1. Department of Rehabilitation Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea, Incheon 403-720, Korea.
2. Department of Orthopedic Surgery, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 137-701, Korea.
3. Department of Radiology, Incheon St. Mary's Hospital, The Catholic University of Korea, Incheon 403-720, Korea.