1. Department of Orthopaedic Surgery, The Second Affiliated Hospital of Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
2. Department of Orthopaedics, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
3. Department of Orthopaedics, The Third Affiliated Hospital of Qiqihar Medical University, Qiqihar, Heilongjiang 161000, P.R. China
4. Department of Orthopaedics (Ⅱ), The First Hospital of Qiqihar City, Qiqihar, Heilongjiang 161005, P.R. China