ABSTRACT
The shoulder is a ball and socket joint. The large humeral head articulates with the relatively small glenoid. This depth of the glenoid is increased by a rim of fibrocartilage, the labrum. The exceptional mobility of the shoulder joint accounts for its being the most commonly dislocated large joint in the body. Over 95% of dislocations are anterior. Most of the rest are posterior with the remaining few being inferior (luxatio erecta) and the extremely rare superior dislocation. Dislocations usually occur in young adults or the elderly.
