Suprascapular nerve anatomy and its implication for approaches to peripheral nerve stimulation of its sensory...

The suprascapular notch (SNo) is used to guide lead placement during peripheral nerve stimulation (PNS) of the suprascapular nerve (SNe) for refractory shoulder pain. Understanding branching patterns of the SNe can help determine the most effective site for lead placement to improve coverage and effective stimulation.

Ninety-three formalin-embalmed cadaveric shoulders were dissected and a morphometric analysis was conducted. The course and initial branch point of the SNe relative to the superior transverse scapular ligament (STSL) at the SNo were described. The width and depth of the SNo, and the diameter of the SNe within the SNo, were measured. Comparisons were performed between donor sex, laterality, and age.

The SNe branched proximal to the SNo in 15% of shoulders, directly at the SNo in 54%, and distal to the SNo in 31%. The SNe occupied the medial third of the SNo in 15%, middle third in 59%, and lateral third in 26%. The SNe branched a mean of 1.5 mm from the SNo. The mean depth of the SNo was 5.8 mm and the mean width was 7.8 mm. The mean diameter of the SNe was significantly greater in males (2.6 mm) than females (2.2 mm) (P < 0.001).

The main branching of the SNe tends to occur proximal to, or directly under, the STSL and in the middle third of the SNo. This knowledge can help guide clinicians when placing PNS leads under fluoroscopic or ultrasound guidance to achieve maximum stimulatory coverage.

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