The technique to estimate three-dimensional position and posture to elucidate the mechanism of a joint in the knees is effective. As one of the technique, the Template Pattern Matching (TPM) method based on 3D bone data is known. A prepared library based on 3D bone data is necessary for the TPM method. Our final goal is to alter the library,3D bone data constructed from simple X-rays image. In this study, proposed method were adapted to tibia and fibula. Tibia and fibula bone model comprised of voxel are prepared. Tibia and fibula bone model are transformed based on X-rays image respectively. When bone models were transformed, there was often a gap between two models. The two models were connected by new voxels. As the result posture estimate precision was θx=1.50 ± 1.29 deg, θy=0.98 ± 0.95 deg. Posture estimate precision of the conventional method with CT data was θx=l.05 ± 1.05 deg, θy=0.25 ± 0.51 deg. θx was inferior than θy to conventional method. The result suggests that the sign of 0k cannot be determined from extracted outlines.
