1 Department of Orthopedic Surgery, Toho University Graduate School of Medicine, 5-21-16 Omorinishi, Ota-ku, Tokyo, 143-8540, Japan.
2 Department of Orthopedic Surgery (Ohashi), School of Medicine, Toho University, 2-22-36 Ohashi, Meguro-ku, Tokyo, 153-8515, Japan.
3 Department of Orthopedic Surgery, Juntendo Shizuoka Hospital, Nagaoka 1129, Izunokuni, Shizuoka, 410-2295, Japan.
4 Department of Medicine for Orthopedic and Motor Organ, Juntendo University Graduate School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
5 Department of Advanced Machinery Engineering, School of Engineering, Tokyo Denki University, 5 Senju Asahi-cho, Adachi-ku, Tokyo, 120-8551, Japan.
6 Department of Orthopedic Surgery (Ohashi), School of Medicine, Toho University, 2-22-36 Ohashi, Meguro-ku, Tokyo, 153-8515, Japan. hiroyasu.ikegami@med.toho-u.ac.jp.