Variable morphology of the suprascapular notch: A proposal for classification in Chinese population

Abstract Background The variable of the suprascapular notch (SSN) is a common cause in suprascapular nerve (SN) entrapment. Hence, knowledge of SSN variations may be predictive valuable for the predisposition to compression of SN. The aim of this study was to propose the classification of SSN in Chinese population and took this complex morphology into account. Material and methods 308 human dry scapulae were analyzed thoroughly and systematically in this study. Morphological variations of the SSN were observed by visual inspection and the classification of SSN was determined by geometrical measurements. Then measurement results were averaged and recorded. Results Chinese dry scapulae were measured, we found seven types of SSN. Type Ⅰ (√, 44.8%) was the most common, followed by type Ⅱ (U, 41.9%) to Ⅶ (double O, 0.6%). Right scapulae were larger in depth of SSN and thickness of A and C. Type Ⅶ (double O) had the deepest SSN and type Ⅰ (√) was widest among five types. For BC, type Ⅰ (√) was shorter than type Ⅲ (V). For thickness of A, type Ⅶ (double O) was greater than type Ⅰ (√). For thickness of C, type Ⅰ (√) and type Ⅱ (U) were shorter than type Ⅲ (V). There were no significant differences in other measurements between types and sides of body. Seven types of SSN in Chinese population were defined in our study. Conclusion These anatomical variations of the SSN may improve the diagnostic rate and success rate of the surgical for the suprascapular nerve entrapment.