THE ORIGIN OF THE LONG HEAD OF THE BICEPS FROM THE SCAPULA AND GLENOID LABRUM - AN ANATOMICAL STUDY OF 100 SHOULDERS

We dissected 105 cadaveric shoulders to study the origin of the tendon of the long head of biceps, and examined histologically the interrela tionship between the tendon, the supraglenoid tubercle and the superio r Iabrum of the glenoid.In all specimens approximately 50% of the bice ps tendon arose directly from the superior glenoid labrum with the rem ainder attached to the supraglenoid tubercle. The main labral origin w as from the posterior labrum in more than half of the specimens, and i n a quarter this was the only labral attachment. On the basis of the b iceps attachment to the anterior or posterior labrum, we distinguished four types of origin. These normal anatomical variations are signific ant for arthroscopic diagnosis and may help to explain the various pat terns of injury seen in partial or complete detachment of the tendon, the labrum or both.