Simultaneous Traumatic Fractures of the Atlas and Axis: Presentation, Management, and Outcomes from a Series of 103 Consecutive Patients.

Background: Simultaneous C1 and C2 fractures are increasingly common, but contemporary series are limited.

Methods: All patients with traumatic fractures of both C1 and C2 admitted to an academic trauma center from 2012 to 2022 were retrospectively analyzed. Multivariable regression was used to identify characteristics relevant to management and outcomes.

Results: Of 103 patients identified, most were ≥80 years old (52.4%), sustained ground-level falls (80.6%), and had minor associated injuries (median Injury Severity Score 1); a 28.2% had a 1-year mortality rate. Landells type 1 fractures were the most common C1 fracture (50.5%), and dens fractures were the most common C2 fracture (74.8%). Most patients did not undergo magnetic resonance imaging, but ligamentous injury was seen in 54.8% of those who did. Fourteen patients (13.6%) had upfront surgery, and 7 patients (6.8%) had surgery after a trial of nonoperative management. Selection for upfront surgery was associated with neurologic deficits (P = 0.010) and age (P = 0.026). Patients with dens fracture tended to have C2 as their lower instrumented vertebra (P = 0.0902), and patients with hangman's fracture tended to have C3 as their lower instrumented vertebra (P = 0.0714). Upfront surgery decreased the odds of bony nonunion (P = 0.0281). In 91.7% of patients with bony nonunion with flexion-extension x-rays, the x-rays showed fibrous nonunion.

Conclusions: Simultaneous atlantoaxial fractures commonly occur in elderly patients after ground-level falls with minor associated injuries. Surgical selection is driven by neurologic deficits and age, and C2 fracture type may influence procedure choice. Surgery decreases the odds of bony nonunion, and fibrous nonunion is common in the absence of surgery.