x-ray anatomy thoracolumbar spine

Question 1

what are the 5 things to be checked when analysing the thoracolumbar spine for injruy

Answer 1

• equal height of vertebral body
• equal thickness of intervertebral disc
• continuity of superior and inferior end plate (not broken)
• distance between spinous process
• trace the posterior elements of body (TP, SP, laminar etc)

Question 2

besides bony and joint injury in thoracolumbar spine, what soft tissue injury should be assessed as well

Answer 2

• soft tissue signs, if there is a widening of the paraspinal (muscle) line adjacent to the thoracic spine

Question 3

what can a widened paraspinal line adjacent to the spine indicate

Answer 3

heamatoma due to fracture (pool of mostly clotted blood that forms in an organ, tissue, or body space)

Question 4

inter-pedicular distance should gradually become wider from L1 to L5

Question 5

what method can be used on a lateral spine projection to assess instability

Answer 5

• misalignment, trace the posterior and spinolaminar lines. If either line are disrupted, the injury is unstable

Question 6

mind that the posterior vertebral body cortex should be slightly concave

Question 7

what are the 3 columns the thoracolumbar spine is split into and it relate to concept of stability

Answer 7

1. anterior = 2/3 of body and disc + anterior longitudinal ligament
2. middle = back 3rd of body and disc + posterior longitudinal ligament
3. posterior = posterior elements e.g TP, SP, lamina, facet joints and associated ligaments

If 2 or more columns is disrupted, the injury is unstable. When middle is disrupted usually the anterior or posterior column is also affected so injury is unstable.

Question 8

where does a wedge fracture occur and what are the radiographic findings

Answer 8

affects anterior aspect of vertebral body

• can be seen collapsing the bone in the front of the spine and leaving the back of the same bone unchanged, which results in the vertebra taking on a wedge shape.

Question 9

what is a burst fracture, how’s it different to wedge or regular compression fracture / what are radiographic findings

Answer 9

• lateral view will demonstrate retropulsion of fragments of posterior vertebral body into spinal canal
• AP view can show widening of inter-pedicle distance
• vertebra is crushed in all directions and is much more severe than compression fractures. The bones spread out in all directions and may damage the spinal cord.

Question 10

what is a chance fracture, how’s it different to burst fracture / what are radiographic findings / what to look out for

Answer 10

• Chance fractures happen when your vertebrae are suddenly pulled away from each other.
• fracture of the posterior elements is horizontal in orientation.
• fracture is thru body and posterior elements where as in burst it is just thru body
• AP shows increase in inter-spinous distance and break in continuity of pedicles/spinous process is sign
• lateral shows increase in inter-spinous distance with horizontal fracture of posterior elements running into vertebral end plates

Question 11

how would you identify fracture-dislocation of thoracolumbar spine

Answer 11

trace anterior and posterior body lines of spine or trace SP etc

Question 12

mind to look veryyyy carefully at transverse process fracture as they are very subtle and can be overlaid by bowel gas

Question 13

what is spondylosis and radiographic findings

Answer 13

• degenerative change to disc space
• narrowing disc space, endplate sclerosis and osteophytes (bony lumps that grow on the bones in the spine or around joints.)

Question 14

what is spondylolysis and its radiographic findings

Answer 14

• fracture extending from inferior facet across the pars interarticularis ( thin bone segment joining two vertebrae/ area of lamina lies within facet) to adjacent superior facet
• can be seen as a dog in lateral view where top ear = superior facet, front legs = inferior facet, nose = transverse process etc

Question 15

what is spondylisthesis and radiographic findings

Answer 15

• widened fracture gap at pars interarticularis either due to/ or causing vertebrae to slip forward/displace

Question 16

what radiographic findings are seen for a metastatic disease to vertebral bodies

Answer 16

moth-eaten appearance or ‘ivory vertebra’ (one or more vertebral bodies become extremely more dense/ sclerotic and show as white)

Question 17

what is ankylosing spondylitis and the radiographic findings

Answer 17

• inflammation of vertebrae that overtime can lead to the fusing of them
• no joint space , ‘bamboo’ (looking) spine