Using the shape recovery of nitinol in the Harrington rod treatment of scoliosis

Abstract

Nitinol, a metal alloy which is able to remember (and return to with slight heating) the shape it had before it was deformed, is demonstrated to be useful in the Harrington rod treatment of scoliosis. A bent nitinol rod can return to its original straight length, applying both axial and lateral forces to the spine during the operation or postoperatively by means of external heating. A research program using simulated spinal forces in a test fixture and implantation in a cadaver was undertaken to show the feasibility of modifying the existing procedure.