The anterior coracoscapular ligament in Thais: Possible etiological factor of suprascapular nerve entrapment.

ABSTRACT

Objective: To study the incidence of anterior coracoscapular ligament in Thais as well as morphology of the ligament. Materials and methods: One hundred and twenty seven scapulae from 64 Thais embalmed cadavers were used to scrutinize the presence of the anterior coracoscapular ligament. Relation between the ligament and the suprescapular nerve was also observed. The incidence, morphological feature and dimension of the anterior coracoscapular ligament were recorded. Simultaneously, the photos were taken. Sample of the ligament was randomly collected to process under standard histological technique for microscopic study. Results: The anterior coracoscapular ligament was found in 19 cadavers (28%), 4 cases (6%) were bilateral and 15 (22%) cases were unilateral. The ligament was a fibrous band located inferior to the superior transverse scapular ligament. The ligament attached proximally to anteromedial surface of the root of coracoid process, fibers descended to anterior surface of the scapular in the vicinity of the suprascapular notch. According to its distal attachment, the anterior coracoscapular ligament was divided into 3 types. Furthermore the dimension of the ligament as well as its microscopic feature was also elaborated. Conclusion: The existence of the anterior coracoscapular ligament caused the reduction in the height or narrowed the suprascapular foramen; together with the configuration of suprascapular notch may be one of the predisposing causes of suprascapular nerve entrapment.