Does the Morphology of Foramen Transversarium Fractures Predict Vertebral Artery Injuries?

Study Design. Retrospective review of foramen transversarium fracture morphology variables and their relationship to vertebral artery injury. Objective. We examined the morphology of foramen transversarium fractures to determine if different patterns of these fractures predicted vertebral artery injury to more specifically identify at risk patterns in which vertebral artery evaluation may be warranted. Summary of Background Data. Risk fractures for vertebral artery injury have been previously reported to include cervical subluxation or dislocations, C1-C3 fractures, and foramen transversarium fractures. There have been no reports determining if specific foramen transversarium fracture patterns are predictive of vertebral artery injuries. Methods. We reviewed the initial cervical CT scans of 171 patients seen in our level one trauma center between January 2002 and March 2008 and identified all patients with foramen transversarium fractures. Additionally, CT angiograms were reviewed in these patients to identify patients with vertebral artery injuries. The morphology of the foramen transversarium fractures was compared in those patients with and without vertebral artery injury to identify fracture patterns predictive of arterial injury. Results. Twenty-one (12%) patients were found to have foramen transversarium fractures with 5 (24%) of these patients having associated vertebral artery injury. Multilevel foramen transversarium fractures (P = 0.025) were significantly more frequent in vertebral artery injuries. Logistic regression identified multilevel fractures (odds ratio 17.33) and fracture comminution (odds ratio 10.50) as significant variables influencing vertebral artery injury after foramen transversarium fracture. Conclusion. We found patients presenting with multilevel foramen transversarium fractures and foramen transversarium fracture comminution to be at significantly increased odds of vertebral artery injury. Patients with these fracture patterns should undergo further evaluation with vertebral artery imaging.