BackgroundGiven the continued growth of reverse shoulder arthroplasty (RSA), it is important to optimize factors that contribute to successful outcomes. Rehabilitation after RSA is critical to achieve successful outcomes including patient function and satisfaction; however, the ideal rehabilitation program has not been established. The purpose of this study was to evaluate the effect of early mobilization (EM) compared with delayed mobilization (DM) on outcomes and function after RSA. MethodsA retrospective study of prospectively collected data was performed comparing 67 patients who underwent RSA in two groups: the EM group began a rehabilitation program immediately after surgery, and the DM group began after 4-6 weeks postoperatively. Preoperative and postoperative Constant shoulder score, American Shoulder and Elbow Surgeons (ASES) score, Penn Shoulder Score (PSS), shoulder satisfaction value as well as demographics, opioid usage, range of motion, 90-day complications, reoperation, and readmission rates were collected. Statistical analysis was performed between each group’s outcomes and for the change (delta) of outcomes from baseline to each postoperative time point. ResultsAt 6 weeks postoperatively, the EM group showed significantly higher scores in ASES function, PSS, active forward elevation, passive forward elevation, active external rotation, and passive external rotation. There was significantly lower narcotic usage in the EM group at 6 weeks. At 3 months postoperatively, the EM group showed a lower numerical rating score for pain and higher active forward elevation. At the last follow-up, there was a lower numerical rating score and greater degree for all ranges of motion for the EM group than that for the DM group. A greater change from baseline to 6 weeks postoperatively was seen for the EM group in shoulder satisfaction value, ASES function, PSS, active forward elevation, passive forward elevation, and internal rotation. From baseline to 3 months postoperatively, ASES pain, PSS, active forward elevation, and passive forward elevation improved significantly in the EM group. At the final follow-up, active forward elevation increased greater for the EM group. There were 3 complications (2 hematomas and 1 infection) in the DM group and none in the EM group. ConclusionThe EM rehabilitation protocol after RSA achieved lower opioid usage at 6 weeks, lower pain scores at each time point, and better range of motion during the final follow-up than DM protocol. There were no complications reported with the EM protocol, suggesting it is a safe alternative for postoperative recovery. Orthopedic surgeons should consider the EM rehabilitation protocol after RSA.