Reverse versus anatomic total shoulder arthroplasty: A large matched cohort analysis.

Introduction: The annual utilization of reverse total shoulder arthroplasty (RTSA) and anatomic total shoulder arthroplasty (ATSA) has grown exponentially, in part due to the expanded indications of RTSA. This evolution in shoulder arthroplasty prompts the need to evaluate outcomes between ATSA and RTSA. However, many other studies comparing outcomes between ATSA and RTSA lacked a large nationally-represented sample, a matched cohort analysis, or both. In this study, we compare outcomes between patients undergoing ATSA or RTSA in a large matched-cohort analysis. Methods: Patients undergoing RTSA or ATSA from the National Inpatient Sample database between 2016 and 2019 were identified. Groups were propensity-matched based on demographics and comorbidities. We compared medical and surgical complications, length of stay, and total hospital charges. T-tests and chi-square tests were performed for continuous and categorical variables, respectively. Odds ratios were calculated as a ratio between RTSA and ATSA groups. Results: Following matching, there were 38,782 patients in the ATSA group and 35,461 patients in the RTSA group. The RTSA group had higher odds of acute renal failure (OR 1.35), blood loss anemia (OR 1.39), and pneumonia (OR 1.19). There were no differences for myocardial infarction, pulmonary embolism, deep venous thrombosis, mortality, periprosthetic fracture, or dislocation. The RTSA group had higher odds of periprosthetic mechanical complication (OR 1.92), but lower odds of periprosthetic joint infection (OR 0.65). The mean length of stay and total hospital charges were both higher in the RTSA group (p < 0.001). Discussion: We found patients undergoing RTSA are at higher odds of inpatient medical complications, including acute renal failure and acute blood loss anemia. RTSA is associated with higher odds of short-term periprosthetic mechanical complications.