Surgical treatment of os odontoideum.

Os odontoideum is a rare disease. There have been few reports of os odontoideum in the literature. In this study we retrospectively reviewed eight surgically treated patients. One patient underwent C1-2 transarticular screw fixation, five patients underwent C1-2 polyaxial screw and rod fixation and two patients with dystopic os odontoideum underwent occipito-cervical (O-C) fusion. Of the eight patients, neck pain was alleviated in seven (87.5%). Of the six patients who had neurological signs and symptoms, five (83.3%) exhibited neurological improvement. Radiologically, solid fusion was observed in seven patients (87.5%). Active surgical treatment should be considered even in patients with os odontoideum who exhibit mild symptoms. In most patients with os odontoideum, use of the C1-2 polyaxial screw and rod technique may be the most appropriate treatment. In patients with dystopic os odontoideum, O-C fusion should be considered.