Here's another recent case. 20-something helmetless motorcyclist launched from his bike on the highway (struck by another car?). Details of accident unclear. I was consulted for management of a traumatic brain injury (he presented unconscious). As I looked into it, I realized his head is disconnected from the spine ironically, the most frequently missed injury. This is called Atlanto-occipital dislocation (occiput to C1), and he also had atlanto-axial dislocation (C1 to C2). Nearly 50% of people with this injury diet at the scene usually unable to breathe spontaneously. This patient still in the hospital but surgery was a success. Will see how he recovers from head injury, etc.
Notice the tip of the skull in front (basion) is separated from the tip of the dens of C2 (looks like thumb). Should be no more than 10-12 mm. He was almost 14 mm. C1 is also widely separated from C2 especially in the back.
The post op alignment is closer to anatomic. Basion-dens interval on post op CT around 10-11 mm, so high end of normal but definitely improved.