[Functional anatomy of the long head of biceps brachii--a comparative study between normal and torn rotator cuff shoulders in cadaver specimens].

In order to clarify the function of the tendinous portion of the long head of biceps brachii, intra-articular lesions of the glenoid labrum and the bicipital long head were investigated on 100 shoulder joints in 50 cadavers. From the point of anatomical features, the glenoid cavity is deepened and widened by the glenoid labrum, and the bicipital long head, which arises from the superior glenoid labrum, covers the humeral head anterosuperiorly and stabilizes the humeral head in the glenoid cavity. The pathological changes of the glenoid labrum with cuff tear (46 joints) included hypertrophy, fraying and erosion, while the bicipital long head was widened and flattened. These pathological changes progressed in company with the extension of the cuff tear. From these results, it is concluded that the intra-articular elements, such as the glenoid labrum and the bicipital long tendon play significant roles as glenohumeral stabilizers.