Piriformis Injection
The piriformis is a small, pear-shaped muscle deep in the buttock that helps rotate the hip. In some patients, this muscle spasms or becomes inflamed — compressing the sciatic nerve as it passes near or through the muscle. The result is buttock pain and sciatica that mimics lumbar disc disease but originates in the soft tissue of the hip.
Piriformis Syndrome
Piriformis syndrome is an underdiagnosed cause of buttock and leg pain. It is estimated to cause 0.3–6% of cases of sciatica. Key features include:
- Deep buttock pain, often worse with sitting for prolonged periods
- Pain that radiates down the back of the thigh (similar to lumbar radiculopathy)
- Tenderness directly over the piriformis muscle on palpation
- Pain reproduced by hip internal rotation or stretching the piriformis muscle (FAIR test)
- MRI of the lumbar spine does not explain the sciatica — or there is disc pathology that doesn't match the symptoms
How a Piriformis Injection Helps
A piriformis injection delivers local anesthetic and steroid (or botulinum toxin for refractory cases) directly into the piriformis muscle under ultrasound or fluoroscopic guidance. The medication relaxes the muscle spasm, reduces inflammation, and decompresses the sciatic nerve.
Botulinum Toxin for Piriformis
For patients with recurrent piriformis syndrome or persistent muscle spasm, injection of botulinum toxin (Botox) into the piriformis muscle is an effective option. Botox relaxes the muscle for 3–6 months, providing prolonged relief and breaking the spasm cycle. Dr. Rubin will discuss whether toxin injection is appropriate for your case.
The Procedure
Under ultrasound guidance, the piriformis muscle is identified in the deep buttock. The needle is advanced to the muscle belly, and medication is injected. The procedure takes 15–20 minutes. You should notice improvement over the following days as muscle spasm resolves.
Contact Us
If you have buttock and leg pain with a normal lumbar MRI — or if sciatica has not improved with spinal injections — piriformis syndrome may be the answer. Call 516-492-3100 to discuss evaluation and treatment.