Piriformis syndrome: a rational approach to management.

Although rarely recognized, the piriformis syndrome appears to be a common cause of buttock and leg pain as a result of injury to the piriformis muscle. Four cases representing a broad spectrum of presentations are described here. The major findings include buttock tenderness extending from the sacrum to the greater trochanter and piriformis tenderness on rectal or pelvic examination. Symptoms are aggravated by prolonged hip flexion, adduction, and internal rotation, in the absence of low back or hip findings. Minor findings may include leg length discrepancy, weak hip abductors, and pain on resisted hip abduction in the sitting position. Myofascial involvement of related muscles and lumbar facet syndromes may occur concurrently. The diagnosis is primarily clinical as no investigations have proved definitive. The role of MRI of the piriformis muscle is assessed and other investigative tools are discussed. A rational management schema is demonstrated: (1) underlying biomechanical factors and associated conditions should be corrected; (2) the patient is instructed in a home program of prolonged piriformis muscle stretching which may be augmented in physical therapy by preceding ultrasound or Fluori-Methane (dichlorodifluoromethane and trichloromonofluoromethane spray); (3) a trial of up to three steroid injections is attempted; and (4) if all these measures fail, consideration should be given to surgical sciatic nerve exploration and piriformis release.