TL Fractures Flashcards
What theory is used to determine stability of TL spinal fractures?
3 column theory of Denis
What makes up the anterior column of the TL spine?
anterior 2/3 of vertebral body
What makes up the middle column of the TL spine?
posterior 1/3 of vertebral body
What makes up the posterior column of the TL spine?
posterior elements
According to the 3 column theory of Denis, when is a fracture considered stable?
if only 1 column is affected
(eg. compression Fx = ant column)
According to the 3 column theory of Denis, when is a fracture considered unstable?
2 or more columns involved (eg. burst fx, chance fx)
Which column of the TL spine cannot fracture by itself? Is this stable or unstable?
middle column = unstable
What is the one exception to the middle column rule regarding TL spine stability?
traumatic posterior limbus bone
What is the stability of a fracture that involves the anterior column only, but greater than 50% vertebral body height is lost?
probably unstable
What populations do compression fractures occur most in?
- 35%: F, >45, w/ postmenopausal osteoporosis
- 30%: secondary osteoporosis
- 25%: acute trauma (otherwise healthy)
What are the possible mechanisms of a compression fracture?
- osteoporosis w/ minor trauma
- insufficiency fx
- acute trauma: hyperflexion and/or axial load
What are the most common sites of compression fractures?
T11-L1
What is the typical shape of a thoraco-lumbar compression fracture?
wedge-shaped
What are the possible shapes of lower lumbar compression fractures?
- wedge
- central endplate fx
- biconcave “fish”
What population are lower lumbar compression fractures common in?
older females
What structures are damaged with a biconcave (fish) shaped compression fracture?
Fx of both sup + inf endplates
What mechanism is indicated by vertebra plana?
pathologic (not traumatic)
What are the 3 most important imaging characteristics to determine a new versus old compression fracture?
New Fx may have:
- zone of impaction
- step defect
- paraspinal edema
(if 1 of 3, likely acute)
When is paraspinal edema visible on x-ray?
- compression Fx of T12 or above
- AP t/s view
What is a zone of impaction?
faint white line on x-ray along compression Fx line
What is the stability of a TL compression fracture?
stable
What is your next step if your patient has a compression fracture?
refer to orthopedist for pain control
Name an indirect indicator of a new compression fracture.
abdominal ileus
(^pain -> ^sympathetic tone + deactivated PSNS -> bowel fills w/ gas due to ^methanogenic bacteria breaking down food)
Name an indirect indicator of an old compression fracture.
Degenerative disc disease (wedge-shaped, osteophytes, less disc space)
(injured jt = ^DJD w/in 2 yrs)
How would a new compression fracture appear on T2 MRI compared to an old fracture?
New Fx has bone marrow edema = bright on T2
What must be ruled out first before diagnosing a compression fracture?
burst & chance Fxs
(both have ant wedging + unstable)
Burst fractures involve how many columns?
2-3
What is the clinical significance of a burst fracture?
up to 50% probability of neurologic injury d/t retropulsion & decreased canal space
(lower % in lumbar)
What is the stability of a fracture if the posterior body is convex?
unstable
(= middle column inj)
What radiographic findings are specific to burst fractures?
- retropulsion of middle column body fragments
- vertical splitting of body
- comminution of body
- focal widening of interpedicle distance (indicates post element fx)
What is your next step for a patient with a burst fracture?
emergency transport
(CT for osseous fragments, MRI for cord/nerve root damage)
What column is involved with a posterior limbus bone?
ONLY the middle column
What is the stability of a posterior limbus bone?
stable
What is the clinical significance of a posterior limbus bone?
concern for neuro compromise from stenosis
What is the mechanism of a transverse process fracture?
direct flank trauma or extension w/ lat flexion
What is the 2nd most common lumbar fracture?
transverse process Fx
What is the differential diagnosis for a TP fracture?
ununited TP ossification center
What organ injury is associated with a TP fracture?
kidney or ureter
What imaging is required to determine organ damage associated with a TP fracture?
abdomen CT w/ IV contrast
What is the stability of a TP fracture?
stable
(typically heal non-union)
What is another name for a chance fracture?
lap belt Fx
What is the mechanism of a chance fracture?
flexion & distraction over a fulcrum
What vertebral structures are damaged with a chance fracture?
horizontal splitting of:
- post vertebral body
- spinous
- pedicles (or lamina)
What radiographic sign is associated with a chance fracture on an AP view?
empty vertebra sign
(d/t splitting & displacement of pedicles)
What organ injury is most commonly damaged in association with a chance fracture?
spleen
(also pancreas, aorta, viscera)
What is the diagnosis?
Compression Fx
What is the diagnosis?
Transverse process fx
What is the diagnosis?
Burst fx
What is the diagnosis?
Butterfly vertebra
What is the stability of this injury?
Stable
(Dx: Compression fracture)
What is the diagnosis? Name a radiographic sign.
Chance Fx
Empty vertebra sign
What is the diagnosis?
Transverse process Fx
What is the diagnosis?
Traumatic pars Fx
What is the diagnosis?
Chance Fx
