Stem design processing of custom-made femoral prosthesis

There is a transitional zone between the compact and the cancellous bone in the metaphyseal area of human femur. On CT scan images, this zone appears as a progressive change in the grey-levels, there is no clear interface between the cortex and the medullary canal. During a preliminary study made with six fresh human femurs, we observed that the grey levels of this transitional zone change according to the region of the femur : 1150 +/−60–100 in the medial metaphyseal area and 1300 +/− 60–150 in the lateral metaphyseal area.