Anatomic observation of the running space of the suprascapular nerve at the suprascapular notch in the same direction as the nerve.

PURPOSE

The configuration of suprascapular notch was previously analysed from the anteroposterior viewing. However, the approach direction of the suprascapular nerve (SSN) to the inlet of the suprascapular notch is consistently craniocaudal and mediolateral. We propose a new method to observe the suprascapular notch according to the running course of the SSN. We reviewed the anatomic characteristics of the suprascapular notch in relation to the nerve.

METHODS

In 30 formalin-fixed cadaveric shoulders, the morphology of the suprascapular notch and the attachments of the superior transverse scapular ligament (STSL) were examined from both the anteroposterior and the nerve approach direction. The dimensions of the opening of the SSN passage were measured.

RESULTS

By observing from the nerve approach direction, the inlet of the suprascapular notch was recognized to be a space-bordered by the medial wall of the coracoid process, the deep fascia of subscapularis, and the STSL. The STSL formed a sheet-like structure, which ran parallel to the nerve and also to the deep fascia of subscapularis. The attachment of the ligament to the coracoid process was located at the posteromedial corner rather than the medial side.

CONCLUSION

Based on the present study, the space between the STSL and deep fascia of the subscapularis formed the space for the nerve to run through. As a clinical implication, this new method to assess the suprascapular notch in the nerve approach direction might develop the imaging techniques for evaluation of SSN entrapment.