Reverse Shoulder Arthroplasty in Upper Extremity Ambulators: A Matched-Cohort Analysis.

Abstract

Upper extremity ambulators (UEA) who require prolonged use of assistive devices for mobility have a high incidence of shoulder pathology secondary to increased stress across the shoulder joint with upper extremity weight bearing. Reverse shoulder arthroplasty (RSA) for rotator cuff arthropathy (RCA) has historically been associated with increased complications in UEA, but more recent studies have shown more promising outcomes. The objective of this study is to evaluate clinical outcomes and complication rates between these two groups to define the relative risk of RSA in the UEA population and identify opportunities to improve treatment outcomes. An IRB-approved retrospective chart review was performed in patients that underwent RSA at our institution by the senior author from 2004-2019. UEA were defined as patients that used regular upper extremity assistive devices for community ambulation prior to initial consultation for the surgical extremity. Pre- and postoperative range of motion (ROM), Visual Analog Scale scores, American Shoulder and Elbow Surgeons (ASES) scores, Constant Murley scores, and Simple Shoulder Test (SST) scores were measured at defined intervals. Complications including infection, instability and need for revision surgery were also compared. All patients were followed for a minimum of two years postoperatively. A total of 159 RSA procedures (70 UEA, 89 controls) were performed during the study period. On average, UEA patients had more preoperative pain and less shoulder function than controls, with statistically significant differences in Visual Analog scores (6.897 vs. 5.532, p=0.0010) and ASES scores (33.50 vs. 40.20, p=0.0290), respectively. Despite the lower baseline values, UEA patients experienced excellent postoperative improvement, leading to similar postoperative pain and shoulder function except for a lower average forward flexion in the UEA group (126.76° vs. 135.45°, p=0.0354). Notching and complication rates were also similar between the two groups, with notching rates of 59% and 50% and complication rates of 14.3% and 13.5% in the UEA and control groups, respectively. RSA in the UEA population can achieve similar pain and functional outcomes as compared to age-matched controls without a significant increase in complication rates; however, further studies are required to assess long-term comparative outcomes in this challenging patient population.