Translational injuries in posterior elbow dislocation.

We describe a new plain radiographic finding in posterior elbow dislocation: a defect in the nonarticular posterior surface of the capitellum caused by impaction of the radial head during dislocation. The defect was visible on a lateral view unobscured by overlying bony structures in the unreduced state and confirmed on both an axial view after reduction and by magnetic resonance imaging. We propose that this lesion is analogous to the Hill-Sachs/Bankart lesion complex seen in translational glenohumeral injury.