Anatomical Course Demarcating the Safe Area for the Superior Gluteal Nerve

Iatrogenic injury to the superior gluteal nerve (SGN) persists despite a safe area being defined. Current descriptions of the course of the SGN are conflicting and do not provide agreeable distances to surface landmarks that are useful for most health care professionals. This study aimed to suggest a more conservative and gender-dependent estimate of the safe area between each buttock and genitals as defined by four bony surface landmarks. The posterior and lateral surfaces of each buttock in eight cadavers, four male and four female, were dissected. The surface anatomy of sixteen SGNs was defined in relation to the quadrate tubercle of the intertronchanteric crest of the femur (QTIF), the most cranial ridge of the iliac crest (IC), the anterior superior iliac spine (ASIS) and the posterior superior iliac spine (PSIS). Between the sexes, no significant difference existed concerning average SGN lengths across each buttock pair, (i.e. SGN length male/female difference df=3 (p=0.273); Pearson = - 0.76). There was no significant difference between both buttock sides concerning the SGN distances from each of the four bony surface landmarks across either sex (e.g. male QTIF df=3 (p=0.284); Pearson correlation = -0.31.) From our measurements we conclude that the standard safe area is too generous and should be half the size immediately adjacent to the tip of the greater trochanter.