Course of the Sciatic nerve: a Review of Cases Seen at Mulago Hospital, Kampala - Uganda

Background: The sciatic nerve is the largest in the body with nerve roots L4, 5 S1, 2, 3. It is commonly injured in the body particularly following administration of gluteal intramuscular injections to children. The nerve usually leaves the pelvis by passing through the greater sciatic foramen below the piriformis and anterior to the superior and inferior gamelli and the obturator internus muscles. However, it should be noted that this usual course varies on many occasions and these variations have been cited as predisposing factors to certain clinical conditions including piriformis syndrome, coccydynia, muscle atrophy, traumatic administration of intramuscular injections leading to foot drop and bilateral gluteal fibrosis. This study describes the course of the sciatic nerve among adult subjects at Mulago hospital complex.
Methods: This was a cross-sectional descriptive study conducted at the department of anatomy dissection laboratory Makerere University and the associated Mulago teaching hospital mortuary. Dissections of the lower limbs from the gluteal region through the thigh to the leg were done to expose the nerves and surrounding structures.
Results: A total of 80 adult thighs and gluteal regions were dissected in 56 males and 24 females to trace and expose sciatic nerves. All sciatic nerves were located in the lower medial quadrant between the ischial tuberosity and the greater trochanter. In the gluteal region, the whole sciatic nerve measured 4.2cm, and among subjects with bifurcated nerves, the tibial and common peroneal nerves were 4.67cm and 3.3cm, respectively, along a perpendicular line drawn medially from the midpoint between the posterior superior iliac spine and the greater trochanter.
Conclusion: The course of the sciatic nerve in the gluteal region is variable and hence, appreciation of these variations can be useful during clinical and surgical procedures in the gluteal and thigh regions.