Surgical treatment of os acromiale with and without associated rotator cuff tears.

Nineteen consecutive patients treated surgically for meso-os acromiale and subacromial pathology were reviewed retrospectively, with a mean length of follow-up of 40 months (range, 24-94 months). Of the patients, 11 (58%) were treated with acromioplasty in the presence of a stable os acromiale; 8 patients (42%) underwent open reduction-internal fixation for an unstable and painful os fragment. Of the 19 patients, 8 (42%) with an os acromiale had an associated full-thickness rotator cuff tear.