1. Department of Orthopaedic Surgery, St. Marianna University School of Medicine, Kawasaki, Japan
2. Spine Center, St. Marianna University Hospital, Kawasaki, Japan
3. Department of Orthopedic Surgery, Seirei Sakura Citizen Hospital, Sakura, Japan
4. Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan
5. Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan