1. G-SPIRIT Study Group, Chiba, Japan
2. Department of Orthopedic Surgery, University of Tsukuba, Tsukuba, Japan
3. Clinical Research Center, Chiba University Hospital, Chiba, Japan
4. Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
5. Department of Orthopedic Surgery, Niigata University Graduate School of Medicine and Dental Sciences, Niigata, Japan
6. Department of Orthopedic Surgery, Kanazawa Medical University, Kanazawa, Japan
7. Department of Orthopedic Surgery, Dokkyo Medical University, Tochigi, Japan
8. Department of Orthopedic Surgery, Tsukuba Medical Center, Tsukuba, Japan
9. Department of Orthopedic Surgery, Funabashi Municipal Medical Center, Chiba, Japan
10. Department of Orthopedic Surgery, Chiba Rosai Hospital, Chiba, Japan
11. Department of Orthopedic Surgery, Kimitsu Chuo Hospital, Chiba, Japan
12. Department of Orthopedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
13. Department of Orthopedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
14. Division of Geriatric Musculoskeletal Health, Hamamatsu University School of Medicine, Hamamatsu, Japan
15. Department of Orthopedic Surgery, Kindai University, Nara Hospital, Nara, Japan
16. Department of Orthopedic Surgery, Hamamatsu Medical Center, Hamamatsu, Japan
17. Department of Orthopedic Surgery, Graduate School of Medicine, Mie University, Mie, Japan
18. Department of Orthopedic Surgery, Kobe Red Cross Hospital, Hyogo, Japan
19. Department of Orthopedic Surgery, JR Hiroshima Hospital, Hiroshima, Japan
20. Department of Orthopedic Surgery, Nihon University, Tokyo, Japan
21. Department of Orthopedic Surgery, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
22. Department of Orthopedic Surgery, Hiroshima City Asa Citizens Hospital, Hiroshima, Japan
23. Department of Orthopedic Surgery, Nagasaki Rosai Hospital, Nagasaki, Japan
24. Department of Orthopedic Surgery, Chubu Rosai Hospital, Aichi, Japan
25. Department of Orthopedic Surgery, Tohoku University School of Medicine, Miyagi, Japan
26. Department of Orthopedic Surgery, Gifu University School of Medicine, Gifu, Japan
27. Yamaguchi Rosai Hospital, Japan Organization of Occupational Health and Safety, Japan
28. Department of Spine and Spinal Cord Surgery, Yamaguchi Rosai Hospital, Japan
29. Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan