[1] Peking Univ, Hosp 3, Dept Orthopaed, 49 North Garden Rd, Beijing 100191, Peoples R China
[2] Capital Med Univ, Beijing Shijitan Hosp, Emergency Dept, 10 TieYi Rd, Beijing 100038, Peoples R China
[3] Peking Univ, Hosp 3, Res Ctr Clin Epidemiol, 49 North Garden Rd, Beijing 100191, Peoples R China