What is a Piriformis Syndrome and why is an injection helpful?

This is a condition characterized by pain in the hip and buttock that can radiate up into the lower back and down the leg especially into the back of the thigh. It is caused by entrapment of the sciatic nerve as it passes through the piriformis muscle in the buttock. The pain is made worse by rotating the femur (big bone of the upper leg) inward, which causes pressing of the sciatic nerve against the origin of the piriformis muscle. Treatment of this condition includes therapy and medication to relieve pressure and reduce muscle spasm and inflammation. An injection into the muscle using a local anesthetic and cortisone medication may be helpful in reducing inflammation and pain which may make it easier to participate in therapy to further reduce pressure, spasm, and inflammation.

What happens during the procedure?

The patient is asked to lie on their abdomen on the x-ray table. The skin on the buttock is cleansed using a sterile solution called Betadine. Next, the physician injects a small area of skin with numbing medicine. This medicine stings for several seconds. After the numbing medicine has been given time to be effective, the physician directs a small needle, using x-ray guidance, into the piriformis muscle. A small amount of contrast (dye) is injected to insure proper needle position. The physician will ask you to move your leg during the procedure: rotate your leg outward and move it straight to the side away from your other leg. A mixture of numbing medicine (anesthetic) and anti-inflammatory (cortisone/steroid) is injected.

What happens after the procedure?

Patients are then moved to the recovery area where they are monitored for 20 minutes and dismissed. If there is significant numbness in the leg after the procedure, which is not unusual in this type of injection, the stay in Recovery will be long enough to insure that you can walk safely. This can be 60 minutes or longer. Patients are then asked to report the relief they experience during the next week by calling the clinic. It may be at least 72 hours before the full effect of the cortisone is apparent. A follow-up appointment will be made.