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Updated: May 11, 2026

A Spine Robotic-Assisted Navigation System for Pedicle Screw Placement
Published on: May 11, 2020
Comparison of freehand versus navigation-assisted C2 pedicle screw fixation: A retrospective accuracy and safety
Ilker Kiraz1, Burak Eral2, Buse Sarigul3
1Department of Neurosurgery, Faculty of Medicine, Pamukkale University, Denizli, Turkey.
Background:
C2 transpedicular screw fixation is a biomechanically robust technique for upper cervical stabilization yet remains technically demanding due to anatomical complexity.
Study Design:
This was a retrospective nonrandomized comparative study.
Objective:
Using validated radiological classification systems, this study aims to compare the accuracy, malposition rates, and complication profiles of C2 screw placement using both freehand and navigation-assisted approaches.
Materials And Methods:
Between 2010 and 2019, 100 patients who underwent C2 pedicle screw fixation at two different institutions were included in a retrospective study. There were 197 screws in all: 45 using a freehand technique (FH group) and 152 using a navigation-assisted approach (NA group). Using both Gertzbein-Robbins classification (GRC) and screw zone classification (SZC), screw accuracy was evaluated. Between the groups, demographic, clinical, and surgical data were statistically compared.
Results:
The mean age was significantly higher in the NA group (75.37 ± 16.15) than in the FH group (46.29 ± 22.14) (P < 0.001). SZC analysis showed zone 2 placement in 86.7% (FH) and 87.5% (NA) of screws (P = 0.028). GRC analysis revealed that 13.3% of FH screws and 12.5% of NA screws were malpositioned (Grades B-D). No neurovascular complications or screw-related revisions occurred in either group. However, five patients in the NA group required revision due to wound dehiscence.
Conclusions:
In C2 pedicle screw placement, both freehand and navigation-assisted techniques showed great accuracy and low complication rates. Although navigation systems provide improved accuracy in the hands of experienced users, the freehand technique remains a safe and efficient alternative. Surgeon experience, patient anatomy, and institutional resources should all help guide the choice of technique.
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