CT images processing as one of the stages in knee joint alloarthroplasty

The main aim of this research is checking the accuracy and ascertaining the quality of a new method of the knee joint alloarthroplasty. The first step of the proposed method is finding the mechanical axis of the lower limb on the basis of fuzzy connectedness concept. In the second step, a radiologist or an orthopedist has to qualify the pathologically modified bone structures within the knee joint. In this way the section planes within femur and tibia are determined. The third step is based on the 3D model of femur and tibia. In order to extract bone structures from the CT slices of the knee joint, the Fuzzy C-Means algorithm with median modification has been implemented. In the next step the impresses of both bones are made and their 3D models are built. On the basis of the CT slices of the knee joint the doctor has to indicate two healthy parts of both bones. Together with the created 3D models they permit building a patient-specific band with two gully holes which are dedicated to serve as location marks for the Kirschner nail.