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

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.