Incidence of os acromiale in patients with shoulder pain.

A prospective case series was undertaken to determine the incidence of os acromiale in patients presenting to an orthopedic clinic with shoulder pain during a 6-month period. Ninety-three shoulders in 88 consecutive patients were evaluated by history, physical examination, and radiographs. Radiographs included anteroposterior, scapular Y, and axillary views in all patients.