Morphology of Coracoacromial Ligament and its Role in Biomechanics of Shoulder Joint along with its Surgical Significance

Abstract

Abstract Background: The coracoacromial ligament is a triangular band, which extends between the coracoid process and the acromion. This ligament, along with the coracoid process and the acromion, forms arch above the humeral head which protects the head of the humerus during abduction. It is important for gleno humeral stability. Coracoacromial ligament may be composed of two strong marginal bands with thinner centre.It may be present in the form of a thick anterolateral bundle and a posteromedial bundle, with a triangular base. Anatomic variants are frequently seen .Sometimes it is Y-shaped, quadrangular and may be straight in shape. Release of Coracoacromial ligament for the treatment of shoulder impingement syndrome has been suggested in surgeries. Aim and Objectives: Aim of the present study is to study the different types of coracoacromial ligament. Cadaveric study was helpful for identifying the types of normal coracohumeral ligaments. Methodology: Fifty upper limbs were procured from the cadavers. Cadavers were embalmed and in 10% formalin. Inclusion criteria for study were intact shoulder joint. Exclusion criteria were disarticulated shoulder joint. Dissection was carried out as per steps given in Cunningham dissecting manual. As dissection of upper limb was already done by undergraduate students, skin was reflected and deltoid was exposed. For further dissection the anterior and middle fibers of deltoid muscle were cut Superior surface of coracoid process and acromion process were exposed to visualised the coracoacromial ligament. Results: Meticulously dissected upper limbs were observed to determine various shapes of CAL. Trapezoid, rectangular, Y shaped, bipartite and tripartite type of choracoacromial ligaments were observed. Conclusion: Advances in understanding Coracoacromial ligament through research outcomes will contribute more to intraoperative decision making for arthroscopic surgeons.