1. Department of Orthopaedics, Beijing Friendship Hospital Pinggu Campus, Capital Medical University, Beijing 101200, P.R. China
2. Department of Orthopaedics, Changzhi Yunfeng Hospital, Changzhi, Shanxi 046000, P.R. China
3. Department of Orthopaedics, Heping Hospital Affiliated to Changzhi Medical College, Changzhi, Shanxi 046000, P.R. China