Accessory ossicle of the anterior arch of the atlas
Citation, DOI & article data
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.
- calcific tendinitis (HADD) of the longus colli insertion (generally more homogeneously dense without a visible cortical rim)
- heterotopic ossification
- calcification of the anterior longitudinal ligament (also more homogeneous and generally more linear)
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