Os acromiale open reduction and internal fixation: a review of iliac crest autogenous bone grafting and local bone grafting

Abstract

Symptomatic os acromiale are fairly uncommon, and treatment has included fragment excision, decompression, and open reduction and internal fixation. Nonunion rates as high as 40% have been reported after fixation of os acromiale. This study assessed whether union of an os acromiale could be reliably achieved without the use of an iliac crest bone graft. This was a retrospective study of 32 consecutive shoulders that were treated with screw fixation and a local bone graft or iliac crest bone graft. The mean age was 50.3 years (range, 21-74 years), and the mean follow-up was 46.9 months (range, 12-120 months). Fusion was assessed clinically and radiologically. All 32 os acromiale were fused by 3 months on x-ray imaging. There were 18 shoulders in the iliac crest bone graft group and 14 in the local bone graft group. Rotator cuff repairs were performed concomitantly in 25 patients. Hardware was removed in 4 patients, a seroma was drained in 1 patient, and a superficial infection occurred in 1 patient. This is the largest study of os acromiale fixation using screws and a tension band to our knowledge. We report a 100% union rate using this technique, with 13% requiring hardware removal and the occurrence of 1 superficial infection. This study shows a local bone graft is as effective as iliac crest bone graft in achieving fusion.