C2-C3 traumatic spondylolisthesis (Hangman's #)

Type I

Minimal translation (<3mm) without C2-C3 angulation. Stable.

Type II

Significant C2-C3 angulation and translation (>3mm). Disc disruption. Unstable.

Type IIA

More angulation than type 2, without translation. Unstable due to flexion-distraction injury.

Type III

Severe C2-C3 angulation and translation. Sometimes uni-/bilateral facet dislocation. Unstable.


Greenberg's Handbook of Neurosurgery, 7th edition