# Predictors of surgical management and its impact on outcomes for combined C1–C2 fractures: National registry study

## TL;DR

This study examines when surgery is used for C1–C2 spinal fractures and finds it improves survival but increases complications.

## Contribution

Provides class II evidence on surgical outcomes for combined C1–C2 fractures using a large national trauma registry.

## Key findings

- Surgical intervention was associated with lower mortality (4.8% vs. 11.3%) in patients with C1–C2 fractures.
- Unstable injuries and specific fracture types increased odds of surgery, while frailty and age decreased them.
- Surgery was linked to higher ICU admission rates and longer hospital stays despite survival benefits.

## Abstract

Introduction: Combined C1–C2 fractures are common upper cervical injuries with high morbidity and mortality. Controversy exists regarding which patients benefit from surgery because this is an understudied population with only class III evidence available. We examined surgical intervention and its impact on outcomes in patients with C1–C2 fractures. Methods: This retrospective cohort study of the National Trauma Data Bank included patients admitted between 1/2017 and 1/2023 for combined C1–C2 fractures (ICD-10 diagnosis codes S12.0 and S12.1). Exclusions were admission to a level III-V or non-trauma center, not admitted (died or discharged from the ED), and non-index/readmission. The first aim was to identify predictors of surgical intervention (vertebral fusion or internal fixation); multivariate backward regression included the following covariates: Patient demographics, injury severity, concomitant injuries, and specific C1 and C2 fractures. The second aim was to compare hospital outcomes between operative and nonoperative groups utilizing a propensity-matched (1:1) analysis: Mortality, ICU admission, complications, and hospital and ICU LOS. Results: There were 19,264 patients, and 3,759 (19.5%) were surgically managed. The adjusted odds of surgical intervention were greater with unstable injuries (displaced C1 fracture, displaced C2 fracture, spinal cord injury, vertebral ligament dislocation), specific C1 and C2 fractures (odontoid fracture, Jefferson burst fracture, posterior arch fracture), whereas surgical intervention odds decreased for frailty (mFI ≥2), ED hemodynamic instability, ED Glasgow coma score ≤8, and increasing age quintile. Propensity matching resulted in 6,710 well-matched patients. After matching, surgical intervention was associated with lower mortality (4.8% vs. 11.3%, p < 0.001) but higher ICU rates, longer LOS, and greater complication rates compared to the nonoperative group. Conclusion: This study of nearly 20,000 patients with combined C1–C2 fractures provides class II evidence for surgical intervention, highlighting the balance between injury characteristics and patient resilience. Surgical intervention was associated with a significant survival benefit, emphasizing its role in select patients.