The piriformis muscle runs from the base of your spine to the greater trochanter of your hip on each side. Tightness and inflammation of this muscle can cause back or buttock pain that is usually worse with prolonged sitting. Additionally, the sciatic nerve may be irritated by tightness of the piriformis muscle, and this can cause nerve pain in the leg that mimics that caused by a herniated lumbar disc. Injections of steroid and local anesthetic directly into the piriformis muscle with x-ray guidance can relax this muscle and relieve painful symptoms.
Injections into the piriformis muscle usually take 10 to 15 minutes.
Relief of buttock and sciatica pain is usually noticed shortly after the injection due to the use of local anesthetic, but steroids take effect in 48-96hrs.
Pain relief is variable, but typically lasts up to 2 months.