A novel technique for C1-C2 posterior screw insertion using patient-specific guides created by CT-based 3D printing

Area of Science:

• Neurosurgery
• Orthopedic Surgery
• Spinal Fusion Techniques

Background:

• Atlantoaxial instability necessitates rigid C1-C2 fixation.
• C1 lateral mass screw (C1 LMS)-C2 pedicle screw fixation offers high fusion rates but carries risks.
• C1 screw placement remains challenging, even with navigation aids.

Purpose of the Study:

• To evaluate the clinical outcomes of C1-C2 posterior fixation using patient-specific screw guide templates (PSGT).
• To compare the accuracy and safety of PSGT with preoperative CT-based navigation for C1 screw insertion.

Main Methods:

• Retrospective study of six patients undergoing posterior cervical spinal fusion with PSGT.
• Comparison with a navigation group (n=15) based on operative time, blood loss, radiation dose, cost, and screw accuracy (Neo's classification).

Main Results:

• PSGT demonstrated comparable operative time, blood loss, and radiation dose to navigation.
• PSGT achieved 100% accuracy in C1 LMS placement, significantly higher than the navigation group (83.3%).
• Minimal deviation at the entry point and small angular differences from the preoperative plan were observed with PSGT.

Conclusions:

• Patient-specific screw guide templates (PSGT) are effective for C1-C2 posterior fixation.
• PSGT significantly improves the accuracy of C1 lateral mass screw insertion.
• PSGT offers a promising alternative for safer and more accurate C1-C2 fixation in spinal surgery.