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 A minimum of 2 years' follow-up was reported, unless failure and operative intervention superseded this duration.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.