[1] Chiba Univ, Grad Sch Med, Dept Orthopaed Surg, Chiba, Japan
[2] Chiba Aoba Municipal Hosp, Dept Orthopaed Surg, Chiba, Japan
[3] Teikyo Univ, Chiba Med Ctr, Dept Orthopaed Surg, Ichihara, Chiba, Japan
[4] Sanmu Med Ctr, Dept Orthopaed Surg, Sanmu, Japan
[5] Seirei Sakura Citizen Hosp, Dept Orthopaed Surg, Sakura, Chiba, Japan
[6] Kashiwa Municipal Hosp, Dept Orthopaed Surg, Kashiwa, Chiba, Japan
[7] Kimitsu Cent Hosp, Dept Orthopaed Surg, Kisarazu, Japan
[8] Chiba Rosai Hosp, Dept Orthopaed Surg, Ichihara, Chiba, Japan
[9] Asahi Gen Hosp, Dept Orthopaed Surg, Asahi, Japan
[10] Shimoshizu Hosp, Natl Hosp Org, Dept Orthopaed Surg, Yotsukaido, Japan
[11] JCHO Chiba Hosp, Dept Orthopaed Surg, Chiba, Japan
[12] Chiba Univ, Grad Sch Med, Dept Bioenvironm, Chiba, Japan
[13] Back Ctr Back Pain Spine Surg, Dept Orthopaed Surg, Melbourne, FL USA
[14] East Chiba Med Ctr, Dept Orthopaed Surg, Togane, Japan