1. Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY
2. University of Tokyo Spine Group (UTSG)
3. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Bunkyo-Ku, Tokyo
4. Department of Orthopaedic Surgery, Takashimadaira Chuo General Hospital, Takashimadaira, Itabashi
5. Department of Spine and Orthopedic Surgery, Japanese Red Cross Medical Center, Shibuya-Ku, Tokyo
6. Department of Orthopedic Surgery, Kanto Rosai Hospital, Nakahara-Ku, Kawasaki
7. Department of Orthopedic Surgery, Yokohama Rosai Hospital, Yokohama City, Kanagawa
8. Department of Spinal Surgery, Japan Community Health-care Organization Tokyo Shinjuku Medical Center, Shinjuku-Ku, Tokyo
9. Spine center, Toranomon Hospital, Minato-Ku, Tokyo
10. Department of Orthopedic Surgery, Japanese Red Cross Musashino Hospital, Musashino City, Tokyo
11. Department of Orthopedic Surgery, Saitama Red Cross Hospital, Saitama City, Saitama
12. Department of Orthopaedic Surgery, Inanami Spine and Joint Hospital, Shinagawa-ku, Tokyo
13. Department of Orthopaedic, Jichi Medical University, Shimotsuke, Tochigi, Japan