Affiliation: | (1) Department of Orthopedic Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan;(2) Department of Advanced Therapy for Spine and Spinal Cord Disorders, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan |