1. Chung-Ang University H.C.S. Hyundae General Hospital, Namyangju, Korea.
2. Department of Orthopaedic Surgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
3. Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.