Hemiarthroplasty for glenohumeral osteoarthritis: results correlated to degree of glenoid wear.

Thirty patients (31 shoulders) were retrospectively reviewed after hemiarthroplasty for glenohumeral osteoarthritis. Ten shoulders had primary osteoarthritis, and 21 shoulders had secondary osteoarthritis. Glenoid surface wear was evaluated and classified as either type I, concentric, (15 shoulders) or type II, nonconcentric, (16 shoulders). Postoperative results were reviewed with the American Shoulder and Elbow Surgeons' evaluation form, Neer classification, and the Constant score. Overall, 23 (74%) shoulders achieved satisfactory results, and 8 (26%) shoulders had unsatisfactory results. Results were similar in the primary and secondary osteoarthritis groups. Outcome correlated most significantly with the status of posterior glenoid wear. Patients with concentric, type I glenoids achieved 86% satisfactory results, whereas patients with nonconcentric, type II glenoids had only 63% satisfactory results. Although pain relief was similar in both groups, the unsatisfactory results were attributed to loss of forward elevation and external rotation in patients with type II glenoids. On the basis of these results hemiarthroplasty can be an effective treatment for both primary and secondary arthritis but should be reserved for patients with a concentric glenoid, which affords a better fulcrum for glenohumeral motion.