Thoracolumbar spine x-rays

Read our step-by-step guide to interpreting thoracic and lumbar spine X-rays. Imaging the thoracolumbar spine X-ray involves two views: anteroposterior (AP) and lateral.

Check if it’s an adequate view

For a lumbar spine view

• You should be able to see L1-L5 but also the full T12 vertebral body, T11/12, and the sacrum on the AP view
• The vertebral bodies, facet joints, and pedicles should be clearly visible on the lateral view
• The transverse processes should also be visible (and are often obscured by gas)

For the thoracic spine view

• Make sure the whole thoracic spine is visible
• You should be able to see the pedicles, spinous processes, and vertebral bodies.
• The ribs can cause difficulty in seeing the thoracic spine on a lateral view.

2. Know your anatomy

• Clavicle is at T3
• Tracheal bifurcation is T4/5
• 12th rib is at T12
• In the lumbar spine, the disc spaces also increase in size, although note that the L5/sacral space is narrower than the L4/L5 space

3. Check the alignment

On the AP check that the vertebral bodies and spinous processes are aligned. On the lateral, check the alignment of the vertebral bodies.

4. Look for loss of vertebral height

In the thoracic spine, the vertebral bodies (and the disc spaces) should gradually increase in size as you get further down the spine.

Check all the vertebral bodies, looking specifically for loss of height. This indicates a compression fracture.

5. Look for widened inter-spinous or inter-pedicle distance and check the processes

Check that all the pedicles, spinal, and transverse processes are intact in the lumbar spine.

See below (under burst fracture) for an example of widened inter-pedicle distance and (under Chance fracture) widened spinous process distance.

6. Check for translation/rotation or distraction

Translation or rotation is displacement in horizontal plane; and distraction is displacement in the vertical plane.

Translation/rotation is due to a side-to-side motion (it can be left-to-right or front-to-back). It is a serious injury that always involves the posterior ligamentous complex.

Distraction occurs when the vertebrae are pulled apart, and it carries a high risk of cord injury. Often, there is compression on the other side (see Chance fracture below).

7. Know the common fracture patterns

Compression fracture

This is the most common type of fracture, identified by loss of vertebral height (see number 4 above). It involves one column only and is a stable fracture.

Burst fracture

25% of burst fractures are misdiagnosed as vertebral compression fractures on X-ray. A burst fracture is where there is a compression, but part of the vertebral body has been projected out anteriorly.

On AP view, there will be an increased interpedicular distance in 80% of burst fractures.

On lateral vie,w there will be reduced vertebral height and disrupted anterior alignment.

A burst fracture involves two columns and is usually considered to be unstable.

Chance fracture

Usually from a seatbelt injury, and is commonly at L2/L3

This is a flexion-distraction injury where there is horizontal splitting of the vertebral body with ligament rupture. This is an unstable fracture and involves all three columns

Sometimes there is increased distance between the spinous processes on the lateral view (but not always).

On the AP view, the distance between the spinous processes at the level of the Chance fracture can be increased.

Jumper’s/lover’s fracture

So-called because it’s usually from people jumping out of windows to escape the police or angry partners. This is severe axial loading leading to compression/burst fractures alongside a calcaneus fracture.

References

Radiology Assistant

Norwich Image Interpretation Course

Radiology Masterclass