Long-term results of anatomic stemless shoulder prosthesis in patients with primary osteoarthritis

Introduction In shoulder arthroplasty shaft-anchored prostheses have long represented the gold standard. The trend has shifted towards bone-preserving, stemless anchoring methods. While promising short- and mid-term clinical results exist, there is still insufficient long-term data available. The aim of this study was to report on the long-term results in patients with primary osteoarthritis treated with a stemless shoulder prosthesis (Total Evolutive Shoulder System, Zimmer/Biomet, Warsaw, USA). Methods This retrospective single-center study was conducted on 27 shoulders in 24 patients, with a mean age of 75 ± 8.3 (60–93) years. Evaluated outcome included the Constant-Murley score, active range of motion, patient satisfaction, revision rate and radiological findings. The mean follow-up period was 142 ± 12.2 (116–158) months. Twenty-one shoulders were treated with total shoulder arthroplasty, six with hemiarthroplasty. Results Constant-Murley score improved from pre- (23.1 ± 9.4 [27.5% ± 11.5 age-adjusted]) to postoperative values (58.8 ± 18.6 [72.3% ± 23 age-adjusted]) (p < 0.001). Range of Motion improved significantly in flexion from 89.5° to 137.2° (p < 0.001), in abduction from 70.9° to 117.2° (p < 0.001), and in external rotation from 10° to 36.8° (p = 0.019). Overall, 85% of patients were very satisfied or satisfied with the shoulder replacement. Two shoulder prostheses were revised and converted to alternative treatment. Two additional patients underwent revision due to loosening and infection but were treated with the same shoulder arthroplasty system. The ten-year survival rate was 89%, and 85% after 12 years. 30% of the implants showed a risk of loosening (according to Molé). Glenoid loosening was not observed in any case. Loosening of the humeral component occurred in one case. Conclusion The clinical, functional, and radiological outcomes of the investigated stemless shoulder arthroplasty system remain satisfactory even in long-term follow-up. High patient satisfaction was observed. The data, which are unique in terms of the length of follow-up, are comparable to those of other stemless shoulder arthroplasty designs.