Regarding Hangman's fracture true is-

It is the second most common type of Axis (C2) fracture, second only to odontoid fractures. Fatalities are common, However, the neurological deficit is unusual as the fracture of posterior arch decompress the spinal cord. Most of the fatalities occur at the scene of injury, acute post admission mortality is low. Successful healing of C2 traumatic spondylolishesis is reported to approach 95%. This is most commonly achieved with non-operative measures, even in the presence of displacement of pars inter-articularis.