[1] Chengdu Univ, Dept Orthoped, Affiliated Hosp, Chengdu, Sichuan, Peoples R China
[2] Sichuan Univ, West China Hosp, Chengdu, Sichuan, Peoples R China
[3] Chengdu Univ, Ctr Evidence Based Med, Affiliated Hosp, Chengdu, Sichuan, Peoples R China
[4] First Peoples Hosp Longquanyi Dist, Chengdu, Sichuan, Peoples R China
[5] Chengdu Univ, Dept Neurosurg, Affiliated Hosp, Chengdu, Sichuan, Peoples R China
[6] Thomas Jefferson Univ, Philadelphia, PA USA