Unfused anterior and posterior arches of C1

Case contributed by Dr James Sheldon


CT to exclude fracture after fall

Patient Data

Age: elderly
Gender: Female

CT cervical spine

Both the anterior and posterior arch of C1 are discontinuous. The margins of the defect are corticated, and the posterior arch is thinner than normal whereas the anterior arch is much thicker.

Features are characteristic of congenital non-fusion. 

There are no spinal fractures but there are minimally displaced fractures of the posterior right first and second ribs.

Case Discussion

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.

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Case information

rID: 21455
Published: 23rd Jan 2013
Last edited: 14th Aug 2019
Inclusion in quiz mode: Excluded

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