Congenital odontoid anomaly + MVA = complete instability of c1-c2. Need advice on fusion with abnormality. Will send images to anyone who can help.

Os odontoideum. Os odontoideum is a small tip of the odontoid (peg of C2) that has become separated either congenitally or from remote trauma. In some patients there is no instability and with an intact transverse ligament no surgery is required. In patients with instability, the surgery can be performed from the back of the neck or through the mouth. Real time fluoroscopic images can determine stability status.