Atlanto-occipital dislocation

There is a dislocation of the occipital condyles (left and right) ventrally on the C1 lateral masses. There is significant prevertebral edema from the skull base through C4. Additional soft tissue stranding and edema are seen in the right lateral neck and along the left scalene musculature, which is also concerning for sequelae of trauma and soft tissue injury.

There is soft tissue density dorsal to the thecal sac at the C1-C2 level concerning edema and/or epidural hematoma with possible ligamentous injury. There is a widening of the dorsal interspace between C1 and C2.

There is congenital nonunion of the posterior arch of C1.

There are mild to moderate degenerative changes of the cervical spine, most pronounced at C4-C5 and C5-C6. No significant osseous canal stenosis is evident on non-contrast CT, but further assessment is recommended given the injury noted above.

There is a minimally displaced fracture of the posterior aspect of the medial left T1 rib.

There is redemonstration of ventrally dislocated occipital condyles on the C1 lateral masses. There is significant prevertebral edema at the level of C3, extending superiorly to the level of the nasopharynx and inferiorly to the level of T1. There are multiple subdural hematomas within the anterior upper cervical spine from C1 to C3. The cervical spinal cord maintains normal caliber and signal intensity.

At C1-C2, sagittal STIR images demonstrate an abnormal signal and irregularity of the tectorial membrane. There is extensive edema within the C1-C2 interspinous ligaments. The posterior atlantooccipital membrane is disrupted. There is likely disruption of the transverse ligament.

There is an increased T1 signal along the anterior longitudinal ligament. No significant spinal canal or foraminal compromise.

Lateral intraoperative radiograph revealing fixation of the occipital bone to C2 and C3 via an occipital plate and bilateral pedicle screws at C2 and C3.