Anterior coracoscapular ligament and suprascapular nerve entrapment

Abstract

A reduction in the height of the suprascapular foramen may predispose to entrapment of the suprascapular nerve. In this study, 16 of 27 cadavers (60%) demonstrated a heretofore unreported ligament located on the anterior aspect of the suprascapular foramen. In 11 of the 27 cadavers (41%), the ligament was observed bilaterally. The ligament decreased the foraminal height from the normative value of 5.6 +/- 0.4 to 2.3 +/- 0.4 mm (mean +/- SEM). Because this ligament, for which we propose the term anterior coracoscapular ligament (ACSL), substantially narrows the suprascapular foramen, it should be considered as a possible etiologic factor in suprascapular nerve entrapment.

A Study on the Morphological Variations of the Suprascapular Notch in the Population of Eastern Delta Region of Tamil Nadu

“…An additional anterior coracoscapular ligament which is arranged either parallel or oblique to STSL in the suprascapular notch was first described by Avery et al [15].The ossification of only this anterior coracoscapular ligament without involving the STSL results in the coexistence of notch and foramen thus increasing the possibility of nerve entrapment in the foramen [16]. This type of presentation does not find a place in Rengachary's classification.…”

Suprascapular foramen: a rare variation caused by ossified suprascapular ligaments

“…Avery et al [2] discovered that the anterior coracoscapular ligament (ACSL) might have been supposed as a new possible mechanism for the formation of this anatomical variation. Polguj et al [38] observed the presence of the ACSL as 60% of 54 dissected shoulders, and they found that the SN always has been passing under the ACSL; therefore, it has been in close contact to the bony floor of the SSN [38].…”

Morphology of suprascapular notch in medieval skeletons from Bulgaria

“…The probable mechanism of formation in cases with parallel course of both bony bridges, as it is in our case, is that either the upper bony bridge was created by ossification of the single bundle superior transverse scapular ligament and the lower one was created by the osseous transformation of the anterior coracoscapular ligament, or both bridges were formed as a result of the ossification of the superior and inferior bands of the trifid superior transverse scapular ligament. As the trifid superior transverse scapular ligament was reported on rare occasions in the literature [25,35], whereas the frequency of anterior coracoscapular ligament varied up to 60% [4], the formation of the lower bony bridge by ossification of the anterior coracoscapular ligament seems to be more probable explanation.…”

“…These cases are associated with suprascapular entrapment neuropathy [5,8,10,24]. Avery et al [4] and Polguj et al [26] considered the ossification of anterior coracoscapular ligament, which causes a reduction in the height of the suprascapular foramen, also as a possible aetiologic factor in suprascapular nerve entrapment. According to Ofusori et al [21], the complete absence of the SSN could be considered as a possible cause of suprascapular nerve entrapment as well.…”