Thoracolumbar spine fractures

Written by the X-Ray Atlas editorial team from the sources listed below · Medical review pending · Updated 24 October 2026 · Level: Intermediate

Thoracic and lumbar spine fractures come in two very different settings. In major trauma they are usually found on CT, and the plain film's role is limited. In older people with osteoporosis, vertebral fragility fractures are extremely common, frequently painless or attributed to "back pain", and very often visible on a chest or lumbar film taken for another reason, yet they are under-reported. Recognising them matters because one vertebral fragility fracture strongly predicts the next. This page covers both: how to read the film, how to tell a stable wedge from an unstable burst or Chance fracture, and when to move to CT or MRI.

1. How to look

Thoracic and lumbar series are an AP and a lateral. In a trauma patient, imaging is guided by the major trauma pathway; in UK practice adults with significant blunt trauma usually have CT, and the spine is reformatted from the chest, abdomen and pelvis scan (NICE NG39). On plain films:

1. Alignment on the lateral: the anterior and posterior vertebral lines should be smooth curves (thoracic kyphosis, lumbar lordosis) without steps.
2. Vertebral body height: compare the anterior, middle and posterior heights of each body with its neighbours. A body that is shorter than those above and below needs explaining.
3. Posterior body wall: is it straight or concave, as normal, or bowed backwards into the canal (retropulsion)?
4. On the AP: the pedicles form paired ovals at each level. Check that each is present (a missing pedicle suggests a destructive lesion) and that the interpedicular distance increases gradually down the spine without a sudden widening.
5. Spinous processes should be in a straight line, evenly spaced. A widened gap suggests posterior ligamentous disruption.
6. Paraspinal soft tissues: a widened paraspinal line in the thoracic spine can indicate haematoma around a fracture.
7. Transverse processes and the lowest ribs.

The thoracolumbar junction (T10–L2) is the most common site of injury, because the rigid thoracic spine (splinted by the ribs) meets the mobile lumbar spine there.

2. The three-column model

The Denis three-column model is still the simplest way to think about stability:

Column	Structures
Anterior	Anterior longitudinal ligament and the anterior two-thirds of the vertebral body and disc
Middle	Posterior third of the vertebral body and disc, and the posterior longitudinal ligament
Posterior	Pedicles, facets, laminae, spinous processes and the posterior ligamentous complex

As a rule, involvement of two or more columns suggests instability. Current clinical practice uses the TLICS (Thoracolumbar Injury Classification and Severity Score, which combines fracture morphology, integrity of the posterior ligamentous complex and neurological status) and the AO Spine classification (type A compression, type B tension band/distraction, type C translation). These rely on CT and MRI rather than plain films.

3. Wedge compression and fragility fractures

A wedge compression fracture involves the anterior column only: the anterior height of the body is reduced while the posterior height is preserved and the posterior wall is intact. In trauma it follows a flexion injury; in older people it is the typical osteoporotic fracture, often after minimal or no trauma.

The Royal Osteoporosis Society and the International Osteoporosis Foundation have campaigned for vertebral fragility fractures to be reported explicitly, using the word "fracture" rather than vague terms such as "wedging" or "loss of height", so that the patient can be offered bone health assessment. Look for them at the edges of every lateral chest film: the thoracic vertebrae are in view.

4. Burst fractures

A burst fracture results from axial loading, for example a fall from height landing on the feet, and involves the anterior and middle columns. Fragments of the posterior body wall can be driven backwards into the spinal canal (retropulsion), threatening the cord or cauda equina.

• On the lateral: loss of height of both the anterior and posterior body, with the posterior wall bowed or fragmented into the canal.
• On the AP: widening of the interpedicular distance compared with the levels above and below, and sometimes a vertical fracture through the body or lamina.
• CT is needed for every suspected burst fracture to assess canal compromise and posterior element involvement, with MRI if there are neurological signs or concern about the ligaments.

5. Chance and flexion-distraction injuries

A Chance fracture is a flexion-distraction injury: a horizontal fracture running through the vertebral body, the pedicles and the posterior elements, or through the ligaments and disc. It classically occurs in a car occupant wearing a lap-only seat belt, who flexes violently over the belt. It usually occurs at the thoracolumbar junction, around T12–L2.

• On the lateral: a horizontal fracture line through the posterior elements and body, with widening of the posterior part of the vertebra or the interspinous space.
• On the AP: horizontal fracture lines through the pedicles or spinous process, and the "empty body" sign, in which the vertebral body looks hollow because the posterior elements have separated.
• Chance fractures are strongly associated with intra-abdominal injury, especially of the bowel and mesentery. Figures of up to about half of cases are quoted, varying between series and with seat-belt type. Look for (and ask about) abdominal injury and a seat-belt bruise.

6. Other injuries and pathological fractures

• Fracture-dislocation: translation of one vertebra on another, involving all three columns. Highly unstable, often with neurological injury.
• Transverse process fractures: often stable in isolation, but in the upper lumbar spine (L1–L3) they can accompany renal injury, and multiple fractures signify substantial force.
• Pathological fractures through metastases or myeloma. Clues are destruction of a pedicle on the AP (the "winking owl" sign), a convex (bulging) posterior wall, an associated soft-tissue mass and involvement of the posterior elements. Osteoporotic fractures tend to have a preserved posterior wall and intact pedicles. MRI distinguishes them. See bone tumours.
• Ankylosing spondylitis and DISH: the fused spine is brittle; fractures can follow minor trauma, are often transverse through the disc and all three columns, and are easily missed on plain film. CT or MRI is needed.
• Non-contiguous fractures: once a spinal fracture is found, the rest of the spine should be imaged, because a second fracture at a different level is not rare.

7. Pitfalls and mimics

• Scheuermann disease: wedging of three or more adjacent thoracic vertebrae with irregular endplates and Schmorl's nodes in adolescents and young adults. A developmental condition, not an acute fracture.
• Limbus vertebra: a small corticated triangular fragment at the anterior corner of a vertebral body, caused by disc herniation through the ring apophysis. Smooth margins distinguish it from an acute fracture.
• Normal mild wedging of the mid-thoracic vertebrae and at the thoracolumbar junction. Compare with neighbouring levels and old films.
• Old fractures: a sclerotic, well-defined fracture with osteophytes is likely old. Comparison with previous imaging is essential; MRI shows marrow oedema in acute fractures.
• A normal plain film does not exclude a fracture, particularly in osteoporotic bone, in a rigid spine, and at the cervicothoracic junction where the shoulders obscure the view.

Red flags: act now

What to focus on, by role

Role	Priorities
Medical student	Three columns, wedge vs burst vs Chance, and the seat-belt association.
Nurse	Log-roll and spinal precautions according to local policy; escalate new neurological symptoms immediately.
Junior doctor	Treat suspected burst fractures as unstable until CT. Report fragility fractures with the word "fracture" and refer for bone health assessment.
Radiographer	True laterals without rotation; make sure the thoracolumbar junction is included on both thoracic and lumbar films.
Advanced / FRCR	TLICS and AO Spine, posterior ligamentous complex, osteoporotic vs pathological collapse, and the rigid spine.

Practise on real spine X-rays →

References

1. Genant HK, et al. Vertebral fracture assessment using a semiquantitative technique. J Bone Miner Res 1993;8:1137–48.
2. Denis F. The three column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine 1983;8:817–31.
3. Radiopaedia. Chance fracture. radiopaedia.org
4. NICE NG39. Major trauma: assessment and initial management. nice.org.uk
5. NICE NG59. Low back pain and sciatica in over 16s. nice.org.uk
6. Royal Osteoporosis Society. Vertebral fracture identification resources. theros.org.uk

For education only. Not a substitute for a formal report, senior review or your local policy. Never use this page to make decisions about a real patient.