Updated March 07, 2014.

Definition: A Hill-Sachs injury is a shoulder problem that causes damage to the head of the humerus (arm bone). A Hill-Sachs lesion is a complication of a shoulder dislocation. When the shoulder dislocates, the smooth cartilage surface of the humerus hits against the rim of the scapula (glenoid).  This impact can cause injury to the humeral head, known as a Hill-Sachs defect.