Today's POTD is on trauma, which will be the topic every Tuesday. The mnemonic to remember unstable C-spine fractures and dislocations is "Jefferson bit off a hangman's thumb."
Jefferson burst fracture - Axial loading force (diving) transmitted to C1 causing a bilateral fracture of the ring.
- Associated with other cervical fractures, vertebral aa injury.
Bilateral facet dislocation - Hyperflexion injury (rapid deceleration) causing anterior dislocation of superior vertebral body by 50% of the body's AP diameter. - Anterior and posterior ligaments are disrupted.
Odontoid type II and type III fractures
- Fracture of the dens of C2 - Type II - fracture through waist, or base of odontoid near attachment to C2 - Type III - extension of fracture to the upper portion of body
- Called "internal decapitation" because it is frequently fatal.
- Flexion injury with injury to ligaments stabilizing atlanto-occipital joint.
Hangman's fracture - Extreme hyperextension injury - MVC, diving, judicial hangings. - Bilateral C2 pedicle fracture, causing anterior dislocation of C2 vertebral body onto C3.
Teardrop fracture - Hyperextension of the anterior longitudinal ligament avulsing a teardrop fragment of the body.
- Or hyperflexion causing the vertebrae bodies to collide and form a teardrop fragment of the superior vertebrae displacing the body and disrupting the posterior longitudinal ligament.
Rosen's (ed 8), ch 43
Young, N, et al. Unstable spine fractures (wikem.org/wiki/Unstable_spine_fractures)