1. Thoracic and Lumbar Trauma

2. Thoracic Compression Fracture
M.C. at T11 and T12
Hematoma may cause displacement of the paraspinal stripe on AP film
Wedge shape vertebra on lateral film
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3. Thoracic Fracture-Dislocation
M.C. T4-T7
Often associated with neurological damage because canal is small and blood supply is sparse
Rad features include loss of
vert. body height, displacement,
widened interpediculate
distance and widened paraspinal
stripe
*Best appreciated on CT

4. Lumbar compression Fractures
M.C. fxs. of L/S; L1 is m.c.
In elderly, due to osteoporosis (insufficiency fx)
Stability is determined based on Denis’ 3-column model
Anterior- from ALL to mid-vertebral body
Middle- from mid-vert. body to PLL
Posterior- from PLL to supraspinous lig.
Disruption of 2 or 3 columns implies instability
Likelihood of neurological injury is high and
interventional surgery is likely necessary

5. Rad. Signs of Vert. Compression Fxs.
Step defect- buckling of the anterior cortex, near the superior vertebral endplate on lateral view
Wedge deformity- anterior depression of the vertebral body occurs, creating a triangular wedge shape
Up to 30% or greater loss in anterior height may be required before the deformity is readily apparent on convention x-rays
Normal variant anterior wedging of 10-15% or 1-3 mm is common thought the T/S and most marked at T11-L2

6. Rad. Signs of Vert. Compression Fxs.
Zone of Condensation- band of radiopacity below sup. Endplate represents the early site of bone impaction following a forceful flexion injury where the bones are driven together
If present, denotes a fracture of recent origin (<2 months’ duration)
Paraspinal edema- U/L or B/L hemmorrhage may occur
Displaces paraspinal stripe on AP T/S; creates asymmetrical densities or bulges in psoas margins on AP L/S
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7. Rad. Signs of Vert. Compression Fxs.
Abdominal ileus- seen radiographically as excessive amount of small or large bowel has in a slightly distended lumen
Warns that the trauma was severe and fracture is likely
Results from disturbance to the
visceral autonomic nerves or
ganglia from pain, paraspinal
soft tissue injury, edema or
hematoma
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8. Old Vs. New Compression Fracture
Previously mentioned signs disappear with healing, which could be up to 3 months in adult
DJD develops due to altered mechanics
MRI reveals bone marrow edema with recent fracture up to 6 weeks post
trauma

9. Burst Fractures
Compression fracture where posterosuperior fragment is displaced into the spinal canal
Neurological injury in up to 50% of cases (best demonstrated by MRI or CT)
AP film shows vertical fracture line, which differentiates from simple wedge comp. fx.
Widening of the interpediculate distance signifies a fracture within the neural arch
Acquired coronal cleft vertebra – coronally
oriented fracture the separates the
vertebral body into anterior and posterior
halves
Central depression of the superior and
inferior endplates occurs with
comminution of the vertebral body

10. Burst Fractures

11. Posterior Apophyseal Ring Fractures
Separation of the posterior vertebral body ring apophysis (posterior limbus bone) is a relatively uncommon abnormality
Most common levels are L4/5 and L5/S1
50% are caused by trauma, such as weightlifting, MVAs, gymnastics
Between 15% and 20% are visible on lateral radiographs, but CT is definitive
Surgery may be warranted after failure of conservative care and in the presence of significant
neurological compromise

12. Kummel’s Disease
Post- traumatic vertebral collapse, caused by rarefying process in vert. body months after trauma
Results from complicating avascular necrosis resulting in progressive compression
deformity
Intravertebral vacuum
phenomenon may be evident
on radiographs

13. Fractures of the Neural Arch
Transverse process fractures- 2nd m.c. L/S fx.
Occur from avulsion of the paraspinal muscles, usually secondary to a severe hyperextension and lateral flexion blow to the L/S
M.C. at L2 and L3
Loss of the psoas shadow may occur secondary to hemorrhage
Large forces involved, so organs may be damaged as well
Pars interarticularis fractures- acute fxs
(not stress fxs.) are rare
Violent hyperextension of L/S, usually at L4 or L5
Usually unilateral, not bilateral like stress fx.
Heal without residual defects or anterior
displacement
article/pii/S

14. Chance or Lap Seat Belt Fracture
Aka fulcrum fracture; seat belt acts as fulcrum over abdomen
Horizontal splitting of the spine and neural arch
Internal visceral damage may occur – rupture of the spleen or pancreas and tears of the small bowel and mesentery
M/C location is upper L/S (L1-L3)
AP radiograph shows transverse fracture through the posterior elements and angulation of the superior portion of the fractured vertebra
The resulting widened radios gap between the two fractured segments has been turned empty vertebra
Lateral radiographs shows radiolucent split through spinous process, lamina, pedicle and upper corner of the posterior aspect of the vertebral body

15. Fracture-Dislocation
Usually at thoracolumbar junction after a violent flexion injury
Avulsion fractures (teardrop) are commonly found associated with dislocation of the L/S
Most dislocations are anterior in position, without lateral displacement
Complete luxation with lateral shift of spine may create cord or cauda equina paralysis
Axial CT shows absence of
apposed articular facets
(naked facet sign)

16. References
Yochum, T.R. (2005) Yochum and Rowe’s Essentials of Skeletal Radiology, Third Edition. Lippincott, Williams and Wilkins: Baltimore.