Injury of the suprascapular nerve in shoulder surgery: an anatomic study

Fifty-two shoulders in 26 cadavers were dissected to evaluate the safe zone for avoiding injury of the suprascapular nerve during open surgical procedures and arthroscopic Bankart repairs requiring blind drilling. The course of the suprascapular nerve was given as the shortest distance between the suprascapular nerve and the glenoid rim. A Kirschner wire was inserted from the anterior glenoid rim toward the suprascapular nerve. The insertion angle toward the suprascapular nerve at the base of the scapular spine in the transverse plane averaged 37.0 degrees and in the sagittal plane averaged 17.5 degrees. The insertion angle toward the bifurcation of the infraspinatus motor branch in the transverse plane averaged 44.3 degrees and in the sagittal plane averaged 27.7 degrees. On the basis of the results of the anatomic evaluation, the safe zone was described. An appreciation of this safe zone may help shoulder surgeons avoid iatrogenic injury to the suprascapular nerve.