Geometric model of reduction in basilar invagination with atlantoaxial dislocation and its clinical application

To establish a geometric model of the atlantoaxial dislocation and basilar invagination reduction,and examine its value for clinical application. A retrospective analysis of 35 patients with atlantoaxial dislocation and basilar invagination admitted to the Department of Neurosurgery,First Affiliated Hospital of Chongqing Medical University from May 2018 to May 2020 was conducted.There were 5 males and 30 females,aged (48±15) years(range: 19 to 69 years). The geometric model of the atlantoaxial reduction was established based on the mid-sagittal section of the cervical spine. The relevant data were calculated according to the geometric model before operation,and the fusion cage of the corresponding height was placed into C facet joint of patient for quantitative reduction. The theoretical reset value, actual reset value, postoperative symptoms and complications were collected. The paired -test was used to compare the difference between theoretical and actual reset value to verify the reliability of the geometr