Comparative Outcomes Between the First and Second Operated Shoulders in Bilateral Shoulder Arthroplasty

INTRODUCTION: Studies that report outcomes after staged bilateral shoulder arthroplasty (BSA) are limited. This study compared the overall improvement between the first and second operated shoulders after BSA. METHODS: Preoperative and postoperative motion and patient-reported outcomes for function, pain, and general health were assessed for patients who underwent BSA with a 2-year follow-up. Ultimate outcomes and the efficacy of treatment were compared between the first and second operated shoulders. RESULTS: Seventy-three patients met the inclusion criteria (mean follow-up, 51.4 months). There were no notable differences between the first and second operated shoulders for all preoperative and postoperative variables except for the preoperative 12-item Short-Form Physical Component Score, which was greater in the second shoulder (P = 0.005). The efficacy of treatment was not markedly different except for the Physical Component Score (P = 0.001) and forward elevation (P = 0.01), which were greater after the first surgery. DISCUSSION: Improvements in function, pain, and motion were not markedly different between the first and second shoulder arthroplasty surgeries.