1. Department of Orthopaedic Surgery, Ewha Womans University Mokdong Hospital, Seoul, Korea.
2. Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
3. Biomedical Research Institute, Seoul National University Bundang Hospital, Seongnam, Korea.
4. Department of Orthopaedic Surgery, Myongji Hospital, Goyang, Korea.