| The Ilizarov method is used to correct various bone deformities by using an adjustable mechanical frame to simultaneously align and distract bone fragments after the bone has been cut. We have adapted the idea of fixation-based surgery, which requires computer-assisted planning and guidance, to the Ilizarov method as used with the Taylor spatial frame.; This work incorporates the kinematics of the Taylor frame, which is a type of Stewart platform, into the planning and application phases of surgery. Using 3D models derived from a computed tomography scan of the deformity, a surgeon can use a preoperative software system to plan the correction and determine the placement of the frame. We have developed techniques and software for inverting the correction, finding the kinematics of the Taylor frame so that the frame fits onto the deformed bone, and planning the correction schedule that will gradually remodel the deformity into the desired correction.; We used a computer guidance system to accurately attach the frame to a model of a deformed bone. In a laboratory study that compared the accuracy and repeatability of the new method, we found that the computer-assisted technique was more repeatable than the traditional technique and had a smaller range of errors. The study also showed that the computer-assisted technique required almost no intraoperative X-ray exposure and that complex corrections could easily be achieved. |
