Acceleration injury of the cervical spine by hypertranslation of the head. Part II. Effect of hypertranslation of the head on cervical spine motion: discussion of literature data.

This paper starts from the concept that acceleration injury of the cervical spine is caused by hypertranslation of the head with respect to the trunk, and not by hyperflexion or hyperextension. In this second part of the paper literature describing craniovertebral junction damage after acceleration injury is reviewed. (All other types of lesions are left out of consideration.) Fatal craniocervical disruption has been reported in high-energy acceleration experiments in rhesus monkeys. Comparable craniovertebral disruptions occurred in a large proportion of cervical spine injuries caused by fatal traffic accidents and in some patients surviving such accidents. At least part of these dislocations were inflicted by acceleration injury. Taking hypertranslation of the head as the starting point, reconstruction of the mechanism of injury in these craniovertebral disruptions is done. The "classical" mechanisms, based on hyperflexion or hyperextension, are critically reviewed. It is likely that hypertranslation also plays a role in the less severe whiplash injury, but this is not further elaborated.