1 Graduate School, Inner Mongolia Medical University, Huhehot North Street, Inner Mongolia, 010050, China.
2 Department of Neurosurgery, Inner Mongolia Autonomous Region People's Hospital, Zhaowuda Road, Inner Mongolia, 010010, China.
3 Inner Mongolia Medical University, Department of Orthopedics, Affiliated Hospital of Inner Mongolia Medical University, Huhehot North Street, Inner Mongolia, 010050, China.
4 Department of Neurosurgery, Inner Mongolia Autonomous Region People's Hospital, Zhaowuda Road, Inner Mongolia, 010010, China. Electronic address: wrl0666@hotmail.com.