1. Division of Orthopaedic Surgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Orthopaedic Surgery, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
3. Department of Diagnostic Radiology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
4. Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.