1. Department of Operating Room, Affiliated Hongqi Hospital, Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China
2. Department of Bone Surgery, Affiliated Hongqi Hospital, Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China
3. Department of Anesthesiology, Affiliated Hongqi Hospital, Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China