1. Department of Orthopedic Surgery, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
2. Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul, Korea.
3. Department of Orthopedic Surgery, Kangwon National University Hospital, Chuncheon, Korea.
4. Department of Orthopedic Surgery, Inje University Busan Paik Hospital, Busan, Korea.
5. Department of Orthopedic Surgery, Seoul National University Hospital, Seoul, Korea.