1 Department of Orthopedic Surgery, China Medical University Hospital, No. 2, Yuh-Der Rd, Taichung, Taiwan 404, Republic of China; School of Medicine, China Medical University, No. 91, Hsueh-Shuh Rd, Taichung, Taiwan 40402, Republic of China.
2 Department of Radiology, China Medical University Hospital, No. 2, Yuh-Der Rd, Taichung, Taiwan 404, Republic of China.