Piriformis Syndrome

The piriformis syndrome is a controversial condition in which the piriformis muscle irritates the sciatic nerve  It causes pain in the buttocks which is referred pain along the course of the sciatic nerve. It is one cause of "sciatica." Patients generally complain of pain deep in the buttocks, which is made worse by sitting, climbing stairs, or performing squats. The piriformis muscle assists in abducting (pulling outward) and laterally rotating (turning out) the thigh. Stretching the muscles can duplicates the pain.

Anatomically, the piriformis muscle lies deep to the gluteal muscles. It originates from the sacral spine and attaches to the greater trochanter of the femur, which is the big, bony "bump" on the outside top of the thigh. In approximately 15% of the population, the sciatic nerve travels through the muscle. It is thought that acute or chronic injury causes swelling of the muscle and irritates the sciatic nerve, resulting in sciatica.

The piriformis syndrome is diagnosed primarily on the basis of symptoms and on the physical exam. There are no tests that are 100% accurate,  but X-rays, MRI, and nerve conduction tests may exclude other diseases and a local dye injection can show if the nerve is pinched by the pyriformis muscle.

Treatment is undertaken in a stepwise approach. Initially, progressive piriformis stretching is employed.  If this fails, then injections of a corticosteroid into the piriformis muscle may be tried. Surgery used to be popular for this condition but research shows that it rarely helps.

Go back to the back pain page.

Click here to go the next section on procedures.

The information in this site briefly describes issues related to medical treatments, and has been licensed by from Northern California Neurosurgery Medical Group, Inc., who is solely responsible for said content.  This web site is not a substitute for good medical care or for a consultation with a spine specialist. It should not be used to plan your treatment. The well considered advice of a specialist who has personally examined you is always superior to even the best internet pages.

Copyright 2007, Northern California Neurosurgery Medical Group. All rights are reserved.  No part of this web site may be reproduced, transmitted, or stored, electronically or on paper, without the written permission of the Northern California Neurosurgery Medical Group, Inc.
Last modified: 07/27/08