Morphometry of the suprascapular nerve in the supraspinous fossa

We describe the supraescapular region's anatomy providing distances between osseous landmarks (supraglenoid tubercle, suprascapular notch, glenoid rim, scapular spine) and measuring the total length of the suprascapular nerve (ssn), to determine ideal places or safe zones for shoulder surgery. Fifty shoulders from cadavers belonging to the Human Anatomy and Embryology donated under consent of the Spanish law were studied. The course of the nerve in each shoulder has been defined by measuring the distances from the supraglenoid tubercle to the suprascapular notch and to the scapular spine, the distance from the midpoint of the posterior glenoid rim to the base of the scapular spine, and finally the total length of the nerve. After leaving the suprascapular notch, the ssn courses posteriorly and laterally deep to the supraspinatus muscle to reach the base of the scapular spine. The distance from the supraglenoid tubercle to the notch averaged 3.54 cm (range 3 - 4.1 cm) and the distance to the base of the spine averaged 2.51 cm (range 1.9 - 3 cm). The distance from the midline of the posterior glenoid rim to the scapular base ranged from average 2.42 (range 1.9 - 3.1 cm). The total length of the nerve along the supraspinous fossa averaged 4.22 cm (range 3.6 - 5 cm). A surgical safe zone could be established taking into account these measurements.