1. Department of Orthopedics, The Fourth Hospital Affiliated to Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
2. Community Center, Harbin First Hospital, Harbin, Heilongjiang 150001, P.R. China
3. Department of Orthopedics, The Second Hospital Affiliated to Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China