[1] Tokyo Med & Dent Univ, Dept Orthoped Surg, Bunkyo Ward, 1-5-45 Yushima, Tokyo 1138519, Japan
[2] Keio Univ, Sch Med, Dept Orthoped Surg, Shinjuku Ward, 35 Shinanomachi, Tokyo 1608582, Japan
[3] Natl Hosp Org Okayama Med Ctr, Dept Orthoped Surg, 1711-1 Tamasu, Okayama, Okayama 7011154, Japan
[4] Shiga Univ Med Sci, Dept Orthoped Surg, Tsukinowa Cho, Otsu, Shiga 5202192, Japan
[5] Toyama Univ, Fac Med, Dept Orthoped Surg, 2630 Sugitani, Toyama, Toyama 9300194, Japan
[6] Hirosaki Univ, Grad Sch Med, Dept Orthoped Surg, 53 Honcho, Hirosaki, Aomori 0368203, Japan
[7] Chiba Univ, Grad Sch Med, Dept Orthoped Surg, Chuo Ward, 1-8-1 Inohana, Chiba, Chiba 2600856, Japan
[8] Hamamatsu Univ, Sch Med, Dept Orthoped Surg, 1-20-1 Handayama, Hamamatsu, Shizuoka 4313125, Japan
[9] Jichi Med Univ, Dept Orthoped, 3311-1 Yakushiji, Shimotsuke, Tochigi 3290498, Japan
[10] Kagoshima Univ, Dept Orthoped Surg, Grad Sch Med & Dent Sci, 8-35-1 Sakuragaoka, Kagoshima, Kagoshima 8908520, Japan
[11] Univ Yamanashi, Dept Orthoped Surg, Chuo Ward, 1110 Shimokato, Yamanashi 4093898, Japan
[12] Tokai Univ, Sch Med, Dept Orthoped Surg, Surg Sci, 143 Shimokasuya, Isehara, Kanagawa 2591143, Japan
[13] Niigata Univ Med & Dent Gen Hosp, Dept Orthoped Surg, Chuo Ward, 1-754 Asahimachidori, Niigata, Niigata 9518520, Japan
[14] Tohoku Med & Pharmaceut Univ, Dept Orthopaed Surg, Miyagino Ku, 1-12-1 Fukumuro, Sendai, Miyagi 9838512, Japan
[15] Tohoku Univ, Sch Med, Dept Orthopaed Surg, Aoba Ward, 1-1 Seiryomachi, Sendai, Miyagi 9808574, Japan
[16] Nagoya Univ, Grad Sch Med, Dept Orthoped Surg, Showa Ward, 65 Tsurumaicho, Nagoya, Aichi 4660065, Japan
[17] Kyoto Univ, Grad Sch Med, Dept Orthoped Surg, Sakyo Ward, 54 Kawaharacho, Kyoto, Kyoto 6068507, Japan
[18] Univ Tsukuba, Fac Med, Dept Orthoped Surg, 2-1-1 Amakubo, Tsukuba, Ibaraki 3058576, Japan
[19] Japanese Multictr Res Org Ossificat Spinal Ligame, Otsu, Shiga, Japan