Accuracy of Subaxial Cervical Pedicle Screw Placement Using Direct Visualization Versus Computed Tomography-Based...

Area of Science:

• Spine surgery
• Orthopedic surgery
• Neurosurgery
• Surgical navigation

Background:

• Subaxial cervical pedicle screws offer superior fixation but require high accuracy due to proximity of neurovascular structures.
• Computed tomography (CT)-based neuronavigation is increasingly used for spinal implants, but its accuracy for subaxial pedicle screws needs further evaluation.
• Direct visualization (DV) via hemilaminotomy is a traditional method for pedicle screw placement.

Purpose of the Study:

• To compare the accuracy of CT-based neuronavigation with direct visualization (DV) for subaxial cervical pedicle screw placement.
• To evaluate the safety and efficacy of these two techniques in a cadaveric model.

Main Methods:

• Retrospective analysis of operative data from six fresh-frozen cadaveric cervical spines (occiput to T2).
• Pedicle screws (C3-C7) were placed using either DV or neuronavigation, with pedicles <4 mm excluded.
• Screw accuracy was assessed via postoperative CT, using the Neo classification for breaches.

Main Results:

• No significant difference in overall accuracy was found between neuronavigation and DV techniques.
• The DV group had 12% breaches, while the neuronavigation group had 36% (P=0.10), with no high-grade breaches in the DV group.
• Higher average pedicle bone widths were associated with lower breach rates for both techniques.

Conclusions:

• Both neuronavigation and direct visualization achieve high accuracy for subaxial cervical pedicle screw placement in cadavers.
• The study suggests that both methods are viable options for achieving accurate screw placement in this region.
• Further research may be warranted to explore factors influencing breach rates with neuronavigation.