5 years ago

The prevalence of congenital C1 arch anomalies



To determine the prevalence, radiographic features and reporting rate of, and the association between the congenital anterior and posterior C1 arch anomalies.


The computed tomography (CT) images of the cervical spines of all patients over 18 years who had CT examinations in our hospital during the study period were reviewed to evaluate for congenital anomalies of the anterior and posterior C1 arches. Radiology reports of the corresponding CT examinations were reviewed to determine the reporting rate of these defects.


Of 3273 subjects, 185 (5.65%) had congenital atlas anomalies: 169 isolated posterior (5.16%), 15 combined anterior and posterior (bipartite, 0.46%), and one isolated anterior (0.031%) arch defects. Females had a higher prevalence than males (7.46 versus 4.72%, P = 0.0013). Eighty-three cases (44.9%) of C1 arch anomalies were not reported. The Currarino type A, B, C and E posterior arch defects accounted for 81.6, 8.1, 1.1, and 0.5% of all arch anomalies while type D was not observed. Fifteen patients (0.46%) had combined anterior and posterior arch anomalies (bipartite atlas) versus only one with an isolated anterior C1 defect, indicating a significant association between the anterior and posterior arch defects (P < 0.0001).


Although some types of congenital C1 arch anomalies are rare, type A defects are relatively common radiological findings that are unreported approximately 45% of the time. Based on the significant association between the anterior and posterior arch defects, we propose possible mechanisms for the formation of the bipartite atlas.

Publisher URL: https://link.springer.com/article/10.1007/s00586-017-5283-4

DOI: 10.1007/s00586-017-5283-4

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.