[1] Keio Univ, Sch Med, Dept Orthopaed Surg, Shinjuku Ku, 35 Shinanomachi, Tokyo 1608582, Japan
[2] Fujita Hlth Univ, Dept Orthopaed Surg, 1-98 Dengakugakubo, Toyoake, Aichi 4701192, Japan
[3] Keio Univ, Sch Med, Dept Diagnost Radiol, Shinjuku Ku, 35 Shinanomachi, Tokyo 1608582, Japan
[4] Toho Univ, Fac Med, Dept Social Med, Dept Environm & Occupat Hlth, 5-21-16 Ohmorinishi, Tokyo 1438540, Japan
[5] Isehara Kyodo Hosp, Dept Orthopaed Surg, 345 Tanaka, Isehara, Kanagawa 2591187, Japan
[6] Tokai Univ, Sch Med, Surg Sci, Dept Orthopaed Surg, 143 Shimokasuya, Isehara, Kanagawa 2591193, Japan
[7] Sanokousei Gen Hosp, Spine Ctr, Dept Orthopaed Surg, 1728 Horigome, Sano, Tochigi 3278511, Japan