The acromion: Fractures and os acromiale

Acromial fractures are a rare occurrence, representing less than 1% of all skeletal fractures. When they occur they often do so in association with other injuries and usually as a result of a car accident or other major injury mechanism. Os acromiale, on the other hand, is a relatively more common occurrence representing the failure in fusion of the ossification centers of the acromion. The true incidence of os acromiale is not known as many cases are diagnosed as incidental findings on X-rays taken for other reasons. Further, os acromiale often is asymptomatic. Both acromial fractures and an os acromiale can cause symptoms requiring treatment, including surgical stabilization with either bony union of the fracture or fusion of the os. We discuss the incidence and presentation of each of these entities and a brief discussion of our approach to treating them.