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
(type 3)
Atlanto-occipital dissociation
- 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.
Sources
Rosen's (ed 8), ch 43
Rosh Review
Young, N, et al. Unstable spine fractures (wikem.org/wiki/Unstable_spine_fractures)