Modular Baseplate Augmentation: A Simple and Effective Method for Addressing Eccentric Glenoid Wear.

BACKGROUND: Augmented baseplates can be effective at addressing eccentric glenoid wear in reverse total shoulder arthroplasty (rTSA). However, these implants often come in a limited number of predetermined shapes that require additional reaming to ensure adequate glenoid seating. This typically involves complex instrumentation and can have a negative impact on implant stability. Modular baseplate augmentation based on intra-operative measurements may allow for more precise defect filling while preserving glenoid bone. The purpose of this investigation was to assess the stability of a novel ringed baseplate with modular augmentation in comparison to non-augmented standard and ringed baseplate designs. METHODS: In this biomechanical study, baseplate micromotion was tested for three constructs according to American Society for Testing and Materials (ASTM) guidelines. The constructs included a non-augmented curved baseplate, a non-augmented ringed baseplate and ringed baseplate with an 8 mm locking modular augmentation peg. The non-augmented constructs were mounted flush onto polyurethane (PU) foam blocks, while the augmented baseplate was mounted on a PU block with a simulated defect. Baseplate displacement was measured prior to and after 100,000 cycles of cyclic loading. RESULTS: Prior to cyclic loading, the non-augmented and augmented ringed baseplates both demonstrated significantly less micromotion than the non-augmented curved baseplate design (81.1 µm vs 97.2 µm vs 152.7 µm; p=0.009). After cyclic loading, both ringed constructs continued to have significantly less micromotion compared to the curved design (105.5 µm vs 103.2 µm vs 136.6 µm; p<0.001). The micromotion for both ringed constructs remained below the minimum threshold required for bony ingrowth (150 µm) at all time points. CONCLUSION: In the setting of a simulated glenoid defect, locked modular augmentation of a ringed baseplate does not result in increased baseplate micromotion when compared to full contact, non-augmented baseplates. This design offers a simple method for tailored baseplate augmentation that can match specific variations in glenoid anatomy, limiting the need for excessive reaming and ultimately optimizing the environment for long term implant stability. LEVEL OF EVIDENCE: Basic Science Study; Biomechanics.

Five-Year Mortality Rates Following Elective Shoulder Arthroplasty and Shoulder Arthroplasty for Fracture in Patients Over Age 65.

Background: To effectively counsel patients prior to shoulder arthroplasty, surgeons should understand the overall life trajectory and life expectancy of patients in the context of the patient's shoulder pathology and medical comorbidities. Such an understanding can influence both operative and nonoperative decision-making and implant choices. This study evaluated 5-year mortality following shoulder arthroplasty in patients ≥65 years old and identified associated risk factors. Methods: We utilized Centers for Medicare & Medicaid Services Fee-for-Service inpatient and outpatient claims data to investigate the 5-year mortality rate following shoulder arthroplasty procedures performed from 2014 to 2016. The impact of patient demographics, including fracture diagnosis, year fixed effects, and state fixed effects; patient comorbidities; and hospital-level characteristics on 5-year mortality rates were assessed with use of a Cox proportional hazards regression model. A p value of <0.05 was considered significant. Results: A total of 108,667 shoulder arthroplasty cases (96,104 nonfracture and 12,563 fracture) were examined. The cohort was 62.7% female and 5.8% non-White and had a mean age at surgery of 74.3 years. The mean 5-year mortality rate was 16.6% across all shoulder arthroplasty cases, 14.9% for nonfracture cases, and 29.9% for fracture cases. The trend toward higher mortality in the fracture group compared with the nonfracture group was sustained throughout the 5-year postoperative period, with a fracture diagnosis being associated with a hazard ratio of 1.63 for mortality (p < 0.001). Medical comorbidities were associated with an increased risk of mortality, with liver disease bearing the highest hazard ratio (3.07; p < 0.001), followed by chronic kidney disease (2.59; p < 0.001), chronic obstructive pulmonary disease (1.92; p < 0.001), and congestive heart failure (1.90; p < 0.001). Conclusions: The mean 5-year mortality following shoulder arthroplasty was 16.6%. Patients with a fracture diagnosis had a significantly higher 5-year mortality risk (29.9%) than those with a nonfracture diagnosis (14.9%). Medical comorbidities had the greatest impact on mortality risk, with chronic liver and kidney disease being the most noteworthy. This novel longer-term data can help with patient education and risk stratification prior to undergoing shoulder replacement. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Predictors of poor and excellent outcomes following reverse shoulder arthroplasty for glenohumeral osteoarthritis with an intact rotator cuff.

BACKGROUND: As the indications for reverse total shoulder arthroplasty (RSA) continue to evolve, it has been more commonly utilized for the treatment of glenohumeral osteoarthritis with an intact rotator cuff (GHOA). Given the increased use of RSA for GHOA, it is important to identify factors influential of clinical outcomes. In this study, we sought to identify variables predictive of clinical outcomes following RSA for GHOA. METHODS: Patients undergoing primary RSA for GHOA between 2015 and 2020 were retrospectively identified through a prospectively maintained, single surgeon registry. Eligible patients had complete patient-reported outcome measures and range of motion measurements with a minimum 2-year follow-up. Univariate analysis was utilized to compare characteristics and outcome measures of patients with poor and excellent outcomes, which was defined as postoperative American Shoulder and Elbow Surgeons (ASES) scores in the bottom and top quartiles, respectively. Multivariate linear regression was performed to determine factors independently predictive of postoperative ASES score. RESULTS: A total of 230 patients were included with a mean follow-up of 33.4 months (SD 13.2). The mean age of the study population was 71.9 (SD 6.1). Two hundred twenty-four patients (97.4%) surpassed the minimal clinically important difference and 209 patients (90.1%) achieved substantial clinical benefit for ASES score. Preoperative factors differing between the poor and excellent outcome groups were sex (male: poor 37.9%, excellent 58.6%; P = .041), opioid use (poor 24.1%, excellent 5.2%; P = .009), ASES score (poor 32.9, excellent 41.0; P = .011), and forward elevation (poor 92°, excellent 101°; P = .030). Linear regression demonstrated that Walch B3 glenoids (ß 7.08; P = .010) and higher preoperative ASES scores (ß 0.14; P = .025) were predictors of higher postoperative ASES score, while postoperative complications (ß -18.66; P < .001) and preoperative opioid use (ß -11.88; P < .001) were predictive of lower postoperative ASES scores. CONCLUSION: Over 90% of patients who underwent RSA for GHOA with an intact rotator cuff experienced substantial clinical benefit. An unsurprising handful of factors were associated with postoperative clinical outcomes; higher preoperative ASES scores were slightly associated with higher postoperative ASES, whereas preoperative opioid use and postoperative complications were associated with lower postoperative ASES. Additionally, Walch glenoid type B3 was associated with higher postoperative ASES, indicating that patients with posterior glenoid defects are not predisposed to poor clinical outcomes following RSA. These results serve as a resource to improve preoperative patient counseling and manage postoperative expectations.

Effect of vitamin E-enhanced highly cross-linked polyethylene on wear rate and particle debris in anatomic total shoulder arthroplasty: a biomechanical comparison to ultrahigh-molecular-weight polyethylene.

BACKGROUND: Particle-induced osteolysis resulting from polyethylene wear remains a source of implant failure in anatomic total shoulder designs. Modern polyethylene components are irradiated in an oxygen-free environment to induce cross-linking, but reducing the resulting free radicals with melting or heat annealing can compromise the component's mechanical properties. Vitamin E has been introduced as an adjuvant to thermal treatments. Anatomic shoulder arthroplasty models with a ceramic head component have demonstrated that vitamin E-enhanced polyethylene show improved wear compared with highly cross-linked polyethylene (HXLPE). This study aimed to assess the biomechanical wear properties and particle size characteristics of a novel vitamin E-enhanced highly cross-linked polyethylene (VEXPE) glenoid compared to a conventional ultrahigh-molecular-weight polyethylene (UHMWPE) glenoid against a cobalt chromium molybdenum (CoCrMo) head component. METHODS: Biomechanical wear testing was performed to compare the VEXPE glenoid to UHMWPE glenoid with regard to pristine polyethylene wear and abrasive endurance against a polished CoCrMo alloy humeral head in an anatomic shoulder wear-simulation model. Cumulative mass loss (milligrams) was recorded, and wear rate calculated (milligrams per megacycle [Mc]). Under pristine wear conditions, particle analysis was performed, and functional biologic activity (FBA) was calculated to estimate particle debris osteolytic potential. In addition, 95% confidence intervals for all testing conditions were calculated. RESULTS: The average pristine wear rate was statistically significantly lower for the VEXPE glenoid compared with the HXLPE glenoid (0.81 ± 0.64 mg/Mc vs. 7.00 ± 0.45 mg/Mc) (P < .05). Under abrasive wear conditions, the VEXPE glenoid had a statistically significant lower average wear rate compared with the UHMWPE glenoid comparator device (18.93 ± 5.80 mg/Mc vs. 40.47 ± 2.63 mg/Mc) (P < .05). The VEXPE glenoid demonstrated a statistically significant improvement in FBA compared with the HXLPE glenoid (0.21 ± 0.21 vs. 1.54 ± 0.49 (P < .05). CONCLUSIONS: A new anatomic glenoid component with VEXPE demonstrated significantly improved pristine and abrasive wear properties with lower osteolytic particle debris potential compared with a conventional UHMWPE glenoid component. Vitamin E-enhanced polyethylene shows early promise in shoulder arthroplasty components. Long-term clinical and radiographic investigation needs to be performed to verify if these biomechanical wear properties translate to diminished long-term wear, osteolysis, and loosening.

Outcomes after reverse shoulder arthroplasty for the treatment of glenohumeral osteoarthritis in patients under and over 70 years of age: a propensity score-matched analysis.

INTRODUCTION: As reverse shoulder arthroplasty (RSA) continues to grow in popularity for the treatment of glenohumeral osteoarthritis (GHOA) with an intact rotator cuff, it becomes increasingly important to identify factors that influence postoperative outcome. Although recent studies have demonstrated excellent postoperative range of motion and patient-reported outcome scores following RSA for GHOA, there continues to be surgeon hesitation to adopt RSA as a viable treatment in the younger patient population due to greater functional demands. In this study, we sought to determine the effect of age on clinical outcomes following RSA for GHOA through a comparison of patients over and under the age of 70. METHODS: A retrospective review of prospectively collected data from an institutional registry was performed. Propensity score matching was utilized to match patients under the age of 70 (U-70) to those over 70 (O-70) in a 1:1 ratio based on sex, body mass index (BMI), preoperative ASES score, preoperative active forward elevation (FE), Walch classification, and American Society of Anesthesiologists comorbidity score. Clinical outcomes obtained preoperatively and at a minimum of 2 years postoperatively consisted of Visual Analog Scale (VAS) for pain, Single Assessment Numeric Evaluation (SANE) score, and American Shoulder and Elbow Surgeons (ASES) score, as well as active (FE), internal rotation, and external rotation. Descriptive statistics and univariate analysis were performed to compare cohorts. RESULTS: After matching, each cohort consisted of 66 patients with similar mean follow-up periods (U-70, 28.1 ± 7.5 months vs. O-70, 27.4 ± 7.5 months; P = .887). Mean age of the U-70 cohort was 66.2 ± 3.3 while the O-70 cohort had a mean age of 75.3 ± 3.8. Both groups demonstrated significant improvement in VAS, SANE, and ASES scores, as well as active range of motion in all planes. The only significant difference between cohorts was greater postoperative FE in younger patients (143 ± 16° vs. 136 ± 15°; P = .017), though the baseline-to-postoperative improvement in FE was similar between cohorts (50 ± 29° vs. 43 ± 29°, P = .174). CONCLUSION: RSA is a successful surgical treatment for GHOA regardless of age. Aside from greater postoperative FE in younger patients, there were no other differences in clinical outcomes between younger and older patients in this retrospective analysis, which compared patients who were matched by sex, BMI, and Walch classification, among other factors. Based on our results, 70 years of age should not be used as a threshold in preoperative counseling when determining whether a patient with GHOA with an intact rotator cuff is indicated for reverse shoulder arthroplasty.

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.

Variations in 1-year Trajectories of Levels of Pain and Capability After Shoulder Arthroplasty Are Associated With Baseline Mental Health.

BACKGROUND: There is variability in the trajectories of pain intensity and magnitude of incapability after shoulder arthroplasty. A better understanding of the degree to which variation in recovery trajectories relates to aspects of mental health can inform the development of comprehensive biopsychosocial care strategies. QUESTIONS/PURPOSES: (1) Do pain intensities at baseline and the trajectories during recovery differ between groups when stratified by mental health composite summary score, arthroplasty type, and revision surgery? (2) Do magnitudes of capability at baseline and the trajectories during recovery differ between these groups? METHODS: We used a registry of 755 patients who underwent shoulder arthroplasty by a single surgeon at a specialized urban orthopaedic hospital that recorded the mental component summary (MCS) score of the Veterans RAND 12, a measure of shoulder-specific comfort and capability (American Shoulder and Elbow Surgeons [ASES] score, which ranges from 0 to 100 points, with a score of 0 indicating worse capability and pain and 100 indicating better capability and pain and a minimum clinically important difference of 6.4), and the VAS for pain intensity (range 0 [representing no pain] to 10 [representing the worst pain possible], with a minimum clinically important difference of 1.4) preoperatively, 2 weeks postoperatively, and 6 weeks, 3 months, 6 months, and 1 year after surgery. Forty-nine percent (368 of 755) of the patients were men, with a mean age of 68 ± 8 years, and 77% (585) were treated with reverse total shoulder arthroplasty (rTSA). Unconditional linear and quadratic growth models were generated to identify the general shape of recovery for both outcomes (linear versus quadratic). We then constructed conditional growth models and curves for pain intensity and the magnitude of capability showing mean baseline scores and the rates of recovery that determine the trajectory, accounting for mental health (MCS) quartiles, primary or revision arthroplasty, and TSA or reverse TSA in separate models. Because pain intensity and capability showed quadratic trends, we created trajectories using the square of time. RESULTS: Patients in the worst two MCS quartiles had greater pain intensity at baseline than patients in the best quartile (difference in baseline for bottom quartile: 0.93 [95% CI 0.72 to 1.1]; p < 0.01; difference in baseline for next-worst quartile: 0.36 [95% CI 0.16 to 0.57]; p < 0.01). The rates of change in recovery from pain intensity were not different among groups (p > 0.10). Patients with revision surgery had greater baseline pain (difference: 1.1 [95% CI 0.7 to 1.5]; p < 0.01) but no difference in rates of recovery (difference: 0.031 [95% CI 0.035 to 0.097]; p = 0.36). There were no differences in baseline pain intensity and rates of recovery between patients with reverse TSA and those with TSA (baseline pain difference: -0.20 [95% CI -0.38 to -0.03]; p = 0.18; difference in rate of recovery: -0.005 [95% CI -0.035 to 0.025]; p = 0.74). Patients in the worst two MCS quartiles had worse baseline capability than patients in the best quartile (difference in baseline for bottom quartile: -8.9 [95% CI -10 to -7.4]; p < 0.001; difference in baseline for the next-worst quartile: -4.9 [95% CI -6.4 to -3.4]; p < 0.01), with no differences in rates of recovery (p > 0.10). Patients with revision surgery had lower baseline capability (difference in baseline: -13 [95% CI -15 to -9.7]; p < 0.01), with a slower rate of recovery (difference in rate of recovery: -0.56 [95% CI -1.0 to -0.079]; p = 0.021). There were no differences in baseline capability or rates of recovery between TSA and reverse TSA. CONCLUSION: The observation that preoperative and 1-year comfort and capability are associated with mental health factors and with similar recovery trajectories reminds us that assessment and treatment of mental health is best considered an integral aspect of musculoskeletal care. Future studies can address how prioritization of mental health in musculoskeletal care strategies might reduce variation in the 1-year outcomes of discretionary surgeries such as shoulder arthroplasty. LEVEL OF EVIDENCE: Level III, therapeutic study.

Indication matters: effect of indication on clinical outcome following reverse total shoulder arthroplasty-a multicenter study.

BACKGROUND: As the utilization and success of reverse total shoulder arthroplasty (RTSA) have continued to grow, so have its surgical indications. Despite the adoption of RTSA for the treatment of glenohumeral osteoarthritis (GHOA) with an intact rotator cuff and irreparable massive rotator cuff tears (MCTs) without arthritis, the literature remains sparse regarding the differential outcomes after RTSA among these varying indications. Thus, the purpose of this study was to examine the postoperative clinical outcomes of RTSA based on indication. METHODS: A retrospective review of 2 large institutional databases was performed to identify all patients who underwent RTSA between 2015 and 2019 with minimum 2-year follow-up. Patients were stratified by indication into 3 cohorts: GHOA, rotator cuff tear arthropathy (CTA), and MCT. Baseline demographic characteristics were collected to determine differences between the 3 cohorts. Clinical outcomes were measured preoperatively and postoperatively, including active range of motion, American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation score, and visual analog scale pain score. Multivariate linear regression was performed to determine the factors independently predictive of the postoperative ASES score. RESULTS: A total of 625 patients (383 with GHOA, 164 with CTA, and 78 with MCTs) with a mean follow-up period of 33.4 months were included in the analysis. Patients with GHOA had superior ASES scores (85.6 ± 15.7 vs. 76.6 ± 20.8 in CTA cohort [P < .001] and 75.9 ± 19.9 in MCT cohort [P < .001]), Single Assessment Numeric Evaluation scores (86 ± 20.9 vs. 76.7 ± 24.1 in CTA cohort [P < .001] and 74.2 ± 25.3 in MCT cohort [P < .001]), and visual analog scale pain scores (median [interquartile range], 0.0 [0.0-1.0] vs. 0.0 [0.0-2.0] in CTA cohort [P < .001] and 0.0 [0.0-2.0] in MCT cohort [P < .001]) postoperatively. Postoperative active forward elevation (P < .001) and improvement in active external rotation (P < .001) were greatest in the GHOA cohort compared with other indications. Multivariate linear regression demonstrated that the factors independently associated with the postoperative ASES score included a diagnosis of GHOA (ß coefficient, 7.557 [P < .001]), preoperative ASES score (ß coefficient, 0.114 [P = .009]), female sex (ß coefficient, -4.476 [P = .002]), history of surgery (ß coefficient, -3.957 [P = .018]), and postoperative complication (ß coefficient, -13.550 [P < .001]). CONCLUSION: RTSA for the treatment of GHOA generally has superior patient-reported and functional outcomes when compared with CTA and MCTs without arthritis. Long-term follow-up is needed to identify the lasting implications of such outcome differences.

Anatomic and reverse shoulder arthroplasty for management of type B2 and B3 glenoids: a matched-cohort analysis.

BACKGROUND: Severe glenohumeral osteoarthritis (GHOA) with posterior glenoid erosion remains challenging to address for shoulder surgeons. Whereas anatomic total shoulder arthroplasty (TSA) has historically been the treatment of choice, reverse shoulder arthroplasty (RSA) offers an alternative option. Limited evidence exists directly comparing these 2 treatments in a similar patient population. The purpose of this study was to compare the clinical outcomes of patients with GHOA and Walch type B2 and B3 glenoid morphologies treated with TSA vs. RSA. METHODS: We performed a multicenter retrospective cohort study of patients with GHOA who were treated with primary shoulder arthroplasty and had a minimum follow-up period of 2 years. Preoperative computed tomography was used to determine type B2 and B3 glenoid morphology as described by the modified Walch classification. Three-dimensional perioperative planning software was used to characterize glenoid retroversion and humeral subluxation. Patients were categorized based on type of arthroplasty (TSA or RSA) and were matched 1:1 by sex, Walch classification, and age. Patient-reported outcome measures, active range of motion, presence and severity of glenoid loosening, and complications were compared. The percentage of patients who reached previously established clinically significant thresholds of the minimal clinically important difference and substantial clinical benefit for the American Shoulder and Elbow Surgeons score was also comparatively assessed. RESULTS: In total, 202 patients (101 per group) with GHOA and type B2 or B3 glenoids were included in the 1:1 matched analysis. The mean length of follow-up (± standard deviation) was 39 ± 18.7 months. The cohorts were well matched, with no differences in sex, age, American Society of Anesthesiologists score, body mass index, preoperative glenoid morphology (Walch classification), glenoid retroversion, or posterior subluxation (P > .05). RSA was associated with a lower postoperative visual analog scale pain score (0.5 in RSA group vs. 1.2 in TSA group, P = .036); however, no other no other significant differences in patient-reported significant differences in patient-reported outcome measures were found. Most patients in both groups (95.0% in TSA group vs. 98.0% in RSA group, P = .436) reached the minimal clinically important difference, and 82% of TSA patients and 90% of RSA patients reached the substantial clinical benefit value (P = .292). No significant differences in the overall complication rate (P = .781) and active range of motion were found, with the exception of internal rotation (scored on a numeric scale) being worse in the RSA group (2.7 preoperatively and 5.2 postoperatively in RSA group vs. 3.9 and 6.5, respectively, in TSA group; P < .001). Baseplate loosening occurred in 2 RSA cases, and 29 TSA cases had glenoid radiolucencies (P < .001), with 3 grossly loose glenoid components. CONCLUSION: Primary RSA results in short-term outcomes largely comparable to those of TSA in patients with Walch type B2 or B3 glenoid morphology. Both TSA and RSA provide substantial clinical benefit to patients with significant posterior glenoid wear.

Wide Geographic Variation in Resource Utilization after Shoulder Arthroplasty.

Background: There is growing interest in optimizing cost and resource utilization after shoulder arthroplasty, but little data to guide improvement efforts. Objective: The purpose of this study was to evaluate geographic variation in length of stay and home discharge disposition after shoulder arthroplasty across the United States. Methods: The Centers for Medicare and Medicaid Services database was used to identify Medicare discharges following shoulder arthroplasties performed from April 2019 through March 2020. National, regional (Northeast, Midwest, South, West), and state-level variation in length of stay and home discharge disposition rates were examined. The degree of variation was assessed using the coefficient of variation, with a value greater than 0.15 being considered as "substantial" variation. Geographic maps were created for visual representation of the data. Results: There was substantial state-level variation in home discharge disposition rates (64% in Connecticut to 96% in West Virginia) and length of stay (1.01 days in Delaware to 1.86 days in Kansas). There was wide regional variation in length of stay (1.35 days in the West to 1.50 days in the Northeast) and home discharge disposition rates (73% in the Northeast to 85% in the West). Conclusions: There is wide variation in resource utilization after shoulder arthroplasty across the United States. Certain patterns emerge from our data; for instance, the Northeast has the longest hospital stays with the lowest home discharge rates. This study provides important information for the implementation of targeted strategies to effectively reduce geographic variation in healthcare resource utilization.

Higher Surgeon Volume is Associated With a Lower Rate of Subsequent Revision Procedures After Total Shoulder Arthroplasty: A National Analysis.

BACKGROUND: Studies assessing the relationship between surgeon volume and outcomes have shown mixed results, depending on the specific procedure analyzed. This volume relationship has not been well studied in patients undergoing total shoulder arthroplasty (TSA), but it should be, because this procedure is common, expensive, and potentially morbid. QUESTIONS/PURPOSES: We performed this study to assess the association between increasing surgeon volume and decreasing rate of revision at 2 years for (1) anatomic TSA (aTSA) and (2) reverse TSA (rTSA) in the United States. METHODS: In this retrospective study, we used Centers for Medicare and Medicaid Services (CMS) fee-for-service inpatient and outpatient data from 2015 to 2021 to study the association between annual surgeon aTSA and rTSA volume and 2-year revision shoulder procedures after the initial surgery. The CMS database was chosen for this study because it is a national sample and can be used to follow patients over time. We included patients with Diagnosis-related Group code 483 and Current Procedural Terminology code 23472 for TSA (these codes include both aTSA and rTSA). We used International Classification of Diseases, Tenth Revision, procedural codes. Patients who underwent shoulder arthroplasty for fracture (10% [17,524 of 173,242]) were excluded. We studied the variables associated with the subsequent procedure rate through a generalized linear model, controlling for confounders such as patient age, comorbidity risk score, surgeon and hospital volume, surgeon graduation year, hospital size and teaching status, assuming a binomial distribution with the dependent variable being whether an episode had at least one subsequent procedure within 2 years. The regression was fitted with standard errors clustered at the hospital level, combining all TSAs and within the aTSA and rTSA groups, respectively. Hospital and surgeon yearly volumes were calculated by including all TSAs, primary procedure and subsequent, during the study period. Other hospital-level and surgeon-level characteristics were obtained through public files from the CMS. The CMS Hierarchical Condition Category risk score was controlled because it is a measure reflecting the expected future health costs for each patient based on the patient's demographics and chronic illnesses. We then converted regression coefficients to the percentage change in the odds of having a subsequent procedure. RESULTS: After controlling for confounding variables including patient age, comorbidity risk score, surgeon and hospital volume, surgeon graduation year, and hospital size and teaching status, we found that an annual surgeon volume of ≥ 10 aTSAs was associated with a 27% decreased odds of revision within 2 years (95% confidence interval 13% to 39%; p < 0.001), while surgeon volume of ≥ 29 aTSAs was associated with a 33% decreased odds of revision within 2 years (95% CI 18% to 45%; p < 0.001) compared with a volume of fewer than four aTSAs per year. Annual surgeon volume of ≥ 29 rTSAs was associated with a 26% decreased odds of revision within 2 years (95% CI 9% to 39%; p < 0.001). CONCLUSION: Surgeons should consider modalities such as virtual planning software, templating, or enhanced surgeon training to aid lower-volume surgeons who perform aTSA and rTSA. More research is needed to assess the value of these modalities and their relationship with the rates of subsequent revision. LEVEL OF EVIDENCE: Level III, therapeutic study.

The impact of the COVID-19 pandemic on racial disparities in patients undergoing total shoulder arthroplasty in the United States.

Introduction: The purpose of this study was to assess racial disparities in total shoulder arthroplasty (TSA) in the United States and to determine whether these disparities were affected by the COVID-19 pandemic. Methods: Centers for Medicare and Medicaid Services (CMS) 100% sample was used to examine primary TSA volume from April to December from 2019 to 2020. Utilization was assessed for White, Black, Hispanic, and Asian populations to determine if COVID-19 affected these groups differently. A regression model adjusted for age, sex, CMS-hierarchical condition categories (HCC) score, dual enrollment (proxy for socioeconomic status), time-fixed effects, and core-based statistical area fixed effects was used to study difference across groups. Results: In 2019, the TSA volume per 1000 beneficiaries was 1.51 for White and 0.57 for non-White, with a 2.6-fold difference. In 2020, the rate of TSA in White patients (1.30/1000) was 2.9 times higher than non-White (0.45/1000) during the COVID-19 pandemic (P < .01). There was an overall 14% decrease in TSA volume per 1000 Medicare beneficiaries in 2020; non-White patients had a larger percentage decrease in TSA volume than White (21% vs. 14%, estimated difference; 8.7%, P = .02). Black patients experienced the most pronounced disparity with estimated difference of 10.1%, P = .05, compared with White patients. Similar disparities were observed when categorizing procedures into anatomic and reverse TSA, but not proximal humerus fracture. Conclusions: During the COVID-19 pandemic, overall TSA utilization decreased by 14% with White patients experiencing a decrease of 14%, and non-White patients experiencing a decrease of 21%. This trend was observed for elective TSA, while disparities were less apparent for proximal humerus fracture.

Strong Public Desire for Quality and Price Transparency in Shoulder Arthroplasty.

INTRODUCTION: Concerted efforts to optimize outcomes and data transparency in shoulder arthroplasty have led to the creation of the American Academy of Orthopaedic Surgeons (AAOS) Shoulder and Elbow Registry, the first nationwide registry of its kind. We used online crowdsourcing to explore the general public's perceptions and beliefs toward the disclosure of quality and price data in shoulder arthroplasty. METHODS: A total of 498 participants recruited using Amazon Mechanical Turk (MTurk) completed a survey regarding beliefs about public disclosure of quality and price data in shoulder arthroplasty. The MTurk is an online marketplace for crowdsourcing tasks (e.g., answering surveys) to a pool of over 500,000 registered workers in exchange for financial compensation. Requesters post human-intelligence tasks, and workers can respond to those that they are interested in completing. This web-based platform is an efficient survey tool for medical research, with comparable national representativeness to traditional convenience samples. RESULTS: The majority (95%) of respondents believed surgeons and hospitals should share their data with national registries such as the AAOS Shoulder and Elbow Registry. Most believed that patients considering shoulder arthroplasty should have public access to surgeons' outcomes and complication rates (96%), years of experience (95%), and case volume (92%). Most respondents desired price transparency in implant costs (95%), surgeon reimbursement (80%), and hospital reimbursement (84%). In decreasing order of importance, the top three factors guiding surgeon choice were: (1) surgeon included in the insurer's network, (2) annual case volume, and (3) publicly available outcomes. CONCLUSION: Increased quality and price transparency in shoulder arthroplasty may empower patients to make better-informed decisions about their care and ultimately enhance value. Given the strong public desire for data transparency and the notion that public disclosure of data is intrinsically associated with performance improvement, surgeons and hospitals should strongly consider submitting their data to national registries such as the AAOS Shoulder and Elbow Registry.

Impact of the COVID-19 pandemic on shoulder arthroplasty: surgical trends and postoperative care pathway analysis.

BACKGROUND: COVID-19 triggered disruption in the conventional care pathways for many orthopedic procedures. The current study aims to quantify the impact of the COVID-19 pandemic on shoulder arthroplasty hospital surgical volume, trends in surgical case distribution, length of hospitalization, posthospital disposition, and 30-day readmission rates. METHODS: This study queried all Medicare (100% sample) fee-for-service beneficiaries who underwent a shoulder arthroplasty procedure (Diagnosis-Related Group code 483, Current Procedural Terminology code 23472) from January 1, 2019, to December 18, 2020. Fracture cases were separated from nonfracture cases, which were further subdivided into anatomic or reverse arthroplasty. Volume per 1000 Medicare beneficiaries was calculated from April to December 2020 and compared to the same months in 2019. Length of stay (LOS), discharged-home rate, and 30-day readmission for the same period were obtained. The yearly difference adjusted for age, sex, race (white vs. nonwhite), Centers for Medicare & Medicaid Services Hierarchical Condition Category risk score, month fixed effects, and Core-Based Statistical Area fixed effects, with standard errors clustered at the provider level, was calculated using a multivariate analysis (P < .05). RESULTS: A total of 49,412 and 41,554 total shoulder arthroplasty (TSA) cases were observed April through December for 2019 and 2020, respectively. There was an overall decrease in shoulder arthroplasty volume per 1000 Medicare beneficiaries by 14% (19% reduction in anatomic TSA, 13% reduction in reverse shoulder arthroplasty, and 3% reduction in fracture cases). LOS for all shoulder arthroplasty cases decreased by 16% (-0.27 days, P < .001) when adjusted for confounders. There was a 5% increase in the discharged-home rate (88.0% to 92.7%, P < .001), which was most prominent in fracture cases, with a 20% increase in discharged-home cases (65.0% to 73.4%, P < .001). There was no significant change in 30-day hospital readmission rates overall (P = .20) or when broken down by individual procedures. CONCLUSIONS: There was an overall decrease in shoulder arthroplasty volume per 1000 Medicare beneficiaries by 14% during the COVID-19 pandemic. A decrease in LOS and increase in the discharged-home rates was also observed with no significant change in 30-day hospital readmission, indicating that a shift toward an outpatient surgical model can be performed safely and efficiently and has the potential to provide value.

Outcomes After Anatomic and Reverse Shoulder Arthroplasty for the Treatment of Glenohumeral Osteoarthritis: A Propensity Score-Matched Analysis.

BACKGROUND: Reverse shoulder arthroplasty (RSA) is increasingly being utilized for the treatment of primary osteoarthritis. However, limited data are available regarding the outcomes of RSA as compared with anatomic total shoulder arthroplasty (TSA) in the setting of osteoarthritis. METHODS: We performed a retrospective matched-cohort study of patients who had undergone TSA and RSA for the treatment of primary osteoarthritis and who had a minimum of 2 years of follow-up. Patients were propensity score-matched by age, sex, body mass index (BMI), preoperative American Shoulder and Elbow Surgeons (ASES) score, preoperative active forward elevation, and Walch glenoid morphology. Baseline patient demographics and clinical outcomes, including active range of motion, ASES score, Single Assessment Numerical Evaluation (SANE), and visual analog scale (VAS) for pain, were collected. Clinical and radiographic complications were evaluated. RESULTS: One hundred and thirty-four patients (67 patients per group) were included; the mean duration of follow-up (and standard deviation) was 30 ± 10.7 months. No significant differences were found between the TSA and RSA groups in terms of the baseline or final VAS pain score (p = 0.99 and p = 0.99, respectively), ASES scores (p = 0.99 and p = 0.49, respectively), or SANE scores (p = 0.22 and p = 0.73, respectively). TSA was associated with significantly better postoperative active forward elevation (149° ± 13° versus 142° ± 15°; p = 0.003), external rotation (63° ± 14° versus 57° ± 18°; p = 0.02), and internal rotation (≥L3) (68.7% versus 37.3%; p < 0.001); however, there were only significant baseline-to-postoperative improvements in internal rotation (gain of ≥4 levels in 53.7% versus 31.3%; p = 0.009). The overall complication rate was 4.5% (6 of 134), with no significant difference between TSA and RSA (p = 0.99). Radiolucent lines were observed in association with 14.9% of TSAs, with no gross glenoid loosening. One TSA (1.5%) was revised to RSA for the treatment of a rotator cuff tear. No loosening or revision was encountered in the RSA group. CONCLUSIONS: When performed for the treatment of osteoarthritis, TSA and RSA resulted in similar short-term patient-reported outcomes, with better postoperative range of motion after TSA. Longer follow-up is needed to determine the ultimate value of RSA in the setting of osteoarthritis. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Neighborhood socioeconomic disadvantage does not predict outcomes or cost after elective shoulder arthroplasty.

BACKGROUND: There is growing evidence that the variation in value of shoulder arthroplasty may be mediated by factors external to surgery. We sought to determine if neighborhood-level socioeconomic deprivation is associated with postoperative outcomes and cost among patients undergoing elective shoulder arthroplasty. METHODS: We identified 380 patients undergoing elective total shoulder arthroplasty (anatomic or reverse) between 2015 and 2018 in our institutional registry with minimum 2-year follow-up. Each patient's home address was mapped to the area deprivation index in order to determine the level of socioeconomic disadvantage. The area deprivation index is a validated composite measure of 17 census variables encompassing income, education, employment, and housing conditions. Patients were categorized into 3 groups based on socioeconomic disadvantage (least disadvantaged [deciles 1-3], middle group [4-6], and most disadvantaged [7-10]). Bivariate analysis was performed to determine associations between the level of socioeconomic deprivation with hospitalization time-driven activity-based costs and 2-year postoperative American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE), and pain intensity scores. RESULTS: Overall 19% of patients were categorized as most disadvantaged. These patients were found to have equivalent preoperative pain intensity (P = .51), SANE (P = .50), and ASES (P = .72) scores compared to the middle and least disadvantaged groups, as well as similar outcome improvement at 2 years postoperatively (ASES): least disadvantaged group [35.7-84.3], middle group [35.1-82.4], and most disadvantaged group [37.1-84.0] [P = .56]; SANE: least disadvantaged group [31.8-87.1], middle group [30.8-84.8], and most disadvantaged group [34.2-85.1] [P = .42]; and pain: least disadvantaged group [6.0-0.97], middle group [6-0.97], and most disadvantaged group [5.6-0.80] [P = .88]. No differences in hospitalization costs were noted between groups (P = .77). CONCLUSIONS: Patients undergoing elective shoulder arthroplasty residing in the most disadvantaged neighborhoods demonstrate equivalent preoperative and postoperative outcomes as others, without incurring higher costs. These findings support continued efforts to provide equitable access to orthopedic care across the socioeconomic spectrum.

Patients with limited health literacy have worse preoperative function and pain control and experience prolonged hospitalizations following shoulder arthroplasty.

BACKGROUND: Patients with limited health literacy (LHL) may have difficulty understanding and acting on medical information, placing them at risk for potential misuse of health services and adverse outcomes. The purposes of our study were to determine (1) the prevalence of LHL in patients undergoing inpatient shoulder arthroplasty, (2) the association of LHL with the degree of preoperative symptom intensity and magnitude of limitations, (3) and the effects of LHL on perioperative outcomes including postoperative length of stay (LOS), total inpatient costs, and inpatient opioid consumption. METHODS: We retrospectively identified 230 patients who underwent elective inpatient reverse or anatomic shoulder arthroplasty between January 2018 and May 2021 from a prospectively maintained single-surgeon registry. The health literacy of each patient was assessed preoperatively using the validated 4-item Brief Health Literacy Screening Tool. Patients with a Brief Health Literacy Screening Tool score ≤ 17 were categorized as having LHL. The outcomes of interest were preoperative patient-reported outcome scores and range of motion, LOS, total postoperative inpatient opioid consumption, and total inpatient costs as calculated using time-driven activity-based costing methodology. Univariate analysis was performed to determine associations between LHL and patient characteristics, as well as the outcomes of interest. Multivariable linear regression modeling was used to determine the association between LHL and LOS while controlling for potentially confounding variables. RESULTS: Overall, 58 patients (25.2%) were classified as having LHL. Prior to surgery, these patients had significantly higher rates of opioid use (P = .002), more self-reported allergies (P = .007), and worse American Shoulder and Elbow Surgeons scores (P = .001), visual analog scale pain scores (P = .020), forward elevation (P < .001), and external rotation (P = .022) but did not significantly differ in terms of any additional demographic or clinical characteristics (P > .05). Patients with LHL had a significantly longer LOS (1.84 ± 0.92 days vs. 1.57 ± 0.58 days, P = .012) but did not differ in terms of total hospitalization costs (P = .65) or total inpatient opioid consumption (P = .721). On multivariable analysis, LHL was independently predictive of a significantly longer LOS (ß, 0.14; 95% confidence interval, 0.02-0.42; P = .035). CONCLUSION: LHL is commonplace among patients undergoing elective shoulder arthroplasty and is associated with greater preoperative symptom severity and activity intolerance. Its association with longer hospitalizations suggests that health literacy is an important factor to consider for postoperative disposition planning.

Baseplate retroversion does not affect postoperative outcomes after reverse shoulder arthroplasty.

BACKGROUND: There is concern that excessive glenoid component retroversion leads to altered biomechanics and baseplate failure in reverse shoulder arthroplasty (RSA). However, much of this has been rooted in the total shoulder arthroplasty experience. In the current literature, it is not well defined whether glenoid baseplate positioning in reverse arthroplasty affects functional outcomes. Our practice has been to preserve glenoid bone stock without aiming for a certain degree of retroversion. We aimed to evaluate the correlation between pre- and postoperative retroversion in a cohort of RSAs and determine the effect of glenoid retroversion on functional outcomes, range of motion, and postoperative complications. METHODS: A retrospective review of patients who had an RSA between 2017 and 2019 was performed. Preoperative computed tomography scans were used to assess preoperative retroversion, and axillary radiographs were used for postoperative retroversion. Outcome measures included American Shoulder and Elbow Surgeons score, visual analog scale for pain score, Single Assessment Numeric Evaluation score, range of motion, radiographic lucency, and complications. RESULTS: A total of 271 patients were eligible for the study. There was a 76.9% 2-year follow-up rate. In total 161 patients had postoperative retroversion ≤15° (group A), and 110 patients had retroversion >15° (group B). There were no significant differences in American Shoulder and Elbow Surgeons, visual analog scale, or Single Assessment Numeric Evaluation scores. There were also no significant differences in postoperative range of motion. There was 1 baseplate failure in each group, and there was 1 patient in group B with asymptomatic radiographic loosening (baseplate at risk). The mean change in pre- to postoperative retroversion was 1° and 4° in groups A and B, respectively. CONCLUSION: There was no significant difference in postoperative functional outcomes, range of motion, or complications between patients who had baseplate retroversion ≤15° vs. those who had retroversion >15°.

The association between anterior shoulder joint capsule thickening and glenoid deformity in primary glenohumeral osteoarthritis.

BACKGROUND: Anterior shoulder joint capsule thickening is typically present in osteoarthritic shoulders, but its association with specific patterns of glenoid wear is incompletely understood. We sought to determine the relationship between anterior capsular thickening and glenoid deformity in primary glenohumeral osteoarthritis. METHODS: We retrospectively identified 134 consecutive osteoarthritic shoulders with magnetic resonance imaging and computed tomography scans performed. Axial fat-suppressed magnetic resonance imaging slices were used to quantify the anterior capsular thickness in millimeters, measured at its thickest point below the subscapularis muscle. Computed tomography scans were used to classify glenoid deformity according to the Walch classification, and an automated 3-dimensional software program provided values for glenoid retroversion and humeral head subluxation. Multinomial and linear regression models were used to characterize the association of anterior capsular thickening with Walch glenoid type, glenoid retroversion, and posterior humeral head subluxation while controlling for patient age and sex. RESULTS: The anterior capsule was thickest in glenoid types B2 (5.5 mm, 95% confidence interval [CI]: 5.0-6.0) and B3 (6.1 mm, 95% CI: 5.6-6.6) and thinnest in A1 (3.7 mm, 95% CI: 3.3-4.2; P < .001). Adjusted for age and sex, glenoid types B2 (odds ratio: 4.4, 95% CI: 2.3-8.4, P < .001) and B3 (odds ratio: 5.4, 95% CI: 2.8-10.4, P < .001) showed the strongest association with increased anterior capsule thickness, compared to glenoid type A1. Increased capsular thickness correlated with greater glenoid retroversion (r = 0.57; P < .001) and posterior humeral head subluxation (r = 0.50; P < .001). In multivariable analysis, for every 1-mm increase in anterior capsular thickening, there was an adjusted mean increase of 3.2° (95% CI: 2.4-4.1) in glenoid retroversion and a 3.8% (95% CI: 2.7-5.0) increase in posterior humeral head subluxation. CONCLUSIONS: Increased thickening of the anterior shoulder capsule is associated with greater posterior glenoid wear and humeral head subluxation. Additional research should determine whether anterior capsular disease plays a causative role in the etiology or progression of eccentric glenohumeral osteoarthritis.