Arthroscopic treatment of piriformis syndrome by perineural cyst on the sciatic nerve: a case report.

This is a case report of an arthroscopic treatment performed on a patient with piriformis syndrome due to perineural cyst on piriformis muscle and sciatic nerve. Confirmation, incision, and drainage of benign cystic lesion on the sciatic nerve below the piriformis muscle were performed following the release of the piriformis tendon through the posterior and posteroinferior arthroscopic portal. Recurrence of the symptoms has not been observed since postoperative period of 20 months. Nor did the MRI taken after the procedure reveal any such recurrence.