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Accessory ossicle of the anterior arch of the atlas

Last revised by Dr Francis Deng on 30 Mar 2020

The accessory ossicle of the anterior arch of the atlas is a normal variant and is best appreciated on a lateral cervical/sagittal study. It is observed as a circular and corticated osseous density that articulates with the inferior aspect of the anterior arch of the atlas

It is not associated with patient symptomatology. Historical and clinical correlation of injury or other disease states may reveal the other differential considerations as possibilities if radiographic findings are nonspecific. 

Differential diagnosis

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Cases and figures

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