The Anatomical Structure of the Coracohumeral Ligament and Its Relationship to the Subscapularis

Abstract

Our previous study revealed that the most proximal portion of the subscapularis tendon extended a thin tendinous slip to the fovea capitis of the humerus, and that the coracohumeral ligament (CHL) together with the SGHL was shaped like a spiral sling, supporting the long head of biceps and attached to the tendinous slip. Little information is available, however, regarding the relationship between CHL and the insertion of subscapularis on the lesser tuberosity. To clarify the significance of CHL, we examined the morphology of CHL and the subscapularis insertion in 20 cadaveric shoulders. The anterior portion of CHL arises from the base of the coracoid process and fans out laterally and inferiorly on the subscapularis. The fibers envelop the tendinous portion of the subscapularis on either side. As a result, the ligament forms a cable-like anterior leading edge over the rotator interval. The subscapularis tendon can appear in relative anatomic position unless the arm is brought into internal rotation and relaxation is achieved. We also demonstrated that CHL was associated with opening the bicipital sheath along its medial border during shoulder elevation. The coracohumeral ligament might contribute to the stability of the subscapularis tendon and to the morphology of the bicipital groove.