Our Experience with Traumatic Atlanto-occipital Dislocation

Purpose: Atlanto-occipital dislocation (AOD) is a relatively uncommon injury among patients involved in high-speed motor vehicle accidents. Victims usually succumb to the injury of the high spinal cord/medulla or to associated injuries. Survivors often suffer from severe neurological deficits; however, cases with minor neurological deficits have also been reported. The purpose of this session is to report our experience with traumatic AOD.

Method: Medical records and radiographic images of patients who suffered traumatic AOD were reviewed.

Result: There were six patients, two men and four women, with a mean age of 36.2 years and age range 9 to 57 years. The injury mechanism included high-velocity motor vehicle accident in four cases, sport injury in one case, and in the last case the cause was not known. According to the classification system of Traynelis, four patients suffered type I injury (anterior dislocation of condyles), two patients suffered type II injury (longitudinal distraction); the type III injury (posterior dislocation of occiput) was not encountered in our series. Associated injuries of the C0-C2 area included occipital condyle avulsion (one case), C1-2 dislocation (one case), medullary contusion (all cases), disruption of arteria basilaris (one case). Five of the six patients presented in deep coma on arrival and died shortly after diagnosis. The last patient, a 53-year-old woman, underwent posterior transarticular C0-C2 fixation. She remained quadriplegic and ventilator-dependent; however, she died on postoperative day 59 because of respiratory failure.

Conclusion: Traumatic AOD represents a severe injury with high morbidity-mortality (100% mortality in our series) and should be excluded in any trauma where suspicion for cervical spine injury is present. The study of choice is computer tomography, which also allows assessment of associated abnormalities in the C0-C2 complex; however, magnetic resonance completes the information regarding injuries to the ligaments and nervous tissue. Posterior occipitocervical fusion is the preferred treatment method.