Mortality After Simultaneous Fractures of the Atlas and Axis from Ground-Level Falls

Introduction: The advanced age and high mortality rate of patients with simultaneous fractures of the atlas and axis complicates decision-making. This study identifies clinical and demographic predictors of mortality in this patient population

Methods: We performed a retrospective cohort study of all patients with simultaneous fractures of the atlas and axis due to ground-level falls treated at our institution from 2012 to 2022. We used multivariable methods to identify predictors of mortality in this population.

Results: 83 patients were identified. The population was disproportionately female (62.2%, p=0.0352), and mostly age≥80 years (59.0%) with a severe comorbid disease burden (Charlson Comorbidity Index ≥5 for 54.9%). Most falls resulted in minor trauma, with most patients (57.7%) having no other injuries, and only 3 (3.7%) having a major trauma (injury severity score (ISS) ≥15). Mortality was 11.4% at 30 days, 17.3% at 90 days, 22.5% at 6 months, 28.4% at 12 months, 38.7% at 18 months, and 40.7% at 24 months, which followed a linear trend (R-squared=0.9719, p=0.0003). On Cox proportional hazards analysis, mortality was associated with older age (HR=1.048, p=0.0420), male sex (HR 4.554, p=0.0009) and dementia (HR=5.419, p=0.0011). Patients with dementia had a higher early mortality rate (40.0% vs. 4.7% at 30 days, OR=13.56, p=0.0011) that converged over time with patients without dementia (p=0.0373). Men and women had a similar mortality rate at 30 days, but their mortality rates diverged over time (p=0.0460). Male sex with dementia had a 100% positive predictive value (PPV) for death by 2 years (PPV=1.00 [0.61, 1.00], p=0.0039).

Conclusion : Patients with simultaneous atlantoaxial fractures from falls are typically female octogenarians with severe comorbid disease burdens and only minor associated injuries. Mortality rates are high. Dementia and male sex are both independently associated with mortality. The gap in mortality rate between patients with and without dementia narrows over time, and the gap in mortality rate between men and women widens over time.