1. Department of Orthopedic Surgery, Anam Hospital, Korea University College of Medicine, Seoul, Korea.
2. Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
3. Department of Orthopedic Surgery, Seoul National University Hospital, Seoul, Korea.
4. Division of Mechanical and Biomedical Engineering, Ewha Womans University, Seoul, Korea.