed through the previous deltopectoral approach in the beach chair position under general anesthesia with an interscalene block. Adhesions of the deep part of the deltoid were carefully released. The conjoint tendon was released, and the location of the musculocutaneous and axillary nerves was identified before any retractor was placed. In the 10 cases where the subscapularis was intact, it was peeled off the medial border of the bicipital groove to obtain sufficient length for a tension-free reinsertion.

The anatomical head of the humeral implant was disconnected from the stem and removed. All stems were found to be well fixed; there were no cases of loosening or evidence of infection. A circumferential capsular release was systematically carried out. The polyethylene glenoid onlay was then unlocked from the baseplate.

The quality of the fixation of the glenoid baseplate was systematically evaluated; no screw was found to be loose, and the fixation of all baseplates was stable. Therefore, there was no need to revise the glenoid baseplate, even when its position was considered excessively retroverted (Glenoid B2) or high. A glenosphere was impacted on the baseplate, and a polyethylene humeral bearing was then implanted on the humeral stem. The thinnest polyethylene bearing available (number 0) was chosen in all cases, and a size 36 glenosphere was chosen in 12 out of 13 cases. Intraoperative stability of the implant was satisfactory, and no impingement was found posteriorly, anteriorly, or inferiorly.

In one case, the humeral stem was a first-generation humeral implant which was not compatible with the new-generation humeral bearing, and the humeral stem had to be replaced.

In 2 cases, reduction of the RSA was either impossible or felt to be too tight, even after extensive soft-tissue release and resection of the remaining supraspinatus. The main reason for this was an excessively proud humeral stem because of an onlay polyethylene humeral bearing instead of an inlay design. However, removal of the uncemented humeral stem was always possible with no osteotomy or cortical window of the humeral shaft as the humeral stem has been designed with a bone ingrowth surface only on the metaphyseal part with a smooth surface on diaphyseal part. After removal of the stem, a small amount of humeral metaphysis was cut, and a new humeral stem was press-fit in a lower position. This allowed restoration of an appropriate tension of the soft tissue and, therefore, an easier reduction. The subscapularis was medialized and reinserted transosseously when possible with a double-row repair. In 3 cases, the subscapularis was torn and retracted at the level of the glenoid, or impossible to identify to allow its reinsertion.

Continue to: According to our infectious disease department...

According to our infectious disease department, we made a minimum of 5 cultures for each revision case looking for a possible low-grade infection. All cultures in our group are held for 14 days to assess for Propionibacterium acnes.

POSTOPERATIVE MANAGEMENT

A shoulder splint in neutral rotation was used for the first 4 weeks. Passive range of motion (ROM) was started immediately with pendulum exercises and passive anterior elevation. Active assisted and active ROM were allowed after 4 weeks, and physiotherapy was continued for 6 months. Elderly patients were referred to a center of rehabilitation. We found only 1 or 2 positive cultures (Propionibacterium acnes) for 4 patients, and we decided to consider them as a contamination. None of the patients were treated with antibiotics.

CLINICAL AND RADIOLOGICAL ASSESSMENT

Clinical evaluation included pre- and postoperative pain scores (visual analog scale [VAS]), ROM, the Constant-Murley¹³ score, the Simple Shoulder Test (SST),¹⁴ and the subjective shoulder value.¹⁵ Subjective satisfaction was assessed by asking the patients at follow-up how they felt compared with before surgery and was graded using a 4-point scale: 1, much better; 2, better; 3, the same; and 4, worse. Radiographic evaluation was performed on pre- and postoperative standard anteroposterior, outlet, and axillary views. Radiographs were reviewed to determine the presence of glenohumeral subluxation, periprosthetic lucency, component shift in position, and scapular notching.

STATISTICAL ANALYSIS

Descriptive statistics are reported as mean (range) for continuous measures and number (percentage) for discrete variables. The Wilcoxon signed-rank test was used for preoperative vs postoperative changes. The alpha level for all tests was set at 0.05 for statistical significance.

RESULTS

CLINICAL OUTCOME

At a mean of 22 months (range, 7-38 months) follow-up after revision, active ROM was significantly improved. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021). Active external rotation with the elbow on the side increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°) (P = 0.034), and increased with the arm held at 90° abduction from 13° (range, 0°-20°) to 49° (range, 0°-80°) (P = 0.025). Mean pain scores improved from 4.2 to 13.3 points (P < 0.001). VAS improved significantly from 9 to 1 (P < 0.0001). The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90) (P = 0.006). The final SST was 7 per 12. Subjectively, 4 patients rated their shoulder as much better, 8 as better, and 1 as the same as preoperatively. No intra- or postoperative complications, including infections, were observed. The mean duration of the procedure was 60 minutes (range, 30-75 minutes).

Continue to: RADIOLOGICAL OUTCOME

No periprosthetic lucency or shift in component was observed at the last follow-up. There was no scapular notching. No resorption of the tuberosities, and no fractures of the acromion or the scapular spine were observed.

DISCUSSION

In this retrospective study, failure of TSA with a metal-backed glenoid implant was successfully revised to RSA. In 10 patients, the use of a universal platform system allowed an easier conversion without removal of the humeral stem or the glenoid component (Figures 3A-3D). Twelve of the 13 patients were satisfied or very satisfied at the last follow-up. None of the patients were in pain, and the mean Constant score was 63. In all the cases, the glenoid baseplate was not changed. In 3 cases the humeral stem was changed without any fracture of the tuberosities of need for an osteotomy. This greatly simplified the revision procedure, as glenoid revisions can be very challenging. Indeed, it is often difficult to assess precisely preoperatively the remaining glenoid bone stock after removal of the glenoid component and the cement. Many therapeutic options to deal with glenoid loosening have been reported in the literature: glenoid bone reconstruction after glenoid component removal and revision to a hemiarthroplasty (HA),^10,16-18 glenoid bone reconstruction after glenoid component removal and revision to a new TSA with a cemented glenoid implant,^16,17,19,20 and glenoid reconstruction after glenoid component removal and revision to a RSA.^12,21 These authors reported that glenoid reconstruction frequently necessitates an iliac bone graft associated with a special design of the baseplate with a long post fixed into the native glenoid bone. However, sometimes implantation of an uncemented glenoid component can be unstable with a high risk of early mobilization of the implant, and 2 steps may be necessary. Conversion to a HA,^10,16-18 or a TSA^16,17,19,20 with a new cemented implant have both been associated with poor clinical outcome, with a high rate of recurrent glenoid loosening for the TSAs.

In our retrospective study, we reported no intra- or postoperative complications. Flury and colleagues²² reported a complication rate of 38% in 21 patients after conversion from a TSA to a RSA with a mean follow-up of 46 months. They removed all the components of the prosthesis with a crack or fracture of the humerus and/or the glenoid. Ortmaier and colleagues²³ reported a rate of complication of 22.7% during the conversion of TSA to RSA. They did an osteotomy of the humeral diaphysis to extract the stem in 40% of cases and had to remove the glenoid cement in 86% of cases with severe damage of the glenoid bone in 10% of cases. Fewer complications were found in our study, as we did not need any procedure such as humeral osteotomy, cerclage, bone grafting, and/or reconstruction of the glenoid. The short operative time and the absence of extensive soft-tissue dissection, thanks to a standard deltopectoral approach, could explain the absence of infection in our series.

Other authors shared our strategy of a universal convertible system and reported their results in the literature. Castagna and colleagues²⁴ in 2013 reported the clinical and radiological results of conversions of HA or TSA to RSA using a modular, convertible system (SMR Shoulder System, Lima Corporate). In their series, only 8 cases of TSAs were converted to RSA. They preserved, in each case, the humeral stem and the glenoid baseplate. There were no intra- or postoperative complications. The mean VAS score decreased from 8 to 2. Weber-Spickschen and colleague²⁵ reported recently in 2015 the same experience with the same system (SMR Shoulder System). They reviewed 15 conversions of TSAs to RSAs without any removal of the implants at a mean 43-month follow-up. They reported excellent pain relief (VAS decreased from 8 to 1) and improvement in shoulder function with a low rate of complications.

Kany and colleagues²⁶ in 2015 had already reported the advantages of a shoulder platform system for revisions. In their series, the authors included cases of failure of HAs and TSAs with loose cemented glenoids and metal-backed glenoids. The clinical and radiological results were similar, with a final Constant score of 60 (range, 42-85) and a similar rate of humeral stems which had to be changed (24%). These stems were replaced either because they were too proud or because there was not enough space to add an onlay polyethylene socket.

Continue to: Despite the encouraging results...

Despite the encouraging results reported in this study, there are some limitations. Firstly, no control group was used. Attempting to address this issue, we compared our results with the literature. Secondly, the number of patients in our study was small. Finally, the follow-up duration (mean 22 months) did not provide long-term outcomes.

CONCLUSION

This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function. A platform system on both the humeral and the glenoid side reduces the operative time of the conversion with a low risk of complications.

ABSTRACT

Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. The purpose of this study was to demonstrate the feasibility of revisions with a completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

Between 2003 and 2011, 104 primary total shoulder arthroplasties (TSAs) were performed with an uncemented glenoid component in our group. Of these patients, 13 (average age, 64 years) were revised to reverse shoulder arthroplasty (RSA) using a modular convertible platform system and were included in this study. Average follow-up after revision was 22 months. Outcome measures included pain, range of motion, Constant-Murley scores, Simple Shoulder Tests, and subjective shoulder values. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021), and active external rotation increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°). Mean pain scores significantly improved from 4.2 to 13.3 points. The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90). Subjectively, 12 patients rated their shoulder as better or much better than preoperatively. This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function.

Continue to: Polyethylene glenoid components...

Polyethylene glenoid components are the gold standard in anatomic total shoulder arthroplasty (TSA). However, even though TSA survivorship exceeds 95% at 10-year follow-up,¹ glenoid component loosening remains the main complication and the weak link in these implants. This complication accounts for 25% of all complications related to TSA in the literature.² In most cases, glenoid component loosening is not isolated but combined with a rotator cuff tear, glenohumeral instability, or component malposition.^3-5 Therefore, revision of TSA to reverse shoulder arthroplasty (RSA) often requires the removal of both the humeral stem and glenoid component. Removal of the humeral stem can be challenging and can necessitate removal of the cement and osteotomy of the diaphysis, risking fracture and extensive damage to the soft tissue (Figures 1A, 1B).^6-8 Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. Allografts and specific designs with a longer post can be mandatory to obtain a stable fixation of the new baseplate.^9-12

We hypothesized that a completely convertible platform system on both the humeral and the glenoid side could facilitate the revision of a failed TSA to a RSA. This would enable the surgeon to leave the humeral stem and the glenoid baseplate in place, avoiding the difficulty of stem removal and the reimplantation of a glenoid component, especially in osteoporotic glenoid bone and elderly patients. The revision procedure would then only consist of replacing the humeral head by a metallic tray and polyethylene bearing on the humeral side and by impacting a glenosphere on the glenoid baseplate (Figures 2A, 2B).

The purpose of this study was to demonstrate the feasibility of revisions with this completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

MATERIALS AND METHODS

PATIENT SELECTION

Between 2003 and 2011, 104 primary TSAs were performed with an uncemented glenoid component in our group. Of these patients, 18 underwent revision (17.3%). Among these 18 patients, 13 were revised to RSA using a modular convertible platform system and were included in this study, while 5 patients were revised to another TSA (2 dissociations of the polyethylene glenoid implant, 2 excessively low implantations of the glenoid baseplate, and 1 glenoid loosening). The mean age of the 13 patients (9 women, 4 men) included in this retrospective study at the time of revision was 64 years (range, 50-75 years). The reasons for revision surgery were rotator cuff tear (5, among which 2 were posterosuperior tears, and 3 were tears of the subscapularis), dislocations (5 posterior and 1 anterior, among which 4 had a B2 or C glenoid), suprascapular nerve paralysis (1), and dissociation of the polyethylene (1). The initial TSA was indicated for primary osteoarthritis with a normal cuff (9), primary osteoarthritis with a reparable cuff tear (2), posttraumatic osteoarthritis (1), and chronic dislocation (1). The right dominant shoulder was involved in 10 cases. The mean time interval between the primary TSA and the revision was 15 months (range, 1-61 months).

OPERATIVE TECHNIQUE

PREOPERATIVE PLANNING

Revision of a failed TSA is always a difficult challenge, and evaluation of bone loss on both the humeral and the glenoid sides, as well as the status of the cuff, is mandatory, even with a completely convertible arthroplasty system. The surgeon must be prepared to remove the humeral stem in case reduction of the joint is impossible. We systematically performed standard radiographs (anteroposterior, axillary, and outlet views) and computed tomography (CT) scans in order to assess both the version and positioning, as well as potential signs of loosening of the implants and the status of the cuff (continuity, degree of muscle trophicity, and fatty infiltration). A preoperative leucocyte count, sedimentation rate, and C-reactive protein rates were requested in every revision case, even if a mechanical etiology was strongly suspected.

Continue to: REVISION PROCEDURE

All the implants that had been used in the primary TSAs were Arrow Universal Shoulder Prostheses (FH Orthopedics). All revisions were performed through the previous deltopectoral approach in the beach chair position under general anesthesia with an interscalene block. Adhesions of the deep part of the deltoid were carefully released. The conjoint tendon was released, and the location of the musculocutaneous and axillary nerves was identified before any retractor was placed. In the 10 cases where the subscapularis was intact, it was peeled off the medial border of the bicipital groove to obtain sufficient length for a tension-free reinsertion.

The anatomical head of the humeral implant was disconnected from the stem and removed. All stems were found to be well fixed; there were no cases of loosening or evidence of infection. A circumferential capsular release was systematically carried out. The polyethylene glenoid onlay was then unlocked from the baseplate.

The quality of the fixation of the glenoid baseplate was systematically evaluated; no screw was found to be loose, and the fixation of all baseplates was stable. Therefore, there was no need to revise the glenoid baseplate, even when its position was considered excessively retroverted (Glenoid B2) or high. A glenosphere was impacted on the baseplate, and a polyethylene humeral bearing was then implanted on the humeral stem. The thinnest polyethylene bearing available (number 0) was chosen in all cases, and a size 36 glenosphere was chosen in 12 out of 13 cases. Intraoperative stability of the implant was satisfactory, and no impingement was found posteriorly, anteriorly, or inferiorly.

In one case, the humeral stem was a first-generation humeral implant which was not compatible with the new-generation humeral bearing, and the humeral stem had to be replaced.

In 2 cases, reduction of the RSA was either impossible or felt to be too tight, even after extensive soft-tissue release and resection of the remaining supraspinatus. The main reason for this was an excessively proud humeral stem because of an onlay polyethylene humeral bearing instead of an inlay design. However, removal of the uncemented humeral stem was always possible with no osteotomy or cortical window of the humeral shaft as the humeral stem has been designed with a bone ingrowth surface only on the metaphyseal part with a smooth surface on diaphyseal part. After removal of the stem, a small amount of humeral metaphysis was cut, and a new humeral stem was press-fit in a lower position. This allowed restoration of an appropriate tension of the soft tissue and, therefore, an easier reduction. The subscapularis was medialized and reinserted transosseously when possible with a double-row repair. In 3 cases, the subscapularis was torn and retracted at the level of the glenoid, or impossible to identify to allow its reinsertion.

Continue to: According to our infectious disease department...

According to our infectious disease department, we made a minimum of 5 cultures for each revision case looking for a possible low-grade infection. All cultures in our group are held for 14 days to assess for Propionibacterium acnes.

POSTOPERATIVE MANAGEMENT

A shoulder splint in neutral rotation was used for the first 4 weeks. Passive range of motion (ROM) was started immediately with pendulum exercises and passive anterior elevation. Active assisted and active ROM were allowed after 4 weeks, and physiotherapy was continued for 6 months. Elderly patients were referred to a center of rehabilitation. We found only 1 or 2 positive cultures (Propionibacterium acnes) for 4 patients, and we decided to consider them as a contamination. None of the patients were treated with antibiotics.

CLINICAL AND RADIOLOGICAL ASSESSMENT

Clinical evaluation included pre- and postoperative pain scores (visual analog scale [VAS]), ROM, the Constant-Murley¹³ score, the Simple Shoulder Test (SST),¹⁴ and the subjective shoulder value.¹⁵ Subjective satisfaction was assessed by asking the patients at follow-up how they felt compared with before surgery and was graded using a 4-point scale: 1, much better; 2, better; 3, the same; and 4, worse. Radiographic evaluation was performed on pre- and postoperative standard anteroposterior, outlet, and axillary views. Radiographs were reviewed to determine the presence of glenohumeral subluxation, periprosthetic lucency, component shift in position, and scapular notching.

STATISTICAL ANALYSIS

Descriptive statistics are reported as mean (range) for continuous measures and number (percentage) for discrete variables. The Wilcoxon signed-rank test was used for preoperative vs postoperative changes. The alpha level for all tests was set at 0.05 for statistical significance.

RESULTS

CLINICAL OUTCOME

At a mean of 22 months (range, 7-38 months) follow-up after revision, active ROM was significantly improved. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021). Active external rotation with the elbow on the side increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°) (P = 0.034), and increased with the arm held at 90° abduction from 13° (range, 0°-20°) to 49° (range, 0°-80°) (P = 0.025). Mean pain scores improved from 4.2 to 13.3 points (P < 0.001). VAS improved significantly from 9 to 1 (P < 0.0001). The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90) (P = 0.006). The final SST was 7 per 12. Subjectively, 4 patients rated their shoulder as much better, 8 as better, and 1 as the same as preoperatively. No intra- or postoperative complications, including infections, were observed. The mean duration of the procedure was 60 minutes (range, 30-75 minutes).

Continue to: RADIOLOGICAL OUTCOME

No periprosthetic lucency or shift in component was observed at the last follow-up. There was no scapular notching. No resorption of the tuberosities, and no fractures of the acromion or the scapular spine were observed.

DISCUSSION

In this retrospective study, failure of TSA with a metal-backed glenoid implant was successfully revised to RSA. In 10 patients, the use of a universal platform system allowed an easier conversion without removal of the humeral stem or the glenoid component (Figures 3A-3D). Twelve of the 13 patients were satisfied or very satisfied at the last follow-up. None of the patients were in pain, and the mean Constant score was 63. In all the cases, the glenoid baseplate was not changed. In 3 cases the humeral stem was changed without any fracture of the tuberosities of need for an osteotomy. This greatly simplified the revision procedure, as glenoid revisions can be very challenging. Indeed, it is often difficult to assess precisely preoperatively the remaining glenoid bone stock after removal of the glenoid component and the cement. Many therapeutic options to deal with glenoid loosening have been reported in the literature: glenoid bone reconstruction after glenoid component removal and revision to a hemiarthroplasty (HA),^10,16-18 glenoid bone reconstruction after glenoid component removal and revision to a new TSA with a cemented glenoid implant,^16,17,19,20 and glenoid reconstruction after glenoid component removal and revision to a RSA.^12,21 These authors reported that glenoid reconstruction frequently necessitates an iliac bone graft associated with a special design of the baseplate with a long post fixed into the native glenoid bone. However, sometimes implantation of an uncemented glenoid component can be unstable with a high risk of early mobilization of the implant, and 2 steps may be necessary. Conversion to a HA,^10,16-18 or a TSA^16,17,19,20 with a new cemented implant have both been associated with poor clinical outcome, with a high rate of recurrent glenoid loosening for the TSAs.

In our retrospective study, we reported no intra- or postoperative complications. Flury and colleagues²² reported a complication rate of 38% in 21 patients after conversion from a TSA to a RSA with a mean follow-up of 46 months. They removed all the components of the prosthesis with a crack or fracture of the humerus and/or the glenoid. Ortmaier and colleagues²³ reported a rate of complication of 22.7% during the conversion of TSA to RSA. They did an osteotomy of the humeral diaphysis to extract the stem in 40% of cases and had to remove the glenoid cement in 86% of cases with severe damage of the glenoid bone in 10% of cases. Fewer complications were found in our study, as we did not need any procedure such as humeral osteotomy, cerclage, bone grafting, and/or reconstruction of the glenoid. The short operative time and the absence of extensive soft-tissue dissection, thanks to a standard deltopectoral approach, could explain the absence of infection in our series.

Other authors shared our strategy of a universal convertible system and reported their results in the literature. Castagna and colleagues²⁴ in 2013 reported the clinical and radiological results of conversions of HA or TSA to RSA using a modular, convertible system (SMR Shoulder System, Lima Corporate). In their series, only 8 cases of TSAs were converted to RSA. They preserved, in each case, the humeral stem and the glenoid baseplate. There were no intra- or postoperative complications. The mean VAS score decreased from 8 to 2. Weber-Spickschen and colleague²⁵ reported recently in 2015 the same experience with the same system (SMR Shoulder System). They reviewed 15 conversions of TSAs to RSAs without any removal of the implants at a mean 43-month follow-up. They reported excellent pain relief (VAS decreased from 8 to 1) and improvement in shoulder function with a low rate of complications.

Kany and colleagues²⁶ in 2015 had already reported the advantages of a shoulder platform system for revisions. In their series, the authors included cases of failure of HAs and TSAs with loose cemented glenoids and metal-backed glenoids. The clinical and radiological results were similar, with a final Constant score of 60 (range, 42-85) and a similar rate of humeral stems which had to be changed (24%). These stems were replaced either because they were too proud or because there was not enough space to add an onlay polyethylene socket.

Continue to: Despite the encouraging results...

Despite the encouraging results reported in this study, there are some limitations. Firstly, no control group was used. Attempting to address this issue, we compared our results with the literature. Secondly, the number of patients in our study was small. Finally, the follow-up duration (mean 22 months) did not provide long-term outcomes.

CONCLUSION

This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function. A platform system on both the humeral and the glenoid side reduces the operative time of the conversion with a low risk of complications.

ABSTRACT

The use of arthroscopy for purely diagnostic purposes has been largely supplanted by noninvasive technologies, such as magnetic resonance imaging (MRI). The mi-eye^+TM (Trice Medical) technology is a small-bore needle unit for in-office arthroscopy. We conducted a pilot study comparing the mi-eye^+TM unit with MRI, using surgical arthroscopy as a gold-standard reference. We hypothesized that the mi-eye^+TM needle arthroscope, which can be used in an office setting, would be equivalent to MRI for the diagnosis of intra-articular pathology of the knee.

This prospective, multicenter, observational study was approved by the Institutional Review Board. There were 106 patients (53 males, 53 females) in the study. MRIs were interpreted by musculoskeletally trained radiologists. The study was conducted in the operating room using the mi-eye^+TM device. The mi-eye^{+ TM} device findings were compared with the MRI findings within individual pathologies, and a “per-patient” analysis was performed to compare the arthroscopic findings with those of the mi-eye^+TM and the MRI. Additionally, we identified all mi-eye^+TM findings and MRI findings that exactly matched the surgical arthroscopy findings.

The mi-eye^+TM demonstrated complete accuracy of all pathologies for 97 (91.5%) of the 106 patients included in the study, whereas MRI demonstrated complete accuracy for 65 patients (61.3%) (P < .0001). All discrepancies between mi-eye^+TM and arthroscopy were false-negative mi-eye^+TM results, as the mi-eye^+TM did not reveal some aspect of the knee’s pathology for 9 patients. The mi-eye^+TM was more sensitive than MRI in identifying meniscal tears (92.6% vs 77.8%; P = .0035) and more specific in diagnosing these tears (100% vs 41.7%; P < .0001).

The mi-eye^+TM device proved to be more sensitive and specific than MRI for intra-articular findings at time of knee arthroscopy. Certainly there are contraindications to using the mi-eye^+TM, and our results do not obviate the need for MRI, but our study did demonstrate that the mi-eye^+TM needle arthroscope can safely provide excellent visualization of intra-articular knee pathology.

Continue to: Surgical arthroscopy is the gold standard...

Surgical arthroscopy is the gold standard for the diagnosis of intra-articular knee pathologies. Nevertheless, the use of arthroscopy for purely diagnostic purposes has been largely supplanted by noninvasive technologies, such as magnetic resonance imaging (MRI). Although MRI is considered the standard diagnostic tool for acute and chronic soft-tissue injuries of the knee, its use is not without contraindication and some potential inconveniences. Contraindications to MRI are well documented. In terms of inconvenience, MRI usually requires a separate visit followed by another visit to the prescribing physician. In addition, required interpretation by a radiologist may lead to a delay in care and increase in cost.

In the early 1990s, in-office needle arthroscopy was described as a viable means of diagnosing pathologies and obtaining synovial biopsies from the knee.^1-3 Initial results were good, and the procedures had very low complication rates. Nevertheless, in-office arthroscopy of the knee is not yet widely performed, likely given concerns about the technical difficulties of in-office arthroscopy, the potential for patient discomfort, and the cumbersomeness of in-office arthroscopy units. However, significant advances have been made in the resolution capability of small-bore needle arthroscopy, resulting in much less painful procedures. Additionally, the early hardware designs, which mimicked operating room setups using towers, fluid irrigation systems, and larger arthroscopes, have been replaced with small-needle arthroscopes that use syringes for irrigation and tablet computers for visualization (Figures 1A, 1B).  

The mi-eye^+TM technology (Trice Medical) is a small-bore needle unit for in-office arthroscopy with digital optics that does not need an irrigation tower. We conducted a pilot study of the sensitivity and specificity of the mi-eye^+TM unit in comparison with MRI, using surgical arthroscopy as a gold-standard reference. We hypothesized that the mi-eye^+TM needle arthroscope, which can be used in an office setting, would be equivalent to the standard of care (MRI) for the diagnosis of intra-articular pathology of the knee.

METHODS

Central regulatory approval for this prospective, multicenter, observational study was obtained from the Western Institutional Review Board for 3 of the sites, and 1 institution required and was granted internal Institutional Review Board approval.

The study was performed by 4 sports medicine orthopedic surgeons experienced in using the mi-eye^+TM in-office arthroscope. Patients were enrolled from December 2015 through June 2016. Inclusion criteria were an indication for an arthroscopic procedure of the knee based on history, physical examination, and MRI findings. Patients were excluded from the study if there were any contraindications to completing an MRI. Acute hemarthroses of the knee or active systemic infections were also excluded. Once a patient was identified as meeting the criteria for participation, informed consent was obtained. Of the 113 patients who enrolled, 7 did not have a complete study dataset available, leaving 106 patients (53 males, 53 females) in the study. Mean age was 47 years (range, 18-82 years).

Continue to: A test result form was used...

A test result form was used to record mi-eye^+TM, surgical arthroscopy, and MRI results. This form required a “positive” or “negative” result for all of several diagnoses: medial and lateral meniscal tears, intra-articular loose body, osteoarthritis (OA), osteochondritis dissecans (OCD), and tears of the anterior and posterior cruciate ligaments (ACL, PCL). MRI was performed at a variety of imaging facilities, but the images were interpreted by musculoskeletally trained radiologists.

The study was conducted in the operating room. After the patient was appropriately anesthetized, and the extremity prepared and draped, the mi-eye^+TM procedure was performed immediately prior to surgical arthroscopy. A tourniquet was not used. At surgeon discretion, medial, lateral, or both approaches were used with the mi-eye^+TM, and diagnostic arthroscopy was performed. During the procedure, the mi-eye^+TM was advanced into the knee. Once in the synovial compartment, the external 14-gauge needle was retracted, exposing the unit’s optics. Visualization was improved by injecting normal saline through the lure lock in the mi-eye^+TM needle arthroscope. An average of 20 mL of saline was used, though the amount varied with surgeon discretion. Subsequently, the surgeon visualized structures in the knee and documented all findings.

At the end of the mi-eye^+TM procedure, the scheduled surgical arthroscopy was performed. After the surgical procedure, if there were no issues or complications, the patient was discharged from the study. No follow-up was required for the study, as arthroscopic findings served as the conclusive diagnosis for each patient, and no interventions were being studied. There were no complications related to use of the mi-eye^+TM.

The mi-eye^+TM device findings were compared with the MRI findings within individual pathologies, and a “per-patient” analysis was performed to compare the arthroscopic findings with those of the mi-eye^+TM and the MRI. Additionally, we identified all mi-eye^+TM findings and MRI findings that exactly matched the surgical arthroscopy findings. When a test had no false-positive or false-negative findings in comparison with surgical arthroscopy, it was identified as having complete accuracy for all intra-articular knee pathologies. For these methods, the 95% confidence interval was determined based on binomial distribution.

RESULTS

The mi-eye^{+ TM} demonstrated complete accuracy of all pathologies for 97 (91.5%) of the 106 patients included in the study, whereas MRI demonstrated complete accuracy for 65 patients (61.3%) (P < .0001). All discrepancies between mi-eye^+TM and surgical arthroscopy were false-negative mi-eye^+TM results, as the mi-eye^+TM did not reveal some aspect of the knee’s pathology for 9 patients. On the other hand, MRI demonstrated both false-negative and false-positive results, failing to reveal some aspect of the knee’s pathology for 31 patients, and potentially overcalling some aspect of the knee’s pathology among 18 patients.

Continue to: The pathology most frequently...

The pathology most frequently identified in the study was a meniscal tear. The mi-eye^+TM was more sensitive than MRI in identifying meniscal tears (92.6% vs 77.8%; P = .0035) and more specific in diagnosing these tears (100% vs 87.5%; P < .0002). The difference in specificity resulted from the false MRI diagnosis of a meniscal tear among 24 patients, who were found to have no tear by both mi-eye^+TM and surgical arthroscopy.

Table 1. Raw Data of mi-eye^+TM and Magnetic Resonance Imaging Findings

The second most frequent pathology was an intra-articular loose body. The mi-eye^+TM was more sensitive than MRI in identifying loose bodies (86.7% vs 20%; P = .0007). The specificity of the mi-eye^+TM and the specificity of MRI were equivalent in diagnosing loose bodies (100%). Table 1 and Table 2 show the complete set of diagnoses and associated diagnostic profiles.

Table 2. Diagnostic Profiles: Sensitivity and Specificity of mi-eye^+TM and Magnetic Resonance Imaging

^aBold P values are significant. Abbreviations: CI, confidence interval; MRI, magnetic resonance imaging; N/A, not applicable.

DISCUSSION

The overall accuracy of the mi-eye^+TM was superior to that of MRI relative to the arthroscopic gold standard in this pilot study. Other studies have demonstrated the accuracy, feasibility, and cost-efficacy of in-office arthroscopy. However, likely because of the cumbersomeness of in-office arthroscopy equipment and the potential for patient discomfort, the technique is not yet standard in the field. Recent advances in small-bore technology, digital optics, and ergonomics have addressed the difficulties associated with in-office arthroscopy, facilitating a faster and more efficient procedure. Our goal in this study was to evaluate the diagnostic capability of the mi-eye^+TM in-office arthroscopy unit, which features a small bore, digital optics, and functionality without an irrigation tower.

This study of 106 patients demonstrated equivalent or better accuracy of the mi-eye^+TM relative to MRI when compared with the gold standard of surgical arthroscopy. This was not surprising given that both the mi-eye^+TM and surgical arthroscopy are based on direct visualization of intra-articular pathology. The mi-eye^+TM unit identified more meniscal tears, intra-articular loose bodies, ACL tears, and OCD lesions than MRI did, and with enough power to demonstrate statistically significant improved sensitivity for meniscal tears and loose bodies. Furthermore, MRI demonstrated false-positive meniscal tears, ACL tears, OCD lesions, and OA, whereas the mi-eye^+TM did not demonstrate any false-positive results in comparison with surgical arthroscopy. This study demonstrated statistically significant improved specificity of the mi-eye⁺ compared with MRI in the diagnosis of meniscal tears and OA.

There are several limitations to our study. We refer to it as a pilot study because it was performed in a standard operating room. Before taking the technology to an outpatient setting, we wanted to confirm efficacy and safety in an operating room. However, the techniques used in this study are readily transferable to the outpatient clinic setting and to date have been used in more than 2000 cases.

Continue to: The specificity of MRI...

The specificity of MRI for meniscal tears was unexpectedly low compared with previous studies, which may reflect the multi-institution, multi-surgeon, multi-radiologist involvement in MRI interpretation.^4-10 MRI was performed at a variety of institutions without a standardized protocol. This lack of standardization of image capture and interpretation may have contributed to the suboptimal performance of MRI, falsely decreasing the potential ideal specificity for meniscal tears. Although this study may have underestimated the specificity of MRI for meniscal tears, we think the mi-eye^+TM and MRI results reported here reflect the findings of standard practice, without the standardization usually applied in studies. For example, a study of 139 knee MRI reports at 14 different institutions confirmed arthroscopic findings and concluded that 37% of the operations supported by a significant MRI finding were unjustified.¹¹ The authors attributed the rate of false-positive MRI findings to the wide variety of places where patients had their MRIs performed, and the subsequent variation in quality of imaging and MRI reader skill level.¹¹

Before inserting the mi-eye^+TM needle arthroscope, the surgeons had a working diagnosis of the pathology based on their clinical examination and MRI results. Clearly, this introduced a bias. Further studies will be conducted in a prospective, blinded manner to address this limitation.

Although studies of in-office arthroscopy technology date to the 1990s, there is an overall lack of data comparing in-office arthroscopy with MRI. Halbrecht and Jackson² conducted a study of 20 knee patients with both MRI and in-office needle arthroscopy. Overall, MRI was poor in detecting cartilage defects, with sensitivity of 34.6%, using the in-office arthroscopy as the confirmatory diagnosis. Although the authors did not compare in-office diagnoses with surgical arthroscopic findings, they concluded that office arthroscopy is an accurate and cost-efficient alternative to MRI in diagnostic evaluation of knee patients. Xerogeanes and colleagues¹² studied 110 patients in a prospective, blinded, multicenter trial comparing a minimally invasive office-based arthroscopy with MRI, using surgical arthroscopy as the confirmatory diagnosis. They concluded that the office-based arthroscope was statistically equivalent to diagnostic surgical arthroscopy and that it outperformed MRI in helping make accurate diagnoses. The authors applied a cost analysis to their findings and determined that office-based arthroscopy could result in an annual potential savings of $177 million for the healthcare system.¹²

Modern imaging sequences on high-Tesla MRI machines provide excellent visualization. Nevertheless, a significant number of patients do not undergo MRI, owing to time constraints, contraindications, body habitus, or anxiety/claustrophobia. Our study results confirmed that doctors treating such patients now have a viable alternative to help diagnose pathology.

CONCLUSION

The mi-eye^+TM device proved to be more sensitive and specific than MRI for intra-articular findings at the time of knee arthroscopy. Certainly there are contraindications to using the mi-eye^+TM, and our results do not obviate the need for MRI; our study did demonstrate that the mi-eye^+TM needle arthroscope can safely provide excellent visualization of intra-articular knee pathology. More studies of the mi-eye^+TM device in a clinical setting are warranted.

ABSTRACT

The use of arthroscopy for purely diagnostic purposes has been largely supplanted by noninvasive technologies, such as magnetic resonance imaging (MRI). The mi-eye^+TM (Trice Medical) technology is a small-bore needle unit for in-office arthroscopy. We conducted a pilot study comparing the mi-eye^+TM unit with MRI, using surgical arthroscopy as a gold-standard reference. We hypothesized that the mi-eye^+TM needle arthroscope, which can be used in an office setting, would be equivalent to MRI for the diagnosis of intra-articular pathology of the knee.

This prospective, multicenter, observational study was approved by the Institutional Review Board. There were 106 patients (53 males, 53 females) in the study. MRIs were interpreted by musculoskeletally trained radiologists. The study was conducted in the operating room using the mi-eye^+TM device. The mi-eye^{+ TM} device findings were compared with the MRI findings within individual pathologies, and a “per-patient” analysis was performed to compare the arthroscopic findings with those of the mi-eye^+TM and the MRI. Additionally, we identified all mi-eye^+TM findings and MRI findings that exactly matched the surgical arthroscopy findings.

The mi-eye^+TM demonstrated complete accuracy of all pathologies for 97 (91.5%) of the 106 patients included in the study, whereas MRI demonstrated complete accuracy for 65 patients (61.3%) (P < .0001). All discrepancies between mi-eye^+TM and arthroscopy were false-negative mi-eye^+TM results, as the mi-eye^+TM did not reveal some aspect of the knee’s pathology for 9 patients. The mi-eye^+TM was more sensitive than MRI in identifying meniscal tears (92.6% vs 77.8%; P = .0035) and more specific in diagnosing these tears (100% vs 41.7%; P < .0001).

The mi-eye^+TM device proved to be more sensitive and specific than MRI for intra-articular findings at time of knee arthroscopy. Certainly there are contraindications to using the mi-eye^+TM, and our results do not obviate the need for MRI, but our study did demonstrate that the mi-eye^+TM needle arthroscope can safely provide excellent visualization of intra-articular knee pathology.

Continue to: Surgical arthroscopy is the gold standard...

Surgical arthroscopy is the gold standard for the diagnosis of intra-articular knee pathologies. Nevertheless, the use of arthroscopy for purely diagnostic purposes has been largely supplanted by noninvasive technologies, such as magnetic resonance imaging (MRI). Although MRI is considered the standard diagnostic tool for acute and chronic soft-tissue injuries of the knee, its use is not without contraindication and some potential inconveniences. Contraindications to MRI are well documented. In terms of inconvenience, MRI usually requires a separate visit followed by another visit to the prescribing physician. In addition, required interpretation by a radiologist may lead to a delay in care and increase in cost.

In the early 1990s, in-office needle arthroscopy was described as a viable means of diagnosing pathologies and obtaining synovial biopsies from the knee.^1-3 Initial results were good, and the procedures had very low complication rates. Nevertheless, in-office arthroscopy of the knee is not yet widely performed, likely given concerns about the technical difficulties of in-office arthroscopy, the potential for patient discomfort, and the cumbersomeness of in-office arthroscopy units. However, significant advances have been made in the resolution capability of small-bore needle arthroscopy, resulting in much less painful procedures. Additionally, the early hardware designs, which mimicked operating room setups using towers, fluid irrigation systems, and larger arthroscopes, have been replaced with small-needle arthroscopes that use syringes for irrigation and tablet computers for visualization (Figures 1A, 1B).  

The mi-eye^+TM technology (Trice Medical) is a small-bore needle unit for in-office arthroscopy with digital optics that does not need an irrigation tower. We conducted a pilot study of the sensitivity and specificity of the mi-eye^+TM unit in comparison with MRI, using surgical arthroscopy as a gold-standard reference. We hypothesized that the mi-eye^+TM needle arthroscope, which can be used in an office setting, would be equivalent to the standard of care (MRI) for the diagnosis of intra-articular pathology of the knee.

METHODS

Central regulatory approval for this prospective, multicenter, observational study was obtained from the Western Institutional Review Board for 3 of the sites, and 1 institution required and was granted internal Institutional Review Board approval.

The study was performed by 4 sports medicine orthopedic surgeons experienced in using the mi-eye^+TM in-office arthroscope. Patients were enrolled from December 2015 through June 2016. Inclusion criteria were an indication for an arthroscopic procedure of the knee based on history, physical examination, and MRI findings. Patients were excluded from the study if there were any contraindications to completing an MRI. Acute hemarthroses of the knee or active systemic infections were also excluded. Once a patient was identified as meeting the criteria for participation, informed consent was obtained. Of the 113 patients who enrolled, 7 did not have a complete study dataset available, leaving 106 patients (53 males, 53 females) in the study. Mean age was 47 years (range, 18-82 years).

Continue to: A test result form was used...

A test result form was used to record mi-eye^+TM, surgical arthroscopy, and MRI results. This form required a “positive” or “negative” result for all of several diagnoses: medial and lateral meniscal tears, intra-articular loose body, osteoarthritis (OA), osteochondritis dissecans (OCD), and tears of the anterior and posterior cruciate ligaments (ACL, PCL). MRI was performed at a variety of imaging facilities, but the images were interpreted by musculoskeletally trained radiologists.

The study was conducted in the operating room. After the patient was appropriately anesthetized, and the extremity prepared and draped, the mi-eye^+TM procedure was performed immediately prior to surgical arthroscopy. A tourniquet was not used. At surgeon discretion, medial, lateral, or both approaches were used with the mi-eye^+TM, and diagnostic arthroscopy was performed. During the procedure, the mi-eye^+TM was advanced into the knee. Once in the synovial compartment, the external 14-gauge needle was retracted, exposing the unit’s optics. Visualization was improved by injecting normal saline through the lure lock in the mi-eye^+TM needle arthroscope. An average of 20 mL of saline was used, though the amount varied with surgeon discretion. Subsequently, the surgeon visualized structures in the knee and documented all findings.

At the end of the mi-eye^+TM procedure, the scheduled surgical arthroscopy was performed. After the surgical procedure, if there were no issues or complications, the patient was discharged from the study. No follow-up was required for the study, as arthroscopic findings served as the conclusive diagnosis for each patient, and no interventions were being studied. There were no complications related to use of the mi-eye^+TM.

The mi-eye^+TM device findings were compared with the MRI findings within individual pathologies, and a “per-patient” analysis was performed to compare the arthroscopic findings with those of the mi-eye^+TM and the MRI. Additionally, we identified all mi-eye^+TM findings and MRI findings that exactly matched the surgical arthroscopy findings. When a test had no false-positive or false-negative findings in comparison with surgical arthroscopy, it was identified as having complete accuracy for all intra-articular knee pathologies. For these methods, the 95% confidence interval was determined based on binomial distribution.

RESULTS

The mi-eye^{+ TM} demonstrated complete accuracy of all pathologies for 97 (91.5%) of the 106 patients included in the study, whereas MRI demonstrated complete accuracy for 65 patients (61.3%) (P < .0001). All discrepancies between mi-eye^+TM and surgical arthroscopy were false-negative mi-eye^+TM results, as the mi-eye^+TM did not reveal some aspect of the knee’s pathology for 9 patients. On the other hand, MRI demonstrated both false-negative and false-positive results, failing to reveal some aspect of the knee’s pathology for 31 patients, and potentially overcalling some aspect of the knee’s pathology among 18 patients.

Continue to: The pathology most frequently...

The pathology most frequently identified in the study was a meniscal tear. The mi-eye^+TM was more sensitive than MRI in identifying meniscal tears (92.6% vs 77.8%; P = .0035) and more specific in diagnosing these tears (100% vs 87.5%; P < .0002). The difference in specificity resulted from the false MRI diagnosis of a meniscal tear among 24 patients, who were found to have no tear by both mi-eye^+TM and surgical arthroscopy.

Table 1. Raw Data of mi-eye^+TM and Magnetic Resonance Imaging Findings

The second most frequent pathology was an intra-articular loose body. The mi-eye^+TM was more sensitive than MRI in identifying loose bodies (86.7% vs 20%; P = .0007). The specificity of the mi-eye^+TM and the specificity of MRI were equivalent in diagnosing loose bodies (100%). Table 1 and Table 2 show the complete set of diagnoses and associated diagnostic profiles.

Table 2. Diagnostic Profiles: Sensitivity and Specificity of mi-eye^+TM and Magnetic Resonance Imaging

^aBold P values are significant. Abbreviations: CI, confidence interval; MRI, magnetic resonance imaging; N/A, not applicable.

DISCUSSION

The overall accuracy of the mi-eye^+TM was superior to that of MRI relative to the arthroscopic gold standard in this pilot study. Other studies have demonstrated the accuracy, feasibility, and cost-efficacy of in-office arthroscopy. However, likely because of the cumbersomeness of in-office arthroscopy equipment and the potential for patient discomfort, the technique is not yet standard in the field. Recent advances in small-bore technology, digital optics, and ergonomics have addressed the difficulties associated with in-office arthroscopy, facilitating a faster and more efficient procedure. Our goal in this study was to evaluate the diagnostic capability of the mi-eye^+TM in-office arthroscopy unit, which features a small bore, digital optics, and functionality without an irrigation tower.

This study of 106 patients demonstrated equivalent or better accuracy of the mi-eye^+TM relative to MRI when compared with the gold standard of surgical arthroscopy. This was not surprising given that both the mi-eye^+TM and surgical arthroscopy are based on direct visualization of intra-articular pathology. The mi-eye^+TM unit identified more meniscal tears, intra-articular loose bodies, ACL tears, and OCD lesions than MRI did, and with enough power to demonstrate statistically significant improved sensitivity for meniscal tears and loose bodies. Furthermore, MRI demonstrated false-positive meniscal tears, ACL tears, OCD lesions, and OA, whereas the mi-eye^+TM did not demonstrate any false-positive results in comparison with surgical arthroscopy. This study demonstrated statistically significant improved specificity of the mi-eye⁺ compared with MRI in the diagnosis of meniscal tears and OA.

There are several limitations to our study. We refer to it as a pilot study because it was performed in a standard operating room. Before taking the technology to an outpatient setting, we wanted to confirm efficacy and safety in an operating room. However, the techniques used in this study are readily transferable to the outpatient clinic setting and to date have been used in more than 2000 cases.

Continue to: The specificity of MRI...

The specificity of MRI for meniscal tears was unexpectedly low compared with previous studies, which may reflect the multi-institution, multi-surgeon, multi-radiologist involvement in MRI interpretation.^4-10 MRI was performed at a variety of institutions without a standardized protocol. This lack of standardization of image capture and interpretation may have contributed to the suboptimal performance of MRI, falsely decreasing the potential ideal specificity for meniscal tears. Although this study may have underestimated the specificity of MRI for meniscal tears, we think the mi-eye^+TM and MRI results reported here reflect the findings of standard practice, without the standardization usually applied in studies. For example, a study of 139 knee MRI reports at 14 different institutions confirmed arthroscopic findings and concluded that 37% of the operations supported by a significant MRI finding were unjustified.¹¹ The authors attributed the rate of false-positive MRI findings to the wide variety of places where patients had their MRIs performed, and the subsequent variation in quality of imaging and MRI reader skill level.¹¹

Before inserting the mi-eye^+TM needle arthroscope, the surgeons had a working diagnosis of the pathology based on their clinical examination and MRI results. Clearly, this introduced a bias. Further studies will be conducted in a prospective, blinded manner to address this limitation.

Although studies of in-office arthroscopy technology date to the 1990s, there is an overall lack of data comparing in-office arthroscopy with MRI. Halbrecht and Jackson² conducted a study of 20 knee patients with both MRI and in-office needle arthroscopy. Overall, MRI was poor in detecting cartilage defects, with sensitivity of 34.6%, using the in-office arthroscopy as the confirmatory diagnosis. Although the authors did not compare in-office diagnoses with surgical arthroscopic findings, they concluded that office arthroscopy is an accurate and cost-efficient alternative to MRI in diagnostic evaluation of knee patients. Xerogeanes and colleagues¹² studied 110 patients in a prospective, blinded, multicenter trial comparing a minimally invasive office-based arthroscopy with MRI, using surgical arthroscopy as the confirmatory diagnosis. They concluded that the office-based arthroscope was statistically equivalent to diagnostic surgical arthroscopy and that it outperformed MRI in helping make accurate diagnoses. The authors applied a cost analysis to their findings and determined that office-based arthroscopy could result in an annual potential savings of $177 million for the healthcare system.¹²

Modern imaging sequences on high-Tesla MRI machines provide excellent visualization. Nevertheless, a significant number of patients do not undergo MRI, owing to time constraints, contraindications, body habitus, or anxiety/claustrophobia. Our study results confirmed that doctors treating such patients now have a viable alternative to help diagnose pathology.

CONCLUSION

The mi-eye^+TM device proved to be more sensitive and specific than MRI for intra-articular findings at the time of knee arthroscopy. Certainly there are contraindications to using the mi-eye^+TM, and our results do not obviate the need for MRI; our study did demonstrate that the mi-eye^+TM needle arthroscope can safely provide excellent visualization of intra-articular knee pathology. More studies of the mi-eye^+TM device in a clinical setting are warranted.

ABSTRACT

The use of arthroscopy for purely diagnostic purposes has been largely supplanted by noninvasive technologies, such as magnetic resonance imaging (MRI). The mi-eye^+TM (Trice Medical) technology is a small-bore needle unit for in-office arthroscopy. We conducted a pilot study comparing the mi-eye^+TM unit with MRI, using surgical arthroscopy as a gold-standard reference. We hypothesized that the mi-eye^+TM needle arthroscope, which can be used in an office setting, would be equivalent to MRI for the diagnosis of intra-articular pathology of the knee.

This prospective, multicenter, observational study was approved by the Institutional Review Board. There were 106 patients (53 males, 53 females) in the study. MRIs were interpreted by musculoskeletally trained radiologists. The study was conducted in the operating room using the mi-eye^+TM device. The mi-eye^{+ TM} device findings were compared with the MRI findings within individual pathologies, and a “per-patient” analysis was performed to compare the arthroscopic findings with those of the mi-eye^+TM and the MRI. Additionally, we identified all mi-eye^+TM findings and MRI findings that exactly matched the surgical arthroscopy findings.

The mi-eye^+TM demonstrated complete accuracy of all pathologies for 97 (91.5%) of the 106 patients included in the study, whereas MRI demonstrated complete accuracy for 65 patients (61.3%) (P < .0001). All discrepancies between mi-eye^+TM and arthroscopy were false-negative mi-eye^+TM results, as the mi-eye^+TM did not reveal some aspect of the knee’s pathology for 9 patients. The mi-eye^+TM was more sensitive than MRI in identifying meniscal tears (92.6% vs 77.8%; P = .0035) and more specific in diagnosing these tears (100% vs 41.7%; P < .0001).

The mi-eye^+TM device proved to be more sensitive and specific than MRI for intra-articular findings at time of knee arthroscopy. Certainly there are contraindications to using the mi-eye^+TM, and our results do not obviate the need for MRI, but our study did demonstrate that the mi-eye^+TM needle arthroscope can safely provide excellent visualization of intra-articular knee pathology.

Continue to: Surgical arthroscopy is the gold standard...

Surgical arthroscopy is the gold standard for the diagnosis of intra-articular knee pathologies. Nevertheless, the use of arthroscopy for purely diagnostic purposes has been largely supplanted by noninvasive technologies, such as magnetic resonance imaging (MRI). Although MRI is considered the standard diagnostic tool for acute and chronic soft-tissue injuries of the knee, its use is not without contraindication and some potential inconveniences. Contraindications to MRI are well documented. In terms of inconvenience, MRI usually requires a separate visit followed by another visit to the prescribing physician. In addition, required interpretation by a radiologist may lead to a delay in care and increase in cost.

In the early 1990s, in-office needle arthroscopy was described as a viable means of diagnosing pathologies and obtaining synovial biopsies from the knee.^1-3 Initial results were good, and the procedures had very low complication rates. Nevertheless, in-office arthroscopy of the knee is not yet widely performed, likely given concerns about the technical difficulties of in-office arthroscopy, the potential for patient discomfort, and the cumbersomeness of in-office arthroscopy units. However, significant advances have been made in the resolution capability of small-bore needle arthroscopy, resulting in much less painful procedures. Additionally, the early hardware designs, which mimicked operating room setups using towers, fluid irrigation systems, and larger arthroscopes, have been replaced with small-needle arthroscopes that use syringes for irrigation and tablet computers for visualization (Figures 1A, 1B).  

The mi-eye^+TM technology (Trice Medical) is a small-bore needle unit for in-office arthroscopy with digital optics that does not need an irrigation tower. We conducted a pilot study of the sensitivity and specificity of the mi-eye^+TM unit in comparison with MRI, using surgical arthroscopy as a gold-standard reference. We hypothesized that the mi-eye^+TM needle arthroscope, which can be used in an office setting, would be equivalent to the standard of care (MRI) for the diagnosis of intra-articular pathology of the knee.

METHODS

Central regulatory approval for this prospective, multicenter, observational study was obtained from the Western Institutional Review Board for 3 of the sites, and 1 institution required and was granted internal Institutional Review Board approval.

The study was performed by 4 sports medicine orthopedic surgeons experienced in using the mi-eye^+TM in-office arthroscope. Patients were enrolled from December 2015 through June 2016. Inclusion criteria were an indication for an arthroscopic procedure of the knee based on history, physical examination, and MRI findings. Patients were excluded from the study if there were any contraindications to completing an MRI. Acute hemarthroses of the knee or active systemic infections were also excluded. Once a patient was identified as meeting the criteria for participation, informed consent was obtained. Of the 113 patients who enrolled, 7 did not have a complete study dataset available, leaving 106 patients (53 males, 53 females) in the study. Mean age was 47 years (range, 18-82 years).

Continue to: A test result form was used...

A test result form was used to record mi-eye^+TM, surgical arthroscopy, and MRI results. This form required a “positive” or “negative” result for all of several diagnoses: medial and lateral meniscal tears, intra-articular loose body, osteoarthritis (OA), osteochondritis dissecans (OCD), and tears of the anterior and posterior cruciate ligaments (ACL, PCL). MRI was performed at a variety of imaging facilities, but the images were interpreted by musculoskeletally trained radiologists.

The study was conducted in the operating room. After the patient was appropriately anesthetized, and the extremity prepared and draped, the mi-eye^+TM procedure was performed immediately prior to surgical arthroscopy. A tourniquet was not used. At surgeon discretion, medial, lateral, or both approaches were used with the mi-eye^+TM, and diagnostic arthroscopy was performed. During the procedure, the mi-eye^+TM was advanced into the knee. Once in the synovial compartment, the external 14-gauge needle was retracted, exposing the unit’s optics. Visualization was improved by injecting normal saline through the lure lock in the mi-eye^+TM needle arthroscope. An average of 20 mL of saline was used, though the amount varied with surgeon discretion. Subsequently, the surgeon visualized structures in the knee and documented all findings.

At the end of the mi-eye^+TM procedure, the scheduled surgical arthroscopy was performed. After the surgical procedure, if there were no issues or complications, the patient was discharged from the study. No follow-up was required for the study, as arthroscopic findings served as the conclusive diagnosis for each patient, and no interventions were being studied. There were no complications related to use of the mi-eye^+TM.

The mi-eye^+TM device findings were compared with the MRI findings within individual pathologies, and a “per-patient” analysis was performed to compare the arthroscopic findings with those of the mi-eye^+TM and the MRI. Additionally, we identified all mi-eye^+TM findings and MRI findings that exactly matched the surgical arthroscopy findings. When a test had no false-positive or false-negative findings in comparison with surgical arthroscopy, it was identified as having complete accuracy for all intra-articular knee pathologies. For these methods, the 95% confidence interval was determined based on binomial distribution.

RESULTS

The mi-eye^{+ TM} demonstrated complete accuracy of all pathologies for 97 (91.5%) of the 106 patients included in the study, whereas MRI demonstrated complete accuracy for 65 patients (61.3%) (P < .0001). All discrepancies between mi-eye^+TM and surgical arthroscopy were false-negative mi-eye^+TM results, as the mi-eye^+TM did not reveal some aspect of the knee’s pathology for 9 patients. On the other hand, MRI demonstrated both false-negative and false-positive results, failing to reveal some aspect of the knee’s pathology for 31 patients, and potentially overcalling some aspect of the knee’s pathology among 18 patients.

Continue to: The pathology most frequently...

The pathology most frequently identified in the study was a meniscal tear. The mi-eye^+TM was more sensitive than MRI in identifying meniscal tears (92.6% vs 77.8%; P = .0035) and more specific in diagnosing these tears (100% vs 87.5%; P < .0002). The difference in specificity resulted from the false MRI diagnosis of a meniscal tear among 24 patients, who were found to have no tear by both mi-eye^+TM and surgical arthroscopy.

Table 1. Raw Data of mi-eye^+TM and Magnetic Resonance Imaging Findings

The second most frequent pathology was an intra-articular loose body. The mi-eye^+TM was more sensitive than MRI in identifying loose bodies (86.7% vs 20%; P = .0007). The specificity of the mi-eye^+TM and the specificity of MRI were equivalent in diagnosing loose bodies (100%). Table 1 and Table 2 show the complete set of diagnoses and associated diagnostic profiles.

Table 2. Diagnostic Profiles: Sensitivity and Specificity of mi-eye^+TM and Magnetic Resonance Imaging

^aBold P values are significant. Abbreviations: CI, confidence interval; MRI, magnetic resonance imaging; N/A, not applicable.

DISCUSSION

The overall accuracy of the mi-eye^+TM was superior to that of MRI relative to the arthroscopic gold standard in this pilot study. Other studies have demonstrated the accuracy, feasibility, and cost-efficacy of in-office arthroscopy. However, likely because of the cumbersomeness of in-office arthroscopy equipment and the potential for patient discomfort, the technique is not yet standard in the field. Recent advances in small-bore technology, digital optics, and ergonomics have addressed the difficulties associated with in-office arthroscopy, facilitating a faster and more efficient procedure. Our goal in this study was to evaluate the diagnostic capability of the mi-eye^+TM in-office arthroscopy unit, which features a small bore, digital optics, and functionality without an irrigation tower.

This study of 106 patients demonstrated equivalent or better accuracy of the mi-eye^+TM relative to MRI when compared with the gold standard of surgical arthroscopy. This was not surprising given that both the mi-eye^+TM and surgical arthroscopy are based on direct visualization of intra-articular pathology. The mi-eye^+TM unit identified more meniscal tears, intra-articular loose bodies, ACL tears, and OCD lesions than MRI did, and with enough power to demonstrate statistically significant improved sensitivity for meniscal tears and loose bodies. Furthermore, MRI demonstrated false-positive meniscal tears, ACL tears, OCD lesions, and OA, whereas the mi-eye^+TM did not demonstrate any false-positive results in comparison with surgical arthroscopy. This study demonstrated statistically significant improved specificity of the mi-eye⁺ compared with MRI in the diagnosis of meniscal tears and OA.

There are several limitations to our study. We refer to it as a pilot study because it was performed in a standard operating room. Before taking the technology to an outpatient setting, we wanted to confirm efficacy and safety in an operating room. However, the techniques used in this study are readily transferable to the outpatient clinic setting and to date have been used in more than 2000 cases.

Continue to: The specificity of MRI...

The specificity of MRI for meniscal tears was unexpectedly low compared with previous studies, which may reflect the multi-institution, multi-surgeon, multi-radiologist involvement in MRI interpretation.^4-10 MRI was performed at a variety of institutions without a standardized protocol. This lack of standardization of image capture and interpretation may have contributed to the suboptimal performance of MRI, falsely decreasing the potential ideal specificity for meniscal tears. Although this study may have underestimated the specificity of MRI for meniscal tears, we think the mi-eye^+TM and MRI results reported here reflect the findings of standard practice, without the standardization usually applied in studies. For example, a study of 139 knee MRI reports at 14 different institutions confirmed arthroscopic findings and concluded that 37% of the operations supported by a significant MRI finding were unjustified.¹¹ The authors attributed the rate of false-positive MRI findings to the wide variety of places where patients had their MRIs performed, and the subsequent variation in quality of imaging and MRI reader skill level.¹¹

Before inserting the mi-eye^+TM needle arthroscope, the surgeons had a working diagnosis of the pathology based on their clinical examination and MRI results. Clearly, this introduced a bias. Further studies will be conducted in a prospective, blinded manner to address this limitation.

Although studies of in-office arthroscopy technology date to the 1990s, there is an overall lack of data comparing in-office arthroscopy with MRI. Halbrecht and Jackson² conducted a study of 20 knee patients with both MRI and in-office needle arthroscopy. Overall, MRI was poor in detecting cartilage defects, with sensitivity of 34.6%, using the in-office arthroscopy as the confirmatory diagnosis. Although the authors did not compare in-office diagnoses with surgical arthroscopic findings, they concluded that office arthroscopy is an accurate and cost-efficient alternative to MRI in diagnostic evaluation of knee patients. Xerogeanes and colleagues¹² studied 110 patients in a prospective, blinded, multicenter trial comparing a minimally invasive office-based arthroscopy with MRI, using surgical arthroscopy as the confirmatory diagnosis. They concluded that the office-based arthroscope was statistically equivalent to diagnostic surgical arthroscopy and that it outperformed MRI in helping make accurate diagnoses. The authors applied a cost analysis to their findings and determined that office-based arthroscopy could result in an annual potential savings of $177 million for the healthcare system.¹²

Modern imaging sequences on high-Tesla MRI machines provide excellent visualization. Nevertheless, a significant number of patients do not undergo MRI, owing to time constraints, contraindications, body habitus, or anxiety/claustrophobia. Our study results confirmed that doctors treating such patients now have a viable alternative to help diagnose pathology.

CONCLUSION

The mi-eye^+TM device proved to be more sensitive and specific than MRI for intra-articular findings at the time of knee arthroscopy. Certainly there are contraindications to using the mi-eye^+TM, and our results do not obviate the need for MRI; our study did demonstrate that the mi-eye^+TM needle arthroscope can safely provide excellent visualization of intra-articular knee pathology. More studies of the mi-eye^+TM device in a clinical setting are warranted.

‌

According to industry estimates, roughly 64% of US adults were smartphone users in 2015.¹ Smartphones enable users to utilize mobile applications (apps) that can perform a variety of functions in many categories, including business, music, photography, entertainment, education, social networking, travel, and lifestyle. The widespread adoption and use of mobile apps has implications for medical practice. Mobile apps have the capability to serve as information sources for patients, educational tools for students, and diagnostic aids for physicians.² Consequently, a number of medical and health care–oriented apps have already been developed³ and are increasingly utilized by patients and providers.⁴

Given its visual nature, dermatology is particularly amenable to the integration of mobile medical apps. A study by Brewer et al⁵ identified more than 229 dermatology-related apps in categories ranging from general dermatology reference, self-surveillance and diagnosis, disease guides, educational aids, sunscreen and UV recommendations, and teledermatology. Patients served as the target audience and principal consumers of more than half of these dermatology apps.⁵

Mobile medical and health care apps demonstrate great potential for serving as valuable information sources for patients with dermatologic conditions; however, the content, functions, accuracy, and educational value of dermatology mobile apps are not well characterized, making it difficult for patients and health care providers to select and recommend appropriate apps.⁶ In this study, we created a rubric to objectively grade 44 publicly available mobile dermatology apps with the primary focus of patient education.

Methods

We conducted a search of dermatology-related educational mobile apps that were publicly available via the App Store (Apple Inc) from January 2016 to November 2016. (The pricing, availability, and other features of these apps may have changed since the study period.) The following search terms were used: dermatology, dermoscopy, melanoma, skin cancer, psoriasis, rosacea, acne, eczema, dermal fillers, and Mohs surgery. We excluded apps that were not in English; had a solely commercial focus; were mobile textbooks or scientific journals; were used to provide teledermatology services with no educational purpose; were solely focused on homeopathic, alternative, and/or complementary medicine; or were intended primarily as a reference for students or health care professionals. Our search yielded 44 apps with patient education as a primary objective. The apps were divided into 6 categories based on their focus: general dermatology, cosmetic dermatology, acne, eczema, psoriasis, and skin cancer.

Each app was reviewed using a quantified grading rubric developed by the researchers. In a prior evaluation, Handel⁷ reviewed 35 health and wellness mobile apps utilizing the categories of ease of use, reliability, quality, scope of information, and aesthetics.⁴ These criteria were modified and adapted for the purposes of this study, and a 4-point scale was applied to each criterion. The final criteria were (1) educational objectives, (2) content, (3) accuracy, (4) design, and (5) conflict of interest. The quantified grading rubric is described in Table 1.

Results

The possible range of scores based on the grading rubric was 5 to 20. The actual range of scores was 8 to 19 (Table 2). The 44 reviewed apps were categorized by topic as acne, cosmetic dermatology, eczema, general dermatology, psoriasis, or skin cancer. A sample of 15 apps selected to represent the distribution of scores and their grading on the rubric are presented in Table 3.

Comment

The number of dermatology-related apps available to mobile users continues to grow at an increasing rate.⁸ The apps vary in many aspects, including their purpose, scope, intended audience, and goals of the app publisher. In turn, more individuals are turning to mobile apps for medical information,⁴ especially in dermatology, thus it is necessary to create a systematic way to evaluate the quality and utility of each app to assist users in making informed decisions about which apps will best meet their needs in the midst of a wide array of choices.

For the purpose of this study, an objective rubric was created that can be used to evaluate the quality of medical apps for patient education in dermatology. An app’s adequacy and usefulness for patient education was thought to depend on 3 possible score ranges into which the app could fall based on the grading rubric. An app with a total score in the range of 5 to 10 was not thought to be useful and may even be detrimental to patients. An app with a total score in the range of 11 to 15 may be used for patient education with some reservations based on shortcomings for certain criteria. An app with a score in the range of 16 to 20 was thought to be valuable and adequate for patient education. For example, the How to Treat Acne app received a total score of 8 and therefore would not be recommended to patients based on the grading rubric used in this study. This particular app provided sparse and sometimes inaccurate information, had a confusing user interface, and contained many obstructive advertisements. In contrast, the Eczema Doc app received a total score of 19, which indicates a quality app deemed to be useful for patient information based on the established rubric. This app met all the objectives that it advertised, contained accurate information with verified citation of sources, and was very easy for users to navigate.

Of the 44 graded apps, only 9 (20.5%) received scores in the highest range of 16 to 20, which indicates a need for improvements in mobile dermatology apps intended for patient education. Adopting the grading rubric developed in this study as a standard in the creation of medical apps could have beneficial implications in disseminating accurate, safe, unbiased, and easy-to-understand information to patients.

‌

According to industry estimates, roughly 64% of US adults were smartphone users in 2015.¹ Smartphones enable users to utilize mobile applications (apps) that can perform a variety of functions in many categories, including business, music, photography, entertainment, education, social networking, travel, and lifestyle. The widespread adoption and use of mobile apps has implications for medical practice. Mobile apps have the capability to serve as information sources for patients, educational tools for students, and diagnostic aids for physicians.² Consequently, a number of medical and health care–oriented apps have already been developed³ and are increasingly utilized by patients and providers.⁴

Given its visual nature, dermatology is particularly amenable to the integration of mobile medical apps. A study by Brewer et al⁵ identified more than 229 dermatology-related apps in categories ranging from general dermatology reference, self-surveillance and diagnosis, disease guides, educational aids, sunscreen and UV recommendations, and teledermatology. Patients served as the target audience and principal consumers of more than half of these dermatology apps.⁵

Mobile medical and health care apps demonstrate great potential for serving as valuable information sources for patients with dermatologic conditions; however, the content, functions, accuracy, and educational value of dermatology mobile apps are not well characterized, making it difficult for patients and health care providers to select and recommend appropriate apps.⁶ In this study, we created a rubric to objectively grade 44 publicly available mobile dermatology apps with the primary focus of patient education.

Methods

We conducted a search of dermatology-related educational mobile apps that were publicly available via the App Store (Apple Inc) from January 2016 to November 2016. (The pricing, availability, and other features of these apps may have changed since the study period.) The following search terms were used: dermatology, dermoscopy, melanoma, skin cancer, psoriasis, rosacea, acne, eczema, dermal fillers, and Mohs surgery. We excluded apps that were not in English; had a solely commercial focus; were mobile textbooks or scientific journals; were used to provide teledermatology services with no educational purpose; were solely focused on homeopathic, alternative, and/or complementary medicine; or were intended primarily as a reference for students or health care professionals. Our search yielded 44 apps with patient education as a primary objective. The apps were divided into 6 categories based on their focus: general dermatology, cosmetic dermatology, acne, eczema, psoriasis, and skin cancer.

Each app was reviewed using a quantified grading rubric developed by the researchers. In a prior evaluation, Handel⁷ reviewed 35 health and wellness mobile apps utilizing the categories of ease of use, reliability, quality, scope of information, and aesthetics.⁴ These criteria were modified and adapted for the purposes of this study, and a 4-point scale was applied to each criterion. The final criteria were (1) educational objectives, (2) content, (3) accuracy, (4) design, and (5) conflict of interest. The quantified grading rubric is described in Table 1.

Results

The possible range of scores based on the grading rubric was 5 to 20. The actual range of scores was 8 to 19 (Table 2). The 44 reviewed apps were categorized by topic as acne, cosmetic dermatology, eczema, general dermatology, psoriasis, or skin cancer. A sample of 15 apps selected to represent the distribution of scores and their grading on the rubric are presented in Table 3.

Comment

The number of dermatology-related apps available to mobile users continues to grow at an increasing rate.⁸ The apps vary in many aspects, including their purpose, scope, intended audience, and goals of the app publisher. In turn, more individuals are turning to mobile apps for medical information,⁴ especially in dermatology, thus it is necessary to create a systematic way to evaluate the quality and utility of each app to assist users in making informed decisions about which apps will best meet their needs in the midst of a wide array of choices.

For the purpose of this study, an objective rubric was created that can be used to evaluate the quality of medical apps for patient education in dermatology. An app’s adequacy and usefulness for patient education was thought to depend on 3 possible score ranges into which the app could fall based on the grading rubric. An app with a total score in the range of 5 to 10 was not thought to be useful and may even be detrimental to patients. An app with a total score in the range of 11 to 15 may be used for patient education with some reservations based on shortcomings for certain criteria. An app with a score in the range of 16 to 20 was thought to be valuable and adequate for patient education. For example, the How to Treat Acne app received a total score of 8 and therefore would not be recommended to patients based on the grading rubric used in this study. This particular app provided sparse and sometimes inaccurate information, had a confusing user interface, and contained many obstructive advertisements. In contrast, the Eczema Doc app received a total score of 19, which indicates a quality app deemed to be useful for patient information based on the established rubric. This app met all the objectives that it advertised, contained accurate information with verified citation of sources, and was very easy for users to navigate.

Of the 44 graded apps, only 9 (20.5%) received scores in the highest range of 16 to 20, which indicates a need for improvements in mobile dermatology apps intended for patient education. Adopting the grading rubric developed in this study as a standard in the creation of medical apps could have beneficial implications in disseminating accurate, safe, unbiased, and easy-to-understand information to patients.

‌

According to industry estimates, roughly 64% of US adults were smartphone users in 2015.¹ Smartphones enable users to utilize mobile applications (apps) that can perform a variety of functions in many categories, including business, music, photography, entertainment, education, social networking, travel, and lifestyle. The widespread adoption and use of mobile apps has implications for medical practice. Mobile apps have the capability to serve as information sources for patients, educational tools for students, and diagnostic aids for physicians.² Consequently, a number of medical and health care–oriented apps have already been developed³ and are increasingly utilized by patients and providers.⁴

Given its visual nature, dermatology is particularly amenable to the integration of mobile medical apps. A study by Brewer et al⁵ identified more than 229 dermatology-related apps in categories ranging from general dermatology reference, self-surveillance and diagnosis, disease guides, educational aids, sunscreen and UV recommendations, and teledermatology. Patients served as the target audience and principal consumers of more than half of these dermatology apps.⁵

Mobile medical and health care apps demonstrate great potential for serving as valuable information sources for patients with dermatologic conditions; however, the content, functions, accuracy, and educational value of dermatology mobile apps are not well characterized, making it difficult for patients and health care providers to select and recommend appropriate apps.⁶ In this study, we created a rubric to objectively grade 44 publicly available mobile dermatology apps with the primary focus of patient education.

Methods

We conducted a search of dermatology-related educational mobile apps that were publicly available via the App Store (Apple Inc) from January 2016 to November 2016. (The pricing, availability, and other features of these apps may have changed since the study period.) The following search terms were used: dermatology, dermoscopy, melanoma, skin cancer, psoriasis, rosacea, acne, eczema, dermal fillers, and Mohs surgery. We excluded apps that were not in English; had a solely commercial focus; were mobile textbooks or scientific journals; were used to provide teledermatology services with no educational purpose; were solely focused on homeopathic, alternative, and/or complementary medicine; or were intended primarily as a reference for students or health care professionals. Our search yielded 44 apps with patient education as a primary objective. The apps were divided into 6 categories based on their focus: general dermatology, cosmetic dermatology, acne, eczema, psoriasis, and skin cancer.

Each app was reviewed using a quantified grading rubric developed by the researchers. In a prior evaluation, Handel⁷ reviewed 35 health and wellness mobile apps utilizing the categories of ease of use, reliability, quality, scope of information, and aesthetics.⁴ These criteria were modified and adapted for the purposes of this study, and a 4-point scale was applied to each criterion. The final criteria were (1) educational objectives, (2) content, (3) accuracy, (4) design, and (5) conflict of interest. The quantified grading rubric is described in Table 1.

Results

The possible range of scores based on the grading rubric was 5 to 20. The actual range of scores was 8 to 19 (Table 2). The 44 reviewed apps were categorized by topic as acne, cosmetic dermatology, eczema, general dermatology, psoriasis, or skin cancer. A sample of 15 apps selected to represent the distribution of scores and their grading on the rubric are presented in Table 3.

Comment

The number of dermatology-related apps available to mobile users continues to grow at an increasing rate.⁸ The apps vary in many aspects, including their purpose, scope, intended audience, and goals of the app publisher. In turn, more individuals are turning to mobile apps for medical information,⁴ especially in dermatology, thus it is necessary to create a systematic way to evaluate the quality and utility of each app to assist users in making informed decisions about which apps will best meet their needs in the midst of a wide array of choices.

For the purpose of this study, an objective rubric was created that can be used to evaluate the quality of medical apps for patient education in dermatology. An app’s adequacy and usefulness for patient education was thought to depend on 3 possible score ranges into which the app could fall based on the grading rubric. An app with a total score in the range of 5 to 10 was not thought to be useful and may even be detrimental to patients. An app with a total score in the range of 11 to 15 may be used for patient education with some reservations based on shortcomings for certain criteria. An app with a score in the range of 16 to 20 was thought to be valuable and adequate for patient education. For example, the How to Treat Acne app received a total score of 8 and therefore would not be recommended to patients based on the grading rubric used in this study. This particular app provided sparse and sometimes inaccurate information, had a confusing user interface, and contained many obstructive advertisements. In contrast, the Eczema Doc app received a total score of 19, which indicates a quality app deemed to be useful for patient information based on the established rubric. This app met all the objectives that it advertised, contained accurate information with verified citation of sources, and was very easy for users to navigate.

Of the 44 graded apps, only 9 (20.5%) received scores in the highest range of 16 to 20, which indicates a need for improvements in mobile dermatology apps intended for patient education. Adopting the grading rubric developed in this study as a standard in the creation of medical apps could have beneficial implications in disseminating accurate, safe, unbiased, and easy-to-understand information to patients.

Rankings of US residency programs based on academic achievement are a resource for fourth-year medical students applying for residency through the National Resident Matching Program. They also highlight the leading academic training programs in each medical specialty. Currently, the Doximity Residency Navigator (https://residency.doximity.com) provides rankings of US residency programs based on either subjective or objective criteria. The subjective rankings utilize current resident and recent alumni satisfaction surveys as well as nominations from board-certified Doximity members who were asked to nominate up to 5 residency programs in their specialty that offer the best clinical training. The objective rankings are based on measurement of research output, which is calculated from the collective h-index of publications authored by graduating alumni within the last 15 years as well as the amount of research funding awarded.¹

Aquino et al² provided a ranking of US dermatology residency programs using alternative objective data measures (as of December 31, 2008) from the Doximity algorithm, including National Institutes of Health (NIH) and Dermatology Foundation (DF) funding, number of publications by full-time faculty members, number of faculty lectures given at annual meetings of 5 societies, and number of full-time faculty members serving on the editorial boards of 6 dermatology journals. The current study is an update to those rankings utilizing data from 2014.

Methods

The following data for each dermatology residency program were obtained to formulate the rankings: number of full-time faculty members, amount of NIH funding received in 2014 (https://report.nih.gov/), number of publications by full-time faculty members in 2014 (http://www.ncbi.nlm.nih.gov/pubmed/), and the number of faculty lectures given at annual meetings of 5 societies in 2014 (American Academy of Dermatology, the Society for Investigative Dermatology, the American Society of Dermatopathology, the Society for Pediatric Dermatology, and the American Society for Dermatologic Surgery). This study was approved by the institutional review board at Kaiser Permanente Southern California.

The names of all US dermatology residency programs were obtained as of December 31, 2014, from FREIDA Online using the search term dermatology. An email was sent to a representative from each residency program (eg, residency program coordinator, program director, full-time faculty member) requesting confirmation of a list of full-time faculty members in the program, excluding part-time and volunteer faculty. If a response was not obtained or the representative declined to participate, a list was compiled using available information from that residency program’s website.

National Institutes of Health funding for 2014 was obtained for individual faculty members from the NIH Research Portfolio Online Reporting Tools expenditures and reports (https://projectreporter.nih.gov/reporter.cfm) by searching the first and last name of each full-time faculty member along with their affiliated institution. The search results were filtered to only include NIH funding for full-time faculty members listed as principal investigators rather than as coinvestigators. The fiscal year total cost by institute/center for each full-time faculty member’s projects was summated to obtain the total NIH funding for the program.

The total number of publications by full-time faculty members in 2014 was obtained utilizing a PubMed search of articles indexed for MEDLINE using each faculty member’s first and last name. The authors’ affiliations were verified for each publication, and the number of publications was summed for all full-time faculty members at each residency program. If multiple authors from the same program coauthored an article, it was only counted once toward the total number of faculty publications from that program.

Program brochures for the 2014 meetings of the 5 societies were reviewed to quantify the number of lectures given by full-time faculty members in each program.

Each residency program was assigned a score from 0 to 1.0 for each of the 4 factors of academic achievement analyzed. The program with the highest number of faculty publications was assigned a score of 1.0 and the program with the lowest number of publications was assigned a score of 0. The programs in between were subsequently assigned scores from 0 to 1.0 based on the number of publications as a percentage of the number of publications from the program with the most publications.

A weighted ranking scheme was used to rank residency programs based on the relative importance of each factor. There were 3 factors that were deemed to be the most reflective of academic achievement among dermatology residency programs: amount of NIH funding received in 2014, number of publications by full-time faculty members in 2014, and number of faculty lectures given at society meetings in 2014; thus, these factors were given a weight of 1.0. The remaining factor— total number of full-time faculty members—was given a weight of 0.5. Values were totaled and programs were ranked based on the sum of these values. All quantitative analyses were performed using an electronic spreadsheet program.

Results

The overall ranking of the top 20 US dermatology residency programs in 2014 is presented in Table 1. The top 5 programs based on each of the 3 factors most reflective of academic achievement used in the weighted ranking algorithm are presented in Tables 2 through 4.

Comment

The ranking of US residency programs involves using data in an unbiased manner while also accounting for important subjective measures. In a 2015 survey of residency applicants (n=6285), the 5 most important factors for applicants in selecting a program were the program’s ability to prepare residents for future training or position, resident esprit de corps, faculty availability and involvement in teaching, depth and breadth of faculty, and variety of patients and clinical resources.³ However, these subjective measures are difficult to quantify in a standardized fashion. In its ranking of residency programs, the Doximity Residency Navigator utilizes surveys of current residents and recent alumni as well as nominations from board-certified Doximity members.¹

One of the main issues in utilizing survey data to rank residency programs is the inherent bias that most residents and alumni possess toward their own program. Moreover, the question arises whether most residents, faculty members, or recent alumni of residency programs have sufficient knowledge of other programs to rank them in a well-informed manner.

Wu et al⁴ used data from 2004 to perform the first algorithmic ranking of US dermatology programs, which was based on publications in 2001 to 2004, the amount of NIH funding in 2004, DF grants in 2001 to 2004, faculty lectures delivered at national conferences in 2004, and number of full-time faculty members on the editorial boards of the top 3 US dermatology journals and the top 4 subspecialty journals. Aquino et al² provided updated rankings that utilized a weighted algorithm to collect data from 2008 related to a number of factors, including annual amount of NIH and DF funding received, number of publications by full-time faculty members, number of faculty lectures given at 5 annual society meetings, and number of full-time faculty members who were on the editorial boards of 6 dermatology journals with the highest impact factors. The top 5 ranked programs based on the 2008 data were the University of California, San Francisco (San Francisco, California); Northwestern University (Chicago, Illinois); University of Pennsylvania (Philadelphia, Pennsylvania); Yale University (New Haven, Connecticut); and Stanford University (Stanford, California).²

The current ranking algorithm is more indicative of a residency program’s commitment to research and scholarship, with an assumption that successful clinical training is offered. Leading researchers in the field also are usually known to be clinical experts, but the current data does not take into account the frequency, quality, or methodology of teaching provided to residents. Perhaps the most objective measure reflecting the quality of resident education would be American Board of Dermatology examination scores, but these data are not publically available. Additional factors such as the percentage of residents who received fellowship positions; diversity of the patient population; and number and extent of surgical, cosmetic, or laser procedures performed also are not readily available. Doximity provides board pass rates for each residency program, but these data are self-reported and are not taken into account in their rankings.¹

The current study aimed to utilize publicly available data to rank US dermatology residency programs based on objective measures of academic achievement. A recent study showed that 531 of 793 applicants (67%) to emergency medicine residency programs were aware of the Doximity residency rankings.One-quarter of these applicants made changes to their rank list based on this data, demonstrating that residency rankings may impact applicant decision-making.⁵ In the future, the most accurate and unbiased rankings may be performed if each residency program joins a cooperative effort to provide more objective data about the training they provide and utilizes a standardized survey system for current residents and recent graduates to evaluate important subjective measures.

Conclusion

Based on our weighted ranking algorithm, the top 5 dermatology residency programs in 2014 were Harvard University (Boston, Massachusetts); University of California, San Francisco (San Francisco, California); Stanford University (Stanford, California); University of Pennsylvania (Philadelphia, Pennsylvania); and Emory University (Atlanta, Georgia).

Acknowledgments
We thank all of the program coordinators, full-time faculty members, program directors, and chairs who provided responses to our inquiries for additional information about their residency programs.

Rankings of US residency programs based on academic achievement are a resource for fourth-year medical students applying for residency through the National Resident Matching Program. They also highlight the leading academic training programs in each medical specialty. Currently, the Doximity Residency Navigator (https://residency.doximity.com) provides rankings of US residency programs based on either subjective or objective criteria. The subjective rankings utilize current resident and recent alumni satisfaction surveys as well as nominations from board-certified Doximity members who were asked to nominate up to 5 residency programs in their specialty that offer the best clinical training. The objective rankings are based on measurement of research output, which is calculated from the collective h-index of publications authored by graduating alumni within the last 15 years as well as the amount of research funding awarded.¹

Aquino et al² provided a ranking of US dermatology residency programs using alternative objective data measures (as of December 31, 2008) from the Doximity algorithm, including National Institutes of Health (NIH) and Dermatology Foundation (DF) funding, number of publications by full-time faculty members, number of faculty lectures given at annual meetings of 5 societies, and number of full-time faculty members serving on the editorial boards of 6 dermatology journals. The current study is an update to those rankings utilizing data from 2014.

Methods

The following data for each dermatology residency program were obtained to formulate the rankings: number of full-time faculty members, amount of NIH funding received in 2014 (https://report.nih.gov/), number of publications by full-time faculty members in 2014 (http://www.ncbi.nlm.nih.gov/pubmed/), and the number of faculty lectures given at annual meetings of 5 societies in 2014 (American Academy of Dermatology, the Society for Investigative Dermatology, the American Society of Dermatopathology, the Society for Pediatric Dermatology, and the American Society for Dermatologic Surgery). This study was approved by the institutional review board at Kaiser Permanente Southern California.

The names of all US dermatology residency programs were obtained as of December 31, 2014, from FREIDA Online using the search term dermatology. An email was sent to a representative from each residency program (eg, residency program coordinator, program director, full-time faculty member) requesting confirmation of a list of full-time faculty members in the program, excluding part-time and volunteer faculty. If a response was not obtained or the representative declined to participate, a list was compiled using available information from that residency program’s website.

National Institutes of Health funding for 2014 was obtained for individual faculty members from the NIH Research Portfolio Online Reporting Tools expenditures and reports (https://projectreporter.nih.gov/reporter.cfm) by searching the first and last name of each full-time faculty member along with their affiliated institution. The search results were filtered to only include NIH funding for full-time faculty members listed as principal investigators rather than as coinvestigators. The fiscal year total cost by institute/center for each full-time faculty member’s projects was summated to obtain the total NIH funding for the program.

The total number of publications by full-time faculty members in 2014 was obtained utilizing a PubMed search of articles indexed for MEDLINE using each faculty member’s first and last name. The authors’ affiliations were verified for each publication, and the number of publications was summed for all full-time faculty members at each residency program. If multiple authors from the same program coauthored an article, it was only counted once toward the total number of faculty publications from that program.

Program brochures for the 2014 meetings of the 5 societies were reviewed to quantify the number of lectures given by full-time faculty members in each program.

Each residency program was assigned a score from 0 to 1.0 for each of the 4 factors of academic achievement analyzed. The program with the highest number of faculty publications was assigned a score of 1.0 and the program with the lowest number of publications was assigned a score of 0. The programs in between were subsequently assigned scores from 0 to 1.0 based on the number of publications as a percentage of the number of publications from the program with the most publications.

A weighted ranking scheme was used to rank residency programs based on the relative importance of each factor. There were 3 factors that were deemed to be the most reflective of academic achievement among dermatology residency programs: amount of NIH funding received in 2014, number of publications by full-time faculty members in 2014, and number of faculty lectures given at society meetings in 2014; thus, these factors were given a weight of 1.0. The remaining factor— total number of full-time faculty members—was given a weight of 0.5. Values were totaled and programs were ranked based on the sum of these values. All quantitative analyses were performed using an electronic spreadsheet program.

Results

The overall ranking of the top 20 US dermatology residency programs in 2014 is presented in Table 1. The top 5 programs based on each of the 3 factors most reflective of academic achievement used in the weighted ranking algorithm are presented in Tables 2 through 4.

Comment

The ranking of US residency programs involves using data in an unbiased manner while also accounting for important subjective measures. In a 2015 survey of residency applicants (n=6285), the 5 most important factors for applicants in selecting a program were the program’s ability to prepare residents for future training or position, resident esprit de corps, faculty availability and involvement in teaching, depth and breadth of faculty, and variety of patients and clinical resources.³ However, these subjective measures are difficult to quantify in a standardized fashion. In its ranking of residency programs, the Doximity Residency Navigator utilizes surveys of current residents and recent alumni as well as nominations from board-certified Doximity members.¹

One of the main issues in utilizing survey data to rank residency programs is the inherent bias that most residents and alumni possess toward their own program. Moreover, the question arises whether most residents, faculty members, or recent alumni of residency programs have sufficient knowledge of other programs to rank them in a well-informed manner.

Wu et al⁴ used data from 2004 to perform the first algorithmic ranking of US dermatology programs, which was based on publications in 2001 to 2004, the amount of NIH funding in 2004, DF grants in 2001 to 2004, faculty lectures delivered at national conferences in 2004, and number of full-time faculty members on the editorial boards of the top 3 US dermatology journals and the top 4 subspecialty journals. Aquino et al² provided updated rankings that utilized a weighted algorithm to collect data from 2008 related to a number of factors, including annual amount of NIH and DF funding received, number of publications by full-time faculty members, number of faculty lectures given at 5 annual society meetings, and number of full-time faculty members who were on the editorial boards of 6 dermatology journals with the highest impact factors. The top 5 ranked programs based on the 2008 data were the University of California, San Francisco (San Francisco, California); Northwestern University (Chicago, Illinois); University of Pennsylvania (Philadelphia, Pennsylvania); Yale University (New Haven, Connecticut); and Stanford University (Stanford, California).²

The current ranking algorithm is more indicative of a residency program’s commitment to research and scholarship, with an assumption that successful clinical training is offered. Leading researchers in the field also are usually known to be clinical experts, but the current data does not take into account the frequency, quality, or methodology of teaching provided to residents. Perhaps the most objective measure reflecting the quality of resident education would be American Board of Dermatology examination scores, but these data are not publically available. Additional factors such as the percentage of residents who received fellowship positions; diversity of the patient population; and number and extent of surgical, cosmetic, or laser procedures performed also are not readily available. Doximity provides board pass rates for each residency program, but these data are self-reported and are not taken into account in their rankings.¹

The current study aimed to utilize publicly available data to rank US dermatology residency programs based on objective measures of academic achievement. A recent study showed that 531 of 793 applicants (67%) to emergency medicine residency programs were aware of the Doximity residency rankings.One-quarter of these applicants made changes to their rank list based on this data, demonstrating that residency rankings may impact applicant decision-making.⁵ In the future, the most accurate and unbiased rankings may be performed if each residency program joins a cooperative effort to provide more objective data about the training they provide and utilizes a standardized survey system for current residents and recent graduates to evaluate important subjective measures.

Conclusion

Based on our weighted ranking algorithm, the top 5 dermatology residency programs in 2014 were Harvard University (Boston, Massachusetts); University of California, San Francisco (San Francisco, California); Stanford University (Stanford, California); University of Pennsylvania (Philadelphia, Pennsylvania); and Emory University (Atlanta, Georgia).

Acknowledgments
We thank all of the program coordinators, full-time faculty members, program directors, and chairs who provided responses to our inquiries for additional information about their residency programs.

Rankings of US residency programs based on academic achievement are a resource for fourth-year medical students applying for residency through the National Resident Matching Program. They also highlight the leading academic training programs in each medical specialty. Currently, the Doximity Residency Navigator (https://residency.doximity.com) provides rankings of US residency programs based on either subjective or objective criteria. The subjective rankings utilize current resident and recent alumni satisfaction surveys as well as nominations from board-certified Doximity members who were asked to nominate up to 5 residency programs in their specialty that offer the best clinical training. The objective rankings are based on measurement of research output, which is calculated from the collective h-index of publications authored by graduating alumni within the last 15 years as well as the amount of research funding awarded.¹

Aquino et al² provided a ranking of US dermatology residency programs using alternative objective data measures (as of December 31, 2008) from the Doximity algorithm, including National Institutes of Health (NIH) and Dermatology Foundation (DF) funding, number of publications by full-time faculty members, number of faculty lectures given at annual meetings of 5 societies, and number of full-time faculty members serving on the editorial boards of 6 dermatology journals. The current study is an update to those rankings utilizing data from 2014.

Methods

The following data for each dermatology residency program were obtained to formulate the rankings: number of full-time faculty members, amount of NIH funding received in 2014 (https://report.nih.gov/), number of publications by full-time faculty members in 2014 (http://www.ncbi.nlm.nih.gov/pubmed/), and the number of faculty lectures given at annual meetings of 5 societies in 2014 (American Academy of Dermatology, the Society for Investigative Dermatology, the American Society of Dermatopathology, the Society for Pediatric Dermatology, and the American Society for Dermatologic Surgery). This study was approved by the institutional review board at Kaiser Permanente Southern California.

The names of all US dermatology residency programs were obtained as of December 31, 2014, from FREIDA Online using the search term dermatology. An email was sent to a representative from each residency program (eg, residency program coordinator, program director, full-time faculty member) requesting confirmation of a list of full-time faculty members in the program, excluding part-time and volunteer faculty. If a response was not obtained or the representative declined to participate, a list was compiled using available information from that residency program’s website.

National Institutes of Health funding for 2014 was obtained for individual faculty members from the NIH Research Portfolio Online Reporting Tools expenditures and reports (https://projectreporter.nih.gov/reporter.cfm) by searching the first and last name of each full-time faculty member along with their affiliated institution. The search results were filtered to only include NIH funding for full-time faculty members listed as principal investigators rather than as coinvestigators. The fiscal year total cost by institute/center for each full-time faculty member’s projects was summated to obtain the total NIH funding for the program.

The total number of publications by full-time faculty members in 2014 was obtained utilizing a PubMed search of articles indexed for MEDLINE using each faculty member’s first and last name. The authors’ affiliations were verified for each publication, and the number of publications was summed for all full-time faculty members at each residency program. If multiple authors from the same program coauthored an article, it was only counted once toward the total number of faculty publications from that program.

Program brochures for the 2014 meetings of the 5 societies were reviewed to quantify the number of lectures given by full-time faculty members in each program.

Each residency program was assigned a score from 0 to 1.0 for each of the 4 factors of academic achievement analyzed. The program with the highest number of faculty publications was assigned a score of 1.0 and the program with the lowest number of publications was assigned a score of 0. The programs in between were subsequently assigned scores from 0 to 1.0 based on the number of publications as a percentage of the number of publications from the program with the most publications.

A weighted ranking scheme was used to rank residency programs based on the relative importance of each factor. There were 3 factors that were deemed to be the most reflective of academic achievement among dermatology residency programs: amount of NIH funding received in 2014, number of publications by full-time faculty members in 2014, and number of faculty lectures given at society meetings in 2014; thus, these factors were given a weight of 1.0. The remaining factor— total number of full-time faculty members—was given a weight of 0.5. Values were totaled and programs were ranked based on the sum of these values. All quantitative analyses were performed using an electronic spreadsheet program.

Results

The overall ranking of the top 20 US dermatology residency programs in 2014 is presented in Table 1. The top 5 programs based on each of the 3 factors most reflective of academic achievement used in the weighted ranking algorithm are presented in Tables 2 through 4.

Comment

The ranking of US residency programs involves using data in an unbiased manner while also accounting for important subjective measures. In a 2015 survey of residency applicants (n=6285), the 5 most important factors for applicants in selecting a program were the program’s ability to prepare residents for future training or position, resident esprit de corps, faculty availability and involvement in teaching, depth and breadth of faculty, and variety of patients and clinical resources.³ However, these subjective measures are difficult to quantify in a standardized fashion. In its ranking of residency programs, the Doximity Residency Navigator utilizes surveys of current residents and recent alumni as well as nominations from board-certified Doximity members.¹

One of the main issues in utilizing survey data to rank residency programs is the inherent bias that most residents and alumni possess toward their own program. Moreover, the question arises whether most residents, faculty members, or recent alumni of residency programs have sufficient knowledge of other programs to rank them in a well-informed manner.

Wu et al⁴ used data from 2004 to perform the first algorithmic ranking of US dermatology programs, which was based on publications in 2001 to 2004, the amount of NIH funding in 2004, DF grants in 2001 to 2004, faculty lectures delivered at national conferences in 2004, and number of full-time faculty members on the editorial boards of the top 3 US dermatology journals and the top 4 subspecialty journals. Aquino et al² provided updated rankings that utilized a weighted algorithm to collect data from 2008 related to a number of factors, including annual amount of NIH and DF funding received, number of publications by full-time faculty members, number of faculty lectures given at 5 annual society meetings, and number of full-time faculty members who were on the editorial boards of 6 dermatology journals with the highest impact factors. The top 5 ranked programs based on the 2008 data were the University of California, San Francisco (San Francisco, California); Northwestern University (Chicago, Illinois); University of Pennsylvania (Philadelphia, Pennsylvania); Yale University (New Haven, Connecticut); and Stanford University (Stanford, California).²

The current ranking algorithm is more indicative of a residency program’s commitment to research and scholarship, with an assumption that successful clinical training is offered. Leading researchers in the field also are usually known to be clinical experts, but the current data does not take into account the frequency, quality, or methodology of teaching provided to residents. Perhaps the most objective measure reflecting the quality of resident education would be American Board of Dermatology examination scores, but these data are not publically available. Additional factors such as the percentage of residents who received fellowship positions; diversity of the patient population; and number and extent of surgical, cosmetic, or laser procedures performed also are not readily available. Doximity provides board pass rates for each residency program, but these data are self-reported and are not taken into account in their rankings.¹

The current study aimed to utilize publicly available data to rank US dermatology residency programs based on objective measures of academic achievement. A recent study showed that 531 of 793 applicants (67%) to emergency medicine residency programs were aware of the Doximity residency rankings.One-quarter of these applicants made changes to their rank list based on this data, demonstrating that residency rankings may impact applicant decision-making.⁵ In the future, the most accurate and unbiased rankings may be performed if each residency program joins a cooperative effort to provide more objective data about the training they provide and utilizes a standardized survey system for current residents and recent graduates to evaluate important subjective measures.

Conclusion

Based on our weighted ranking algorithm, the top 5 dermatology residency programs in 2014 were Harvard University (Boston, Massachusetts); University of California, San Francisco (San Francisco, California); Stanford University (Stanford, California); University of Pennsylvania (Philadelphia, Pennsylvania); and Emory University (Atlanta, Georgia).

Acknowledgments
We thank all of the program coordinators, full-time faculty members, program directors, and chairs who provided responses to our inquiries for additional information about their residency programs.

Deep venous thrombosis and pulmonary embolism, collectively known as venous thromboembolism (VTE), affect up to 600,000 Americans a year.¹ Most of these are hospital-associated venous thromboembolisms (HA-VTE).^1,2 VTE poses a substantial risk of mortality and long-term morbidity, and its treatment poses a risk of major bleeding.¹ As appropriate VTE prophylaxis (“prophylaxis”) can reduce the risk of VTE by 40% to 80% depending on the patient population,³ VTE risk assessment and prophylaxis is endorsed by multiple guidelines^4-7 and supported by regulatory agencies.^8-10

However, despite extensive study, consensus about the impact of prophylaxis^4,11 and the optimal method of risk assessment^4,5,7,12 is lacking. Meanwhile, implementation of prophylaxis in real-world settings is poor; only 40% to 60% of at-risk patients receive prophylaxis,¹³ and as few as <20% receive optimal prophylaxis.¹⁴ Both systematic reviews^15,16 and experience with VTE prevention collaboratives^17,18 found that multifaceted interventions and alerts may be most effective in improving prophylaxis rates, but without proof of improved VTE rates.¹⁵ There is limited experience with large-scale VTE prevention. Organizations like The Joint Commission (TJC)⁸ and the Surgical Care Improvement Project have promoted quality measures but without clear evidence of improvement.¹⁹ In addition, an analysis of over 20,000 medical patients at 35 hospitals found no difference in VTE rates between high- and low-performing hospitals,²⁰ suggesting that aggressive prophylaxis efforts may not reduce VTE, at least among medical patients.²¹ However, a 5-hospital University of California collaborative was associated with improved VTE rates, chiefly among surgical patients.²²

In 2011, Dignity Health targeted VTE for improvement after investigations of potentially preventable HA-VTE revealed variable patterns of prophylaxis. In addition, improvement seemed feasible because there is a proven framework for VTE quality improvement (QI) projects^17,18 and a record of success with the following 3 specific strategies: quality mentorship,²³ use of a simple VTE risk assessment method, and active surveillance (real-time monitoring targeting suboptimal prophylaxis with concurrent intervention). This active surveillance technique has been used successfully in prior improvement efforts, often termed measure-vention.^17,18,22,24

Setting and Participants

The QI collaborative was performed at 35 Dignity Health community hospitals in California, Arizona, and Nevada. Facilities ranged from 25 to 571 beds in size with a mixture of teaching and nonteaching hospitals. Prior to the initiative, prophylaxis improvement efforts were incomplete and inconsistent at study facilities. All adult acute care inpatients at all facilities were included except rehabilitation, behavioral health, skilled nursing, hospice, other nonacute care, and inpatient deliveries.

Design Overview

We performed a prospective, unblinded, open-intervention study of a QI collaborative in 35 community hospitals and studied the effect on prophylaxis and VTE rates with historical controls. The 35 hospitals were organized into 2 cohorts. In the “pilot” cohort, 9 hospitals (chosen to be representative of the various settings, size, and teaching status within the Dignity system) received funding from the Gordon and Betty Moore Foundation (GBMF) for intensive, individualized QI mentorship from experts as well as active surveillance (see “Interventions”). The pilot sites led the development of the VTE risk assessment and prophylaxis protocol (“VTE protocol”), measures, order sets, implementation tactics, and lessons learned, assisted by the mentor experts. Dissemination to the 26-hospital “spread” cohort was facilitated by the Dignity Health Hospital Engagement Network (HEN) infrastructure.

Timeline

Two of the pilot sites, acting as leads on the development of protocol and order set tools, formed improvement teams in March 2011, 6 to 12 months earlier than other Dignity sites. Planning and design work occurred from March 2011 to September 2012. Most implementation at the 35 hospitals occurred in a staggered fashion during calendar year (CY) 2012 and 2013 (see Figure 1). As few changes were made until mid-2012, we considered CY 2011 the baseline for comparison, CY 2012 to 2013 the implementation years, and CY 2014 the postimplementation period.

The project was reviewed by the Institutional Review Board (IRB) of Dignity Health and determined to be an IRB-exempt QI project.

Interventions

Collaborative Infrastructure

Multidisciplinary Teams

Improvement teams formed between March 2011 and September 2012. Members included a physician champion, frontline nurses and physicians, an administrative liaison, pharmacists, quality and data specialists, clinical informatics staff, and stakeholders from key clinical services. Teams met at least monthly at each site.

Physician Mentors

The 9 pilot sites received individualized mentorship provided by outside experts (IJ or GM) based on a model pioneered by the Society of Hospital Medicine’s (SHM) Mentored Implementation programs.²³ Each pilot site completed a self-assessment survey¹⁷ (see supplementary Appendix A) about past efforts, team composition, current performance, aims, barriers, and opportunities. The mentors reviewed the completed questionnaire with each hospital and provided advice on the VTE protocol and order set design, measurement, and benchmarking during 3 webinar meetings scheduled at 0, 3, and 9 months, plus as-needed e-mail and phone correspondence. After each webinar, the mentors provided detailed improvement suggestions (see supplementary Appendix B). Several hospitals received mentor site visits, which focused on unit rounding, active surveillance, staff and provider education, and problem-solving sessions with senior leadership, physician leadership, and the improvement team.

VTE Protocol

After a literature review and consultation with the mentors, Dignity Health developed and implemented a VTE protocol, modified from a model used in previous improvement efforts.^18,22-24 Its risk assessment method is often referred to as a “3 bucket” model because it assigns patients to high-, moderate-, or low-risk categories based on clinical factors (eg, major orthopedic surgery, prior VTE, and others), and the VTE protocol recommends interventions based on the risk category (see supplementary Appendix C). Dignity Health was transitioning to a single electronic health record (Cerner Corporation, North Kansas City, MO) during the study, and study hospitals were using multiple platforms, necessitating the development of both paper and electronic versions of the VTE protocol. The electronic version required completion of the VTE protocol for all inpatient admissions and transfers. The VTE protocol was completed in November 2011 and disseminated to other sites in a staggered fashion through November 2012. Completed protocols and improvement tips were shared by the project lead and by webinar sessions. Sites were also encouraged to implement a standardized practice that allowed nurses to apply sequential compression devices to at-risk patients without physician orders when indicated by protocol, when contraindications such as vascular disease or ulceration were absent.

Education

Staff were educated about the VTE protocol by local teams, starting between late 2011 and September 2012. The audience (physicians, nurses, pharmacists, etc.) and methods (conferences, fliers, etc.) were determined by local teams, following guidance by mentors and webinar content. Active surveillance provided opportunities for in-the-moment, patient-specific education and protocol reinforcement. Both mentors delivered educational presentations at pilot sites.

Active Surveillance

Sites were encouraged to perform daily review of prophylaxis adequacy for inpatients and correct lapses in real time (both under- and overprophylaxis). Inappropriate prophylaxis orders were addressed by contacting providers to change the order or document the rationale not to. Lapses in adherence to prophylaxis were addressed by nursing correction and education of involved staff. Active surveillance was funded for 10 hours a week at pilot sites. Spread sites received only minimal support from HEN monies. All sites used daily prophylaxis reports, enhanced to include contraindications like thrombocytopenia and coagulopathy, to facilitate efforts. Active surveillance began in May 2012 in the lead pilot hospitals and was implemented in other sites between October 2012 and February 2013.

Metrics

Prophylaxis Rates

Measurement of prophylaxis did not begin until 2012 to 2013; thus, the true baseline rate for prophylaxis was not captured. TJC metrics (VTE-1 and VTE-2)²⁵ were consolidated into a composite TJC prophylaxis rate from January 2012 to December 2014 for both pilot and spread hospitals. These measures assess the percentage of adult inpatients who received VTE prophylaxis or have documentation of why no prophylaxis was given the day of or day after hospital admission (VTE-1) or the day of or day after ICU admission or transfer (VTE-2). These measures are met if any mechanical or pharmacologic prophylaxis was delivered.

In addition to the TJC metric, the 9 pilot hospitals monitored rates of protocol-compliant prophylaxis for 12 to 20 months. Each patient’s prophylaxis was considered protocol compliant if it was consistent with the prophylaxis protocol at the time of the audit or if contraindications were documented (eg, patients eligible for, but with contraindications to, pharmacologic prophylaxis had to have an order for mechanical prophylaxis or documented contraindication to both modalities). As this measure was initiated in a staggered fashion, the rate of protocol-compliant prophylaxis is summarized for consecutive months of measurement rather than consecutive calendar months.

HA-VTE Rates

VTE events were captured by review of electronic coding data for the International Classification of Diseases, 9th Revision (ICD-9) codes 415.11-415.19, 453.2, 453.40-453.42, and 453.8-453.89. HA-VTE was defined as either new VTE not present on admission (NPOA HA-VTE) or new VTE presenting in a readmitted patient within 30 days of discharge (Readmit HA-VTE). Cases were stratified based on whether the patient had undergone a major operation (surgery patients) or not (medical patients) as identified by Medicare Services diagnosis-related group codes.

Control Measures

Potential adverse events were captured by review of electronic coding data for ICD-9 codes 289.84 (heparin-induced thrombocytopenia [HIT]) and E934.2 (adverse effects because of anticoagulants).

Statistical Analysis

Statistical process control charts were used to depict changes in prophylaxis rates over the 3 years for which data was collected. For VTE and safety outcomes, Pearson χ² value with relative risk (RR) calculations and 95% confidence intervals (CIs) were used to compare proportions between groups at baseline (CY 2011) versus postimplementation (CY 2014). Differences between the means of normally distributed data were calculated, and a 95% CI for the difference between the means was performed to assess statistical difference. Nonparametric characteristics were described by quartiles and interquartile range, and the 2-sided Mann-Whitney U test was performed to assess statistical difference between the CY 2011 and CY 2014 period.

Role of the Funding Source

The GBMF funded the collaborative and supported authorship of the manuscript but had no role in the design or conduct of the intervention, the collection or analysis of data, or the drafting of the manuscript.

Population Demographics

There were 1,155,069 adult inpatient admissions during the 4-year study period (264,280 in the 9 pilot sites, 890,789 in the 26 spread sites). There were no clinically relevant changes in gender distribution, mortality rate, median age, case mix index, or hospital length of stay in 2011 versus 2014. Men comprised 47.1% of the patient population in 2011 and 47.7% in 2014. The mortality rate was 2.7% in both years. Median age was 62 in 2011 and 63 in 2014. The mean case mix index (1.58 vs 1.65) and mean length of stay (4.29 vs 4.33 days) were similar in the 2 time periods.

Prophylaxis Rates

TJC Prophylaxis rates

Rates of Protocol-Compliant Prophylaxis

There were 34,071 active surveillance audits across the 20 months of reporting in the pilot cohort (mean, 1817 audits per month). The rate of protocol-compliant prophylaxis improved from 89% at month 1 of observation to 93% during month 2 and 97% by the last 3 months (Pearson χ² P < .001 for both comparisons).

HA-VTE

HA-VTE characteristics

Improved HA-VTE over Time

Four hundred twenty-eight fewer HA-VTEs occurred in 2014 than in 2011 (RR 0.78; 95% CI, 0.73-0.85) (Table and Figure 3). Readmission HA-VTEs were reduced by 315 (RR 0.72; 95% CI, 0.65-0.80), while the reduction in NPOA HA-VTEs was less robust (RR 0.88; 95% CI, 0.79-0.99). Pilot sites enjoyed a more robust reduction in HA-VTEs than spread sites (26% vs 20%), largely because the pilot cohort enjoyed a 34% reduction in NPOA HA-VTEs and a 20% reduction in Readmit HA-VTEs, while the spread cohort only achieved reductions in Readmit HA-VTEs.

Safety

Rates of HIT and adverse effects because of anticoagulants were low (Table). The rate of HIT declined from 178 events in 2011 to 109 in 2014 (RR 0.66; 95% CI, 0.52-0.84), and the RR of anticoagulant adverse events remained stable (RR 1.01; 95% CI, 0.87-1.15).

Our QI project, based on a proven collaborative approach and mentorship,^18,22,24 order set redesign, and active surveillance, was associated with 26% less VTEs in the pilot cohort and 20% less VTEs in the spread cohort. These gains, down to a final rate of approximately 4 HA-VTEs per 1000 admissions, occurred despite a low baseline HA-VTE rate. Dignity Health achieved these improvements in 35 hospitals with varied sizes, settings, ordering systems, and teaching statuses, achieving what is to our knowledge the largest VTE QI initiative yet reported.

Implementation experiences were not systematically recorded, and techniques were not compared with a control group. However, we believe that Dignity Health’s organizational commitment to improvement and centralized support were crucial for success. In addition, the pilot sites received grant support from the GBMF for intensive quality mentoring, a strategy with demonstrated value.²³ Mentors and team members noted that system-wide revision to the computerized physician order entry system was easiest to implement, while active surveillance represented the most labor-intensive intervention. Other experiences echoed lessons from previous VTE mentorship efforts.^17,18

The selection of a VTE protocol conducive to implementation and provider use was a key strategy. The ideal approach to VTE risk assessment is not known,^12,26 but guidelines either offer no specific guidance⁷ or would require implementation of 3 different systems per hospital.^4,5 Several of these are point scoring systems, which may have lower clinician acceptance or require programming to improve real-world use^18,26,27; the Padua score was derived from a patient population that differs significantly from those in the United States.¹² Our study provides more practical experience with a “3-bucket” model, which has previously shown high interobserver reliability, good clinician acceptance, and meaningful reductions of VTE, including in American patient populations.^18,22,24

The value of VTE prophylaxis is still disputed in many inpatient groups. The overall rate of HA-VTE is low, so the per-patient benefit of prophylaxis is low, and many patients may be overprophylaxed.^4,11,12 Recently, Flanders et al.²⁰ reported that HA-VTE rates among 20,800 medical inpatients in Michigan were low (about 1%) and similar at hospitals in the top (mean prophylaxis rate 86%) or bottom (mean prophylaxis rate 56%) tertiles of performance. Possible explanations for the differences between their multicenter experience and ours include our sample size (55 times larger) and the possibility that targeting prophylaxis to patients at highest need (captured in our protocol-compliant prophylaxis rates) matters more than prophylaxing a percent of the population.

Further research is needed to develop simple, easy-to-implement methods to identify inpatients who do not, or no longer, require prophylaxis.¹² Hospital systems also need methods to determine if prophylaxis improvement efforts can lower their HA-VTE rates and in which subpopulations. For example, a collaborative effort at the University of California lowered HA-VTE rates toward a common improved rate of 0.65% to 0.73%,²² while Dignity Health achieved improvement despite starting with an even lower baseline. In the University of California collaborative, benefits were limited chiefly to surgical patients, while Dignity Health achieved most improvement in medical patients, particularly in Readmit HA-VTE. If future research uncovers the reasons for these differences, it could help hospitals decide where to target improvement efforts.

Our study has several limitations. First, we used a nonrandomized time series design, so we cannot exclude other potential explanations for the change in VTE rates. However, there were no major changes in patient populations or concurrent projects likely to have influenced event rates. While we did not collect detailed demographic information on subjects, the broad inclusion criteria and multicenter design suggests a high degree of generalizability. Second, we followed inpatient VTE events and VTE-related readmissions, but not VTE treated in the outpatient setting. This did not change over the study, but the availability of all-oral therapy for VTE could have caused underdetection if clinic or emergency room doctors sent home more patients on oral therapy instead of readmitting them to the hospital. Third, implementation was enhanced by GBMF funds (at 9 sites, with the remainder benefitting from their experience), a shared electronic medical record at many sites, and a strong organizational safety culture, which may limit generalizability. However, spread sites showed similar improvement, paper-based sites were included, and the mentorship and quality collaborative models are scalable at low cost. Fourth, some QI efforts began at some pilot sites in CY 2011, so we could not compare completely clean pre- and postproject timeframes. However, early improvement would have resulted in an underestimation of the project’s impact. Lastly, the reason for a decline in HIT rates is not known. Standardized order sets promoted preferential use of low molecular weight heparin, which is less likely to induce HIT, and active surveillance targeted overprophylaxis as well as underprophylaxis, but we do not have data on heparin utilization patterns to confirm or refute these possibilities.

Strengths of our study include reductions in HA-VTE, both with and without access to GBMF funds, by using broadly available QI strategies.¹⁷ This real-world success and ease of dissemination are particularly important because the clinical trials of prophylaxis have been criticized for using highly selected patient populations,¹¹ and prophylaxis QI studies show an inconsistent impact on VTE outcomes.¹⁵ In previous studies, two of the authors monitored orders for prophylaxis^22,24; during this project, delivery for both pharmacologic and mechanical VTE prophylaxis was monitored, confirming that patient care actually changed.

Our multicenter VTE prophylaxis initiative, featuring a “3-bucket” VTE protocol, QI mentorship, and active surveillance as key interventions, was associated with improved prophylaxis rates and a reduction in HA-VTE by 22% with no increase in adverse events. This project provides a model for hospital systems seeking to optimize their prophylaxis efforts, and it supports the use of collaborative QI initiatives and SHM’s quality mentorship program as methods to drive improvement across health systems.

Disclosure

None of the authors have any conflicts of interest related to any topics or products discussed in the article. Dignity Health provided a stipend for writing the manuscript to GM and IJ, as noted in the article, but had no role in data analysis, writing, or decision to submit.

Deep venous thrombosis and pulmonary embolism, collectively known as venous thromboembolism (VTE), affect up to 600,000 Americans a year.¹ Most of these are hospital-associated venous thromboembolisms (HA-VTE).^1,2 VTE poses a substantial risk of mortality and long-term morbidity, and its treatment poses a risk of major bleeding.¹ As appropriate VTE prophylaxis (“prophylaxis”) can reduce the risk of VTE by 40% to 80% depending on the patient population,³ VTE risk assessment and prophylaxis is endorsed by multiple guidelines^4-7 and supported by regulatory agencies.^8-10

However, despite extensive study, consensus about the impact of prophylaxis^4,11 and the optimal method of risk assessment^4,5,7,12 is lacking. Meanwhile, implementation of prophylaxis in real-world settings is poor; only 40% to 60% of at-risk patients receive prophylaxis,¹³ and as few as <20% receive optimal prophylaxis.¹⁴ Both systematic reviews^15,16 and experience with VTE prevention collaboratives^17,18 found that multifaceted interventions and alerts may be most effective in improving prophylaxis rates, but without proof of improved VTE rates.¹⁵ There is limited experience with large-scale VTE prevention. Organizations like The Joint Commission (TJC)⁸ and the Surgical Care Improvement Project have promoted quality measures but without clear evidence of improvement.¹⁹ In addition, an analysis of over 20,000 medical patients at 35 hospitals found no difference in VTE rates between high- and low-performing hospitals,²⁰ suggesting that aggressive prophylaxis efforts may not reduce VTE, at least among medical patients.²¹ However, a 5-hospital University of California collaborative was associated with improved VTE rates, chiefly among surgical patients.²²

In 2011, Dignity Health targeted VTE for improvement after investigations of potentially preventable HA-VTE revealed variable patterns of prophylaxis. In addition, improvement seemed feasible because there is a proven framework for VTE quality improvement (QI) projects^17,18 and a record of success with the following 3 specific strategies: quality mentorship,²³ use of a simple VTE risk assessment method, and active surveillance (real-time monitoring targeting suboptimal prophylaxis with concurrent intervention). This active surveillance technique has been used successfully in prior improvement efforts, often termed measure-vention.^17,18,22,24

Setting and Participants

The QI collaborative was performed at 35 Dignity Health community hospitals in California, Arizona, and Nevada. Facilities ranged from 25 to 571 beds in size with a mixture of teaching and nonteaching hospitals. Prior to the initiative, prophylaxis improvement efforts were incomplete and inconsistent at study facilities. All adult acute care inpatients at all facilities were included except rehabilitation, behavioral health, skilled nursing, hospice, other nonacute care, and inpatient deliveries.

Design Overview

We performed a prospective, unblinded, open-intervention study of a QI collaborative in 35 community hospitals and studied the effect on prophylaxis and VTE rates with historical controls. The 35 hospitals were organized into 2 cohorts. In the “pilot” cohort, 9 hospitals (chosen to be representative of the various settings, size, and teaching status within the Dignity system) received funding from the Gordon and Betty Moore Foundation (GBMF) for intensive, individualized QI mentorship from experts as well as active surveillance (see “Interventions”). The pilot sites led the development of the VTE risk assessment and prophylaxis protocol (“VTE protocol”), measures, order sets, implementation tactics, and lessons learned, assisted by the mentor experts. Dissemination to the 26-hospital “spread” cohort was facilitated by the Dignity Health Hospital Engagement Network (HEN) infrastructure.

Timeline

Two of the pilot sites, acting as leads on the development of protocol and order set tools, formed improvement teams in March 2011, 6 to 12 months earlier than other Dignity sites. Planning and design work occurred from March 2011 to September 2012. Most implementation at the 35 hospitals occurred in a staggered fashion during calendar year (CY) 2012 and 2013 (see Figure 1). As few changes were made until mid-2012, we considered CY 2011 the baseline for comparison, CY 2012 to 2013 the implementation years, and CY 2014 the postimplementation period.

The project was reviewed by the Institutional Review Board (IRB) of Dignity Health and determined to be an IRB-exempt QI project.

Interventions

Collaborative Infrastructure

Multidisciplinary Teams

Improvement teams formed between March 2011 and September 2012. Members included a physician champion, frontline nurses and physicians, an administrative liaison, pharmacists, quality and data specialists, clinical informatics staff, and stakeholders from key clinical services. Teams met at least monthly at each site.

Physician Mentors

The 9 pilot sites received individualized mentorship provided by outside experts (IJ or GM) based on a model pioneered by the Society of Hospital Medicine’s (SHM) Mentored Implementation programs.²³ Each pilot site completed a self-assessment survey¹⁷ (see supplementary Appendix A) about past efforts, team composition, current performance, aims, barriers, and opportunities. The mentors reviewed the completed questionnaire with each hospital and provided advice on the VTE protocol and order set design, measurement, and benchmarking during 3 webinar meetings scheduled at 0, 3, and 9 months, plus as-needed e-mail and phone correspondence. After each webinar, the mentors provided detailed improvement suggestions (see supplementary Appendix B). Several hospitals received mentor site visits, which focused on unit rounding, active surveillance, staff and provider education, and problem-solving sessions with senior leadership, physician leadership, and the improvement team.

VTE Protocol

After a literature review and consultation with the mentors, Dignity Health developed and implemented a VTE protocol, modified from a model used in previous improvement efforts.^18,22-24 Its risk assessment method is often referred to as a “3 bucket” model because it assigns patients to high-, moderate-, or low-risk categories based on clinical factors (eg, major orthopedic surgery, prior VTE, and others), and the VTE protocol recommends interventions based on the risk category (see supplementary Appendix C). Dignity Health was transitioning to a single electronic health record (Cerner Corporation, North Kansas City, MO) during the study, and study hospitals were using multiple platforms, necessitating the development of both paper and electronic versions of the VTE protocol. The electronic version required completion of the VTE protocol for all inpatient admissions and transfers. The VTE protocol was completed in November 2011 and disseminated to other sites in a staggered fashion through November 2012. Completed protocols and improvement tips were shared by the project lead and by webinar sessions. Sites were also encouraged to implement a standardized practice that allowed nurses to apply sequential compression devices to at-risk patients without physician orders when indicated by protocol, when contraindications such as vascular disease or ulceration were absent.

Education

Staff were educated about the VTE protocol by local teams, starting between late 2011 and September 2012. The audience (physicians, nurses, pharmacists, etc.) and methods (conferences, fliers, etc.) were determined by local teams, following guidance by mentors and webinar content. Active surveillance provided opportunities for in-the-moment, patient-specific education and protocol reinforcement. Both mentors delivered educational presentations at pilot sites.

Active Surveillance

Sites were encouraged to perform daily review of prophylaxis adequacy for inpatients and correct lapses in real time (both under- and overprophylaxis). Inappropriate prophylaxis orders were addressed by contacting providers to change the order or document the rationale not to. Lapses in adherence to prophylaxis were addressed by nursing correction and education of involved staff. Active surveillance was funded for 10 hours a week at pilot sites. Spread sites received only minimal support from HEN monies. All sites used daily prophylaxis reports, enhanced to include contraindications like thrombocytopenia and coagulopathy, to facilitate efforts. Active surveillance began in May 2012 in the lead pilot hospitals and was implemented in other sites between October 2012 and February 2013.

Metrics

Prophylaxis Rates

Measurement of prophylaxis did not begin until 2012 to 2013; thus, the true baseline rate for prophylaxis was not captured. TJC metrics (VTE-1 and VTE-2)²⁵ were consolidated into a composite TJC prophylaxis rate from January 2012 to December 2014 for both pilot and spread hospitals. These measures assess the percentage of adult inpatients who received VTE prophylaxis or have documentation of why no prophylaxis was given the day of or day after hospital admission (VTE-1) or the day of or day after ICU admission or transfer (VTE-2). These measures are met if any mechanical or pharmacologic prophylaxis was delivered.

In addition to the TJC metric, the 9 pilot hospitals monitored rates of protocol-compliant prophylaxis for 12 to 20 months. Each patient’s prophylaxis was considered protocol compliant if it was consistent with the prophylaxis protocol at the time of the audit or if contraindications were documented (eg, patients eligible for, but with contraindications to, pharmacologic prophylaxis had to have an order for mechanical prophylaxis or documented contraindication to both modalities). As this measure was initiated in a staggered fashion, the rate of protocol-compliant prophylaxis is summarized for consecutive months of measurement rather than consecutive calendar months.

HA-VTE Rates

VTE events were captured by review of electronic coding data for the International Classification of Diseases, 9th Revision (ICD-9) codes 415.11-415.19, 453.2, 453.40-453.42, and 453.8-453.89. HA-VTE was defined as either new VTE not present on admission (NPOA HA-VTE) or new VTE presenting in a readmitted patient within 30 days of discharge (Readmit HA-VTE). Cases were stratified based on whether the patient had undergone a major operation (surgery patients) or not (medical patients) as identified by Medicare Services diagnosis-related group codes.

Control Measures

Potential adverse events were captured by review of electronic coding data for ICD-9 codes 289.84 (heparin-induced thrombocytopenia [HIT]) and E934.2 (adverse effects because of anticoagulants).

Statistical Analysis

Statistical process control charts were used to depict changes in prophylaxis rates over the 3 years for which data was collected. For VTE and safety outcomes, Pearson χ² value with relative risk (RR) calculations and 95% confidence intervals (CIs) were used to compare proportions between groups at baseline (CY 2011) versus postimplementation (CY 2014). Differences between the means of normally distributed data were calculated, and a 95% CI for the difference between the means was performed to assess statistical difference. Nonparametric characteristics were described by quartiles and interquartile range, and the 2-sided Mann-Whitney U test was performed to assess statistical difference between the CY 2011 and CY 2014 period.

Role of the Funding Source

The GBMF funded the collaborative and supported authorship of the manuscript but had no role in the design or conduct of the intervention, the collection or analysis of data, or the drafting of the manuscript.

Population Demographics

There were 1,155,069 adult inpatient admissions during the 4-year study period (264,280 in the 9 pilot sites, 890,789 in the 26 spread sites). There were no clinically relevant changes in gender distribution, mortality rate, median age, case mix index, or hospital length of stay in 2011 versus 2014. Men comprised 47.1% of the patient population in 2011 and 47.7% in 2014. The mortality rate was 2.7% in both years. Median age was 62 in 2011 and 63 in 2014. The mean case mix index (1.58 vs 1.65) and mean length of stay (4.29 vs 4.33 days) were similar in the 2 time periods.

Prophylaxis Rates

TJC Prophylaxis rates

Rates of Protocol-Compliant Prophylaxis

There were 34,071 active surveillance audits across the 20 months of reporting in the pilot cohort (mean, 1817 audits per month). The rate of protocol-compliant prophylaxis improved from 89% at month 1 of observation to 93% during month 2 and 97% by the last 3 months (Pearson χ² P < .001 for both comparisons).

HA-VTE

HA-VTE characteristics

Improved HA-VTE over Time

Four hundred twenty-eight fewer HA-VTEs occurred in 2014 than in 2011 (RR 0.78; 95% CI, 0.73-0.85) (Table and Figure 3). Readmission HA-VTEs were reduced by 315 (RR 0.72; 95% CI, 0.65-0.80), while the reduction in NPOA HA-VTEs was less robust (RR 0.88; 95% CI, 0.79-0.99). Pilot sites enjoyed a more robust reduction in HA-VTEs than spread sites (26% vs 20%), largely because the pilot cohort enjoyed a 34% reduction in NPOA HA-VTEs and a 20% reduction in Readmit HA-VTEs, while the spread cohort only achieved reductions in Readmit HA-VTEs.

Safety

Rates of HIT and adverse effects because of anticoagulants were low (Table). The rate of HIT declined from 178 events in 2011 to 109 in 2014 (RR 0.66; 95% CI, 0.52-0.84), and the RR of anticoagulant adverse events remained stable (RR 1.01; 95% CI, 0.87-1.15).

Our QI project, based on a proven collaborative approach and mentorship,^18,22,24 order set redesign, and active surveillance, was associated with 26% less VTEs in the pilot cohort and 20% less VTEs in the spread cohort. These gains, down to a final rate of approximately 4 HA-VTEs per 1000 admissions, occurred despite a low baseline HA-VTE rate. Dignity Health achieved these improvements in 35 hospitals with varied sizes, settings, ordering systems, and teaching statuses, achieving what is to our knowledge the largest VTE QI initiative yet reported.

Implementation experiences were not systematically recorded, and techniques were not compared with a control group. However, we believe that Dignity Health’s organizational commitment to improvement and centralized support were crucial for success. In addition, the pilot sites received grant support from the GBMF for intensive quality mentoring, a strategy with demonstrated value.²³ Mentors and team members noted that system-wide revision to the computerized physician order entry system was easiest to implement, while active surveillance represented the most labor-intensive intervention. Other experiences echoed lessons from previous VTE mentorship efforts.^17,18

The selection of a VTE protocol conducive to implementation and provider use was a key strategy. The ideal approach to VTE risk assessment is not known,^12,26 but guidelines either offer no specific guidance⁷ or would require implementation of 3 different systems per hospital.^4,5 Several of these are point scoring systems, which may have lower clinician acceptance or require programming to improve real-world use^18,26,27; the Padua score was derived from a patient population that differs significantly from those in the United States.¹² Our study provides more practical experience with a “3-bucket” model, which has previously shown high interobserver reliability, good clinician acceptance, and meaningful reductions of VTE, including in American patient populations.^18,22,24

The value of VTE prophylaxis is still disputed in many inpatient groups. The overall rate of HA-VTE is low, so the per-patient benefit of prophylaxis is low, and many patients may be overprophylaxed.^4,11,12 Recently, Flanders et al.²⁰ reported that HA-VTE rates among 20,800 medical inpatients in Michigan were low (about 1%) and similar at hospitals in the top (mean prophylaxis rate 86%) or bottom (mean prophylaxis rate 56%) tertiles of performance. Possible explanations for the differences between their multicenter experience and ours include our sample size (55 times larger) and the possibility that targeting prophylaxis to patients at highest need (captured in our protocol-compliant prophylaxis rates) matters more than prophylaxing a percent of the population.

Further research is needed to develop simple, easy-to-implement methods to identify inpatients who do not, or no longer, require prophylaxis.¹² Hospital systems also need methods to determine if prophylaxis improvement efforts can lower their HA-VTE rates and in which subpopulations. For example, a collaborative effort at the University of California lowered HA-VTE rates toward a common improved rate of 0.65% to 0.73%,²² while Dignity Health achieved improvement despite starting with an even lower baseline. In the University of California collaborative, benefits were limited chiefly to surgical patients, while Dignity Health achieved most improvement in medical patients, particularly in Readmit HA-VTE. If future research uncovers the reasons for these differences, it could help hospitals decide where to target improvement efforts.

Our study has several limitations. First, we used a nonrandomized time series design, so we cannot exclude other potential explanations for the change in VTE rates. However, there were no major changes in patient populations or concurrent projects likely to have influenced event rates. While we did not collect detailed demographic information on subjects, the broad inclusion criteria and multicenter design suggests a high degree of generalizability. Second, we followed inpatient VTE events and VTE-related readmissions, but not VTE treated in the outpatient setting. This did not change over the study, but the availability of all-oral therapy for VTE could have caused underdetection if clinic or emergency room doctors sent home more patients on oral therapy instead of readmitting them to the hospital. Third, implementation was enhanced by GBMF funds (at 9 sites, with the remainder benefitting from their experience), a shared electronic medical record at many sites, and a strong organizational safety culture, which may limit generalizability. However, spread sites showed similar improvement, paper-based sites were included, and the mentorship and quality collaborative models are scalable at low cost. Fourth, some QI efforts began at some pilot sites in CY 2011, so we could not compare completely clean pre- and postproject timeframes. However, early improvement would have resulted in an underestimation of the project’s impact. Lastly, the reason for a decline in HIT rates is not known. Standardized order sets promoted preferential use of low molecular weight heparin, which is less likely to induce HIT, and active surveillance targeted overprophylaxis as well as underprophylaxis, but we do not have data on heparin utilization patterns to confirm or refute these possibilities.

Strengths of our study include reductions in HA-VTE, both with and without access to GBMF funds, by using broadly available QI strategies.¹⁷ This real-world success and ease of dissemination are particularly important because the clinical trials of prophylaxis have been criticized for using highly selected patient populations,¹¹ and prophylaxis QI studies show an inconsistent impact on VTE outcomes.¹⁵ In previous studies, two of the authors monitored orders for prophylaxis^22,24; during this project, delivery for both pharmacologic and mechanical VTE prophylaxis was monitored, confirming that patient care actually changed.

Our multicenter VTE prophylaxis initiative, featuring a “3-bucket” VTE protocol, QI mentorship, and active surveillance as key interventions, was associated with improved prophylaxis rates and a reduction in HA-VTE by 22% with no increase in adverse events. This project provides a model for hospital systems seeking to optimize their prophylaxis efforts, and it supports the use of collaborative QI initiatives and SHM’s quality mentorship program as methods to drive improvement across health systems.

Disclosure

None of the authors have any conflicts of interest related to any topics or products discussed in the article. Dignity Health provided a stipend for writing the manuscript to GM and IJ, as noted in the article, but had no role in data analysis, writing, or decision to submit.

Deep venous thrombosis and pulmonary embolism, collectively known as venous thromboembolism (VTE), affect up to 600,000 Americans a year.¹ Most of these are hospital-associated venous thromboembolisms (HA-VTE).^1,2 VTE poses a substantial risk of mortality and long-term morbidity, and its treatment poses a risk of major bleeding.¹ As appropriate VTE prophylaxis (“prophylaxis”) can reduce the risk of VTE by 40% to 80% depending on the patient population,³ VTE risk assessment and prophylaxis is endorsed by multiple guidelines^4-7 and supported by regulatory agencies.^8-10

However, despite extensive study, consensus about the impact of prophylaxis^4,11 and the optimal method of risk assessment^4,5,7,12 is lacking. Meanwhile, implementation of prophylaxis in real-world settings is poor; only 40% to 60% of at-risk patients receive prophylaxis,¹³ and as few as <20% receive optimal prophylaxis.¹⁴ Both systematic reviews^15,16 and experience with VTE prevention collaboratives^17,18 found that multifaceted interventions and alerts may be most effective in improving prophylaxis rates, but without proof of improved VTE rates.¹⁵ There is limited experience with large-scale VTE prevention. Organizations like The Joint Commission (TJC)⁸ and the Surgical Care Improvement Project have promoted quality measures but without clear evidence of improvement.¹⁹ In addition, an analysis of over 20,000 medical patients at 35 hospitals found no difference in VTE rates between high- and low-performing hospitals,²⁰ suggesting that aggressive prophylaxis efforts may not reduce VTE, at least among medical patients.²¹ However, a 5-hospital University of California collaborative was associated with improved VTE rates, chiefly among surgical patients.²²

In 2011, Dignity Health targeted VTE for improvement after investigations of potentially preventable HA-VTE revealed variable patterns of prophylaxis. In addition, improvement seemed feasible because there is a proven framework for VTE quality improvement (QI) projects^17,18 and a record of success with the following 3 specific strategies: quality mentorship,²³ use of a simple VTE risk assessment method, and active surveillance (real-time monitoring targeting suboptimal prophylaxis with concurrent intervention). This active surveillance technique has been used successfully in prior improvement efforts, often termed measure-vention.^17,18,22,24

Setting and Participants

The QI collaborative was performed at 35 Dignity Health community hospitals in California, Arizona, and Nevada. Facilities ranged from 25 to 571 beds in size with a mixture of teaching and nonteaching hospitals. Prior to the initiative, prophylaxis improvement efforts were incomplete and inconsistent at study facilities. All adult acute care inpatients at all facilities were included except rehabilitation, behavioral health, skilled nursing, hospice, other nonacute care, and inpatient deliveries.

Design Overview

We performed a prospective, unblinded, open-intervention study of a QI collaborative in 35 community hospitals and studied the effect on prophylaxis and VTE rates with historical controls. The 35 hospitals were organized into 2 cohorts. In the “pilot” cohort, 9 hospitals (chosen to be representative of the various settings, size, and teaching status within the Dignity system) received funding from the Gordon and Betty Moore Foundation (GBMF) for intensive, individualized QI mentorship from experts as well as active surveillance (see “Interventions”). The pilot sites led the development of the VTE risk assessment and prophylaxis protocol (“VTE protocol”), measures, order sets, implementation tactics, and lessons learned, assisted by the mentor experts. Dissemination to the 26-hospital “spread” cohort was facilitated by the Dignity Health Hospital Engagement Network (HEN) infrastructure.

Timeline

Two of the pilot sites, acting as leads on the development of protocol and order set tools, formed improvement teams in March 2011, 6 to 12 months earlier than other Dignity sites. Planning and design work occurred from March 2011 to September 2012. Most implementation at the 35 hospitals occurred in a staggered fashion during calendar year (CY) 2012 and 2013 (see Figure 1). As few changes were made until mid-2012, we considered CY 2011 the baseline for comparison, CY 2012 to 2013 the implementation years, and CY 2014 the postimplementation period.

The project was reviewed by the Institutional Review Board (IRB) of Dignity Health and determined to be an IRB-exempt QI project.

Interventions

Collaborative Infrastructure

Multidisciplinary Teams

Improvement teams formed between March 2011 and September 2012. Members included a physician champion, frontline nurses and physicians, an administrative liaison, pharmacists, quality and data specialists, clinical informatics staff, and stakeholders from key clinical services. Teams met at least monthly at each site.

Physician Mentors

The 9 pilot sites received individualized mentorship provided by outside experts (IJ or GM) based on a model pioneered by the Society of Hospital Medicine’s (SHM) Mentored Implementation programs.²³ Each pilot site completed a self-assessment survey¹⁷ (see supplementary Appendix A) about past efforts, team composition, current performance, aims, barriers, and opportunities. The mentors reviewed the completed questionnaire with each hospital and provided advice on the VTE protocol and order set design, measurement, and benchmarking during 3 webinar meetings scheduled at 0, 3, and 9 months, plus as-needed e-mail and phone correspondence. After each webinar, the mentors provided detailed improvement suggestions (see supplementary Appendix B). Several hospitals received mentor site visits, which focused on unit rounding, active surveillance, staff and provider education, and problem-solving sessions with senior leadership, physician leadership, and the improvement team.

VTE Protocol

After a literature review and consultation with the mentors, Dignity Health developed and implemented a VTE protocol, modified from a model used in previous improvement efforts.^18,22-24 Its risk assessment method is often referred to as a “3 bucket” model because it assigns patients to high-, moderate-, or low-risk categories based on clinical factors (eg, major orthopedic surgery, prior VTE, and others), and the VTE protocol recommends interventions based on the risk category (see supplementary Appendix C). Dignity Health was transitioning to a single electronic health record (Cerner Corporation, North Kansas City, MO) during the study, and study hospitals were using multiple platforms, necessitating the development of both paper and electronic versions of the VTE protocol. The electronic version required completion of the VTE protocol for all inpatient admissions and transfers. The VTE protocol was completed in November 2011 and disseminated to other sites in a staggered fashion through November 2012. Completed protocols and improvement tips were shared by the project lead and by webinar sessions. Sites were also encouraged to implement a standardized practice that allowed nurses to apply sequential compression devices to at-risk patients without physician orders when indicated by protocol, when contraindications such as vascular disease or ulceration were absent.

Education

Staff were educated about the VTE protocol by local teams, starting between late 2011 and September 2012. The audience (physicians, nurses, pharmacists, etc.) and methods (conferences, fliers, etc.) were determined by local teams, following guidance by mentors and webinar content. Active surveillance provided opportunities for in-the-moment, patient-specific education and protocol reinforcement. Both mentors delivered educational presentations at pilot sites.

Active Surveillance

Sites were encouraged to perform daily review of prophylaxis adequacy for inpatients and correct lapses in real time (both under- and overprophylaxis). Inappropriate prophylaxis orders were addressed by contacting providers to change the order or document the rationale not to. Lapses in adherence to prophylaxis were addressed by nursing correction and education of involved staff. Active surveillance was funded for 10 hours a week at pilot sites. Spread sites received only minimal support from HEN monies. All sites used daily prophylaxis reports, enhanced to include contraindications like thrombocytopenia and coagulopathy, to facilitate efforts. Active surveillance began in May 2012 in the lead pilot hospitals and was implemented in other sites between October 2012 and February 2013.

Metrics

Prophylaxis Rates

Measurement of prophylaxis did not begin until 2012 to 2013; thus, the true baseline rate for prophylaxis was not captured. TJC metrics (VTE-1 and VTE-2)²⁵ were consolidated into a composite TJC prophylaxis rate from January 2012 to December 2014 for both pilot and spread hospitals. These measures assess the percentage of adult inpatients who received VTE prophylaxis or have documentation of why no prophylaxis was given the day of or day after hospital admission (VTE-1) or the day of or day after ICU admission or transfer (VTE-2). These measures are met if any mechanical or pharmacologic prophylaxis was delivered.

In addition to the TJC metric, the 9 pilot hospitals monitored rates of protocol-compliant prophylaxis for 12 to 20 months. Each patient’s prophylaxis was considered protocol compliant if it was consistent with the prophylaxis protocol at the time of the audit or if contraindications were documented (eg, patients eligible for, but with contraindications to, pharmacologic prophylaxis had to have an order for mechanical prophylaxis or documented contraindication to both modalities). As this measure was initiated in a staggered fashion, the rate of protocol-compliant prophylaxis is summarized for consecutive months of measurement rather than consecutive calendar months.

HA-VTE Rates

VTE events were captured by review of electronic coding data for the International Classification of Diseases, 9th Revision (ICD-9) codes 415.11-415.19, 453.2, 453.40-453.42, and 453.8-453.89. HA-VTE was defined as either new VTE not present on admission (NPOA HA-VTE) or new VTE presenting in a readmitted patient within 30 days of discharge (Readmit HA-VTE). Cases were stratified based on whether the patient had undergone a major operation (surgery patients) or not (medical patients) as identified by Medicare Services diagnosis-related group codes.

Control Measures

Potential adverse events were captured by review of electronic coding data for ICD-9 codes 289.84 (heparin-induced thrombocytopenia [HIT]) and E934.2 (adverse effects because of anticoagulants).

Statistical Analysis

Statistical process control charts were used to depict changes in prophylaxis rates over the 3 years for which data was collected. For VTE and safety outcomes, Pearson χ² value with relative risk (RR) calculations and 95% confidence intervals (CIs) were used to compare proportions between groups at baseline (CY 2011) versus postimplementation (CY 2014). Differences between the means of normally distributed data were calculated, and a 95% CI for the difference between the means was performed to assess statistical difference. Nonparametric characteristics were described by quartiles and interquartile range, and the 2-sided Mann-Whitney U test was performed to assess statistical difference between the CY 2011 and CY 2014 period.

Role of the Funding Source

The GBMF funded the collaborative and supported authorship of the manuscript but had no role in the design or conduct of the intervention, the collection or analysis of data, or the drafting of the manuscript.

Population Demographics

There were 1,155,069 adult inpatient admissions during the 4-year study period (264,280 in the 9 pilot sites, 890,789 in the 26 spread sites). There were no clinically relevant changes in gender distribution, mortality rate, median age, case mix index, or hospital length of stay in 2011 versus 2014. Men comprised 47.1% of the patient population in 2011 and 47.7% in 2014. The mortality rate was 2.7% in both years. Median age was 62 in 2011 and 63 in 2014. The mean case mix index (1.58 vs 1.65) and mean length of stay (4.29 vs 4.33 days) were similar in the 2 time periods.

Prophylaxis Rates

TJC Prophylaxis rates

Rates of Protocol-Compliant Prophylaxis

There were 34,071 active surveillance audits across the 20 months of reporting in the pilot cohort (mean, 1817 audits per month). The rate of protocol-compliant prophylaxis improved from 89% at month 1 of observation to 93% during month 2 and 97% by the last 3 months (Pearson χ² P < .001 for both comparisons).

HA-VTE

HA-VTE characteristics

Improved HA-VTE over Time

Four hundred twenty-eight fewer HA-VTEs occurred in 2014 than in 2011 (RR 0.78; 95% CI, 0.73-0.85) (Table and Figure 3). Readmission HA-VTEs were reduced by 315 (RR 0.72; 95% CI, 0.65-0.80), while the reduction in NPOA HA-VTEs was less robust (RR 0.88; 95% CI, 0.79-0.99). Pilot sites enjoyed a more robust reduction in HA-VTEs than spread sites (26% vs 20%), largely because the pilot cohort enjoyed a 34% reduction in NPOA HA-VTEs and a 20% reduction in Readmit HA-VTEs, while the spread cohort only achieved reductions in Readmit HA-VTEs.

Safety

Rates of HIT and adverse effects because of anticoagulants were low (Table). The rate of HIT declined from 178 events in 2011 to 109 in 2014 (RR 0.66; 95% CI, 0.52-0.84), and the RR of anticoagulant adverse events remained stable (RR 1.01; 95% CI, 0.87-1.15).

Our QI project, based on a proven collaborative approach and mentorship,^18,22,24 order set redesign, and active surveillance, was associated with 26% less VTEs in the pilot cohort and 20% less VTEs in the spread cohort. These gains, down to a final rate of approximately 4 HA-VTEs per 1000 admissions, occurred despite a low baseline HA-VTE rate. Dignity Health achieved these improvements in 35 hospitals with varied sizes, settings, ordering systems, and teaching statuses, achieving what is to our knowledge the largest VTE QI initiative yet reported.

Implementation experiences were not systematically recorded, and techniques were not compared with a control group. However, we believe that Dignity Health’s organizational commitment to improvement and centralized support were crucial for success. In addition, the pilot sites received grant support from the GBMF for intensive quality mentoring, a strategy with demonstrated value.²³ Mentors and team members noted that system-wide revision to the computerized physician order entry system was easiest to implement, while active surveillance represented the most labor-intensive intervention. Other experiences echoed lessons from previous VTE mentorship efforts.^17,18

The selection of a VTE protocol conducive to implementation and provider use was a key strategy. The ideal approach to VTE risk assessment is not known,^12,26 but guidelines either offer no specific guidance⁷ or would require implementation of 3 different systems per hospital.^4,5 Several of these are point scoring systems, which may have lower clinician acceptance or require programming to improve real-world use^18,26,27; the Padua score was derived from a patient population that differs significantly from those in the United States.¹² Our study provides more practical experience with a “3-bucket” model, which has previously shown high interobserver reliability, good clinician acceptance, and meaningful reductions of VTE, including in American patient populations.^18,22,24

The value of VTE prophylaxis is still disputed in many inpatient groups. The overall rate of HA-VTE is low, so the per-patient benefit of prophylaxis is low, and many patients may be overprophylaxed.^4,11,12 Recently, Flanders et al.²⁰ reported that HA-VTE rates among 20,800 medical inpatients in Michigan were low (about 1%) and similar at hospitals in the top (mean prophylaxis rate 86%) or bottom (mean prophylaxis rate 56%) tertiles of performance. Possible explanations for the differences between their multicenter experience and ours include our sample size (55 times larger) and the possibility that targeting prophylaxis to patients at highest need (captured in our protocol-compliant prophylaxis rates) matters more than prophylaxing a percent of the population.

Further research is needed to develop simple, easy-to-implement methods to identify inpatients who do not, or no longer, require prophylaxis.¹² Hospital systems also need methods to determine if prophylaxis improvement efforts can lower their HA-VTE rates and in which subpopulations. For example, a collaborative effort at the University of California lowered HA-VTE rates toward a common improved rate of 0.65% to 0.73%,²² while Dignity Health achieved improvement despite starting with an even lower baseline. In the University of California collaborative, benefits were limited chiefly to surgical patients, while Dignity Health achieved most improvement in medical patients, particularly in Readmit HA-VTE. If future research uncovers the reasons for these differences, it could help hospitals decide where to target improvement efforts.

Our study has several limitations. First, we used a nonrandomized time series design, so we cannot exclude other potential explanations for the change in VTE rates. However, there were no major changes in patient populations or concurrent projects likely to have influenced event rates. While we did not collect detailed demographic information on subjects, the broad inclusion criteria and multicenter design suggests a high degree of generalizability. Second, we followed inpatient VTE events and VTE-related readmissions, but not VTE treated in the outpatient setting. This did not change over the study, but the availability of all-oral therapy for VTE could have caused underdetection if clinic or emergency room doctors sent home more patients on oral therapy instead of readmitting them to the hospital. Third, implementation was enhanced by GBMF funds (at 9 sites, with the remainder benefitting from their experience), a shared electronic medical record at many sites, and a strong organizational safety culture, which may limit generalizability. However, spread sites showed similar improvement, paper-based sites were included, and the mentorship and quality collaborative models are scalable at low cost. Fourth, some QI efforts began at some pilot sites in CY 2011, so we could not compare completely clean pre- and postproject timeframes. However, early improvement would have resulted in an underestimation of the project’s impact. Lastly, the reason for a decline in HIT rates is not known. Standardized order sets promoted preferential use of low molecular weight heparin, which is less likely to induce HIT, and active surveillance targeted overprophylaxis as well as underprophylaxis, but we do not have data on heparin utilization patterns to confirm or refute these possibilities.

Strengths of our study include reductions in HA-VTE, both with and without access to GBMF funds, by using broadly available QI strategies.¹⁷ This real-world success and ease of dissemination are particularly important because the clinical trials of prophylaxis have been criticized for using highly selected patient populations,¹¹ and prophylaxis QI studies show an inconsistent impact on VTE outcomes.¹⁵ In previous studies, two of the authors monitored orders for prophylaxis^22,24; during this project, delivery for both pharmacologic and mechanical VTE prophylaxis was monitored, confirming that patient care actually changed.

Our multicenter VTE prophylaxis initiative, featuring a “3-bucket” VTE protocol, QI mentorship, and active surveillance as key interventions, was associated with improved prophylaxis rates and a reduction in HA-VTE by 22% with no increase in adverse events. This project provides a model for hospital systems seeking to optimize their prophylaxis efforts, and it supports the use of collaborative QI initiatives and SHM’s quality mentorship program as methods to drive improvement across health systems.

Disclosure

None of the authors have any conflicts of interest related to any topics or products discussed in the article. Dignity Health provided a stipend for writing the manuscript to GM and IJ, as noted in the article, but had no role in data analysis, writing, or decision to submit.