1. Medical School, Kunming University of Science and Technology, Kunming, Yunnan 650500, P.R. China
2. Department of Orthopedics, The First People's Hospital of Yunnan Province, Kunming, Yunnan 650034, P.R. China
3. Department of Orthopedics, Kunming 311 Hospital, Kunming, Yunnan 650100, P.R. China