Long head of the biceps tendon and rotator interval

Abstract

The term "biceps brachii" is a Latin phrase meaning "two-headed (muscle) of the arm." As its name suggests, this muscle has two separate origins. The short head of biceps is extraarticular in location, originates from the coracoid process of the scapula, having a common tendon with the coracobrachialis muscle. The long head of biceps tendon (LBT) has a much more complex course, having an intracapsular and an extracapsular portion. The LBT originates from the supraglenoid tubercle, and in part, from the glenoid labrum; the main labral attachments vary arising from the posterior, the anterior of both aspects of the superior labrum (Bletran et al. in Top Magn Reson Imaging 14:35-49, 2003; Vangsness et al. in J Bone Joint Surg Br 76:951-954, 1994). Before entering the bicipital groove (extracapsular portion), the LBT passes across the "rotator cuff interval" (intracapsular portion). Lesions of the pulley system, the LBT, and the supraspinatus tendon, as well as the subscapularis, are commonly associated (Valadie et al. in J Should Elbow Surg 9:36-46, 2000). The pulley lesion can be caused by trauma or degenerative changes (LeHuec et al. in J Should Elbow Surg 5:41-46, 1996). MR arthrography appears to be a promising imaging modality for evaluation of the biceps pulley, through the distention of the capsule of the rotator interval space and depiction of the associated ligaments.