1. Department of Orthopaedics, The Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China
2. Department of Orthopaedics, Nankai Hospital, Tianjin 300100, P.R. China
3. Department of Orthopaedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China