Minimum Five-Year Outcomes of Anatomic Total Shoulder Arthroplasty with the Arthrosurface Aspherical Humerus and Inlay Glenoid

BACKGROUND: Aseptic glenoid loosening is the most common cause of revision after anatomic total shoulder arthroplasty (aTSA). Inlay glenoid components have been shown to reduce edge loading and opposite-edge lift-off forces compared with onlay glenoids. Early clinical results of inlay glenoids have been promising, although there is a paucity of literature detailing mid- to long-term follow-up. We report the minimum five-year clinical and radiographic outcomes after aTSA with the Arthrosurface inlay glenoid component and a stemless, aspherical humeral head in an active, young patient population. METHODS: A retrospective review of aTSA with an inlay glenoid component and an aspherical humeral head component was performed for 45 shoulders. Patients were evaluated with patient-reported outcome measures, range of motion, and radiographs. Return to occupational and sporting activity, complications, and reoperations were analyzed. RESULTS: A total of 45 patients were available for an average follow up of 82.2 ± 21.7 months. The average age of the cohort was 54.9 +/- 7.6 years and 41/45 (91.1%) were males. ASES, VAS, SANE, and SF-12 physical patient reported outcome measures (PROMs) were all significantly improved. Each of these improvements in PROMs also exceeded the established minimum clinically important difference (MCID). Active forward elevation significantly improved from 116.0 +/- 28.4 degrees pre-operatively to 158.8 +/- 20.6 degrees post-operatively. Active external rotation significantly improved from 26.0 +/- 14.5 degrees to 53.3 +/- 16.2 degrees. Five total patients underwent a revision shoulder arthroplasty during the study period. Four had revision to a reverse total shoulder arthroplasty (rTSA) for subscapularis failure (2), superior rotator cuff failure (1), and stiffness (1). No patient was revised for symptomatic glenoid loosening. Another patient had an antibiotic spacer placed for infection. Among the 30 patients with five-year radiographic follow-up, there was no significant progression of radiolucency around the glenoid component between initial post-operative films and final follow-up. CONCLUSION: Anatomic total shoulder arthroplasty with the Arthrosurface inlay glenoid coupled with a stemless, aspherical humeral head in a young, active population results in durable improvements in function and range of motion with minimal evidence of glenoid loosening at mid-term follow-up.