1. Department of Orthopedic Surgery, Chungnam National University School of Medicine, Daejeon, Korea
2. Department of Orthopedic Surgery, Konyang University Hospital, Daejeon, Korea
3. Department of Orthopedic Surgery, Yeonsei Barochuk Hospital, Seoul, Korea
4. Department of Orthopedic Surgery, Keck School of Medicine of University of Southern California, CA, USA