Lateralized Versus Nonlateralized Reverse Shoulder Arthroplasty: Impact on Clinical and Functional Outcomes

The aim of this study was to compare the early clinical and functional outcomes of patients who received the 2 major variations of reverse shoulder arthroplasty (RSA). The nonlateralized Aequalis Reversed Shoulder System (Tornier, Nice, France) was followed by the lateralized Encore Reverse Shoulder Prosthesis (DJO Surgical, Austin, Texas). Patient-determined pain and functional scores and examiner-determined range of motion and strength were assessed preoperatively and postoperatively at 1, 6, 12 weeks, and 6 months. Seventy RSAs performed in 66 consecutive patients: 35 shoulders in the lateralized group and 35 shoulders in the nonlateralized group met the inclusion criteria and formed the cohorts. Both groups experienced similar excellent clinical outcomes, with the exception that the lateralized group had better internal rotation range of motion (L3-4 vs. S1, P=0.03), lower frequency of pain during sleep (P=0.04), less severe pain at rest (P=0.03) and higher involvement in sporting activities (P=0.04) at 24 weeks. In conclusion, patients who underwent RSA with a lateralized glenosphere had better internal rotation range of motion, less pain, and better function than those who received a nonlateralized prosthesis. These differences were apparent within 6 months postsurgery. Level of Evidence: Level III.