# Accuracy and safety of navigated pedicle screw insertion in cervical spine fractures

## TL;DR

This study shows that using navigation systems to insert pedicle screws in cervical spine fractures is accurate and has a low risk of serious complications.

## Contribution

The study provides population-based evidence on the accuracy and safety of navigated pedicle screw insertion for cervical spine fractures.

## Key findings

- 90% of navigated pedicle screws had less than 2 mm of breach, indicating high accuracy.
- Surgery-related complications occurred in 6.7% of patients, with a 0.8% per-screw complication risk.
- No new-onset spinal cord injuries or screw pull-outs were observed.

## Abstract

Pedicle screw (PS) fixation provides superior biomechanical stability compared with lateral mass screw (LMS) fixation for unstable cervical spine fractures (CS-Fx) but is associated with a risk of neurovascular injury. Navigation systems have improved PS placement accuracy, although most published studies remain small and underpowered to assess rare complications.

To evaluate the accuracy and safety of navigation-assisted PS fixation for unstable CS-Fx in a population-based cohort.

All consecutive patients with unstable CS-Fx who underwent navigated PS fixation at Oslo University Hospital between 2015 and 2024 were included in this study. Navigation was performed using preoperative CT-based surface matching. Postoperative CT scans obtained within 24 h were used to grade PS accuracy as Grade 1 (<2 mm breach), Grade 2 (2–4 mm), or Grade 3 (>4 mm). Complications related to PS placement were recorded.

A total of 345 patients (median age 68 years; 75% males) underwent fixation with 1,347 navigated PSs. Screw accuracy was Grade 1 in 90% of cases, Grade 2 in 8% of cases, and Grade 3 in 2% of cases. Surgery-related complications occurred in 23 patients (6.7%), of whom 11 experienced complications directly related to PS placement. The per-screw complication risk was 0.8%, increasing with decreasing accuracy: 0.1% (Grade 1), 6% (Grade 2), and 14% (Grade 3). Vertebral artery injury occurred in seven patients; two patients experienced new-onset nerve root injury, one had a misplaced screw breaching the atlanto-occipital joint, and one developed significant perioperative bleeding. No cases of new-onset spinal cord injury or screw pull-out were observed. Surgical site infections occurred in 3.5% of patients and were successfully treated with debridement and antibiotics in all cases, without the need for implant removal.

Navigated cervical PS fixation is accurate and associated with a low rate of serious complications. Meticulous planning and surgical technique remain essential despite the use of navigation assistance.