Mizuguchi T
Arch Surg. 1976 Jun;111(6):719-22. doi: 10.1001/archsurg.1976.01360240099019.
Division of the pyriformis muscle at its tendinous insertion was employed for the treatment of sciatica in 14 patients with postlaminectomy syndrome and osteoarthritis of the spine. Of these patients, 85% had satisfactory results. It is logical that the pyriformis muscle can play an important role in the production of sciatic associated with intraspinal lesions. Tension on the sciatic nerve, which passes in close approximation to the pyriformis muscle anteriorly, can be relieved by division of the pyriformis muscle.