The aim of present study was to demonstrate the variations of piriformis muscle, sciatic nerve and its branches and discuss their clinical importance.
Materials and Methods: Fifty-two gluteal and lower limb regions of 26 formalin fixed male cadavers were evaluated in Ege University Faculty of Medicine, Department of Anatomy. The anatomical relationship between the sciatic nerve and the piriformis muscle, and division level of sciatic nerve in thigh was recorded.
Results: The sciatic nerve exited the pelvis as a single branch through the infrapiriform foramen with no variation in 84.62% of the lower limbs. The division variations of sciatic nerve were determined in 23.08%. In 8 of 12 high divisions were observed in gluteal regions (15.38%). The common peroneal nerve and the tibial nerve entered deep gluteal region via the greater sciatic foramen below piriformis muscle separately in four lower limbs (7.69%). Two separate nerve divisions passed above and through (or below) the piriformis muscle and then combined together to form common peroneal nerve while tibial nerve passing below the piriformis muscle in 4 lower limbs (7.69%). In 2 of 12, high division occurred in the 1/3 upper portion of the thigh unilaterally (3.85%). The division of sciatic nerve in the popliteal fossa was seen in two lower limbs (3.85%).
Conclusion: The clinical importance of the sciatic nerve around the piriformis muscle or in the thigh was discussed for piriformis syndrome, palsy after total hip arthroplasty, intramuscular injections in gluteal region and failed popliteal nerve block.