1. Department of Orthopaedics, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan 450001, P.R. China
2. Department of Neurosurgery, First Affiliated Hospital of Harbin Medical University and Institute of Brain Science, Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
3. Department of Orthopaedics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, School of Clinical Medicine, Henan University, Zhengzhou, Henan 450001, P.R. China
4. Department of Orthopaedics, Henan University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, Henan 450001, P.R. China