Video tracking of vertebral displacement for intraoperative evaluation of scoliosis correction

Scoliosis disturbs normal spinal alignment in various planes. When surgery is performed, visual appreciation of correction under progress does not give any adequate three-dimensional information. To allow for an adequation between surgical correction and three-dimensional deformity, it is necessary to know the modification of vertebral positions. Based on the principle of three dimensional telemetry from a single perspective view, which is entirely original, we present a method of intra-operative video tracking of vertebral displacements. At the present time, principle and methods have been validated on vertebral specimens using an of-the-shelf camera connected to a PC-AT 486 computer. Practical use as a surgical tool in the operating room is under development, the main limitation being the precision obtained in the knowledge of the geometry of the vertebrae to be tracked.