Mortality after simultaneous fractures of the atlas and axis from ground-level falls

Abstract

Objective: The advanced age and high mortality rate of patients with simultaneous fractures of the atlas and axis complicates decision-making. The aim of this study was to identify clinical and demographic predictors of mortality in this patient population.

Methods: This retrospective cohort study included all patients with simultaneous fractures of the atlas and axis due to ground-level falls treated at a single institution from 2012 to 2022. Multivariable methods were used to identify predictors of mortality.

Results: Eighty-three patients (median age 83 years [IQR 77, 89 years]) with simultaneous C1 and C2 fractures due to ground-level falls were included. The cohort was disproportionately female (61.4%) and had a severe comorbid disease burden (Charlson Comorbidity Index ≥ 5 for 54.2%). Most falls resulted in minor trauma, with 57.7% of patients having no other injuries, while 3.7% of patients had a major trauma (Injury Severity Score ≥ 15). Overall mortality was 11.4% at 30 days, 17.3% at 90 days, 23.5% at 6 months, 28.4% at 12 months, 38.7% at 18 months, and 40.7% at 24 months, which followed a linear trend (R2 = 0.9520, p = 0.0009). In the 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). Surgery did not affect mortality (p = 0.8025). Patients with dementia had a higher early mortality rate (40.0% vs. 4.7% at 30 days, p = 0.0011) that converged over time with that of patients without dementia. Male and female patients had a similar mortality rate at 30 days, but mortality rates diverged over time (p = 0.0460). Male sex combined with dementia (n = 10) had a 100% positive predictive value for death by 2 years (p = 0.0039). The observed survival in this cohort was lower than the actuarial expected survival (p = 0.0202).

Conclusions: Patients with simultaneous fractures of the atlas and axis due to falls were typically female octogenarians with severe comorbid disease burdens and only minor associated injuries. Mortality rates were high in this cohort, and the observed survival rate was lower than the actuarial expected survival rate. Surgery was not associated with mortality. The combination of dementia and male sex was associated with mortality. The difference in mortality rates between patients with and without dementia narrowed over time, and the difference in mortality rates between male and female patients widened over time.

Keywords: C1; C2; atlas; axis; cervical fracture; spine fracture; trauma.