Optimizing Muscle-Tendon Lengths in Reverse Total Shoulder Arthroplasty: Evaluation of Surgical and Implant-Design-Related Parameters.

BACKGROUND: Optimizing the function of muscles that cross the glenohumeral articulation in reverse total shoulder arthroplasty (RTSA) is controversial. The current study used a geometric model of the shoulder to systematically examine surgical placement and implant-design parameters to determine which RTSA configuration most closely reproduces native muscle-tendon lengths of the deltoid and rotator cuff. METHODS: A geometric model of the glenohumeral joint was developed and adjusted to represent small, medium, and large shoulders. Muscle-tendon lengths were assessed for the anterior deltoid, middle deltoid, posterior deltoid, and supraspinatus from 0 to 90° of scaption; for the subscapularis from 0° to 60° of internal rotation (IR) and 0° to 60° of scaption; for the infraspinatus from 0° to 60° of external rotation (ER) and 0° to 60° of scaption; and for the teres minor from 0° to 60° of ER at 90° of scaption. RTSA designs were virtually implanted using the following parameters: (1) surgical placement with a centered or inferior glenosphere position and a humeral offset of 0, 5, or 10 mm relative to the anatomic neck plane, (2) implant design involving a glenosphere size of 30, 36, or 42 mm, glenosphere lateralization of 0, 5, or 10 mm, and humeral neck-shaft angle of 135°, 145°, or 155°. Thus, 486 RTSA-shoulder size combinations were analyzed. Linear regression assessed the strength of association between parameters and the change in each muscle-tendon length from the native length. RESULTS: The configuration that most closely restored anatomic muscle-tendon lengths in a small shoulder was a 30-mm glenosphere with a centered position, 5 mm of glenoid lateralization, 0 mm of humeral offset, and a 135° neck-shaft angle. For a medium shoulder, the corresponding combination was 36 mm, centered, 5 mm, 0 mm, and 135°. For a large shoulder, it was 30 mm, centered, 10 mm, 0 mm, and 135°. The most important implant-design parameter associated with restoration of native muscle-tendon lengths was the neck-shaft angle, with a 135° neck-shaft angle being favored (ß = 0.568 to 0.657, p < 0.001). The most important surgical parameter associated with restoration of native muscle-tendon lengths was humeral offset, with a humeral socket placed at the anatomic neck plane being favored (ß = 0.441 to 0.535, p < 0.001). CONCLUSIONS: A combination of a smaller, lateralized glenosphere, a humeral socket placed at the anatomic neck plane, and an anatomic 135° neck-shaft angle best restored native deltoid and rotator cuff muscle-tendon lengths in RTSA. CLINICAL RELEVANCE: This study of surgical and implant factors in RTSA highlighted optimal configurations for restoration of native muscle-tendon lengths of the deltoid and rotator cuff, which has direct implications for surgical technique and implant selection. Additionally, it demonstrated the most influential surgical and implant factors with respect to muscle-tendon lengths, which can be used to aid intraoperative decision-making.

Common Factors in Shoulder and Hip Arthroplasty Implant Failures: A Historical Review.

In this era of subspecialty care in orthopedics, iterations of implant design can occur in a silo which then precludes gaining knowledge from failures of implant design that may have occurred in different subspecialties. This literature review describes the history of failures in hip and shoulder arthroplasties with the purpose of identifying similar factors that led to previous implant failures. A review of the literature was performed by two reviewers assessing articles that described failed hip and shoulder arthroplasty systems over time. We identified and analyzed 53 implant failures-23 in hip arthroplasty and 30 in shoulder arthroplasty. These failures were categorized as material, mechanical, and technical. In hip arthroplasty, 48% were material, 39% mechanical, and 13% technical failures. In shoulder arthroplasty, the distribution was 10% material, 70% mechanical, and 20% technical failures. The distribution of these failures highlights similar and sometimes repeated failure mechanisms between subspecialties. This accentuates the importance of a collaborative approach to improve future arthroplasty designs.

Factors affecting risk of recurrence with periprosthetic infection in shoulder arthroplasty.

BACKGROUND: The goal of treating periprosthetic infection, besides its eradication, is to avoid recurrence. The purpose of this study was to evaluate the impact of increasing Infection Severity (IS) score (based on the 2018 International Consensus Meeting on Orthopedic Infections statement), single-stage revision, and pathogenicity of the infective organism on the risk of infection recurrence. METHODS: A database of 790 revisions performed by a single surgeon from 2004-2020 was reviewed for patients with minimum 2-year follow-up and ≥1 positive culture finding and/or pathology result from the revision surgical procedure. In total, 157 cases performed in 144 patients met the inclusion criteria. These cases were then categorized by infection probability (IS score) according to the 2018 consensus statement. Of 157 cases, 46 (29%) were classified as definitely or probably infected; 25 (16%), possibly infected; and 86 (55%), unlikely to be infected. Additionally, patients were grouped by single-stage surgery and pathogenicity of the infective organism. RESULTS: A recurrence in this study was classified as the growth of the same organism in any patient requiring revision surgery. The 86 cases in the group with unlikely infection showed a recurrence rate of 2.3%. The 25 cases in the group with possible infection showed a recurrence rate of 12%. The 46 cases in the group with definite or probable infection showed a recurrence rate of 17.4%. Patients in the definite/probable infection group had a higher rate of recurrence than those in the groups with possible infection and unlikely infection (P = .009). The IS score was higher in the recurrence group than the non-recurrence group (7.5 ± 4.3 vs. 3.9 ± 3.4, P < .001). Overall, patients who underwent 1-stage revision had a 5.0% recurrence rate, but among the 34 patients with an infection classification of definite or probable who underwent 1-stage revision, the recurrence rate was 5.9%. Cases of highly virulent methicillin-resistant Staphylococcus aureus also showed a recurrence rate of 30.8% compared with 4.0% and 5.9% for Cutibacterium acnes and coagulase-negative staphylococci, respectively (P = .005). CONCLUSION: Recurrent infection after treatment of a periprosthetic infection is associated with increasing severity scores, as defined in the 2018 consensus statement, and more aggressive microorganisms. However, a single-stage surgical procedure, even in patients with higher IS scores, did not impart a significantly increased risk of recurrence.

Do preoperative scapular fractures affect long-term outcomes after reverse shoulder arthroplasty?

BACKGROUND: Postoperative scapular stress fractures (SSFs) are a formidable problem after reverse shoulder arthroplasty (RSA). Less is known about patients who have these fractures preoperatively. The primary aim of this study was to examine postoperative satisfaction in patients undergoing primary RSA who have preoperative SSF and compared to a matched cohort without preoperative fracture. The secondary aim was to examine the differences in patient-reported outcomes between and within study cohorts. METHODS: A retrospective chart review of primary RSAs performed by a single surgeon from 2000 to 2020 was conducted. Patients diagnosed with cuff tear arthropathy (CTA), massive cuff tear (MCT), or rheumatoid arthritis (RA) were included. Five hundred twenty-five shoulders met inclusion criteria. Fractures identified on preoperative computed tomography scans were divided into 3 groups: (1) os acromiale, (2) multifragments (MFs), and (3) Levy types. Seventy-two shoulders had an occurrence of SSF. The remaining 453 shoulders were separated into a nonfractured cohort. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and visual analog scale (VAS) scores were compared pre- and postoperatively in the total fracture group and the nonfractured group cohort. The multifragment subgroup was also compared to the pooled Os/Levy subgroup. RESULTS: The total incidence of SSF in all shoulders was 13.7%. There was a difference in satisfaction scores at all time points between the nonfracture (7.9 ± 2.8) and total fracture group (5.4 ± 3.6, P < .001, at last visit). There was also a greater ASES total score in the nonfractured group vs the total fracture group at the final visit (69.4 ± 23.4 and 62.1 ± 24.2; P = .02). The MF group had worse ASES functional or VAS functional scores than the Os/Levy group at all time points: at 1 year, ASES function: MF 24.2 ± 14.5 and Os/Levy 30.7 ± 14.2 (P = .045); at 2 years, ASES function: MF 21.4 ± 14.4 and Os/Levy 35.5 ± 10.6 (P < .001); and at last follow-up, VAS function: MF 4.8 ± 2.8 and Os/Levy 6.4 ± 3.2 (P = .023). DISCUSSION: Scapular fractures were proportionally most common in patients diagnosed with CTA (16.3%) compared with a 9.2% and 8.6% incidence in patients diagnosed with MCT and RA, respectively. Patients with preoperative SSF still see an improvement in ASES scores after RSA but do have lower satisfaction scores compared with the nonfractured cohort. The multifragment fracture group has lower functional and satisfaction scores at all postoperative time points compared with both the nonfracture and the Os/Levy fracture group.

Revision reverse shoulder arthroplasty for the management of baseplate failure: an analysis of 676 revision reverse shoulder arthroplasty procedures.

BACKGROUND: Baseplate failure in reverse shoulder arthroplasty (RSA) is a rare but potentially catastrophic complication owing to poor patient outcomes and significant glenoid bone loss. The purpose of this study was to report on the prevalence, causes, and outcomes of revision RSA (rRSA) for baseplate failure or loosening. METHODS: A retrospective review of our institutional database was performed to identify all patients treated for a failed RSA from 2006 to 2021 who required revision to another RSA (rRSA) performed by a single surgeon. A total of 676 failed RSA procedures were identified, and further analysis identified 46 patients (6.8%) who underwent rRSA for baseplate failure with a confirmed loose baseplate at the time of rRSA. The primary outcome was repeated failure of the reimplanted baseplate following rRSA. The mode of failure associated with baseplate failure was stratified into 1 of 3 groups: aseptic, septic, or traumatic. Twenty-four patients underwent primary revision, and 22 had undergone >1 previous arthroplasty prior to undergoing re-revision. Five patients underwent previous rRSA for baseplate failure performed by an outside surgeon. The criteria for secondary outcome analysis of final American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, and range of motion were met by 32 patients and 23 patients at 1- and 2-year follow-up, respectively. RESULTS: Three patients (6.5%) had repeated baseplate failure requiring re-revision; 2 had baseplate failure at <1 year with associated periprosthetic infections and underwent conversion to hemiarthroplasty. The third patient experienced traumatic failure at 10 years and underwent successful rRSA. The mean American Shoulder and Elbow Surgeons scores at 1 and 2 years were 62.3 and 61.7, respectively. There was no significant difference in outcomes based on mode of baseplate failure (P = .232) or total arthroplasty burden (P = .305) at 1 year. There were 13 total complications in 11 patients, 5 of which required reoperation for reasons other than baseplate failure. CONCLUSION: In this study, rRSA for baseplate failure constituted 6.8% of all revisions performed over a period of 15 years. Re-revision for recurrent baseplate failure was required in 3 of 46 patients (6.5%). Complications and reoperation rates were higher than those for primary RSA but outcomes were comparable for revision of failed anatomic shoulder arthroplasty.

How to avoid baseplate failure: the effect of compression and reverse shoulder arthroplasty baseplate design on implant stability.

BACKGROUND: Failure to achieve fixation of the glenoid baseplate will lead to clinical failure. The fixation of the baseplate to the scapula must be able to withstand sufficient shear forces to allow bony ingrowth. The importance of compression to neutralize the forces at the baseplate-bone interface has been assumed to be critical in limiting excessive micromotion. The purpose of this study is to determine the effect of compression on implant stability with different baseplate designs. METHODS: Various baseplate designs (1-piece monolithic central screw [1P], 2-piece locking central screw [2PL], and 2-piece nonlocking center screw [2PNL]) were investigated at 3 different compressive forces (high [810 N], medium [640 N], and low [530 N]). Synthetic bone cylinders were instrumented, and peripheral screws were used in all models. The combination of 1 locking and 3 nonlocking peripheral screw fixation was selected as worst-case scenario. Dynamic testing protocol followed the ASTM F2028-17 standard. The baseplate micromotion at high compression was compared to low compression. Additionally, the baseplate micromotion for each design was compared at baseline (first 50 cycles) and at 10,000 cycles for the 3 different compressive forces where motion above 150 µm was defined as failure. RESULTS: Baseplate micromotion was found to negatively correlate with compression (rpb = -0.83, P < .0001). At baseline, all baseplate designs were considered stable, regardless of compression. With high compression, average micromotion at the glenoid baseplate-bone interface remained below the 150-µm threshold for all baseplate designs at 10,000 cycles (1P: 50 ± 10 µm; 2PL: 78 ± 32 µm; 2PNL: 79 ± 8 µm; P = .060). With medium compression, average micromotion at 10,000 cycles for all 3 designs remained below the 150-µm threshold (1P: 88 ± 22 µm; 2PL: 132 ± 26 µm; 2PNL: 107 ± 39 µm). The 2PL design had the highest amount of micromotion (P = .013). With low compression, both 2-piece designs had an average micromotion above the 150-µm threshold whereas the 1-piece design did not (1P: 133 ± 35 µm; 2PL: 183 ± 21 µm; 2PNL: 166 ± 39 µm). The 2PL design had significantly higher micromotion when compared to 1P design (P = .041). DISCUSSION: The stability of a central screw baseplate correlates with the amount of compression obtained and is affected by implant design. For the same amount of compression, more micromotion is observed in a 2-piece design than a 1-piece design.

Glenoid-based reference system to differentiate shoulder pathologies on plain radiographs.

BACKGROUND: Shoulder radiographs are used for evaluation and the planning of treatment of various pathologies. Making a diagnosis of these pathologies on plain radiographs occurs by recognizing the relationship of the humeral head on the registry of the glenoid. Quantification of these changes in registry does not currently exist. We hypothesize that a geometric relationship of the humeral head and the glenoid exists that is defined on an anteroposterior Grashey view radiograph by the relationship of the best-fit circle of the humeral head relative to the best-fit circle of the glenoid such that relative measurements will define the normal shoulder and the pathologic shoulder. METHODS: One hundred fifty-six shoulders were included: 53 normal shoulders, 51 with primary glenohumeral osteoarthritis (GHOA), and 52 with cuff tear arthropathy (CTA). Humeral head best-fit circle was used to define the circle of the humeral head (cHH). A glenoid best-fit circle (cG) was defined by the following rules: (1) best fit of the glenoid articular surface and (2) was limited by the acromion such that either (a) it reaches maximal interaction with the inferior surface of the acromion or (b) the perimeter of the circle is at the lateralmost point of the acromion. The relationship between cHH and cG is defined by measurement of cHH in horizontal and vertical planes relative to the glenoid circle reference. The horizontal displacement angle (HDA) measures the horizontal position of cHH relative to cG, representing the degree of medialization toward the glenoid. The vertical displacement angle (VDA) measures the vertical position of cHH relative to cG, representing the degree of superiorization toward the acromion. Angles were compared by diagnosis and sex. RESULTS: The mean HDA was 61.0° (95% confidence interval [CI] 60.3°-61.7°) in normal shoulders, 79.9° (95% CI 76.9°-82.9°) in GHOA, and 63.4° (95% CI 61.7°-65.1°) in CTA (P < .001). The mean VDA was 43.1° (95% CI 42.2°-44.0°) in normal shoulders, 40.9° (95% CI 39.9°-42.0°) in GHOA, and 59.7° (95% CI 57.6°-61.7°) in CTA (P < .001). Interobserver reliability was 0.991 (95% CI 0.94-1.0) and intraobserver reliability was 0.998 (95% CI 0.99-1.0). The geometric relationship of cHH to the glenoid circle reference was plotted for each group. CONCLUSION: A geometric relationship exists of the humeral head in reference to the glenoid circle. Together, the HDA and the VDA distinguish between a normal shoulder and those with GHOA or CTA. This suggests that this novel methodology may provide a preoperative planning tool that is easily accessible.

Impact of reverse shoulder arthroplasty design and patient shoulder size on moment arms and muscle fiber lengths in shoulder abductors.

BACKGROUND: Reverse shoulder arthroplasty (RSA) increases the moment arm of the deltoid; however, there is limited knowledge on the accompanying changes in muscle architecture that play a role in muscle force production. The purpose of this study was to use a geometric shoulder model to evaluate the anterior deltoid, middle deltoid, and supraspinatus regarding (1) the differences in moment arms and muscle-tendon lengths in small, medium, and large native shoulders and (2) the impact of 3 RSA designs on moment arms, muscle fiber lengths, and force-length (F-L) curves. METHODS: A geometric model of the native glenohumeral joint was developed, validated, and adjusted to represent small, medium, and large shoulders. Moment arms, muscle-tendon lengths, and normalized muscle fiber lengths were assessed for the supraspinatus, anterior deltoid, and middle deltoid from 0° to 90° of abduction. RSA designs were modeled and virtually implanted, including a lateralized glenosphere with an inlay 135° humeral component (lateral glenoid-medial humerus [LGMH]), a medialized glenosphere with an onlay 145° humeral component (medial glenoid-lateral humerus [MGLH]), and a medialized glenosphere with an inlay 155° humeral component (medial glenoid-medial humerus [MGMH]). Descriptive statistics were used to compare moment arms and normalized muscle fiber lengths. RESULTS: As shoulder size increased, the moment arms and muscle-tendon lengths for the anterior deltoid, middle deltoid, and supraspinatus increased. All RSA designs achieved greater moment arms for the anterior and middle deltoid, with the MGLH design achieving the largest increase. The resting normalized muscle fiber length of the anterior and middle deltoid was substantially increased in the MGLH (1.29) and MGMH (1.24) designs, shifting the operating ranges of these muscles to the descending portions of their F-L curves, whereas the LGMH design maintained a resting deltoid fiber length (1.14) and operating range similar to the native shoulder. All RSA designs demonstrated a decrease in the native supraspinatus moment arm in early abduction, with the largest decrease in the MGLH design (-59%) and minimal decrease in the LGMH design (-14%). The supraspinatus operated on the ascending limb of its F-L curve in the native shoulder and remained on this portion of the F-L curve for all RSA designs. CONCLUSION: Although the MGLH design maximizes the abduction moment arm for the anterior and middle deltoid, overlengthening of the muscle may compromise deltoid muscle force production by forcing the muscle to operate on the descending portion of its F-L curve. In contrast, the LGMH design increases the abduction moment arm for the anterior and middle deltoid more modestly while allowing the muscle to operate near the plateau of its F-L curve and maximizing its force-producing potential.

Academic productivity metrics correlate positively with industry funding amongst orthopedic shoulder and elbow surgeons.

Background: Research efforts can produce practice-changing results with widespread implications for patient care. While critical to the advancement of the field, such efforts do not often provide direct compensation. However, a researcher's academic productivity may facilitate industry relationships, either as the impetus for the affiliation or a result of collaboration. Methods: Queries of the Centers for Medicaid and Medicare Services publicly available Open Payments System allowed for extraction of industry compensation data for orthopedic surgeons in 7 categories, including royalties and licensing fees, consulting fees, gifts, honoria, and 3 unique speaking fees delineations. This system identifies physicians by taxonomy identifications; however, Centers for Medicaid and Medicare Services does not have a unique code for shoulder and elbow surgeons. Therefore, identification of shoulder and elbow surgeons proceeded utilizing the American Shoulder and Elbow Surgeons (ASES) society 2019 membership directory. Cross-referencing this membership list with extracted Open Payments data provided industry funding information for all ASES members. Physicians then underwent an academic productivity assessment. Queries of Web of Science, Scopus, and Google Scholar User Profile databases provided the Hirsch index (h-index) and m-index for each surgeon. Bivariate and multivariate analyses produced statistical results. Results: From 2016 to 2020, 631,130, 158, and 72 ASES members earned mean annual industry compensation <$1000, between $1001 and $10,000, between $10,001 and $100,000, and >$100,000, respectively. Royalties (91.5%) predominated in the top earning group, compared with consulting fees (58.0%, 55.0%) in the 2 middle-tier groups. H-index and m-index correlated positively with total compensation (h-index: r = 0.18, P < .001; m-index: r = 0.10, P < .001). The highest income group (>$100,000) had higher h-index and m-index scores than either intermediate ($1001-$10,000, $10,001-$100,000) or lowest (<$1000) compensation groups (From lowest to highest income bracket-h-index: 14.8 vs. 16.4 vs. 19.4 vs. 32, P < .001; m-index: 0.79 vs. 0.85 vs. 0.91 vs. 1.18, P = .003). Multivariable analysis of factors associated with increased industry compensation identified only h-index (B = 8046, P < .001) as having a significant association with physician compensation, with each single unit increase in h-index associated with an 18% increase in industry funding. Conclusion: Among a group of academic shoulder and elbow surgeons, industry compensation correlates positively with academic productivity metrics, with an associated $8046/yr increase in industry funding for each single-unit increase in h-index over 9. Future studies may focus on more clearly defining the causal directionality of these results.

What factors can reduce the need for repeated revision for humeral loosening in revision total elbow arthroplasty?

BACKGROUND: This study aimed to determine the re-revision rate in a cohort of patients who underwent revision total elbow arthroplasty (rTEA) for humeral loosening (HL) and identify factors contributing to re-revision. We hypothesized that proportional increases in the stem and flange lengths would stabilize the bone-implant interface significantly more than a disproportional increase in stem or flange length alone. Additionally, we hypothesized that the indication for the index arthroplasty would impact the need for repeated revision for HL. The secondary objective was to describe the functional outcomes, complications, and presence of radiographic loosening after rTEA. METHODS: We retrospectively reviewed 181 rTEAs performed from 2000-2021. We included 40 rTEAs for HL performed on 40 elbows that either required a subsequent revision for HL (10 rTEAs) or had a minimum of 2 years of clinical or radiographic follow-up. One hundred thirty-one cases were excluded. Patients were grouped based on stem and flange length to determine the re-revision rate. Patients were divided based on re-revision status into the single-revision group and the re-revision group. The stem-to-flange length (S/F) ratio was calculated for each surgical procedure. The mean length of clinical and radiographic follow-up was 71 months (range, 18-221 months and 3-221 months, respectively). RESULTS: Rheumatoid arthritis was statistically significant in predicting re-revision total elbow arthroplasty for HL (P = .024). The overall re-revision rate for HL was 25% at an average of 4.2 years (range, 1-19 years) from the revision procedure. There was a significant increase in stem and flange lengths from the index procedure to revision, on average by 70 ± 47 mm (P < .001) and 28 ± 39 mm (P < .001), respectively. In the cases of re-revision (n = 10), 4 patients underwent an excisional procedure; in the remaining 6 cases, the size of the re-revision implant increased on average by 37 ± 40 mm for the stem and 73 ± 70 mm for the flange (P = .075 and P = .046, respectively). Furthermore, the average flange in these 6 cases was 7 times shorter than the average stem (S/F ratio, 6.7 ± 2.2). This ratio was significantly different from that in cases that were not re-revised (P = .03; S/F ratio, 4.2 ± 2). Mean range of moion was 16° (range, 0°-90°; standard deviation, 20°) extension to 119° (range, 0°-160°; standard deviation, 39°) flexion at final follow-up. Complications included ulnar neuropathy (38%), radial neuropathy (10%), infection (14%), ulnar loosening (14%), and fracture (14%). None of the elbows were considered radiographically loose at final follow-up. CONCLUSION: We show that a primary diagnosis of rheumatoid arthritis and a humeral stem with a relatively short flange relative to the stem length significantly contribute to re-revision of total elbow arthroplasty. The use of an implant where the flange can be extended beyond one-fourth of the stem length may increase implant longevity.

Three-Dimensional Scapular Border Method for Glenoid Version Measurements.

Variations among methods to measure glenoid version have created uncertainty regarding which method provides the most consistent measurements of morphology. Greater deformity may also make accurate depiction of the native morphology more challenging. This study examined 4 current methods (Friedman, corrected Friedman, Ganapathi-Iannotti, and Matsumura) and an experimental scapular border-derived coordinate system method, to compare measurement inconsistencies between methods and reference systems and assess the impact of glenoid deformity on measured glenoid version. Methods: Three-dimensional scapulae were created from computed tomography (CT) scans of 74 shoulders that had undergone arthroplasty (28 A2, 22 B2, 10 B3, and 14 C glenoids) and 34 shoulders that had not undergone arthroplasty. Glenoid version measurements were made in Mimics using the 4 methods. For the experimental method, scapulae were reconstructed, and 3 orthogonal global coordinate planes (GCPs) were derived from the medial and lateral borders. Version was measured as the angle between the sagittal reference plane and an anterior-posterior glenoid vector. The intraclass correlation coefficient (ICC) was calculated for the Friedman and corrected Friedman methods. Inconsistencies were assessed for all methods using the interquartile range, mean and standard deviation, and repeated-measures analysis of variance. Concordance correlation coefficients (CCCs) were calculated to assess agreement among the methods. Results: Scapular plane-based methods (experimental, Friedman, and corrected Friedman) yielded an average version between -10° and -12°, with average measurement differences among these methods of <2°. Vault methods (Ganapathi-Iannotti and Matsumura) overestimated or underestimated version by an average of 5° to 7° compared with scapular plane-based methods, and showed significant differences of >12° when compared with each other. Scapular plane-based methods maintained consistency with increasing deformity. Conclusions: The other methods of version measurement using the scapular planes as the reference were highly comparable with the corrected Friedman method. However, when the reference plane was the glenoid vault, version measurements were inconsistent with scapular plane-based methods, which is attributed to differences in the reference systems. In surgical planning, the coordinate system utilized will impact version measurements, which can result in variations in the planned surgical solutions. Additionally, as glenoid deformity increases, this variation resulting from the utilization of different coordinate systems is magnified.

Humeral loosening in reverse shoulder arthroplasty: an analysis of 2,342 cases.

INTRODUCTION: Humeral loosening is a rare complication in reverse shoulder arthroplasty (RSA) representing approximately 1% of total complications. The purpose of this study is to identify patients who underwent RSA and were revised because of loosening of the humeral component, identify patients who are at increased risk, and report on their surgical outcomes. MATERIALS AND METHODS: A retrospective review of all patients who received a primary RSA or revision RSA (rRSA) by a single surgeon from 2002-2021 identified a total of 1591 primary RSA and 751 rRSA procedures. These procedures were then organized based on indication for surgery. Further analysis was performed to identify RSAs that were subsequently revised because of aseptic loosening of the humeral component. A total of 41 surgeries met the inclusion criterion for the study, which was any RSA or rRSA that was revised because of loosening of the humeral component. Exclusion criterion was revision for a reason other than humeral loosening, neurogenic arthritis, or revision for loosening that was not originally implanted by the senior author (9 surgeries). Ultimately, 32 surgeries met criteria for further analysis. These 32 surgeries were organized by indication for preceding RSA or rRSA and were assessed for an association between indication for RSA or rRSA and eventual revision for humeral loosening. Additionally, these procedures were compared to a "control cohort" of procedures that were not revised and that had minimum 2 years' follow-up. To assess outcomes for these patients, pre- and postoperative Simple Shoulder Test, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and ranges of motion were compared. Twenty procedures had sufficient data for outcomes analysis and were followed for an average of 54 months (range: 24-132 months). RESULTS: In primary RSAs, procedures performed for fracture or fracture sequelae were associated with revision for humeral-sided loosening (P = .009). In rRSAs, procedures performed for failed hemiarthroplasty for CTA were associated with rerevision for humeral-sided loosening (P = .009). Nine percent of patients revised for humeral loosening required rerevision for recurrent humeral loosening. Analysis of patients with 2-year clinical follow-up for humeral-sided loosening showed improvement in ASES pain (P = .014), ASES function (P = .042), and total ASES scores (P = .007). CONCLUSION: Humeral loosening is rare in RSA. In our cohort, 0.7% of the primary RSAs performed and 2.8% of the rRSAs performed were eventually revised for humeral loosening. Revisions of RSA for humeral loosening yield modest clinical improvements. Rerevision for humeral loosening was 6.3% of patients in our cohort.

Revision for instability following reverse total shoulder arthroplasty: outcomes and risk factors for failure.

BACKGROUND: Revision of unstable reverse shoulder arthroplasty (RSA) is significantly challenging, with recurrence rates ranging from 20% to 40%. The purpose of this study was to identify factors associated with recurrent instability. The factors studied included (1) indication for revision RSA (failed primary RSA vs. failed revision RSA), (2) previous attempt at stabilization, (3) mechanism of instability, (4) clinical history of instability, and (5) surgical technique. Outcomes were reported in patients with 2-year follow-up. METHODS: All patients undergoing RSA for instability at our institution were identified. A total of 43 surgical procedures in 36 patients were included. Arthroplasty indication prior to instability (14 failed primary RSAs vs. 22 failed revision RSAs), instances of prior attempts at stabilization (14 patients treated at outside institution), mechanism-of-instability classification, clinical history of instability (17 recurrent and 26 chronic cases), and surgical technique were collected. Stability at final follow-up (minimum, 12 months) and clinical outcomes at 2-year follow-up were assessed. RESULTS: Overall, 32 of 36 patients (89%) required 38 revisions to achieve stability at final follow-up (mean, 53 ± 47 months; range, 12-210 months). On comparison of stability by indication, stability was achieved in 13 of 14 patients (93%) in the failed primary group (mean, 65 ± 59 months; range, 12-210 months) compared with 19 of 22 (86%) in the failed revision group (mean, 45 ± 36 months; range, 12-148 months; P = .365). The average number of procedures per patient was 3 (range, 2-10) in the failed primary group vs. 4.5 (range, 3-7) in the failed revision group (P = .008). Stability was achieved in 12 of 14 patients (86%) with a history of failed stabilization procedures. The most common mechanism leading to persistent instability was loss of compression. Stability was achieved in 14 of 16 patients treated for recurrent instability compared with 18 of 20 treated for chronically locked dislocation (P = .813). Continued instability occurred in 33% of patients who underwent glenoid side-only management, 33% who underwent humeral side-only management, and 10% who underwent bipolar revision tactics. At 2-year follow-up, stability was achieved in 18 of 21 patients, with improvements in the American Shoulder and Elbow Surgeons (ASES) score, forward flexion, abduction, external rotation, and the Simple Shoulder Test score (P = .016, P < .01, P = .01, P < .01, and P = .247, respectively). CONCLUSION: Patients who underwent multiple revisions after failed previous arthroplasty will require more surgical attempts to achieve stability compared with patients who underwent a revision after failed primary RSA. Loss of compression was the most common mechanism of persistent instability. Stabilization was more reliably achieved in cases of recurrent instability than in cases of chronically locked dislocation. Continued instability was noted in one-third of patients who underwent humeral side-only or glenoid side-only revisions and in 10% of those who underwent bipolar revisions. Patients in whom stabilization was successful had improved clinical outcomes.

Academic Productivity in Orthopaedic Traumatology Correlates Positively With Industry Compensation.

OBJECTIVE: To determine the association between academic productivity and industry compensation among Orthopaedic Traumatologists. DESIGN: Retrospective cohort study. SETTING: Review of the Centers for Medicaid and Medicare Services Open Payments program from 2016 to 2020. PARTICIPANTS: 1120 Orthopaedic Traumatologists. MAIN OUTCOME MEASUREMENTS: To determine if an Orthopaedic Traumatologist's h-index and m-index, as generated from Web of Science, Scopus, and Google Scholar User Profile databases, correlate with total payments from medical industry in 7 categories, including Royalties and Licensing Fees, Consulting Fees, Gifts, Honoraria, and 3 unique Speaking Fee delineations. RESULTS: Of 30,343 Orthopaedic Surgeons in the Open Payments program, 1120 self-identified with the Orthopaedic Trauma taxonomy. From 2016 to 2020, 499 surgeons (44.6%) received compensation in one of the eligible categories, most commonly from Consulting Fees (67.3%), though payments from Royalties provided the greatest gross income (70.4%). Overall, for all 1120 surgeons, h-index (r = 0.253, P < 0.001) and m-index (r = 0.136, P < 0.01) correlated positively with mean annual total industry compensation. The highest annual compensation group had higher h-index ($0 vs. $1-$1k vs. $1k-$10k vs. >$10k: 5.0 vs. 6.6 vs. 9.6 vs. 16.8, P < 0.001) and m-index ($0 vs. $1-$1k vs. $1k-$10k vs. >$10k: 0.48 vs. 0.60 vs. 0.65 vs. 0.89, P < 0.001) scores than either the intermediate or the no compensation groups. Multivariable analysis of factors associated with increased industry compensation, including H-index and years active, identified both as having significant associations with physician payments [H-index (B = 0.073, P < 0.001); years active (B = 0.059, P < 0.001)]. Subgroup analysis of the highest annual earner group (>$250k/year) also demonstrated the highest overall h-index (27.6, P < 0.001) and m-index (1.23, P = 0.047) scores, even when compared with other high-earners ($10k-$50k, $50k-$250k). Overall, each increase in h-index above an h-index of 3 was associated with an additional $1722 (95% CI: $1298-2146) of annual industry compensation. CONCLUSIONS: Academic productivity metrics have a positive association with industry compensation for Orthopaedic Traumatologists. This may highlight a potential ancillary benefit to scholarly efforts.

The Association Between Orthopaedic Surgeon Academic Productivity Metrics and Compensation from Medical Industry.

INTRODUCTION: Academic research has value well beyond personal financial gain. However, these endeavors do require a notable amount of time and opportunity cost. Academic productivity may raise a researcher's profile within the field, increasing the likelihood for interactions with the medical industry and possibly cultivating relationships with future monetary significance. METHODS: Queries of the Centers for Medicaid and Medicare Services publicly available Open Payments System allowed for extraction of industry compensation data for orthopaedic surgeons. Aggregate data produce three compensation groups (mean annual income) for individual physicians: none; 1 to $100,000; and >$100,000. Physicians in the highest income category were matched 1:1 with physicians in each of the other two compensation groups. Selected physicians then underwent an academic productivity assessment. Queries of Web of Science, Scopus, and Google Scholar User Profile databases provided the h-index and m-index for each surgeon. Bivariate and multivariate analyses produced statistical results. In addition to the analysis of the tiered income groups, analysis of compensation as a continuous variable also occurred. RESULTS: From 2016 to 2020, 636, 7,617, and 22,091 US orthopaedic surgeons earned mean annual industry compensation >$100,000; between $1 and $100,000; and $0, respectively. Royalties (80.8%) predominated in the top earning group, compared with Consulting Fees (46.5%) in the second-tier group. The highest income group had higher h-index ($0 versus $1 to 100,000 versus >$100,000 = 3.6 versus 7.5 versus 20.0, P < 0.001) and m-index ($0 versus $1 to 100,000 versus >$100,000 = 0.26 versus 0.44 versus 0.80, P < 0.001) scores than either the intermediate or no compensation groups. In addition, h-index and m-index correlated positively with total compensation (h-index: r = 0.32, P < 0.001; m-index: r = 0.20, P < 0.001). Multivariable analysis of factors associated with increased industry compensation identified h-index (B = 0.034, P < 0.001) and years active (B = 0.042, P < 0.001) as having significant associations with physician compensation. Physician subspecialty also correlated with industry compensation. DISCUSSION: Academic research can provide invaluable contributions to the improvement of patient care. These efforts often require notable personal sacrifice with minimal direct remuneration. However, academic productivity metrics correlate positively with industry compensation, highlighting a possible supplementary benefit to scholarly efforts. LEVEL OF EVIDENCE: Level III.

Outcomes of femoral head allograft for the management of glenoid bone defects in revision reverse shoulder arthroplasty: a case-controlled study.

BACKGROUND: Revision shoulder arthroplasty often requires management of glenoid bone defects. Options include using allograft, harvesting iliac crest autograft, or using augmented metal components. The purpose of this study is to report outcomes of revision shoulder arthroplasty requiring management of glenoid bone defects with femoral head allograft in a large cohort of patients using a single reverse shoulder implant system and compare them to a matched cohort based on the indication for surgery. Outcomes of patients who had successful glenoid reconstruction were compared to those that required a re-revision, and to a control group that was revised without the need for bone graft. METHODS: This was a retrospective review of data collected from 2009 to 2018. There were 36 patients in the bone graft group and 52 in the control group. All patients underwent revision to a reverse shoulder arthroplasty to manage a failed total shoulder arthroplasty (n = 29 and 11), hemiarthroplasty (n = 1 and 24), or reverse shoulder arthroplasty (n = 6 and 17). All patients had a minimum of 2 yr of clinical follow-up. The primary endpoint was survival of baseplate fixation. Secondary outcomes included range of motion and functional outcome scores. Patients that had recurrent baseplate failure and were re-revised were compared to patients with bone graft that did not require additional surgery, and to patients who were revised without the need for bone graft. Patients who required revisions for reasons other than recurrent baseplate failure were also recorded. RESULTS: Five of 36 (14%) patients had recurrent baseplate failure. Mean time to failure was 12 mo. Three of 5 had successful re-implantation of another baseplate. Two of 5 were revised to a hemi arthroplasty after failure of their revisions. Preoperative American Shoulder and Elbow Surgeons scores were 31 in the grafted patients that did not require re-revision, 39 in the grafted patients that required re-revision, and 33 in the control group. Final American Shoulder and Elbow Surgeons scores were 64, 36, and 56, respectively. One patient required revision surgery not related to baseplate failure. There were no baseplate failures in the control group. CONCLUSION: The use of femoral head allograft to manage glenoid bone defects in the revision setting produces predictable improvement in functional outcomes that is not inferior to those in patients revised without bone graft. However, there is a 14% rate of baseplate failure.

My Reverse Has Failed: Top Five Complications and How to Manage Them.

Reverse total shoulder arthroplasty implantation has increased dramatically over the past 4 decades since it was first introduced in France in 1985. It has greatly improved the ability to treat patients with cuff tear arthropathy, proximal humeral fractures, and osteoarthritis with severe bone loss. However, with the increased implementation of reverse total shoulder arthroplasty, there has been a corresponding rise in complications. Five of the most common complications following reverse total shoulder arthroplasty are instability, scapular fractures, periprosthetic humeral fractures, glenoid baseplate loosening, and infection.

Does improved external rotation following reverse shoulder arthroplasty impact clinical outcomes in patients with rotator cuff pathology and external rotation less than 0°?

BACKGROUND: The purpose of this study was to (1) evaluate whether improved external rotation (ER) in patients with preoperative ER <0° impacts their clinical outcomes following reverse shoulder arthroplasty (RSA) for rotator cuff (RC) pathology and (2) describe the differences in preoperative factors and postoperative outcomes in this patient population. Our hypothesis was that clinical outcomes would not be affected by improvement in ER using a lateralized glenosphere design. METHODS: We retrospectively reviewed 55 patients with preoperative ER <0° who underwent primary RSA for RC pathology with lateralized glenosphere. Pre- and postoperative physician-reported ER was blindly measured using a videographic review of patients externally rotating their arm at the side. Patients were evaluated using 5 different patient-reported outcome score thresholds, measured at 12 months postoperatively: (1) minimal clinically important difference (MCID) for American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores (ie, ≥20-point increase); (2) MCID for Simple Shoulder Test (SST) scores (≥2.4-point increase); (3) visual analog scale (VAS) for pain score >0; (4) mean ASES score (≥75); and (5) mean SST score (≥6.8), each of which was used to stratify the patients into 2 groups-greater than or equal to vs. less than the threshold. This resulted in 5 different evaluations comparing the 2 groups for any difference in postoperative ER or preoperative factors, including Hamada and Goutallier scores. RESULTS: Regardless of the measured outcome, there was no difference in either postoperative physician- or patient-reported ER between patients who achieved scores higher or lower than the thresholds. Both Hamada and Goutallier score distributions were not different between groups across all the evaluated outcomes. Patients who achieved the MCID for ASES had worse preoperative VAS pain (7 vs. 4, P = .011) and SST (1 vs. 3, P = .020) scores. Across all outcome thresholds, except MCID for SST, pain reduction (ΔVAS) was significantly more pronounced in patients exceeding the thresholds. Improved forward flexion rather than ER was observed in those who achieved the ASES (160° vs. 80°, P = .020) and SST MCIDs (150° vs. 90°, P = .037). Finally, patients who exceeded the thresholds experienced higher satisfaction rates. CONCLUSION: Improvement in ER does not appear to impact patient-reported outcome measures, including ASES and SST in patients with preoperative ER <0° undergoing RSA with a lateralized glenosphere. Patients with more severe pain and worse function at baseline experience less postoperative pain and clinically significant improvement in their reported outcomes.