An osseous study of suprascapular notch and various dimentions of safe zone to prevent suprascapular nerve injury

words : 285 Text documents : pages 13 and words 2655 Sources of support : Nil ABSTRACT INTRODUCTION : Suprascapular nerve injuries have become commonly recognized as aINTRODUCTION : Suprascapular nerve injuries have become commonly recognized as a cause of shoulder pain and dysfunction. The entrapment of suprascapular nerve is commonly considered at the level of the suprascapular notch (SSN). It may be injured during arthroscopic shoulder procedures. OBJECTIVES : In the present study, the morphology of suprascapular notch in nerve lesions has been assessed to understand the suprascapular nerve lesion and a safe zone has been measured to avoid injury to the nerve during operative procedures. METHODS : Three hundred scapulae were examined. Three measurements were defined and collected for every SSN: maximum depth (MD), superior transverse diameter (STD) and middle transverse diameters (MTD). The safe zone from the supraglenoid tubercle to the base of SSN (AB) and the distance between the posterior glenoid rim and the base of scapular spine (CD) have also been measured. RESULTS : The SSNs were classified into six types according to Michael Polguj. Type III was the most common type found in 128(42.66%) scapulae. Complete ossification (bony foramen) found in 11 (3.67%) scapulae. Out of these 11 scapulae one scapula had a unique double suprascapular foramen. There was a smaller foramen above the larger one. Four scapulae with a bony canal in the course of the Suprascapular nerve have been found which strongly suggests a possibility of nerve entrapment. We also measured the safe zone from the supraglenoid tubercle to the base of SSN which was 27.77+2.45mm with a range of 20.94-34.48mm and the distance between the posterior glenoid rim and the base of scapular spine which was 15.77+1.51mm with a range of 12.17-19.72mm. CONCLUSIONS : The present study provides precise data to clinicians in diagnosis of the suprascapular nerve entrapment and to make a decision about safe advancement in operative procedure to avoid nerve injury.