1. Department of Orthopaedic Surgery, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China
2. Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
3. Department of Nephrology, Jilin FAW General Hospital, Changchun, Jilin 130011, P.R. China