An anatomical study on various types of suprascapular notch, its relation with glenoid cavity and morphometry of scapula in south Indian population

Abstract

Introduction: Superior border of scapula presents a suprascapular notch. Suprascapular nerve entrapment syndrome may be caused due to compression of the nerve at the notch. Previous studies have shown that there are various types of suprascapular notch and clinicians must be aware of these types and their prevalence. Aim: This study was conducted with the following objectives, a: To know the morphometry and morphological variations of suprascapular notch; b: To measure the safe zone distance necessary to avoid iatrogenic injuries to nerve; c: To correlate the major scapular dimensions with that of suprascapular notch. Materials and Methods: We collected 100 dried human scapulae from department of Anatomy and medical students of AIMS&RC, Devanahalli, Karnataka and Sri Narayana Institute of Medical Sciences, Ernakulam, Kerala. The Suprascapular notch was classified according to Rengachary’s classification. Dimensions of all different class of suprascapular notches, that of scapulae and safe zone distance was measured using digital Vernier calipers. Results: Majority of scapulae had type II SSN (33%) and least common variety found was type IV (4%). Least surface area in type V notch measured was 36.16mm2. Mean safe zone distance between SSN and supraglenoid tubercle (S1) in all 100 scapulae is 30.31+/-3 mm. The mean distance between spinoglenoid notch and posterior rim of glenoid (S2) is 16.82+/-2.19 mm. Mean length of all 100 scapulae is 135.12+/-1 mm. Mean width of scapula is 101.69+/-6.8 mm. Mean length and width of glenoid fossa is 33.83+/- 3.25 mm and 24.2+/-2.34 mm respectively. Conclusion: Ossified superior transverse scapular ligament can compress the nerve causing entrapment syndrome. Since suprascapular notch presents various shapes, this study is an attempt to add further data to the existing studies about suprascapular notch, its morphometry and safe zone distance to avoid injury to nerve during surgery. Keywords: Neuropathy, Scapula, Shoulder join