Bony Bankart Lesion
The shoulder is the most mobile and the most commonly dislocated large joint in the body. Dislocation means that the joint is moved out of position, such that the joint surfaces at the ends of the bones are no longer in contact. Traumatic dislocations of the shoulder can result in a Bankart lesion (tear). The head of the humerus (ball of upper arm bone) is stabilized against the glenoid (socket of the shoulder joint) using a combination of muscles, labrum, and ligaments. Ligaments run from the glenoid to the humeral head and they blend with fibrous tissue called the capsule that encloses the entire joint. When the humeral head is forced forward in a dislocation, the soft tissues stretch or tear, and in some cases, bone is fractured off the glenoid rim, resulting in a bony Bankart lesion.