BONY SUPRASCAPULAR FORAMEN, A POTENTIAL SITE FOR SUPRASCAPULAR NERVE ENTRAPMENT: A MORPHOLOGICAL STUDY ON DRIED HUMAN SCAPULAE

Introduction: The superior transverse scapular ligament (STSL) is present above the suprascapular notch . It joins the two superior corners of this notch and converts it into suprascapular foramen through which passes the suprascapular nerve , while the suprascapular artery and vein usually pass above the ligament . The anterior coracoscapular ligament (ACSL) runs in the suprascapular notch, below the superior transverse scapular ligament. Narrowed bony foramen by ossification of STSL and ACSL is one of the predisposing factor of suprascapular nerve entrapment as well as with an injury to the suprascapular nerve in arthroscopic procedures. Aim: The aim of present study was to know the prevalence of suprascapular foramen in Indian dry scapulae and provide a knowledge on the variations along the course of suprascapular nerve which is essential to understanding the source of entrapment syndrome. Methods and Results: The present study was carried out on 73 dried human scapulae irrespective of age and sex. Visual observation revealed that 3 scapulae (4.1%) had completely ossified superior transverse scapular ligament and 2 scapulae (2.7 %) had partially ossified STSL. The incidence of ossified anterior coracoscapular ligament is 1.3 % ( 1 scapula ) in our study. Conclusion: The knowledge of variations in the suprascapular region and ossification of STSL & ACSL is important for anatomists, orthopaedicians, radiologists and neurosurgeons to obtain a safe zone which would be useful to avoid iatrogenic nerve lesion and for better diagnosis and management of the nerve entrapment syndrome.