Unilateral high division of the Sciatic Nerve with divided Piriformis

Abstract While doing the routine dissection for the undergraduate students in the department of Anatomy, Nil Ratan Sircar Medical College, Kolkata, few variations were found in the gluteal region of a 70 years old male cadaver, in the year 2013. On the right side the sciatic nerve (SN) pierced the piriformis muscle dividing it into superior and inferior slips and then, after a short distance, divided into tibial and common peroneal nerves in the gluteal region. On the left side, sciatic nerve divided into two terminal branches (common peroneal and tibial nerves) in the lower part of the back of the thigh near the apex of the popliteal fossa as usual. This high division of the sciatic nerve may result in nerve injury during deep intramuscular injections in gluteal region, piriformis syndrome due to compression of the nerve, failed SN block in anesthesia and surgical complications