Predictors of dislocations after reverse shoulder arthroplasty: a study by the ASES complications of RSA multicenter research group.

BACKGROUND: Instability after reverse shoulder arthroplasty (RSA) is one of the most frequent complications and remains a clinical challenge. Current evidence is limited by small sample size, single-center, or single-implant methodologies that limit generalizability. We sought to determine the incidence and patient-related risk factors for dislocation after RSA, using a large, multicenter cohort with varying implants. METHODS: A retrospective, multicenter study was performed involving 15 institutions and 24 American Shoulder and Elbow Surgeons members across the United States. Inclusion criteria consisted of patients undergoing primary or revision RSA between January 2013 and June 2019 with minimum 3-month follow-up. All definitions, inclusion criteria, and collected variables were determined using the Delphi method, an iterative survey process involving all primary investigators requiring at least 75% consensus to be considered a final component of the methodology for each study element. Dislocations were defined as complete loss of articulation between the humeral component and the glenosphere and required radiographic confirmation. Binary logistic regression was performed to determine patient predictors of postoperative dislocation after RSA. RESULTS: We identified 6621 patients who met inclusion criteria with a mean follow-up of 19.4 months (range: 3-84 months). The study population was 40% male with an average age of 71.0 years (range: 23-101 years). The rate of dislocation was 2.1% (n = 138) for the whole cohort, 1.6% (n = 99) for primary RSAs, and 6.5% (n = 39) for revision RSAs (P < .001). Dislocations occurred at a median of 7.0 weeks (interquartile range: 3.0-36.0 weeks) after surgery with 23.0% (n = 32) after a trauma. Patients with a primary diagnosis of glenohumeral osteoarthritis with an intact rotator cuff had an overall lower rate of dislocation than patients with other diagnoses (0.8% vs. 2.5%; P < .001). Patient-related factors independently predictive of dislocation, in order of the magnitude of effect, were a history of postoperative subluxations before radiographically confirmed dislocation (odds ratio [OR]: 19.52, P < .001), primary diagnosis of fracture nonunion (OR: 6.53, P < .001), revision arthroplasty (OR: 5.61, P < .001), primary diagnosis of rotator cuff disease (OR: 2.64, P < .001), male sex (OR: 2.21, P < .001), and no subscapularis repair at surgery (OR: 1.95, P = .001). CONCLUSION: The strongest patient-related factors associated with dislocation were a history of postoperative subluxations and having a primary diagnosis of fracture nonunion. Notably, RSAs for osteoarthritis showed lower rates of dislocations than RSAs for rotator cuff disease. These data can be used to optimize patient counseling before RSA, particularly in male patients undergoing revision RSA.

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.

Risk factors of acromial and scapular spine stress fractures differ by indication: a study by the ASES Complications of Reverse Shoulder Arthroplasty Multicenter Research Group.

BACKGROUND: Both patient and implant related variables have been implicated in the incidence of acromial (ASF) and scapular spine fractures (SSF) following reverse shoulder arthroplasty (RSA); however, previous studies have not characterized nor differentiated risk profiles for varying indications including primary glenohumeral arthritis with intact rotator cuff (GHOA), rotator cuff arthropathy (CTA), and massive irreparable rotator cuff tear (MCT). The purpose of this study was to determine patient factors predictive of cumulative ASF/SSF risk for varying preoperative diagnosis and rotator cuff status. METHODS: Patients consecutively receiving RSA between January 2013 and June 2019 from 15 institutions comprising 24 members of the American Shoulder and Elbow Surgeons (ASES) with primary, preoperative diagnoses of GHOA, CTA and MCT were included for study. Inclusion criteria, definitions, and inclusion of patient factors in a multivariate model to predict cumulative risk of ASF/SSF were determined through an iterative Delphi process. The CTA and MCT groups were combined for analysis. Consensus was defined as greater than 75% agreement amongst contributors. Only ASF/SSF confirmed by clinical and radiographic correlation were included for analysis. RESULTS: Our study cohort included 4764 patients with preoperative diagnoses of GHOA, CTA, or MCT with minimum follow-up of 3 months (range: 3-84). The incidence of cumulative stress fracture was 4.1% (n = 196). The incidence of stress fracture in the GHOA cohort was 2.1% (n = 34/1637) compared to 5.2% (n = 162/3127) (P < .001) in the CTA/MCT cohort. Presence of inflammatory arthritis (odds ratio [OR] 2.90, 95% confidence interval [CI] 1.08-7.78; P = .035) was the sole predictive factor of stress fractures in GHOA, compared with inflammatory arthritis (OR 1.86, 95% CI 1.19-2.89; P = .016), female sex (OR 1.81, 95% CI 1.20-2.72; P = .007), and osteoporosis (OR 1.56, 95% CI 1.02-2.37; P = .003) in the CTA/MCT cohort. CONCLUSION: Preoperative diagnosis of GHOA has a different risk profile for developing stress fractures after RSA than patients with CTA/MCT. Though rotator cuff integrity is likely protective against ASF/SSF, approximately 1/46 patients receiving RSA with primary GHOA will have this complication, primarily influenced by a history of inflammatory arthritis. Understanding risk profiles of patients undergoing RSA by varying diagnosis is important in counseling, expectation management, and treatment by surgeons.

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.

A comparison of patient same-day discharge selection after shoulder arthroplasty before and after the COVID-19 pandemic.

Background: Early discharge has been a target of cost control efforts, given the growing demand for joint replacement surgery. Select patients are given the choice for same-day discharge (SDD) or overnight stay after shoulder arthroplasty. The COVID-19 pandemic changed patient perspectives regarding hospital visitation and admission. The purpose of this study was to determine if the COVID-19 pandemic impacted the utilization of SDD after shoulder arthroplasty. We hypothesize that patients undergoing shoulder arthroplasty after the start of the COVID-19 pandemic will have higher rates of SDD. Methods: A retrospective continuous review was performed on 370 patients who underwent a primary anatomic (total shoulder arthroplasty) or reverse shoulder arthroplasty between August 2019 and December 2020 by a single surgeon. This group of patients represent the 185 arthroplasty cases completed before the COVID-19 pandemic and the first 185 patients after the start of the pandemic. April 1, 2020, was chosen as the cutoff for pre-COVID patients, as this represents the date a statewide ban on elective surgery was declared. All patients were counseled preoperatively regarding SDD and given the choice to stay overnight, unless medically contraindicated. Demographics, medical history, length of stay, 30- and 90-day readmissions, and 90-day emergency room (ER) and urgent care visits were obtained from medical records and compared. Two-tailed student t-tests, chi-square tests, and Fischer's exact were performed where appropriate. Results: The 2 groups were similar in age, body mass index, gender distribution, and Outpatient Arthroplasty Risk Assessment score. During the collection period, there were more anatomic shoulder arthroplasties performed after (54%) than before (44%) the COVID-19 pandemic (P = .029). Patients treated after the start of the COVID-19 pandemic were almost 3 times more likely to have an SDD (P < .001), with 85.4% (158/185) of patients being discharged the same day after COVID-19, compared with 34.6% (64/185) before COVID-19. Discharge disposition (location of discharge) was significantly different, as 99% (183/185) of patients undergoing surgery after the start of the COVID-19 pandemic were discharged home, compared with 94% (174/185) of patients before COVID-19. There was no difference in 30-day readmissions, 90-day readmissions, and 90-day (ER) and urgent care visits between the 2 groups. Conclusion: Our study suggests that the COVID-19 pandemic has dramatically impacted patient choices for SDD within a single surgeon's practice, with nearly 3 times as many patients electing for SDD. Readmissions and ER visits were similar, indicating that SDD remains a safe alternative for patients after total shoulder arthroplasty and reverse shoulder arthroplasty. Level of evidence: Level III; Retrospective Comparative Study.