[Factors of severity in the fractures of the odontoid process (author's transl)].

The authors think that the prognosis in fractures of the odontoid process could be based on an evaluation of the stability and on the direction of the fracture line. The stability depends on the integrity of the common posterior spinal ligament. When it is disrupted, the spine should be surgically fixed. When it is intact, conservative treatment is indicated. The stability should be appreciated on dynamic X rays 15 days after the trauma. The fracture lines oblique anteriorly are more stable than the fracture lines oblique posteriorly. The comminuted type, like "English policeman's hat" are very unstable.