Abstract:
Sciatic nerve, the thickest nerve in the
body, is formed in the pelvis from the
sacral plexus. It is comprised of both
anterior and posterior divisions of fourth
lumbar to third sacral spinal nerves [1].
Having left the pelvis through the greater
sciatic foramen, it courses beneath the
piriformis and enters the gluteal region.
Then it travels over the gamelli,
obturator internus and quadratus femoris
and descends vertically midway between
greater trochanter and ischial tuberosity
[1].
During its course in the posterior
compartment of the thigh, it divides into
tibial and common peroneal nerves. This
division is observed to occur usually a
hands breath above the knee joint [1].
However, numerous variations have
been reported with regard to its course
and divisions. Clinical consequences
such as entrapment syndromes and
failure of regional nerve blocks are
known to be associated with variant
courses and divisions [2, 3]. Bilateral
division of the sciatic nerve deep to the
piriformis muscle and a variant course of
its common peroneal branch seen on a
cadaver is discussed.
