Glenohumeral shoulder dislocations are injuries where the humeral head (ball) of the 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 of 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, including the bone of the humeral head and glenoid, the glenoid labrum (a thickening of soft tissue surrounding the glenoid socket), the capsule and ligaments that connect the humerus to the glenoid, and the tendons of the rotator cuff muscles that surround the shoulder.
Any or all of these structures may be damaged with a shoulder dislocation and may require repair.
Frequent Signs and Symptoms
- Apprehension or feeling like the shoulder is going to “pop out”
- Pain with moving the shoulder, especially when reaching overhead
- Pain with heavy lifting or carrying objects with the arm at the side
- Pain that awakens you at night
- Loss of shoulder strength and function
- Tenderness and occasional swelling
- Numbness or paralysis in the upper arm and deltoid muscle from pinching, stretching, or pressure on blood vessels or nerves
- Crepitation (a “crackling” feeling or sound) when the injured area is touched or with shoulder motion
- Repeat dislocations