Risser cast /ris″ər/ [Joseph C. Risser, American surgeon, 1892–1942] , an orthopedic device for encasing the entire trunk of the body, extending over the cervical area to the chin. In rare cases it extends over the hips to the knees. The Risser cast is made of plaster of paris or fiberglass and is used to immobilize the trunk in the treatment of scoliosis and in the preoperative or postoperative correction or maintenance of correction of scoliosis. Compare body jacket, turnbuckle cast.