Variations in the origin of long head of biceps - A Cadaveric Study

Background:Biceps brachii derives its name from two proximally attached heads. The origin of long head starts within the capsule of the shoulder joint, runs from the supraglenoid tubercle of the scapula at the apex, along with the glenoidal labrum. Theyarch over the humeral head and descend in the intertubercular sulcus. Aim:The study was designed to assess the variations in the origin of long head of biceps brachii from the glenoid labrum of the scapula. Materials and methods:The shoulder joint cavity of 50 [adult & fetal] male & female cadavers was extensively studied in the Department of Anatomy, Kasturba Medical College and Manipal. Recordings of the percentage of fibers arising from the tubercle, the anterior labrum, and the posterior labrum were assessed. Results:58% all the labral part of the attachment was to the posterior labrum, with few fibers to the anterior labrum,39% equal contributions to anterior and posterior labrum and 3% most attached to the anterior labrum, with a small contribution to the posterior labrum. Conclusion:An understanding of these normal anatomical variations is essential in evaluating and treating labral pathology in throwing athletes. Shoulder instability in baseball pitchers is related to forceful contraction of the injured biceps tendon.The pathology correlates with the immense stress placed on the shoulder and the biceps brachialis muscle during the throwing motion. In geriatric population, minimum intervention (debridement, biceps tenodesis/tenotomy) to these lesions resulted in excellent patient satisfaction and outcomes.