Predictors of unsatisfactory patient outcomes in primary reverse total shoulder arthroplasty

Background: Despite favorable clinical and functional results for reverse total shoulder arthroplasty (RSA), there remains a group of patients without postoperative complications who demonstrate poor improvement and overall outcome. Methods: Using a single surgeon shoulder arthroplasty registry, we identified patients who underwent RSA from 2013 to 2016 with minimum of 2-year postoperative follow-up. Patients with intra-and postoperative complications were excluded. Poor postoperative clinical outcome was defined as those patients within the bottom 30th percentile for American Shoulder and Elbow Surgeons (ASES) score. Poor postoperative improvement was defined as the bottom 30th percentile of ASES improvement, measured preoperatively to the 2-year postoperative mark. Multivariate logistic regression modeling was used to determine preoperative characteristics (e.g., demographics, comorbidities, preoperative ASES score) associated with poor outcome. Results: A total of 137 patients met the inclusion and exclusion criteria. Multivariable logistic regression modeling found that prior shoulder surgery, the majority (75%) of which were arthroscopic, was the only independent factor associated with both poor improvement (adjusted odds ratio, 2.46 [1.03-5.83]) and outcome (adjusted odds ratio, 4.92 [1.74-14.961). Preoperative opioid use was associated with poor outcomes only, whereas the high preoperative ASES score was associated with poor postoperative improvement. Conclusions: Prior ipsilateral shoulder surgery was strongly associated with poor clinical improvement and outcome after RSA. No other factors correlated with both poor improvement and outcome. This association is important to decision making for any shoulder surgery, given the long-term implications. (C) 2019 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.