1. Department of Orthopaedic Surgery, Kangdong Sacred Heart Hospital, Medical College of Hallym University, Seoul, Korea.
2. Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, Korea.
3. Spine and Scoliosis Service, Hospital for Special Surgery, New York, NY, USA.
4. Department of Orthopaedic Surgery, Hallym University Sacred Heart Hospital, Medical College of Hallym University, Anyang, Korea.