Abstract: Objective To analyze the data of atlantoaxial pedicle screw channel measured by spiral CT, so as to guide the clinical reasonable placement of pedicle screws. Methods From the database of the image center of our hospital, 100 patients’ cervical CT data from May 2017 to may 2019 were retrieved and used to measure the anatomical indicators of atlantoaxial pedicle screw channel by MPR. For patients who needed surgery, the measurement data were used to reasonably insert the pedicle screws. Comparisons were made in the indicators of atlas and axis between males and females, operation time, the amount of bleeding during operation, the success rate of one-time screw placement, and the length of hospital stay. Results There were no significant differences between males and females in the atlas L₁, L₂, L₃, L₄, L₅, α angle, and β angle （P>0.05）, and the axis L₁, L₂, L₃, L₄, γ angle, and θ angle （P>0.05） .The average operation time of the 100 patients was （110.98±10.07） min, the average bleeding volume was （162.37±11.28） mL, the average hospitalization time was （14.79±1.27） d, and the success rate of one-time screw placement was 98.39%. Conclusion Applying spiral CT to obtain accurate anatomical data of atlantoaxial pedicle screw channel, in combination with multi-plane reconstruction technology to optimize screw channel selection plane, can improve the success rate of one-time screw placement.

Key words: Measurement, Screw channel, Computed tomography, Pedicle screw, Atlantoaxial