Polyethylene insert exchange for wear after total shoulder arthroplasty

Virtually no information is available in the literature to guide clinical decision-making in regard to modular polyethylene exchange with metal-backed glenoid components in total shoulder arthroplasty for the indication of polyethylene wear. This level IV study reports our experience with exchange of the modular polyethylene glenoid component during revision total shoulder arthroplasty. We retrospectively identified 12 shoulders in 11 patients who underwent exchange of the modular polyethylene glenoid component during revision arthroplasty. The primary reason for revision arthroplasty with polyethylene exchange was wear-through or displacement of the polyethylene portion of the glenoid component, but rotator cuff tearing and instability often coexisted. The average follow-up from time of revision to latest evaluation or repeat revision arthroplasty was 68 months. Preoperative pain was a mean of 4.5 (range, 4-5), and postoperative pain was a mean of 2.6 (range, 1-5). Preoperative average active forward elevation was 93 degrees, and external rotation was 51 degrees. Postoperative active forward elevation was 89 degrees, and external rotation was 64 degrees. Average patient satisfaction was rated as the same. According to the modified Neer rating system, 4 shoulders (33%) had a satisfactory result, and 8 (62%) had an unsatisfactory result. Polyethylene exchange of glenoid component after total shoulder arthroplasty can be an effective treatment option in patients who do not have coexistent rotator cuff tear or instability. For most, instability, rotator cuff tear, and glenoid wear occur together, and this is a challenging problem to treat successfully.