Prior fragility fractures are associated with a higher risk of 8-year complications following total shoulder arthroplasty.

Patients who sustain fragility fractures prior to total shoulder arthroplasty have significantly higher risk for bone health-related complications within 8 years of procedure. Identification of these high-risk patients with an emphasis on preoperative, intraoperative, and postoperative bone health optimization may help minimize these preventable complications. PURPOSE: As the population ages, more patients with osteoporosis are undergoing total shoulder arthroplasty (TSA), including those who have sustained a prior fragility fracture. Sustaining a fragility fracture before TSA has been associated with increased risk of short-term revision rates, periprosthetic fracture (PPF), and secondary fragility fractures but long-term implant survivorship in this patient population is unknown. Therefore, the purpose of this study was to characterize the association of prior fragility fractures with 8-year risks of revision TSA, periprosthetic fracture, and secondary fragility fracture. METHODS: Patients aged 50 years and older who underwent TSA were identified in a large national database. Patients were stratified based on whether they sustained a fragility fracture within 3 years prior to TSA. Patients who had a prior fragility fracture (7631) were matched 1:1 to patients who did not based on age, gender, Charlson Comorbidity Index (CCI), smoking, obesity, diabetes mellitus, and alcohol use. Kaplan-Meier and Cox Proportional Hazards analyses were used to observe the cumulative incidences of all-cause revision, periprosthetic fracture, and secondary fragility fracture within 8 years of index surgery. RESULTS: The 8-year cumulative incidence of revision TSA (5.7% vs. 4.1%), periprosthetic fracture (3.8% vs. 1.4%), and secondary fragility fracture (46.5% vs. 10.1%) were significantly higher for those who had a prior fragility fracture when compared to those who did not. On multivariable analysis, a prior fragility fracture was associated with higher risks of revision (hazard ratio [HR], 1.48; 95% confidence interval [CI], 1.24-1.74; p < 0.001), periprosthetic fracture (HR, 2.98; 95% CI, 2.18-4.07; p < 0.001) and secondary fragility fracture (HR, 8.39; 95% CI, 7.62-9.24; p < 0.001). CONCLUSIONS: Prior fragility fracture was a significant risk factor for revision, periprosthetic fracture, and secondary fragility fracture within 8 years of primary TSA. Identification of these high-risk patients with an emphasis on preoperative and postoperative bone health optimization may help minimize these complications. LEVEL OF EVIDENCE: III.

Orientation of the Scapula in the Standing Position.

OBJECTIVES: A new ultrasound-based device is proposed to non-invasively measure the orientation of the scapula in the standing position to consider this parameter for Total Shoulder Arthroplasty. The aim of this study was to assess the accuracy and reliability of this device. METHODS: Accuracy was assessed by comparing measurements made with the ultrasound device to those acquired with a three-dimensional (3D) optical localization system (Northern Digital, Canada) on a dedicated mechanical phantom. Three users performed 10 measurements on three healthy volunteers with different body mass (BMI) indices to analyze the reliability of the device by measuring the intra and interobserver variabilities. RESULTS: The mean accuracy of the device was 0.9°± 0.7 (0.01-3.03), 1.3°± 0.8 (0.03-4.55), 1.9°± 1.5 (0.05-5.76), respectively, in the axial, coronal, and sagittal planes. The interobserver and intraobserver variabilities were excellent whatever the BMI and the users experience. CONCLUSIONS: The device is accurate and reliable enough for the measurement of the scapula orientation in the standing position.

Comparative efficacy and safety of medical treatments for proximal humerus fractures: a systematic review and network meta-analysis.

BACKGROUND: Various surgical techniques and conservative therapies are useful tools for treating proximal humerus fractures (PHFs), but it is important to understand how to properly utilize them. Therefore, we performed a systematic review and network meta-analysis to compare and rank the efficacy and safety of medical treatments for PHF. METHODS: PubMed, Embase, the Cochrane Library, and the ClinicalTrials.gov databases were systematically searched for eligible randomized controlled trials (RCTs) from inception until June 2022. Conservative therapy-controlled or head-to-head RCTs of open reduction internal fixation (ORIF), intramedullary nailing (IMN), hemiarthroplasty (HA), and reverse total shoulder arthroplasty (RTSA) used for the treatment of adult patients with PHF were included. The surface under the cumulative ranking (SUCRA) probabilities were applied to compare and rank the effects of medical treatments for PHF. RESULTS: Eighteen RCTs involving 1,182 patients with PHF were selected for the final analysis. Mostly baseline characteristics among groups were well balanced, and the imbalanced factors only included age, injury type, medial comminution, blood loss, and cognitive function in single trial. The SUCRA probabilities found that RTSA provided the best effect on the Constant-Murley score (SUCRA: 100.0%), and the disabilities of the arm, shoulder and hand (DASH) score (SUCRA: 99.0%). Moreover, HA (SUCRA: 85.5%) and RTSA (SUCRA: 68.0%) had a relatively better effect on health-related quality of life than the other treatment modalities. Furthermore, conservative therapy (SUCRA: 84.3%) and RTSA (SUCRA: 80.7%) were associated with a lower risk of secondary surgery. Finally, the best effects on the risk of complications are varied, including infection was observed with conservative therapy (SUCRA: 94.2%); avascular necrosis was observed in HA (SUCRA: 78.1%), nonunion was observed in RTSA (SUCRA: 69.6%), and osteoarthritis was observed in HA (SUCRA: 93.9%). CONCLUSIONS: This study found that RTSA was associated with better functional outcomes, while the comparative outcomes of secondary surgery and complications varied. Optimal treatment for PHF should consider patient-specific factors.

Anatomic or Reverse Total Shoulder Arthroplasty? How Fellowship Training Affects Selection of Arthroplasty Type.

BACKGROUND: While both anatomic (ATSA) and reverse total shoulder arthroplasty (RTSA) have been popularized as a means of treating individuals with degenerative shoulder conditions, the indications for each can vary widely amongst providers. While surgeons with differing fellowship training commonly perform these procedures, it is not understood how fellowship training influences choice of implant. METHODS: A national database was queried to identify surgeons performing anatomic and reverse total shoulder arthroplasty. For all surgeons who performed more than 10 cases between 2010-2022, fellowship data was individually collected via online search. For each fellowship group, rates of anatomic and reverse total shoulder arthroplasty were identified using International Classification of Diseases (ICD) procedural codes. Those undergoing revision arthroplasty and those with a history of fracture, infection, or malignancy were excluded. Primary outcome measures included the proportion of primary and revision ATSA and RTSA by fellowship in addition to the rate of RTSA performed for a primary diagnosis of glenohumeral osteoarthritis. RESULTS: A total of 131,974 patients met the inclusion criteria and were retained for this study. RTSA increased from 50.1% of all primary shoulder arthroplasty cases in 2011 to 72.0% in 2022. After adjusting for age and comorbidities, Sports Medicine fellowship-trained (Sports) surgeons opted for primary RTSA over ATSA at a significantly higher rate than Shoulder and Elbow fellowship-trained (Shoulder) surgeons and surgeons who completed another type of fellowship or no fellowship (Other). Sports surgeons also chose RTSA more frequently for the diagnosis of glenohumeral osteoarthritis compared to Shoulder surgeons. Surgeons in the Other cohort were more likely to perform primary ATSA rather than RTSA in comparison to surgeons in the Shoulder and Sports cohorts. Sports surgeons were responsible for the greatest increase in percentage of all shoulder arthroplasty procedures from 2010-2022 (28.4% to 40.4%) while the Other group decreased by a comparable amount (45.9% to 32.4%) over the same period. CONCLUSION: Surgeons who have completed a Sports Medicine fellowship choose RTSA over ATSA at a higher rate than Shoulder and Elbow surgeons, both for all indications and also for a primary diagnosis of glenohumeral osteoarthritis. Those who have no fellowship training or fellowship training outside of Sports Medicine and Shoulder and Elbow surgery have the highest percentage of ATSA in their arthroplasty practice. Revision anatomic and revision reverse total shoulder arthroplasty represents a larger percentage of overall case volume for Shoulder and Elbow surgeons.

Stratification of the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptomatic state after total shoulder arthroplasty by implant type, preoperative diagnosis, and sex.

BACKGROUND: Clinical significance, as opposed to statistical significance, has increasingly been utilized to evaluate outcomes after total shoulder arthroplasty (TSA). The purpose of this study was to identify thresholds of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for TSA outcome metrics and determine if these thresholds are influenced by prosthesis type (anatomic or reverse TSA), sex, or preoperative diagnosis. METHODS: A prospectively collected international multicenter database inclusive of 38 surgeons was queried for patients receiving a primary aTSA or rTSA between 2003 and 2021. Prospectively, outcome metrics including ASES, shoulder function score (SFS), SST, UCLA, Constant, VAS Pain, shoulder arthroplasty smart (SAS) score, forward flexion, abduction, external rotation, and internal rotation was recorded preoperatively and at each follow-up. A patient satisfaction question was administered at each follow-up. Anchor-based MCID, SCB, and PASS were calculated as defined previously overall and according to implant type, preoperative diagnosis, and sex. The percentage of patients achieving thresholds was also quantified. RESULTS: A total of 5851 total shoulder arthroplasties (TSAs) including aTSA (n = 2236) and rTSA (n = 3615) were included in the study cohort. The following were identified as MCID thresholds for the overall (aTSA + rTSA irrespective of diagnosis or sex) cohort: VAS Pain (-1.5), SFS (1.2), SST (2.1), Constant (7.2), ASES (13.9), UCLA (8.2), SPADI (-21.5), and SAS (7.3), Abduction (13°), Forward elevation (16°), External rotation (4°), Internal rotation score (0.2). SCB thresholds for the overall cohort were: VAS Pain (-3.3), SFS (2.9), SST 3.8), Constant (18.9), ASES (33.1), UCLA (12.3), SPADI (-44.7), and SAS (18.2), Abduction (30°), Forward elevation (31°), External rotation (12°), Internal rotation score (0.9). PASS thresholds for the overall cohort were: VAS Pain (0.8), SFS (7.3), SST (9.2), Constant (64.2), ASES (79.5), UCLA (29.5), SPADI (24.7), and SAS (72.5), Abduction (104°), Forward elevation (130°), External rotation (30°), Internal rotation score (3.2). MCID, SCB, and PASS thresholds varied depending on preoperative diagnosis and sex. CONCLUSION: MCID, SCB, and PASS thresholds vary depending on implant type, preoperative diagnosis, and sex. A comprehensive understanding of these differences as well as identification of clinically relevant thresholds for legacy and novel metrics is essential to assist surgeons in evaluating their patient's outcomes, interpreting the literature, and counseling their patients preoperatively regarding expectations for improvement. Given that PASS thresholds are fragile and vary greatly depending on cohort variability, caution should be exercised in conflating them across different studies.

Total shoulder arthroplasty in patients with factor V Leiden.

BACKGROUND: Anatomic and reverse total shoulder arthroplasty (TSA) are effective treatment options for end-stage glenohumeral osteoarthritis. However, consideration for pre-existing conditions must be taken into account. Factor V Leiden (FVL), the most common inherited thrombophilia, is one such condition that predisposes to a prothrombotic state and may affect perioperative and longer-term outcomes following TSA. METHODS: Adult patients undergoing primary TSA for osteoarthritis indication were identified in the 2010 through October 2021 PearlDiver M157 database. Patients with or without FVL were matched at a 1:4 ratio based on age, sex, and Elixhauser Comorbidity Index. Ninety-day adverse events and 5-year revision rates were assessed and compared with multivariable logistic regression and rank-log tests, respectively. Finally, the relative use and bleeding/clotting outcomes were assessed based on venous thromboembolic (VTE) prophylactic agents used, with categories defined as (1) warfarin, heparin, or direct oral anticoagulant (DOAC) or (2) aspirin/no prescription found. RESULTS: Of 104,258 TSA patients, FVL was identified for 283 (0.27%). Based on matching, 1081 patients without FVL and 272 patients with FVL were selected. Multivariable analyses demonstrated that those with FVL displayed independently greater odds ratios (ORs) of deep vein thrombosis (DVT, OR = 9.50, P < .0001), pulmonary embolism (PE, OR = 10.10, P < .0001), and pneumonia (OR = 2.43, P = .0019). Further, these events contributed to the increased odds of aggregated minor (OR = 1.95, P = .0001), serious (OR = 6.38, P < .0001), and all (OR = 3.51, P < .0001) adverse events. All other individual 90-day adverse events, as well as 5-year revision rates, were not different between the study groups. When compared to matched patients without FVL on the same anticoagulant agents, FVL patients on warfarin, heparin, or DOAC agents demonstrated lesser odds of 90-day DVT and PE (OR = 4.25, P < .0001, and OR = 2.54, P = .0065) than those on aspirin/no prescription found (OR = 7.64 and OR = 21.95, P < .0001 for both). Interestingly, those on VTE prophylactic agents were not at greater odds of bleeding complications (hematoma or transfusion). DISCUSSION AND CONCLUSIONS: TSA patients with FVL present a difficult challenge to shoulder reconstruction surgeons. The current study highlights the strong risk of VTE that was reduced but still significantly elevated for those with stronger classes of VTE chemoprophylaxis. Acknowledging this risk is important for surgical planning and patient counseling, but also noted was the reassurance of similar 5-year revision rates for those with vs. without FVL.

Comparable low revision rates of stemmed and stemless total anatomic shoulder arthroplasties after exclusion of metal-backed glenoid components: a collaboration between the Australian and Danish national shoulder arthroplasty registries.

BACKGROUND: The stemmed anatomic total shoulder arthroplasty is the gold standard in the treatment of glenohumeral osteoarthritis. However, the use of stemless total shoulder arthroplasties has increased in recent years. The number of revision procedures are relatively low, and therefore it has been recommended that national joint replacement registries should collaborate when comparing revision rates. Therefore, we aimed to compare the revision rates of stemmed and stemless TSA used for the diagnosis of glenohumeral osteoarthritis using data from both the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the Danish Shoulder Arthroplasty Registry (DSR). METHODS: We included all patients who were registered in the AOANJRR and the DSR from January 1, 2012, to December 2021 with an anatomic total shoulder arthroplasty used for osteoarthritis. Revision for any reason was used as the primary outcome. We used the Kaplan-Meier method to illustrate the cumulative revision rates and a multivariate cox regression model to calculate the hazard ratios. All analyses were performed separately for data from AOANJRR and DSR, and the results were then reported using a qualitative approach. RESULTS: A total of 13,066 arthroplasties from AOANJRR and 2882 arthroplasties from DSR were included. The hazard ratio for revision of stemmed TSA with stemless TSA as reference, adjusted for age and gender, was 1.67 (95% confidence interval [CI] 1.34-2.09, P < .001) in AOANJRR and 0.57 (95% CI 0.36-0.89, P = .014) in DSR. When including glenoid type and fixation, surface bearing (only in AOANJRR), and hospital volume in the cox regression model, the hazard ratio for revision of stemmed TSA compared to stemless TSA was 1.22 (95% CI 0.85-1.75, P = .286) in AOANJRR and 1.50 (95% CI 0.91-2.45, P = .109) in DSR. The adjusted hazard ratio for revision of total shoulder arthroplasties with metal-backed glenoid components compared to all-polyethylene glenoid components was 2.54 (95% CI 1.70-3.79, P < .001) in AOANJRR and 4.1 (95% CI 1.92-8.58, P < .001) in DSR. CONCLUSION: Based on data from 2 national shoulder arthroplasty registries, we found no significant difference in risk of revision between stemmed and stemless total shoulder arthroplasties after adjusting for the type of glenoid component. We advocate that metal-backed glenoid components should be used with caution and not on a routine basis.

Appropriateness of Prior Authorization Requirements for Total Shoulder Arthroplasty: A Systematic Review.

INTRODUCTION: Total shoulder arthroplasty (TSA) has become increasingly utilized for managing glenohumeral osteoarthritis (GHOA), with procedure rates expected to rise. Consequently, there has been a surge in prior authorization (PA) requests for TSA, imposing a substantial administrative burden and highlighting the need for physician advocates to challenge the current PA system. A notable PA requirement is preoperative physical therapy (PT), a treatment modality for GHOA that has not been extensively studied and is not endorsed by the American Academy of Orthopedic Surgery (AAOS) as necessary for the treatment for GHOA. METHODS: We conducted a systematic literature search using PubMed, Embase, and Medline, adhering to PRISMA guidelines. Our search focused on studies with level IV evidence or higher that examined the efficacy preoperative PT for patients with GHOA. RESULTS: We found 210 studies of which three met our inclusion criteria. Our results were mixed, with two of the three studies supporting the use of preoperative PT. Only one study employed a randomized controlled trial (RCT) design, underscoring the need for more high-quality studies in this area. DISCUSSION/CONCLUSION: Our findings suggest that there is limited evidence for the benefit of preoperative PT in GHOA. This contradicts the current PA requirements which require patients to undergo preoperative PT to receive coverage for treatment. This review highlights the need for physician engagement in advocacy efforts to challenge these current requirements and improve patient care.

Comparing revision rates and survival of pyrocarbon and non-pyrocarbon heads in total- and hemi- shoulder arthroplasty.

OBJECTIVE: This retrospective, observational study aimed to assess the revision rates and survival curves in total shoulder arthroplasty (TSA) and hemi-shoulder arthroplasty (HSA) patients, including a sub analysis to investigate the impact of pyrocarbon humeral head in revision rates. METHODS: Data from 92 primary HSA and 508 primary TSA patients performed by seven surgeons at a large private clinic, were analyzed. The study focused on revision rates and identified factors leading to revisions, including rotator cuff insufficiency, dislocation, aseptic loosening, implant material, and glenoid erosion. RESULTS: The overall revision rate for HSA was found to be significantly higher at 7.6% compared to TSA at 1.2% with a maximum follow-up of seven years. Sub-analysis within the HSA group revealed a notably higher revision rate in cases involving a metal head (cobalt-chrome or titanium) at 12.8% compared to those with a pyrocarbon head (2.3%). CONCLUSION: This study underscores the importance of distinguishing between TSA and HSA when evaluating shoulder arthroplasty outcomes. The significantly higher revision rate in HSA, particularly with metal heads, suggests the need for careful consideration of implant selection to optimize long-term success in shoulder arthroplasty procedures.

Postoperative revision, complication and economic outcomes of patients with reverse or anatomic total shoulder arthroplasty at one year: a retrospective, United States hospital billing database analysis.

BACKGROUND: Data on the 1-year postoperative revision, complication, and economic outcomes in a hospital setting after total shoulder arthroplasty (TSA) are sparse. METHODS: A retrospective cohort study using the Premier Healthcare Database, a hospital-billing data source, evaluated 1-year postoperative revision, complication, and economic outcomes of reverse (RTSA) and anatomic (ATSA) TSA for patients who underwent the procedure from 2015 until 2021. All-cause revisits, including revision-related events (categorized as either irrigation and débridement or revision procedures and device removals) and shoulder/nonshoulder complications were collected. The incidences and costs of these revisits were evaluated. Generalized linear models were used to evaluate the associations between patient characteristics and revision and complication occurrences and costs. RESULTS: Among 51,478 RTSA and 34,623 ATSA patients (mean [standard deviation] ages RTSA 71.5 [8.1] years, ATSA 66.8 [9.0] years), 1-year adjusted incidences of all-cause revisits, irrigation/débridement, revision procedures/device removals, and shoulder/nonshoulder complications were RTSA: 45.0% (95% confidence interval (CI): 44.6%-45.5%), 0.1% (95% CI: 0.1%-0.2%), 2.1% (95% CI: 2.0%-2.2%), and 17.8% (95% CI: 17.5%-18.1%) and ATSA: 42.3% (95% CI: 41.8%-42.9%), 0.2% (95% CI: 0.1%-0.2%), 1.9% (95% CI: 1.8%-2.1%), and 14.4% (95% CI: 14.0%-14.8%), respectively; shoulder-related complications were RTSA: 12.4% (95% CI: 12.1%-12.7%) and ATSA: 9.9% (95% CI: 9.6%-10.3%). Significant factors associated with a high risk of revisions and complications included, but were not limited to, chronic comorbidities and noncommercial insurance. Per patient, the mean (standard deviations) total 1-year hospital cost was $25,225 ($15,911) and $21,520 ($13,531) for RTSA and ATSA, respectively. Revision procedures and device removals were most costly, averaging $22,920 ($18,652) and $26,911 ($18,619) per procedure for RTSA and ATSA, respectively. Patients with revision-related events with infections had higher total hospital costs than patients without this event (RTSA: $60,887 (95% CI: $56,951-$64,823) and ATSA: $59,478 (95% CI: $52,312-$66,644)), equating to a mean difference of $36,148 with RTSA and $38,426 with ATSA. Significant factors associated with higher costs of revision-related events and complications included age, race, chronic comorbidities, and noncommercial insurance. CONCLUSIONS: Nearly 45% RTSA and 42% ATSA patients returned to the hospital, most often for shoulder/nonshoulder complications (overall 17.8% RTSA and 14.4% ATSA, and shoulder-related 12.4% RTSA and 9.9% ATSA). Revisions and device removals were most expensive ($22,920 RTSA and $26,911 ATSA). Infection complications requiring revision had the highest 1-year hospital costs (∼$60,000). This study highlights the need for technologies and surgical techniques that may help reduce TSA health care utilization and economic burden.

The effect of lateralization and distalization after Grammont-style reverse total shoulder arthroplasty.

BACKGROUND: The purpose of this study was to evaluate the relationship between multiple radiographic measures of lateralization and distalization and clinical outcome scores after a reverse total shoulder arthroplasty (RTSA). METHODS: We retrospectively evaluated all RTSAs performed by the senior author between January 1, 2007, and November 1, 2017. We then evaluated the visual analog scale for pain (VAS pain), Simple Shoulder Test (SST), and American Shoulder and Elbow Surgeons (ASES) scores and complication and reoperation rates at a minimum of 2-year follow-up. We measured preoperative and postoperative (2-week) radiographs for the lateralization shoulder angle (LSA), the distalization shoulder angle (DSA), lateral humeral offset, and the distance from the glenoid to the lateral aspect of the greater tuberosity. A multivariable analysis was performed to evaluate the effect of the postoperative radiographic measurements on final patient-reported outcomes (ASES scores, SST, and VAS pain). RESULTS: The cohort included 216 shoulders from unique patients who had patient-reported outcome scores available at a minimum of 2-year follow-up (average, 4.0 ± 1.9 years) for a total follow-up rate of 70%. In the multivariable models, more lateralization (LSA) was associated with worse final ASES scores -0.52 (95% confidence interval [CI]: -0.88, -0.17; P = .004), and more distalization (DSA) was associated with better final ASES scores 0.40 (95% CI: 0.11, 0.69; P = .007). More lateralization (LSA) was associated with worse final SST scores -0.06 (95% CI: -0.11, -0.003; P = .039). Finally, greater distalization (DSA) was associated with lower final VAS pain scores, ratio = 0.98 (95% CI: 0.96, 1.00; P = .021). CONCLUSIONS: Greater distalization and less lateralization are associated with better function and less pain after a Grammont-style RTSA. When using a Grammont-style implant, remaining consistent with Grammont's principles of implant placement will afford better final clinical outcomes.

Complications after Reverse Total Shoulder Arthroplasty in the Korean Population: A Single Center Study of 299 Cases.

BACKGROUND: Knowledge regarding differences in the order of frequency of complications after reverse total shoulder arthroplasty (RTSA) between Asian and Western populations is limited. We therefore asked for (1) What is the order of frequency of complications after primary RTSA in the Korean population? (2) What are the rates of complication, reoperation, and revision, and clinical outcomes after index surgery? METHODS: We retrospectively reviewed the 299 consecutive cases who underwent primary RTSA with more than 1 year of follow-up over a period of 12 years. The mean age of the patients was 73.4 years (range, 58-88 years) and the mean follow-up period was 3.8 years (range, 1-11.5 years). Evaluation of the clinical outcomes, complications, and reinterventions was performed at the final follow-up. RESULTS: The mean VAS pain score, UCLA score, ASES score, and SSV improved from 6.7, 10.2, 30.7, and 27.7% before RTSA to 1.4, 26.4, 80.5, 77.2% after RTSA, respectively (P < .001). Overall, 45 complications (15.1%) were observed in 44 patients. The order of frequency of complications was as follows: 16 cases of scapular stress fracture (5.4%), 9 intraoperative or postoperative periprosthetic fracture (3.0%), 6 brachial plexus injury (2.0%), 4 instability (1.3%), 2 glenoid loosening (0.7%), 2 glenoid disassembly (0.7%), 2 periprosthetic joint infection (0.7%), 1 glenoid fixation failure (0.3%), 1 humeral stem fixation failure (0.3%), 1 hematoma (0.3%), and 1 complex regional pain syndrome (0.3%). Reintervention was performed in 15 cases (5.0%) including reoperation (8 cases; 2.7%) and revision surgery (7 cases; 2.3%). CONCLUSION: At a mean follow-up period of 3.8 years, primary RTSA showed satisfactory clinical outcomes with a complication rate of 15.1%, a reoperation rate of 2.7%, and a revision rate of 2.3%. Scapular stress fracture appears to be the most common complication after RTSA in the Korean population.

Shoulder arthroplasty for inflammatory arthritis is associated with higher rates of medical and surgical complications: a nationwide matched cohort analysis from 2016-2020.

BACKGROUND: Inflammatory arthritis (IA) represents a less common indication for anatomic and reverse total shoulder arthroplasty (TSA) than osteoarthritis (OA). The safety and efficacy of anatomic and reverse TSA in this population has not been as well studied compared to OA. We analyzed the differences in outcomes between IA and OA patients undergoing TSA. METHODS: Patients who underwent primary anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) from 2016-2020 were identified in the Premier Healthcare Database. Inflammatory arthritis (IA) patients were identified using International Classification of Diseases, Tenth Revision, diagnosis codes and compared to osteoarthritis controls. Patients were matched in a 1:8 fashion by age (±3 years), sex, race, and presence of pertinent comorbidities. Patient demographics, hospital factors, and patient comorbidities were compared. Multivariate regression was performed following matching to account for any residual confounding and 90-day complications were compared between the 2 cohorts. Descriptive statistics and regression analysis were employed with significance set at P < .05. RESULTS: Prior to matching, 5685 IA cases and 93,539 OA controls were identified. Patients with IA were more likely to be female, have prolonged length of stay and increased total costs (P < .0001). After matching and multivariate analysis, 4082 IA cases and 32,656 controls remained. IA patients were at increased risk of deep wound infection (OR 3.14, 95% CI 1.38-7.16, P = .006), implant loosening (OR 4.11, 95% CI 1.17-14.40, P = .027), and mechanical complications (OR 6.34, 95% CI 1.05-38.20, P = .044), as well as a decreased risk of postoperative stiffness (OR 0.36, 95% CI 0.16-0.83, P = .002). Medically, IA patients were at increased risk of PE (OR 2.97, 95% CI 1.52-5.77, P = .001) and acute blood loss anemia (OR 1.27, 95% CI 1.12-1.44, P < .0001). DISCUSSION AND CONCLUSION: Inflammatory arthritis represents a distinctly morbid risk profile compared to osteoarthritis patients with multiple increased surgical and postoperative medical complications in patients undergoing aTSA and rTSA. Surgeons should consider these potential complications and employ a multidisciplinary approach in preoperative risk stratification of IA undergoing shoulder replacement.

Evaluating the fairness and accuracy of machine learning-based predictions of clinical outcomes after anatomic and reverse total shoulder arthroplasty.

BACKGROUND: Machine learning (ML)-based clinical decision support tools (CDSTs) make personalized predictions for different treatments; by comparing predictions of multiple treatments, these tools can be used to optimize decision making for a particular patient. However, CDST prediction accuracy varies for different patients and also for different treatment options. If these differences are sufficiently large and consistent for a particular subcohort of patients, then that bias may result in those patients not receiving a particular treatment. Such level of bias would deem the CDST "unfair." The purpose of this study is to evaluate the "fairness" of ML CDST-based clinical outcomes predictions after anatomic (aTSA) and reverse total shoulder arthroplasty (rTSA) for patients of different demographic attributes. METHODS: Clinical data from 8280 shoulder arthroplasty patients with 19,249 postoperative visits was used to evaluate the prediction fairness and accuracy associated with the following patient demographic attributes: ethnicity, sex, and age at the time of surgery. Performance of clinical outcome and range of motion regression predictions were quantified by the mean absolute error (MAE) and performance of minimal clinically important difference (MCID) and substantial clinical benefit classification predictions were quantified by accuracy, sensitivity, and the F1 score. Fairness of classification predictions leveraged the "four-fifths" legal guideline from the US Equal Employment Opportunity Commission and fairness of regression predictions leveraged established MCID thresholds associated with each outcome measure. RESULTS: For both aTSA and rTSA clinical outcome predictions, only minor differences in MAE were observed between patients of different ethnicity, sex, and age. Evaluation of prediction fairness demonstrated that 0 of 486 MCID (0%) and only 3 of 486 substantial clinical benefit (0.6%) classification predictions were outside the 20% fairness boundary and only 14 of 972 (1.4%) regression predictions were outside of the MCID fairness boundary. Hispanic and Black patients were more likely to have ML predictions out of fairness tolerance for aTSA and rTSA. Additionally, patients <60 years old were more likely to have ML predictions out of fairness tolerance for rTSA. No disparate predictions were identified for sex and no disparate regression predictions were observed for forward elevation, internal rotation score, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score, or global shoulder function. CONCLUSION: The ML algorithms analyzed in this study accurately predict clinical outcomes after aTSA and rTSA for patients of different ethnicity, sex, and age, where only 1.4% of regression predictions and only 0.3% of classification predictions were out of fairness tolerance using the proposed fairness evaluation method and acceptance criteria. Future work is required to externally validate these ML algorithms to ensure they are equally accurate for all legally protected patient groups.

Clinically significant outcome thresholds and rates of achievement by shoulder arthroplasty type and preoperative diagnosis.

BACKGROUND: Clinically significant outcome (CSO) benchmarks have been previously established for shoulder arthroplasty by assimilating preoperative diagnoses and arthroplasty types. The purpose of this study was to establish unique CSO thresholds and compare the time-to-achievement of these for reverse shoulder arthroplasty (RSA) for osteoarthritis (GHOA), RSA for rotator cuff arthropathy (RCA), and total shoulder arthroplasty (TSA) for GHOA. MATERIALS AND METHODS: Consecutive patients who underwent elective RSA for GHOA, TSA for GHOA, or RSA for RCA between February 2015 and May 2020, with 2-year minimum follow-up, were retrospectively identified from a prospectively maintained single surgeon registry. The American Shoulder and Elbow Surgeons (ASES) score was administered preoperatively and postoperatively at 2-week, 6-week, 3-month, 6-month, 1-year, and 2-year timepoints. Satisfaction and subjective overall improvement anchor questionnaires were administered at the time of final follow-up. Distribution-based methods were used to calculate the Minimal Clinically Important Difference (MCID), and anchor-based methods were used to calculate the Substantial Clinical Benefit (SCB) and the Patient Acceptable Symptom State (PASS) for each patient group. Median time to achievement, individual incidence of achievement at each time point, and cumulative incidence of achievement calculated using Kaplan-Meier survival curve analysis with interval censoring were compared between groups for each CSO. Cox-regression analyses were also performed to determine which patient factors were significantly associated with early or delayed achievement of CSOs. RESULTS: There were 471 patients eligible for study analysis: 276 RSA for GHOA, 107 TSA for GHOA, and 88 RSA for RCA. The calculated MCID, SCB, and PASS scores differed for each group. There were no significant differences in median time to achievement of any CSO between groups. Log-rank testing revealed that cumulative achievements significantly differed between groups for MCID (P = .014) but not for SCB (P = .053) or PASS (P = .620). On cox regression analysis, TSA patients had earlier achievement of SCB, whereas TSA and RSA for GHOA patients had earlier achievement of MCID. At 2-years, a significantly higher percentage of RSA for GHOA patients achieved MCID and SCB compared to RSA for RCA (MCID:100%, 95.5%, P = .003, SCB:94.6%, 86.4%, P = .036). CONCLUSION: Calculated CSO thresholds differ according to preoperative diagnosis and shoulder arthroplasty type. Patients undergoing TSA and RSA for GHOA achieve CSOs earlier than RSA for RCA patients, and a significantly higher percentage of RSA for GHOA patients achieve CSOs by 2 years compared to RSA for RCA patients.

Does achieving clinically important thresholds after first shoulder arthroplasty predict similar outcomes of the contralateral shoulder?

BACKGROUND: Patients are increasingly undergoing bilateral total shoulder arthroplasty (TSA). At present, it is unknown whether success after the first TSA is predictive of success after contralateral TSA. We aimed to determine whether exceeding clinically important thresholds of success after primary TSA predicts similar outcomes for subsequent contralateral TSA. METHODS: We performed a retrospective review of a prospectively collected shoulder arthroplasty database for patients undergoing bilateral primary anatomic (aTSA) or reverse (rTSA) total shoulder arthroplasty since January 2000 with preoperative and 2- or 3-year clinical follow-up. Our primary outcome was whether exceeding clinically important thresholds in the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score for the first TSA was predictive of similar success of the contralateral TSA; thresholds for the ASES score were adopted from prior literature and included the minimal clinically important difference (MCID), the substantial clinical benefit (SCB), 30% of maximal possible improvement (MPI), and the patient acceptable symptomatic state (PASS). The PASS is defined as the highest level of symptom beyond which patients consider themselves well, which may be a better indicator of a patient's quality of life. To determine whether exceeding clinically important thresholds was independently predictive of similar success after second contralateral TSA, we performed multivariable logistic regression adjusted for age at second surgery, sex, BMI, and type of first and second TSA. RESULTS: Of the 134 patients identified that underwent bilateral shoulder arthroplasty, 65 (49%) had bilateral rTSAs, 45 (34%) had bilateral aTSAs, 21 (16%) underwent aTSA/rTSA, and 3 (2%) underwent rTSA/aTSA. On multivariable logistic regression, exceeding clinically important thresholds after first TSA was not associated with greater odds of achieving thresholds after second TSA when success was evaluated by the MCID, SCB, and 30% MPI. In contrast, exceeding the PASS after first TSA was associated with 5.9 times greater odds (95% confidence interval 2.5-14.4, P < .001) of exceeding the PASS after second TSA. Overall, patients who exceeded the PASS after first TSA exceeded the PASS after second TSA at a higher rate (71% vs. 29%, P < .001); this difference persisted when stratified by type of prosthesis for first and second TSA. CONCLUSIONS: Patients who achieve the ASES score PASS after first TSA have greater odds of achieving the PASS for the contralateral shoulder regardless of prostheses type.

Biomechanics of subscapularis V-shaped tenotomy compared to standard tenotomy.

BACKGROUND: Subscapularis function is critical after anatomic total shoulder arthroplasty (aTSA). Recently, however, a technique has been described that features a chevron or V-shaped subscapularis tendon cut (VT). This biomechanical study compared repair of the standard tenotomy (ST), made perpendicular to the subscapularis fibers, to repair of the novel VT using cyclic displacement, creep, construct stiffness, and load to failure. METHODS: This biomechanical study used 6 pairs of fresh frozen paired cadaveric shoulder specimens. One specimen per each pair underwent VT, the other ST. Subscapularis tenotomy was performed 1 cm from the insertion onto the lesser tuberosity. For VT, the apex of the V was 3 cm from the lesser tuberosity. After tenotomy, each humerus underwent humeral head arthroplasty. Eight figure-of-8 sutures were used to repair the tenotomy (Ethibond Excel; Ethicon, US LLC). Specimens were cyclically loaded from 2 to 100 N at 45 degrees abduction at a rate of 1 Hz for 3000 cycles. Cyclic displacement, creep, and stiffness and load to failure were measured. RESULTS: Cyclic displacement did not differ significantly between the ST and VT from 1 to 3000 cycles. The difference in displacement between the V-shaped and standard tenotomy at 3000 cycles was 1.57 mm (3.66 ± 1.55 mm vs. 5.1 ± 2.8 mm, P = .31, respectively). At no point was the V-shape tenotomy (VT) >3 mm of average displacement, whereas the standard tenotomy (ST) averaged 3 mm of displacement after 3 cycles. Creep was significantly lower for VT in cycles 1 through 3. For all cycles, stiffness was not significantly different in the VT group compared with the ST group. Load to failure was not statistically significant in the VT compared to the standard tenotomy throughout all cycles (253.2 ± 27.7 N vs. 213.3 ± 76.04 N; P = .25, respectively). The range of load to failure varied from 100 to 301 N for standard tenotomy compared with 216 to 308 N for VT. CONCLUSION: This study showed that VT and ST demonstrated equivalent stiffness, displacement, and load to failure. VT had the benefit of less creep throughout the first 3 cycles, although there was no difference from cycle 4 to 3000. The VT had equivalent biomechanical properties to the ST at time zero, an important first step in our understanding of the technique. The VT technique warrants further clinical study to determine if the technique has clinical benefits over ST following aTSA.

Social determinants of health disparities impact postoperative complications in patients undergoing total shoulder arthroplasty.

BACKGROUND: Understanding the role of social determinants of health disparities (SDHDs) in surgical outcomes can better prepare providers to improve postoperative care. In this study, we use International Classification of Diseases (ICD) codes to identify SDHDs and investigate the risk of postoperative complication rates among patients undergoing total shoulder arthroplasty (TSA). METHODS: A retrospective cohort analysis was conducted using a national insurance claims database. Using ICD and Current Procedural Terminology (CPT) codes, patients who underwent primary TSA with at least 2 years of follow-up in the database were identified. Patients with a history of SDHDs were identified using appropriate ICD-9 and ICD-10 codes. Patients were grouped in one of 2 cohorts: (1) patients with no history of SDHDs (control) and (2) patients with a history of SDHDs (SDHD group) prior to TSA. The SDHD and control groups were matched 1:1 for comorbidities and demographics prior to conducting multivariable analysis for 90-day medical complications and 2-year surgical complications. RESULTS: After matching, there were 8023 patients in the SDHD group and 8023 patients in the control group. The SDHD group had significantly higher odds for 90-day medical complications including heart failure, cerebrovascular accident, renal failure, deep vein thrombosis, pneumonia, sepsis, and urinary tract infection. Additionally, the SDHD group had significantly higher odds for revision surgery within 2 years following TSA. Patients in the SDHD group also had a significantly longer length of hospital stay following TSA. DISCUSSION: This study highlights the association between SDHDs and postoperative complications following TSA. Quantifying the risk of complications and differences in length of stay for TSA patients with a history of SDHDs is important in determining value-based payment models and risk stratifying to optimize patient care.

Outcomes of total shoulder arthroplasty in patients with prior anterior shoulder instability: minimum 5-year follow-up.

BACKGROUND: Patients with a history of anterior shoulder instability (ASI) commonly progress to glenohumeral arthritis or even dislocation arthropathy and often require total shoulder arthroplasty (TSA). The purposes of this study were to (1) report patient-reported outcomes (PROs) after TSA in patients with a history of ASI, (2) compare TSA outcomes of patients whose ASI was managed operatively vs. nonoperatively, and (3) report PROs of TSA in patients who previously underwent arthroscopic vs. open ASI management. METHODS: Patients were included if they had a history of ASI and had undergone TSA ≥5 years earlier, performed by a single surgeon, between October 2005 and January 2017. The exclusion criteria included prior rotator cuff repair, hemiarthroplasty, or glenohumeral joint infection before the index TSA procedure. Patients were separated into 2 groups: those whose ASI was previously operatively managed and those whose ASI was treated nonoperatively. This was a retrospective review of prospective collected data. Data collected was demographic, surgical and subjective. The PROs used were the American Shoulder and Elbow Surgeons score, Single Assessment Numerical Evaluation score, QuickDASH (Quick Disabilities of the Arm, Shoulder and Hand) score, and 12-item Short Form physical component score. Failure was defined as revision TSA surgery, conversion to reverse TSA, or prosthetic joint infection. Kaplan-Meier survivorship analysis was performed. RESULTS: This study included 36 patients (27 men and 9 women) with a mean age of 56.4 years (range, 18.8-72.2 years). Patients in the operative ASI group were younger than those in the nonoperative ASI group (50.6 years vs. 64.0 years, P < .001). Operative ASI patients underwent 10 open and 11 arthroscopic anterior stabilization surgical procedures prior to TSA (mean, 2 procedures; range, 1-4 procedures). TSA failure occurred in 6 of 21 patients with operative ASI (28.6%), whereas no failures occurred in the nonoperative ASI group (P = .03). Follow-up was obtained in 28 of 30 eligible patients (93%) at an average of 7.45 years (range, 5.0-13.6 years). In the collective cohort, the American Shoulder and Elbow Surgeons score, Single Assessment Numerical Evaluation score, QuickDASH (Quick Disabilities of the Arm, Shoulder and Hand) score, and 12-item Short Form physical component score significantly improved, with no differences in the postoperative PROs between the 2 groups. We found no significant differences when comparing PROs between prior open and prior arthroscopic ASI procedures or when comparing the number of prior ASI procedures. Kaplan-Meier analysis demonstrated a 79% 5-year survivorship rate in patients with prior ASI surgery and a 100% survivorship rate in nonoperatively managed ASI patients (P = .030). CONCLUSION: At mid-term follow-up, patients with a history of ASI undergoing TSA can expect continued improvement in function compared with preoperative values. However, TSA survivorship is decreased in patients with a history of ASI surgery compared with those without prior surgery.

Managing rotator cuff tear arthropathy: a role for cuff tear arthropathy hemiarthroplasty as well as reverse total shoulder arthroplasty.

BACKGROUND: Disabling cuff tear arthropathy (CTA) is commonly managed with reverse shoulder arthroplasty (RSA). However, for patients with CTA having preserved active elevation, cuff tear arthropathy hemiarthroplasty (CTAH) may offer a cost-effective alternative that avoids the complications unique to RSA. We sought to determine the characteristics and outcomes of a series of patients with CTA managed with these procedures. MATERIALS AND METHODS: We retrospectively reviewed 103 patients with CTA treated with shoulder arthroplasty, the type of which was determined by the patient's ability to actively elevate the arm. Outcome measures included the change in the Simple Shoulder Test (SST), the percent maximum improvement in SST (%MPI), and the percentage of patients exceeding the minimal clinically important difference for the change in SST and %MPI. Postoperative x-rays were evaluated to assess the positions of the center of rotation and the greater tuberosity for each implant. RESULTS: Forty-four percent of the 103 patients were managed with CTAH while 56% were managed with RSA. Both arthroplasties resulted in clinically significant improvement. Patients having RSA improved from a mean preoperative SST score of 1.7 (interquartile range [IQR], 0.0-3.0) to a postoperative score of 6.3 (IQR, 2.3-10.0) (P < .01). Patients having CTAH improved from a preoperative SST score of 3.1 (IQR, 1.0-4.0) to a postoperative score of 7.6 (IQR, 5.0-10.) (P < .001). These improvements exceeded the minimal clinically important difference. Instability accounted for most of the RSA complications; however, it did not account for any CTAH complications. The postoperative position of the center of rotation and greater tuberosity on anteroposterior radiographs did not correlate with the clinical outcomes for either procedure. CONCLUSION: For 103 patients with CTA, clinically significant improvement was achieved with appropriately indicated CTAH and RSA. In view of the lower cost of the CTAH implant, it may provide a cost-effective alternative to RSA for patients with retained active elevation.