Piriformis Muscle Injection

The piriformis muscle is present in the buttocks, connecting the sacrum to the outer surface of the hip. This muscle enables us to walk and run. The sciatic nerve is a thick, long nerve passing through or below the piriformis muscle. A spasm of the piriformis muscle can compress the sciatic nerve resulting in severe pain (sciatica). The pain is usually felt over the buttocks but may radiate to the back of the thigh and down the leg as well.

A piriformis muscle injection is used to alleviate the spasm and pain in these patients. The injection comprises an anaesthetic and a steroid to reduce the spasm. In most patients, the pain resolves with 1 or 2 injections, however, 3 injections may be required to achieve complete benefit.


The entire procedure usually takes 15-20 minutes. You will lie on your stomach. A local anaesthetic is used to numb the area of injection. Your doctor will insert the needle into the piriformis muscle under fluoroscopic guidance. A small amount of contrast dye is injected to guide the doctor in proper placement of the needle. After confirming the position of the needle, a steroid-anaesthetic mix is injected into the piriformis muscle. After injecting the medication, the needle is removed, and the injection site is covered with a band-aid.

After the Procedure

Following the procedure, you may experience nausea, sweating, and/or dizziness. You may also develop weakness or numbness in the leg for a few hours. You may also notice a slight swelling, redness, bruising, and tenderness at the injection site, which may subside within a short period of time. Once the physician has confirmed that you are stable, you will be discharged to go home. Additional instructions and a follow-up appointment will be given to you at the time of your discharge.

University of Leeds British Orthopaedic Association Royal College of Surgeons Swansea University NHS Royal College of Surgeons of Edinburgh