Early clinical and radiological outcomes of reverse shoulder arthroplasty with an eccentric all-polyethylene glenosphere to treat failed hemiarthroplasty and the sequelae of proximal humeral fractures

Purpose: The aim of this study was to assess the effectiveness of reverse total shoulder arthroplasty (RTSA) with an all-polyethylene glenosphere in patients with failed hemiarthroplasty (HH) or the sequelae of proximal humeral fractures. Methods: Thirty-six patients were assessed at a mean follow-up of 36 months using clinical scores and recording shoulder range of movement (ROM). Results: Active anterior elevation (p < 0.001), lateral elevation (p < 0.001) and internal rotation (p < 0.0001) improved significantly, whereas improvement in external rotation was not significant. The mean Constant score rose significantly from 8.5 ± 7.6 to 40.7 ± 15.7 (p < 0.001) and the Simple Shoulder Test score from 0.42 ± 0.85 to 5.5 ± 2.6 (p < 0.001). Pain improved significantly from 8.7 ± 0.9 to 2.3 ± 1.2 (p < 0.001). Implant radiographic survivorship was 84.6 %. Scapular notching was detected in 7/36 patients (17.5 %). There were five complications: one (stiffness) among patients with fracture sequelae and four among those with failed HH (instability, n = 2; humeral component disassembly, n = 1; pain, n = 1). The two groups did not exhibit significant differences in pain, clinical scores or ROM. Discussion: RTSA with an all-polyethylene glenosphere may have the potential to reduce the risk of biological notching due to polyethylene osteolysis. Further long-term studies are required to assess its efficacy. Conclusions: The good clinical performance and reasonable rate of notching of the polyethylene glenosphere support its use in primary and revision shoulder arthroplasty. Level of evidence: Level 4, retrospective therapeutic case series