Outcomes of anatomic total shoulder arthroplasty: evaluation of implant-related, radiographic, and demographic factors influencing durability and revision rates.

Abstract

Purpose: To evaluate the impact of implant-associated and radiographic factors on survival rates and revisions of total shoulder arthroplasty (TSA) in patients with primary osteoarthritis (OA).

Methods: This retrospective study included 68 patients who underwent TSA for primary OA at a single institution between 2008 and 2015, with a minimum follow-up of 60 months. Patients with prior shoulder surgeries, perioperative infections, or revisions within 12 months postoperatively were excluded. Patients were divided into Group A (Survivors) and Group B (Revisions) based on implant survival. Radiographic parameters analyzed included critical shoulder angle (CSA), acromiohumeral distance (AHD), lateral offset (LO), humeral head-stem index (HSI), centre of rotation (COR), and glenoid erosion, categorized using Sirveaux, Lévigne, Franceschi, and Walch classifications. Demographic data were also assessed.

Results: Of 68 patients, 57 were in Group A (mean age: 58.5 ± 10.1 years; follow-up: 115.8 months) and 11 in Group B (mean age: 61.4 ± 8.3 years; follow-up: 113.9 months). Implant survival was 84% after 115.8 ± 34.5 months. Baseline demographics were comparable (e.g., smoking: p = 0.75), as was osteolysis prevalence (Group A: 47%; Group B: 45%; p = 0.91). HSI was significantly higher in Group B (0.5 ± 0.1 vs. 0.4 ± 0.1; p = 0.03). No other radiographic differences were significant.

Conclusion: Patients undergoing anatomic total shoulder arthroplasty can expect favourable mid- to long-term outcomes, with implant survival rates of 84% and relatively low complication rates. Although osteolysis is common, it rarely necessitates revision surgery. The role of the humeral head-stem index (HSI) warrants further investigation.

Study design: Level IV; retrospective case study.