Radiological and clinical features of traumatic atlanto-occipital dislocation

We aimed to describe the findings of traumatic atlanto-occipital dislocation (AOD) on cervical spine CTs and differences leading to varying treatment of these patients.

We retrospectively identified 20 adult patients with AOD from cervical spine CTs demonstrating fracture or fracture dislocations over 19 years at 2 major trauma centers. Medical records were reviewed and craniovertebral junction (CVJ) metrics measured on CT. Intubation, Glasgow Coma Scale (GCS), additional injuries, occiput/atlas/axis fracture, concurrent atlantoaxial subluxation, vascular injury on CT angiography, and ligamentous injury on MRI were noted.

Using the Traynelis Classification, eight patients had type 2 and eight patients type 3 AOD. Four of 5 patients who died within 14 days of CT had type 2 AOD. Three patients had medial/lateral AOD. Of the patients who survived initial injuries, a greater percentage who underwent surgical or halo fixation versus non-operatively treated patients had abnormal CVJ measurements including BDI (62.5% vs 0%), atlantoaxial subluxation (75% vs 14.3%), ligamentous injury (80% vs 66.7%), intubation (62.5% vs 28.6%), GCS<8 (62.5% vs 14.3%), and additional injuries (75% vs 71.4%) on presentation. MRI helped identify 2 cases of type 2 AOD and surgical decision making in 8 cases.

Types 2 and 3 were the most common, and type 2 is the deadliest type of AOD. A greater proportion of patients who undergo surgical or halo fixation have abnormal CT/MR findings with neurologic impairment at presentation. MRI aided detection of potentially missed type 2 AOD and was critical for surgical decision making.