[1] Tokyo Med Univ, Dept Orthoped Surg, Shinjuku Ku, 6-7-1 Nishishinjuku, Tokyo 1600023, Japan
[2] Yamagata Univ, Fac Med, Dept Orthopaed Surg, 2-2-2 Iida Nishi, Yamagata 9909585, Japan
[3] Asahikawa Med Univ, Dept Orthopaed Surg, Midorigaoka Higashi 2-1-1-1, Asahikawa, Hokkaido 0788510, Japan