Precision Image Planning and Measurement for C2 Pedicle Screw Placement Using 3D Slicer

Objective: This study aimed to utilize 3D Slicer software for three-dimensional imaging analysis and measurement of the axis (C2) pedicle to provide precise anatomical parameters for pedicle screw placement. Methods: Cervical CT data from 100 healthy adults aged 20 to 30 years, collected between January 2024 and June 2025, were used. 3D models were reconstructed using 3D Slicer, and measurements included the pedicle isthmus diameter, simulated screw trajectory length, medial inclination angle, cephalad inclination angle, and entry point coordinates. Results: The C2 pedicle isthmus diameter was (6.48 ± 1.85) mm, the simulated trajectory length was (24.58 ± 2.59) mm, the medial inclination angle was (23.42 ± 5.40)°, and the cephalad inclination angle was (37.43 ± 6.76)°. The entry point was (3.40 ± 1.02) mm from the laminar plane and (18.52 ± 1.57) mm from the midsagittal plane. No significant differences were found between left and right sides for any parameters (P > 0.05). However, males exhibited significantly larger isthmus diameters, trajectory lengths, and entry point distances from the midline compared to females (P < 0.05). Conclusion: Imaging planning with 3D Slicer can provide individualized, reproducible anatomical references, aiding in improving the safety and accuracy of C2 pedicle screw placement, particularly in patients with significant anatomical variations.