Reverse Shoulder Arthroplasty in Patients with Rheumatoid Arthritis: A Nationwide Analysis

<b>Introduction:</b> Reverse shoulder arthroplasty (RSA) was originally developed for treating rotator cuff arthropathy but is now commonly used for rheumatoid arthritis (RA)-related shoulder degeneration. While previous studies have identified RA to be a risk factor for complications following total shoulder arthroplasty, its specific impact on RSA outcomes remains unclear. This study aims to evaluate the post-operative medical and implant-related complications, and healthcare utilization, among RA patients undergoing RSA. <b>Methods:</b> A retrospective analysis of patients undergoing RSA was conducted using a national administrative claims database from 2010 to 2023. Patients who underwent RSA with and without RA were identified using corresponding diagnoses and procedural codes. Patients with RA who underwent RSA had propensity score matched to a control on a 1:5 basis. The control group consisted of patients who did not have RA and underwent RSA for any other indication. <b>Results:</b> A total of 7232 of RSA patients with RA were matched to 36,054 control patients. The RA cohort had significantly higher rates of 90-day medical complications when compared to the control (<i>p</i> < 0.001), with the highest rates in urinary tract infections (OR: 9.69), pulmonary embolisms (OR: 9.69), and the need for blood transfusions (OR:9.41). Patients with RA had significantly greater odds of developing all implant-related complications within 2 years compared to the control group (<i>p</i> < 0.001). This cohort also had significantly higher fall rates (<i>p</i> < 0.001) and mean lengths of stay (3.42 vs. 2.0 days, <i>p</i> < 0.0001). <b>Conclusions:</b> RSA patients with prior diagnoses of RA face a higher risk of implant-related and medical complications, falls, and prolonged hospital stays compared to the control. These findings suggest that RA is an independent risk factor for reverse total shoulder arthroplasty. Therefore, these patients should be closely monitored post-operatively to reduce complications, cost of care, and length of stay. Level of Evidence: III, retrospective case-control study.