title: Unique formation of sciatic nerve below the piriformis muscle - a case report.
abstract: Dorsal and ventral divisions of ventral rami of lower lumbar and sacral spinal nerve were found to pass ventral and dorsal to the piriformis muscle respectively. These divisions joined each other below the piriformis muscle to form sciatic nerve. This low formation of sciatic nerve was observed in distal part of left gluteal region of a 50-year-old male cadaver. The sciatic nerve thus formed passed caudally into back of thigh and divided into tibial and common peroneal nerves in the upper part of popliteal fossa. In addition, a communicating nerve from the sciatic nerve was found to join the common peroneal nerve in the popliteal fossa. Such variations may lead to piriformis syndrome or non-discogenic sciatica.
authors.affiliation: Lecturer, Department of Anatomy, Melaka Manipal Medical College, Manipal University , Manipal - 576 104, Karnataka, India .
authors.forename: Jyothsna
authors.initials: J
authors.lastname: Patil
authors.affiliation: Lecturer, Department of Anatomy, Melaka Manipal Medical College, Manipal University , Manipal - 576 104, Karnataka, India .
authors.forename: Ravindra S
authors.initials: RS
authors.lastname: Swamy
authors.affiliation: Professor, Department of Anatomy, Melaka Manipal Medical College, Manipal University , Manipal - 576 104, Karnataka, India .
authors.forename: Mohandas K G
authors.initials: MK
authors.lastname: Rao
authors.affiliation: Lecturer, Department of Anatomy, Melaka Manipal Medical College, Manipal University , Manipal - 576 104, Karnataka, India .
authors.forename: Naveen
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Professor,Department of Anatomy, Melaka Manipal Medical College, Manipal University , Manipal - 576 104, Karnataka, India .
authors.forename: S N
authors.initials: SN
authors.lastname: Somayaji
keywords: Common peroneal nerve ligament; Sacral plexus; Tibial nerve