Shoulder arthroplasty in nontraumatic osteonecrosis of the humeral head.

Twelve patients (thirteen shoulders) treated with arthroplasty for nontraumatic osteonecrosis of the humeral head were prospectively evaluated. At a mean follow-up of 30.2 months (range, 14-49 months), shoulder function assessed by the Constant score improved from 18 (adjusted score, 24%) to 51 (adjusted score, 69%; P <.001). Patients older than 65 years obtained lower adjusted scores than patients younger than 65 years (P =.02). The radiographs at follow-up showed radiolucent lines in 2 patients with no evidence of implant migration. Progressive glenoid erosion was identified in 2 patients treated with hemiarthroplasty. The subjective assessment revealed good and excellent results in 4 of 13 patients (numeric rating scale [NRS] 1 and 2). Three patients were unsatisfied with the final outcome (NRS 5). All three patients had abnormal findings with regard to the glenoid, either preoperatively with subtotal destruction of the glenoid or postoperatively with glenoid erosion after hemiarthroplasty or radiolucency around the glenoid component after total joint replacement. Contrary to previously published retrospective studies, we recommend a more cautious prediction of midterm results, especially in patients older than 65 years.