1 Department of Orthopedic Surgery, The Second Affiliated Hospital, Harbin Medical University, Harbin, China.
2 Department of Neurology, The Second Affiliated Hospital, Harbin Medical University, Harbin, China.
3 Department of Orthopedic Surgery, The Second Affiliated Hospital, Harbin Medical University, Harbin, China. Electronic address: liuxqhyd@hotmail.com.