summary Piriformis syndrome is a condition characterized by sciatic symptoms (leg pain) due to extrapelvic sciatic nerve compression at the hip. Diagnosis is made clinically with pain in the posterior gluteal region and migrating down the back of the leg which is made worse with flexion, adduction, and internal rotation of hip. Treatment is rest, NSAIDs, and physical therapy focused on stretching the piriformis muscle and short external rotators. Etiology Pathophysiology pathoanatomy sciatic nerve entrapment occurs anterior to piriformis muscle or posterior to obturator internus/gemelli complex at level of ischial tuberosity anatomic anomalies may contribute to compression including bipartite piriformis variations of sciatic nerve path tumors aneurysm of inferior gluteal artery Associated conditions femoroacetabular impingement decreased internal rotation may contribute to contractures of short external rotators and compression on sciatic nerve Anatomy Sciatic nerve exits inferior to piriformis superior to superior gemellus Muscles external rotators of the thigh include (superior to inferior) piriformis superior gemellus obturator internus inferior gemellus obturator externus quadratus femoris Presentation Symptoms pain in the posterior gluteal region and migrating down the back of the leg pain may be burning or aching in nature similar to sciatica symptoms Physical exam FAIR test Flexion, Adduction, and Internal Rotation of hip can reproduce symptoms maneuver places piriformis muscle on tension Imaging Radiographs unremarkable MRI usually unremarkable lumbar MRI helpful to rule out spine as cause of compression of sciatic nerve Electrodiagnostic studies can document functional impairment of sciatic nerve Treatment Nonoperative rest, NSAIDS, muscle relaxants, PT, steroid injections indications first line of treatment technique focused on stretching the piriformis muscle and short external rotators corticosteroid injection directed near the piriformis muscles Operative piriformis muscle release and external sciatic neurolysis indications only indicated in refractory cases after failed conservative measures