Glenohumeral Shoulder Dislocation

Shoulder dislocations are injuries where the humeral head (ball) of humerus (upper arm bone) is no longer articulating (in contact) with the glenoid (socket) of the shoulder joint. The most common dislocation is anterior (more than 90 percent), where the humeral head dislocates out in front and below the glenoid socket. Because the shoulder has more motion than any other large joint in the body, it is the most commonly dislocated large joint. There are many structures that work together to provide shoulder stability and include the bone of the humeral head and glenoid, the glenoid labrum (a thickening of soft-tissue surrounding the glenoid socket), the capsule and ligaments which connect the humerus to the glenoid, and the tendons of the rotator cuff muscles which surround the shoulder. Any or all of these anatomic structures may be damaged with a shoulder dislocation and may require repair.