Shoulder Arthropathy

Abstract

The shoulder’s range of motion is achieved by a lack of bony support for a joint which is stabilized by musculotendinous structures. The glenoid fossa, a shallow saucer-type structure, is not as flat as it appears on tengential roentgenograms, since it is reinforced at its margin by a fibrocartilaginous la- brum invisible by X-ray, but visible by arthrogram with CT. The humeral head is primarily stabilized by the rotator cuff, consisting of the supraspinatus, infraspinatus, and teres minor tendons, which attach to the greater tuberosity in an anteroposterior order, and the subscapularis, which attaches to the lesser tuberosity. The biceps tendon inserts at the superior margin of the glenoid fossa, while its intraarticular portion traverses the joint and exits through the bicipital groove, covered for a short distance by a synovial sleeve. The deltoid muscle is separated from the rotator cuff by the subdeltoid bursa, which is continuous with the subacromial bursa but which does not communicate with the shoulder joint, being separated from it by the intact rotator cuff.