Volume modeling for orthopedic surgery

Abstract

We present an overview of a volume modeling system developed to custom design knee joint prostheses for total knee replacement surgery. This system uses cross-sectional Computed Tomography (CT) scans to produce a three dimensional contour model of the patient's knee joint. The system uses a dominant points based automatic contour extraction technique. It then allows reconstruction of the 3D surface from the stack of contours for interactive visualization. It also allows the medical professional to interactively edit the contour model against the background CT image. This system interfaces to a CAD system where the prosthesis is designed to fit the patient's specification obtained from the geometric model. A numerically controlled (NC) milling machine is then used to manufacture the knee joint replacement prosthesis. The system is currently undergoing clinical trials and the initial results are very promising. We conclude by describing our current work and future directions.