Durability of partial humeral head resurfacing.

BACKGROUND Partial humeral head resurfacing arthroplasty uses a stemless device, which conserves bone and restores normal anatomy. We hypothesized that this does not offer a reasonable alternative to full resurfacing or total shoulder arthroplasty. METHODS We performed a retrospective study of 39 shoulders with focal chondral defects of the humeral head treated with partial resurfacing arthroplasty. A minimum of 2 years' follow-up was reported, unless failure and operative intervention superseded this duration. The mean follow-up period was 51.3 months. The mean age was 45.6 years (range, 27-76 years). Preoperative and postoperative evaluation included history, physical examination, radiographs, and clinical scoring with the American Shoulder and Elbow Surgeons Shoulder Score Index and Subjective Shoulder Value. RESULTS Of the 39 shoulders, 25 (64.1%) showed functional improvement and decreased pain. Significant mean improvements were observed in forward flexion (121° to 152°, P = .002), external rotation (37° to 58°, P = .0003), mean Subjective Shoulder Value (31% to 74%, P < .0001), and ASES score (29 to 70, P < .0001). However, at a mean of 26.6 months' follow-up, the failure group included 6 patients (15.3%) who underwent revision and another 4 (10.2%) who were recommended to undergo revision. Patients with no prior or concomitant procedures were rare (n = 5) but had the most reliable outcomes with partial resurfacing, with no failures in that group. Of the 24 patients with prior procedures, 5 had undergone revision, and the clinical outcome scores for the remaining patients were consistently lower than those seen in patients without prior procedures. CONCLUSION Concomitant pathology and prior or concomitant surgical procedures potentially impair the outcome of the resurfacing procedure and could be a contraindication. Long-term success remains guarded with this treatment modality, especially in patients whose chondral injury is not an isolated finding.