1. Department of Orthopaedic Surgery, Hyundae General Hospital, Chung-Ang University, Namyangju, Korea.
2. Department of Orthopaedic Surgery, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
3. Department of Orthopaedic Surgery, Chung-Ang University Hospital, Seoul, Korea.