Effect of registration method on clinical accuracy of image guided pedicle screw surgery

This study was performed to test the effect of surface fitting on the clinical accuracy of image guided spine surgery. In all, ten pedicles in the spine of a 95 year old human cadaver were registered using a combination of paired point registration and surface fitting. The apparent position of the pedicle probe was recorded in surgery, and a proxy pedicle screw inserted. Postoperative analysis compared the apparent positions of the pedicle probe using registrations calculated using just the paired points and then the paired point/surface fitting combination with the position of the proxy on a postoperative scan. No statisticlly significant difference was found between the two registration methods, but we caution that these results are still preliminary.