Retropulsion of intervertebral discs associated with traumatic hyperextension of the cervical spine and absence of vertebral fracture: an uncommon mechanism of spinal cord injury

Hayes et al¹ observed, among other pathologies, a posterior C3/4 disc protrusion in a post-mortem study of a fatal cervical hyperextension injury in a 60-year-old man with plain radiographic evidence of degenerative disease.

They attribute the protrusion to the injury, but while the illustration demonstrates acute internal disruption of the disc, they have advanced no histological evidence that would confirm the protrusion as fresh and acute rather than pre-existing. The acute disruption itself appears similar in nature to that illustrated in the two other injured levels, where there was no protrusion. (Presumably the reference to herniation of C4/5 in the caption is an error, as there is no reference to this in the text.)

Cervical disc protrusions are known to be increasingly common with increasing age in asymptomatic individuals.

How can the authors be so sure that the protrusion did not antedate the injury in this case?

I challenge their concept of ‘transiently retropulsed intervertebral discs’ at other levels also. If the discs were ‘retropulsed’ by the injury, would they not remain so?