What is Piriformis Syndrome?
Piriformis syndrome is a painful condition that develops due to irritation or compression of the sciatic nerve near the piriformis muscle. The piriformis muscle connects the lowermost vertebrae with the upper part of the leg after traveling the “sciatic notch,” the opening in the pelvic bone that allows the sciatic nerve to travel into the leg.
What Are The Symptoms?
Piriformis syndrome usually starts with pain, tingling, or numbness in the buttocks. Pain can be severe and extend down the length of the sciatic nerve (called sciatica). The pain is due to the piriformis muscle compressing the sciatic nerve, such as while sitting on a car seat or running. Pain may also be triggered while climbing stairs, applying firm pressure directly over the piriformis muscle, or sitting for long periods of time.
What Are The Causes?
Recognized causes of piriformis syndrome include:
- Abnormal development or location of the piriformis muscle or sciatic nerve
- Abnormal spine alignment (such as scoliosis)
- Leg-length discrepancy (when the legs are of different lengths)
- Prolonged sitting, especially if carrying a thick wallet in a pocket directly behind the piriformis muscle
- Prior hip surgery
- Unusually vigorous exercise
- Foot problems, including Morton’s neuroma.
In many cases the cause cannot be identified.
What Are The Treatments?
While medications, such as pain relievers, muscle relaxants, and anti-inflammatory drugs may be recommended, the mainstay of treatment for piriformis syndrome is physical therapy, exercise, and stretching. Specific treatments may include:
- Adjustments in gait
- Improved mobility of sacroiliac joints
- Stretching to relieve tight piriformis muscles and those surrounding the hip
- Strengthening of the hip abductors (muscles that move the hips outward from the body)
- Application of heat
If these measures are not effective, more invasive treatment can be considered such as:
- Injections of a local anesthetic (similar to Novocain), botulinum toxin, and/or a corticosteroid agent — these injections are generally guided by ultrasound, x-ray, or electromyogram (which detects muscle and nerve activity) to make sure the needle is in the right place.
- Surgery — Although an option of last resort, removing a portion of the piriformis muscle or its tendon has been reported to provide relief in refractory cases.