This issue has come up in Question 3 from the second paper of 2005
It needs to be treated only briefly.
Thus:

Jefferson fracture:
- Burst fracture of the atlas (C1)
- Usually combined anterior and posterior arch fractures
- Results from axial compression of C1
- Load of force must come from the vertex of the head, eg. diving into water head first or being thrown against the roof of a car or aircraft;
- May also result from hyperextension
- Unstable.
Hangman’s fracture:
- Bilateral fracture of the posterior arch of C2 and disruption of the C2-3 junction
- The posterior longitudinal ligament may be severed
- Due tot his, there may be significant anterior displacement of C2 on C3
- This can sever the spinal cord at this level
- Caused by C-spine hyperextension with vertical compression of the posterior column
- One scanrio suggested by the cllege is "a car accident victim’s head striking the dashboard".
- Unstable.
Clay-shoveller’s fracture:
- Fracture of the spinous process only
- An avulsion fracture by the supraspinous ligament of the spinous process caused hyperflexion.
- Stable.