Sciatic nerve is a very important and one of the thickest nerves of the body. It is important for supplying motor function to the muscles of the leg and foot as well as taking sensations from the foot to the brain. Their critical function cannot be replaced by any other nerve or muscle.
Thereby, it is important that the sciatic nerve is functional and present. Very rarely, patients may have tumor involving the sciatic nerve, which may have to be excised and may lead to sacrifice of the sciatic nerve; unless otherwise, the sciatic nerve is never removed due to its critical function.