The indication for reverse total shoulder arthroplasty with a wedged augmented baseplate has an effect on clinical outcomes.

Introduction: Reverse Shoulder Arthroplasty (RSA) was initially designed for low demand patients with cuff tear arthropathy (CTA), but its indications have expanded. The aim was to investigate whether the indication affected the outcome. Methods: This was a prospective study. All patients receiving a Stryker Perform Wedged Augmented Glenoid were included. Patients were classified as glenohumeral arthritis (OA), or CTA, using pre-operative imaging and intra-operative findings. Patients had assessments including range of movement (ROM), ASES, SPADI, DASH and Constant Scores, and complications. Results: 62 patients were included, 30 with OA, and 32 with CTA. Post-operative scores were better in OA for DASH (13.8 vs 24.7, p = 0.02) and Constant (68.2 vs 58.7, p = 0.02).ROM showed improved elevation (139° vs 122°, p = 0.03) and abduction (81° vs 71°, p = 0.046) in OA, with no difference in internal or external rotation.There were significantly more complications in the CTA group (38 % vs 13 %), particularly in acromial stress fractures and reactions (ASFR) (25 % vs 0 %). Discussion: OA patients have better post-operative scores and ROM. They had fewer complications, particularly ASFR. Outcome differences may be partly explained by the complication profiles. The indication for RSA is an important consideration and should be reported in future outcome studies.