Minimal Access Navigated Orthopaedic Surgery (MAcNavOS)

This project brings together recent advances in image registration and shape modelling in an innovation that could revolutionise a very common orthopaedic procedure: total hip replacement. This should bring major improvements to the accuracy and invasiveness of the procedure. Through our industrial collaborator we have access to substantial numbers of CT scans of patients. For the first time we are proposing generation of a computer model of the shapes of the bones of the hip joint, and their variation across the population (a statistical shape model), with sufficient statistical power to fully exploit the potential of these models in a real application: generation of surgical plans and guidance of a surgical procedure. We will undertake fundamental work in statistical shape model definition, carefully analyse how many datasets are required to specify the model with sufficient accuracy for our application and define whether or not specific shape models for sub populations, or particular diseases are required. We will devise new methods for instantiating (reconstructing) these models to guide a particular patient's operation using readily available and low-cost X-ray and ultrasound imaging. Our new methodology will be tested on cadaver data and as part of the associated DTI Technology Programme project will be integrated with commercial electromagnetic tracking technologies into a commercial image guidance system for total hip replacement and evaluated. With this system a surgeon will be able to take the pre-operative X-ray image that is always taken prior to surgery and, with a few sweeps of an ultrasound probe over the patient in the operating room, generate a surgical plan to guide him/her in the placement of the new prosthesis. This will be done without expensive radiation delivering CT scanning and the invasive exposure of bone required in current methods. It will greatly facilitate the introduction of new minimally invasive procedures to this application.