Fig. 3

CT and X-ray detection of screw position. A and (B) are axial views of CT scans after pedicle screw implantation. A was the left screw view that is automatically planned, and (B) was the right screw view that is manually planned. C (D) was the X-ray examination after pedicle screw implantation. C was the bottom view of the vertebrae. The left screw of the image was the manually planned trajectory, and the right screw was the automatically planned trajectory. D was the lateral view of the vertebrae. The upper screw in the image was the manually planned trajectory, and the lower screw was the automatically planned trajectory. Neither screw resulted in pedicle perforation. The automatically planned trajectory has a smaller abduction angle and a larger caudal inclination angle than the manually planned trajectory