Risk Factors for Transverse Ligament Disruption and Vertebral Artery Injury Following an Atlas Fracture.

BACKGROUND: Atlas fracture occurs in 3%-13% of all cervical spinal injuries and is often associated with other injuries. The factors associated with concomitant transverse ligament disruption and vertebral artery injury remain underexamined.

METHODS: We retrospectively reviewed 97 consecutive cases of atlas fractures. We analyzed demographic and clinic characteristics, including mechanism of injury, fracture type, and associated injuries. We identified factors independently associated with vertebral artery injury and/or transverse ligament disruption.

RESULTS: On multivariable analysis, vertebral artery injury was independently, positively associated with injury to the transverse ligament (odds ratio [OR], 8.51 [1.17, 61.72], P = 0.034), associated facial injury (OR, 7.78 [1.05, 57.50]; P = 0.045), intoxication at presentation (OR, 51.42 [1.10, 2408.82]; P = 0.045), and negatively associated with type 3 fractures (OR, 0.081 [0.0081, 0.814]; P = 0.033). There was a trend toward a positive association with a violence mechanism of injury (OR, 33.47 [0.75, 1487.89]; P = 0.070). Transverse ligament injury was independently associated with other injuries to the spine (OR, 13.07362 [2.43, 70.28]; P = 0.003), atlantodental interval (OR, 2.63 [1.02, 6.75]; P = 0.045), lateral mass displacement (OR, 1.78 [1.32, 2.39]; P < 0.001), and male sex (OR, 7.07 [1.47, 34.06]; P = 0.015). There was a trend toward a positive association with injury to the vertebral artery (OR, 5.13 [0.96, 27.35]; P = 0.056).

CONCLUSIONS: Among patients with atlas fractures, vertebral artery injury and transverse ligament disruption are associated with each other. Mechanism of injury, fracture type, and intoxication at the time of injury were associated with vertebral artery injury, and atlantodental interval and lateral mass displacement are associated with magnetic resonance imaging-confirmed injury to the transverse ligament.