Topographical anatomy of the suprascapular nerve and vessels at the suprascapular notch

Abstract

Suprascapular nerve entrapment caused by the superior transverse scapular ligament (STSL) causes pain, and limitation of motion in the shoulder. To relieve these symptoms, suprascapular nerve decompression is performed through the resection of STSL. To describe and classify the topographic anatomy of the suprascapular notch, 103 cadaveric shoulders were dissected. The mean length and width of STSLs were 11.2 and 3.4 mm, respectively. The bony bridges replacing STSL in four shoulders were 8.2 mm long and 3.5 mm wide on average. The suprascapular nerve always ran through the notch under the STSL. All shoulders had a single suprascapular artery, while multiple suprascapular veins appeared in 21.3%. The arrangement of the suprascapular vessels was classified into three types: in Type I (59.4%), all suprascapular vessels ran over the STSL; in Type II (29.7%), the vessels ran over and under the STSL simultaneously; in Type III (10.9%), all vessels ran under the STSL. In 48.9% of cadavers, these types were bilaterally matched. The omohyoid muscle originated distantly from the STSL in 38.0%, was adjacent to it in 44.0%, and was partially over the STSL in 18.0%. The number of suprascapular vessels running under the STSL was positively correlated with the size of the STSL and the middle diameter of the suprascapular notch. Age was inversely correlated with the length of STSL. The STSL was wider in males than in females. This study provides details of the structural variations in the region of the suprascapular notch.

A quantitative study of the arrangement of the suprascapular nerve and vessels in the suprascapular notch region: new findings based on parametric analysis

“…A current bibliography search reveals only two classifications of the suprascapular vein, artery and nerve location at SSN (by Yang et al [22], and by Polguj et al [16]). The present study uses the fourfold, classification defined by Polguj et al [16] as it is clearer and more practical in clinical practice.…”

“…Yang et al [22] distinguish three types of suprascapular vessel arrangement based on an examination of 103 shoulders. In Type I (60 shoulders; 59.4%), all suprascapular vessels run over the STSL; in Type II (30 shoulders; 29.7%), the vessels run over and under the STSL simultaneously; in Type III (11 shoulders; 10.9%), all vessels run under the STSL.…”

“…In another study, Yang et al [22] divide the Type II arrangement into four subtypes. In Type IIA (12 shoulders), the suprascapular artery and vein cross over the STSL and another vein runs under the STSL.…”

“…The natural passage of the SN through the SSN is constant in that it always passes under the superior transverse scapular ligament (STSL) [18,21,22]. However, the locations of the associated suprascapular vein and artery are highly variable [16,20,22].…”

“…However, the locations of the associated suprascapular vein and artery are highly variable [16,20,22].…”