Unfused anterior and posterior arches of C1


Incidental finding of unfused anterior and posterior arch of C1 in an elderly female who had CT to exclude fracture after fall. Congenital abnormalities can create confusion, especially among non-radiologists, when a patient is assessed in the setting of trauma. The presence of cortication along the non-fused bone margins as well as a typical appearance, permit categorical exclusion of an acute fracture.