Use of O-arm navigation in percutaneous pedicle screw fixation for thoracolumbar fractures in patients with ankylosing spinal disorders: reducing intraoperative radiation exposure-a retrospective cohort study.

BACKGROUND

Ankylosing spinal disorders (ASD), including ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis, markedly increase spinal rigidity and susceptibility to highly unstable thoracolumbar fractures. These injuries often require long-segment posterior fixation, which conventionally relies on C-arm fluoroscopy and exposes operating staff to cumulative radiation. O-arm-based intraoperative navigation may reduce radiation exposure while maintaining pedicle screw accuracy; however, evidence in ASD-related fractures remains limited. The aim of this study was to compare intraoperative radiation exposure and pedicle screw placement accuracy between O-arm navigation and C-arm fluoroscopy during percutaneous pedicle screw (PPS) fixation in patients with ASD.

METHODS

This single-center retrospective cohort study included 24 consecutive adults with ASD who sustained thoracolumbar fractures between 2015 and 2024. Patients underwent PPS fixation using either O-arm navigation (n=11) or C-arm fluoroscopy (n=13). Demographic characteristics, operative variables, radiation time, and screw accuracy-assessed using the Heary and Gertzbein classification systems-were compared. Fluoroscopy time served as a surrogate marker of radiation exposure because actual dosimeter data were unavailable.

RESULTS

Radiation exposure time was significantly shorter in the O-arm group than in the C-arm group (2.5±1.8 vs. 16.9±11.4 min; P<0.001). Pedicle screw accuracy was comparable (acceptable accuracy: 88.3% vs. 87.3%, respectively; P>0.99). Operative time, blood loss, and complication rates did not differ significantly between groups. Time from injury to surgery was longer in the O-arm group, reflecting workflow constraints and the use of C-arm fluoroscopy for urgent after-hours cases.

CONCLUSIONS

O-arm navigation markedly reduces intraoperative radiation exposure without compromising pedicle screw accuracy in ASD-related thoracolumbar fractures. Given the substantial occupational radiation risks faced by spine surgeons, O-arm navigation represents a valuable tool for improving radiation safety while maintaining surgical precision. Larger prospective studies are warranted to validate these findings.