Case report of Sciatic nerve variation

Abstract

Sciatic is the thickest nerve of the body with three quarter of an inch. It is forms from L4, L5, S1, S2 and S3 of spinal nerves as a part plexus in pelvis.It leaves the pelvis via great sciatic foramen, and aises in gluteal region in infra piriformis fossa. Then passes between great trochanter and ischial tuberosity and arrives to the posterior surface of thigh. At the level of superior angle of pobliteal fossa, it divides into two common, proneal and tibial branches. Muscular injection in upper lateral part of gluteal region is performed within gluteus medius and minimus muscles. The former is carried out with a considerable distance to avoid any harm to sciatic nerve. However this variation that includes two parts of sciatic nerve passes throw the supra and infra piriformis fossa is an important one. The later variation induces proximity between nerve and injection site, particularly in neo natales, furthermore, recognition of such variation helps in identification of piriformin syndrome. This type of variation is regarded as one of the rarest type of variation, and has not between referred to in many anatomical dictionaries.