Case of the week 8.26.19
Publication Date: 2019-08-26
History
1 year old male chihuahua. Tetraparesis for the last 12 days.
2 images
Findings
Orthogonal radiographs of the cervical spine are available for interpretation. There is mild rotation of the lateral view.
Most noted on the VD view, the dens of the axis is absent. On the lateral view, in neutral positionning, there is no evidence of subluxation of the atlanto-axial joint.
The remainder of the cervical area is within normal limits radiographically.
Diagnosis
Agenesis of the dens of the axis. Based on the patient's clinical presentation, atlanto-axial instability is highly probable.
Flexed view of the cervical spine could be obtained but may result in spinal cord trauma. Advanced imaging such as CT and/or MRI is recommended.
Discussion
The two following images are from the current patient when imaged on CT. The first image is a dorsal reconstruction, the second image is a sagittal reconstruction.
The following images are from a normal patient for comparison. Similar changes can be noted on radiographs but are more subtle. The normal dens has been circled. Also, note the appropriate alignment between the Atlas and Axis (C1-C2)
The current patient is scheduled to undergo surgical stabilization of the atlanto-axial joint.
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