1. Department of Orthopaedic Surgery, Nippon Medical School, Tamanagayama Hospital, 1-7-1, Nagayama, Tama-shi, Tokyo, 206-8512, Japan
2. Department of Orthopaedic Surgery, Nippon Medical School, Main Hospital, 1-1-5, Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan