Comparison of outcomes using anatomic and reverse total shoulder arthroplasty.

UNLABELLED Worldwide, the usage of both anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthro- plasty (rTSA) has increased significantly due, in part, to the predictability of acceptable outcomes achieved with each prosthesis type. This study quantifies outcomes using five different metrics and compares results using one platform total shoulder arthroplasty system that utilizes the same humeral component and instrumentation to perform both aTSA or rTSA. METHODS 200 patients were treated by two orthopaedic surgeons using either aTSA or rTSA. 73 patients received aTSA for treatment of osteoarthritis (OA), and 127 patients received rTSA for treatment of rotator cuff tear arthro- plasty (CTA). Each was scored preoperatively, and at latest follow-up using the SST, UCLA, ASES, Constant, and SPADI metrics, motion was also quantified. The average follow-up for all patients was 31.4 ± 9.7 months. RESULTS All patients demonstrated significant improvements in pain and function following treatment of OA with aTSA and treatment of CTA with rTSA. No instances of instability or glenoid loosening were reported in either cohort; one instance of infection occurred in the rTSA cohort. aTSA was associated with significantly higher pre- and postoperative outcome scores and significantly larger pre- and postoperative range of motion than rTSA. However, rTSA was demonstrated to be significantly more effective at improving outcome scores, active forward flexion, and strength than was aTSA. DISCUSSION AND CONCLUSIONS Significant improvements in outcome scores were observed for both aTSA and rTSA using one platform shoulder system at a mean follow-up of 31.4 months. Significant differences were observed between prosthesis type and between scoring metrics, particularly between the Constant and ASES scoring metrics. Additional and longer term follow-up is required to confirm these observed differences.