Imaging Radiograph: When measuring the atlanto-dens interval on lateral flexion and extension and neutral cervical spine radiographs — If the atlanto-dens interval is greater than 5 millimeters on any view there is instability — If there is greater than 1-2 millimeters of motion at the atlanto-dens interval on flexion when compared to extension there is instability
DDX:
Complications:
Treatment: Surgical fusion
Clinical: Often seen in Trisomy 21
Radiology Cases of Atlanto Axial Instability
Lateral radiographs of the cervical spine show a mildly enlarged atlanto dens interval in neutral position (left), that increases significantly on flexion (center) and reduces on extension (right).
