Hosting 718 files, 2916 images, and 4 contributors.

 
Random Case

Multiple Exostosis Syndrome
Joseph Junewick, MD FACR
over 6 years ago
Enter A Workflow
Standard2   Academic2

Please choose a workflow. A standard workflow allows you to browse the repository with full case detail; the academic workflow allows you to browse the repository with limited case detail revealed. Double click on the images to launch image viewer.

ARSt Case Repository

Third Occipital Condyle

Case Detail

Anatomy: Brain-Spine
Junewick
Joseph Junewick, MD FACR
Diagnostic Category: Normal variant
Created: over 6 years ago
Updated: over 6 years ago
Tags:
Modality/Study Types: CT
Activities:
Adobe32 PDF Imagej32 ImageJA

History

5 year old female with sinus congestion.


Case Images


Diagnosis

Third Occipital Condyle

Findings

CT – Sagittal and coronal images reveal an ossicle in the anterior midline interposed between the clivus and dens.

Discussion

The third occipital condyle (condylus tertius or median occipital condyle) was first described by J.F. Meckel in 1815, as a bony process in the anterior midline of the foramen magnum. It is always present in reptiles; in humans it is found in approximately 0.5% of the population and may exist as a discrete condyle or an isolated osseous element. It may serve as an articulation with the tip of the dens or with the anterior atlantic arch. The third occipital condyle is a vestige of proatlas (a derivative of the 4th occipital and 1st cervical sclerotome). The variations of the anatomic appearances of the third condyle can be explained by the different degrees of persistence. An isolated, articulated condylus tertius, located in the median-sagittal plane and the anterior margin of the foramen occipitale magnum represents the highest degree of persistence.

Reference

Prescher A, , Brors D, Adam G. Anatomic and Radiologic Appearance of Several Variants of the Craniocervical Junction. Skull Base Surgery (1996); 6:83-94.



Corporate Office: 616.363.7272, 3264 North Evergreen Drive, Grand Rapids, MI 49525

Spectrum Health Helen Devos Childrens Hospital GE HealthCare