Hangman Fractures

bilateral C2 pars fractures that can result in C2-3 spondy; classically due to hyperextension and axial loading, but there are multiple possible mechanisms 

These are the levine-edwards classifications, and they are stratified by mechanism of injury 

(A) Type I: hyperextension, axial loading - hairline fractures. Stable, non-op, collar for 4-6 weeks. 

(C) Type II: hyperextension, axial loading + bounceback flexion that can tear PLL/C2-3 disk. depending on how bad the spondy is, you can treat in collar +/- closed reduction, or fuse.

(C) Type IIa: hyperflexion + distraction: the key is you want to apply compression and some extension - i.e. compression halo or neutral collar 4-6 weeks +/- compression closed reduction. Do not distract these people. 

(D) Type III (rare): type II injury with bilateral dislocated facets. Needs reduction + fusion. CTA to look at verts. You may need to operate through aspirin. 

Jefferson Fractures 

Compression-type fractures that can be symmetric (burst from pure axial loading) or asymmetric (fractures biased to one side from hyper flexion/extension/lateral flexion) 

These are typically nonop as long as the transverse ligament is intact. Some people don't even collar these people if the fragments are not that displaced. If the transverse ligament is compromised though, you must operate, most likely O-C2. If the fracture morphology is amenable, C1-2 fusion only may be possible. 

MRI of disrupted transverse ligament 

Image sources

http://www.radiologyassistant.nl/en/p49021535146c5/spine-cervical-injury.html

http://pubs.rsna.org/doi/abs/10.1148/rg.2015150035