Safe Distance for Superior Gluteal Nerve and its Relation with Thigh Length: A Cadaveric Study

Superior gluteal nerve emerges through the greater sciatic foramen above the piriformis muscle. The nerve curves upwards and forwards between the gluteus medius and minimus muscles, supplies both of them and ends by supplying the tensor fasciae latae muscle, from its deep surface. During hip surgeries, this nerve often gets injured resulting in complications. An exact knowledge of its course is helpful in avoiding such injuries. The aims of this study are to find the distance of the most inferior branch of superior gluteal nerve from the tip of the greater trochanter; to find the correlation of this distance with the length of thigh and also to find the safe zone where the chances of injury to superior gluteal nerve, during hip surgeries, would be minimal. 20 lower limbs of formalin fixed cadavers were subjected to dissection for their superior gluteal nerve. The distance of the most inferior branch of superior gluteal nerve from the tip of the greater trochanter was measured in the anterior third, middle third and posterior third of the gluteus medius muscle. The correlation between these distances and the thigh length was evaluated. The range of distance from tip of the greater trochanter to superior gluteal nerve was found to be 4.0-8.3 cm (mean 6.0 cm) in the anterior third, 5.0-7.6 cm (mean 5.9 cm) in the middle third and 5.0-7.8 cm (mean 6.2 cm) in the posterior third of gluteus medius muscle. From the tip of the greater trochanter a distance of 4.0 cm in the anterior third; and 5.0 cm in the middle third and posterior third of the gluteus medius muscle, can be considered safe for the superior gluteal nerve, in hip surgeries. The results of the present study also showed that the there was no statistically significant correlation between distance of most inferior branch of superior gluteal nerve from the tip of the greater trochanter and thigh length.