Anatomical Study of the Suprascapular Notch: Quantitative Analysis and Clinical Considerations for Suprascapular Nerve Entrapment

Introduction: Detailed anatomical knowledge of the suprascapular notch (SSN) is important for the management of entrapment neuropathy and interventional procedures. The objective of the present study was to collect data on the morphological features and anatomical variations of the SSN in an Indian population.

Methods: We studied 268 human scapulae of unknown sex (126 right-sided, 142 left-sided) taken from the Department of Anatomy, Dayanand Medical College and Hospital, India. SSNs were classified as either type I, II, III, IV or V, based on the shape of the inferior border of the incisura, and comparison of the SSN's vertical and transverse diameters. The shape of the SSN (i.e V- or U-shaped), if present, was also recorded.

Results: Type II SSN was the most common (50.00%), followed by type I, type IV and type III (32.46%, 9.70% and 7.84%, respectively). For right-sided type II SSNs, the transverse and vertical diameters were 9.1 ± 3.2 mm and 5.2 ± 1.9 mm, respectively, while those for left-sided type ll SSNs were 9.2 ± 2.4 mm and 5.1 ± 1.8 mm, respectively. Generally, the transverse diameter of type II SSN was found to be greater than that of type III SSN. The incidence of U-shaped SSN was 51.49%, while that of V-shaped SSN was 2.99%.

Conclusion: This study of the morphometrical characteristics and anatomical variations of SSN provides an anatomical database of SSN in the Indian context. This database will be of use in surgical procedures, as the information can be used to ensure adequate access to and complete decompression of the suprascapular nerve.