Abstract
ACL reconstruction is performed to recover the injured knee which often happens in sports activity such as football, and basketball. The ACL reconstruction makes two bone tunnels in the femur and tibia. Then, the harvested graft passes the bone tunnels so that the femur and tibia are connected. However, the bone tunnel is enlarged with time. The bone tunnel enlargement can cause instability of the knee. To examine relationship of the bone tunnel enlargement and clinical results, the bone tunnel should be evaluated quantitatively and three-dimensionally. In MDCT image, intensity distribution around the bone tunnel is unclear so that it is difficult to extract the volume of the bone tunnel with error by simple thresholding method or region growing method. Then, manual extraction needs a lot of time and energy for examiners, because the data size of MDCT image is huge. Therefore, this study proposes an automated extraction method of the bone tunnel from MDCT image by using active contour model. In the experiment, the proposed method and the manual extraction method were applied for six patients who were performed ACL reconstruction. As a result, the proposed method could extract the bone tunnel with the error of 3.5 % in comparing to the manual extraction method.
