The Application Of O-arm Navigation Assisted Technique In The Treatment Of Axis Fractures

Objective: Our purpose was to observe the clinical effect of o-arm navigation assisted technique in the treatment of axis fractures.Methods: From January 2016 to June 2018,77 patients with axis fracture treated with internal fixation were retrospectively analyzed.There were 47 males and 30 females,from 26-66 years,the average age was 45.87 ± 10.23 years.The patients were divided into four groups according to the operation and navigation: group A1(21 cases)underwent anterior cervical odontoid hollow tension screw reduction and internal fixation under o-arm navigation.Group A2(19 cases)underwent anterior cervical odontoid hollow tension screw reduction and internal fixation.Group B1(24 cases)underwent posterior pedicle screw reduction and internal fixation.Group B2(13 cases)was treated with pedicle screw reduction and internal fixation under o-arm navigation.JOA(Japanese Orthopaedic Association Scores)and NDI(Neck Disability Index)scores and operation time and amount of bleeding were used to evaluate the clinical effect of the patients.After the operation,1mm CT plain scan was used to evaluate the screw position.Neo grading was used to evaluate the position relationship between the screw and the bone cortex.Results: All patients successfully completed the operation,and no complications related to neurovascular injury were found during the operation.The JOA score of the four groups after operation and last follow-up was significantly higher than that before operation(P < 0.001),and the NDI score of the four groups after operation and last follow-up was significantly lower than that before operation(P < 0.001).There were significant statistical differences in the operation time(P = 0.007)and bleeding volume(P = 0.032)between group A1 and group A2,and in the operation time(P = 0.029)and bleeding volume(P = 0.037)between group B1 and group B2.The number of screws penetrating cortex in group A1 was 3(14.29%),and that in group A2 was 5(26.32%).There was no significant difference between the two groups(P = 0.165).There were 3 screws(3.49%)penetrating cortex in group B1 and 8 screws(18.18%)penetrating cortex in group B2.There was significant difference between the two groups(P = 0.011).Conclusions: In the treatment of axis fracture,whether it is anterior hollow tension screw internal fixation or posterior cervical pedicle screw internal fixation,the application of o-arm navigation assistance can significantly reduce the operation time and the amount of bleeding.In the process of posterior cervical pedicle screw placement,the application of o-arm navigation assistance technology can significantly improve the accuracy of pedicle screw implantation.