Piriformis Syndrome With Variant Sciatic Nerve Anatomy: A Case Report.

A 68-year-old male long distance runner presented with low back and left buttock pain, which eventually progressed to severe and debilitating pain, intermittently radiating to the posterior thigh and foot. A comprehensive workup ruled out possible spine or hip causes of his symptoms. A pelvic magnetic resonance imaging neurogram with complex oblique planes through the piriformis demonstrated variant anatomy of the left sciatic nerve consistent with the clinical diagnosis of piriformis syndrome. The patient ultimately underwent neurolysis with release of the sciatic nerve and partial resection of the piriformis muscle. After surgery the patient reported significant pain reduction and resumed running 3 months later. Piriformis syndrome is uncommon but should be considered in the differential diagnosis for buttock pain. Advanced imaging was essential to guide management.