The subject was a 51-year-old male. He was the driver of a car involved in a collision in which his car was hit from the left side and overturned. He was not wearing his seatbelt, and his left parietal region was the first area of impact. His car was overturned upside down, and he might receive injury with his own weight being as an external strength. On admission, his conscious level was JCS III-200, and he inflected the right elbow in response to pain stimulation. Since he was in shock and was experiencing respiratory failure, he was intubated and treated with a ventilator. We diagnosed his injury as Grade B according to the Frankel classification. An anteroposterior plain radiograph showed dilation of the left facet joint at the level of C5/6 and dislocation of the C5 vertebral body to the right side. A lateral plain radiograph showed interspinous dilation (Figure 2). We diagnosed a C5/6 fracture dislocation injury of LF Stage 2. Computed tomography (CT) revealed dilation of the C5/6 facet joint and fracture of the right lateral mass of C6 (Figure 3).
We attempted manual reduction but failed. Therefore, while monitoring by X-ray, the loaded weight was gradually increased to be 10 kg; however only intervertebral dilation was observed, and reduction was not achieved. Further traction was considered to be dangerous, and immobilization in a halo vest was performed at the position where reduction could be performed. Due to deterioration of respiratory function, tracheotomy was performed approximately 1 month after the injury. We confirmed the patency of the vertebral and posterior communicating arteries by 3D CT angiography, and posterior fusion using a cervical spine pedicle screw was considered. However, we could not perform the procedure due to the patient's poor general condition. Approximately two months after the injury, we observed callus formation on plain radiographs and changed the halo vest to a Philadelphia collar. During the follow-up period, improvement of paralysis was not observed. He died of pneumonia at another hospital approximately 3 months after injury.