1. Department of Orthopedic Surgery, Chiba University, Inohana Chuo-ku, Chiba, Japan
2. Department of Orthopaedic Surgery, Shimoshizu Hospital, Yotsukaido, Japan
3. Department of Orthopaedic Surgery, East Chiba Medical Center, Togane, Japan
4. Department of Orthopaedic Surgery, Teikyo University Mizonokuchi Hospital, Kawasaki, Japan
5. Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan
6. Department of Orthopaedic Surgery, The Back Pain Spine Surgery Melbourne Florida, Melbourne, Florida, United States