1. Department of Spine Surgery, Hospital for Special Surgery, New York, NY
2. University of Tokyo Spine Group (UTSG), Tokyo, Japan
3. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
4. Department of Spine and Orthopedic Surgery, Japanese Red Cross Medical Center, Tokyo, Japan
5. Department of Orthopedic Surgery, Kanto Rosai Hospital, Kanagawa, Japan
6. Department of Orthopedic Surgery, Yokohama Rosai Hospital, Kanagawa, Japan
7. Spine center, Toranomon Hospital, Tokyo, Japan
8. Department of Spinal Surgery, Japan Community Health-care Organization Tokyo Shinjuku Medical Center, Tokyo, Japan
9. Department of Orthopedic Surgery, Japanese Red Cross Musashino Hospital, Tokyo, Japan
10. Department of Orthopedic Surgery, Saitama Red Cross Hospital, Saitama, Japan
11. Department of Orthopedic Surgery, NTT Medical Center Tokyo, Tokyo, Japan
12. Department of Orthopedic Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
13. Department of Orthopedic Surgery, Tokyo Metropolitan Tama Medical Center, Tokyo, Japan