What Is a Piriformis Injection Used to Treat?

Sometimes the piriformis muscle can become irritated, swollen, and tight due to injury and twitching. It can then press upon the nearby sciatic nerve.

The pyriformis syndrome is a painful neuromuscular condition that develops due to abnormal tightening of the pyriformis muscle situated near the hip joint. The tight muscle irritates or compresses the sciatic nerve in its vicinity and causes pain, tingling, or numbness along the buttock down the back of the leg and into the thigh.

• The piriformis muscle is a flat, band-like muscle located in the buttock near the top of the hip joint. This muscle stabilizes the hip joint and lifts and rotates the thigh away from the body. This enables us to walk, shift our weight from one foot to another, and maintain balance. It is helpful in almost every motion of the hips and legs.
• The sciatic nerve is a thick and long nerve in the body. It passes alongside or through the piriformis muscle, down the back of the leg, and eventually branches off into smaller nerves that end in the feet. Nerve compression can be caused by the constant pressure of the tightened or swollen piriformis muscle.

Sometimes the piriformis muscle can become irritated, swollen and tight due to injury and twitching. It can then press upon the nearby sciatic nerve. This can cause hip and buttock pain that can extend down the leg. A piriformis injection is used to treat pain in the buttock area. During the procedure, a steroid (medication used to reduce swelling) is injected into the piriformis muscle. This reduces swelling and this decreases the pressure on the nerves and reduces the pain. This may allow the muscle to heal, especially with physiotherapy.

• The patient will lie on a table. The area to be treated will be cleaned and covered with a special sheet. This is done to maintain aseptic precautions.
• The doctor will use a special X-ray to view the area and then numb the area with a local anesthetic.
• The doctor may inject contrast (to help highlight the area on X-rays) and then they will inject a drug (steroid + numbing agent combination or botulinum toxin) into the piriformis muscle.
• The procedure usually takes about 10 minutes, and the patient remains awake throughout the procedure.

Complications from piriformis procedures are rare. Possible side effects include:

• Pain, bruising or bleeding at the injection site
• Infection
• Nerve injury
• Increased pain in normal painful areas
• Allergic reaction to the medications used or contrast used.

• The patient may feel sore at the injection site for a few days after the procedure. An ice pack is applied on the injection site for 15-20 minutes at least four times a day for several days. Before using the ice, it is wrapped in a towel, so it does not touch the skin.
• The patient may continue to have the usual pain until the steroid starts to work. This can take up to two weeks. Usually, the doctor recommends over-the-counter pain medications or muscle relaxants.
• Physiotherapy is recommended after the injection to further reduce pain in the muscle.
• Pain relief from a piriformis injection usually last for several months, but this may differ from patient to patient. 
• The patient may have three to four steroid injections a year. If a patient gets no relief from the steroid, doctors will continue to look for the source of the pain and explore other treatment options.