Morphology of the Suprascapular Notch: A Study in Thai Population

Abstract

Background and objective: The suprascapular notch (SSN) located on the upper border of the scapula, medial to the base of the coracoid process.  The superior border of this notch is bridged by superior transverse scapular ligament (STSL) to form a small foramen.  The suprascapular nerve passes through the SSN inferior to the STSL to enter the supraspinous fossa.   The contour of the notch is thought to play a part as the predisposing factor for suprascapular nerve compression.  The purpose of this study was to analyze the variations of the morphology of the suprascapular notch in Thais.

Materials and Methods : A total of 240 human scapulae from 120 Thai adult dried skeletons were explored. The shape of suprascapular notch of each scapula was classified by visual observation, photographed and recorded. 

Results:  It showed that the 240 scapulae have variety shapes of SSN which can be classified into 7 types.  The frequencies were as follows: Type I, absence SSN was found in 25.8%.   Type II, small depression SSN was detected in 35.8%. Type IV, U shaped SSN was seen in 17.1%.    The remaining types were: Type III (V shaped), Type V (J shaped), Type VI (partial ossified) and Type VII (completely ossified STSL) which were lesser than 10% for each type.

Conclusions:  The most two common types of SSN in Thais was the small depression followed by the absence SSN with the frequency of 35.8% and 25.8% , respectively.  The incidence of

 complete ossified STSL converted the notch into a bony foramen (Type VII) was rare, present in only 2.1%