Burst fracture involves fracture of BOTH anterior AND posterior columns of the vertebral body due to axial loading (compression force). It is an unstable fracture type according to the Denis 3-column model. First described by Holdsworth in 1963, classified by Denis with 3-column theory in 1983. The thoracolumbar junction (T12-L1) is the most commonly affected region (50-60%) — this is the transition point from rigid thoracic kyphosis to mobile lumbar lordosis where axial loading concentrates. Retropulsed fragment (displacement of posterior cortical fragment into the spinal canal) is the pathognomonic finding and may cause spinal cord or cauda equina compression. Neurological deficit rate is 30-60%. CT is the primary modality for fracture morphology and canal compromise assessment; MRI is complementary for spinal cord injury, posterior ligamentous complex (PLC) integrity, and bone marrow edema evaluation. TLICS and AO Spine classification systems guide treatment decisions. Burst fractures are subclassified as A3 (incomplete) and A4 (complete).
Age Range
18-65
Peak Age
35
Gender
Male predominant
Prevalence
Uncommon
The mechanism of burst fracture is based on application of high-energy axial compression force to the vertebral body. Typical mechanisms include falls from height (landing on back or feet), motor vehicle accidents, or diving injuries. Axial loading compresses the vertebral body equally from all directions — unlike simple anterior column compression, this leads to 360-degree bursting of the vertebral body. First, the nucleus pulposus is driven into the vertebral body by axial pressure, end-plates fracture, and internal pressure increase causes radial expansion. The posterior cortical fragment (retropulsed fragment) displaces into the spinal canal by centripetal force — causing epidural venous plexus and spinal cord/cauda equina compression. The vertical fracture line (sagittal split) results from axial compression equally splitting both halves. Posterior ligamentous complex (PLC) injury further decreases stability and strengthens surgical indication. On MRI, PLC injury is seen as interspinous hyperintensity on STIR — ligament edema/rupture creates long T2 and STIR hyperintensity. On CT, the retropulsed fragment is recognized by cortical bone density (>1000 HU) seen within the canal. Spinal canal compromise >50% indicates surgical decompression.
Displacement of the posterior vertebral cortical fragment into the spinal canal is the pathognomonic CT finding of burst fracture. The fragment is seen within the spinal canal at cortical bone density (>1000 HU) on axial CT. Midsagittal canal compromise ratio is critical for surgical decision — >50% strengthens surgical indication.
CT axial sections show displacement of the posterior cortical fragment into the spinal canal (retropulsion). The fragment is of cortical bone density (>1000 HU) and is clearly delineated within the canal. Midsagittal canal diameter is measured to calculate canal compromise ratio. Canal compromise >50% strengthens surgical decompression indication.
Report Sentence
Retropulsion of posterior cortical fragment into the spinal canal consistent with burst fracture, with canal compromise ratio calculated as approximately XX%.
CT axial sections show a vertical (sagittal) fracture line in the vertebral body. Sagittal split reflects axial compression splitting the vertebral body in half and is a characteristic CT finding of burst fracture. Coronal fracture line may also accompany (comminution).
Report Sentence
Vertical fracture line (sagittal split) in the vertebral body on axial CT sections, consistent with burst fracture.
MRI STIR sequence evaluates posterior ligamentous complex (PLC) integrity. In PLC injury, hyperintense signal (edema/rupture) is seen at interspinous/supraspinous ligament level. If PLC is intact, conservative treatment may be considered; if injured, surgical indication strengthens. PLC injury adds 3 points in TLICS scoring.
Report Sentence
Hyperintense signal at interspinous ligament level on STIR sequence, consistent with posterior ligamentous complex injury; supporting burst fracture instability.
In burst fracture, signal change within the spinal cord (T2 hyperintense — edema, contusion, myelomalacia) may be seen due to cord compression by retropulsed fragment. Acute T2 hyperintense cord signal change (cord edema/contusion) is a poor prognostic indicator. T1 hypointense + T2 hyperintense cord signal may be consistent with hemorrhage or myelomalacia.
Report Sentence
Spinal cord compression by retropulsed fragment with T2 hyperintense signal change within the cord, consistent with cord contusion/edema.
CT coronal reformats or AP view show increased interpedicular distance. Normal interpedicular distance gradually increases caudally (L1-L5). In burst fracture, axial bursting force causes bilateral lateral expansion, increasing interpedicular distance compared to levels above and below.
Report Sentence
Increased interpedicular distance at the fracture level, supporting lateral vertebral expansion consistent with burst fracture.
Criteria
Partial burst with fracture of one end-plate — superior or inferior end-plate involvement
Distinct Features
Single end-plate involvement, smaller retropulsed fragment, canal compromise usually <50%, lower neurological deficit risk; conservative treatment often sufficient (if PLC intact)
Criteria
Complete burst with fracture of both end-plates — complete fragmentation of vertebral body
Distinct Features
Bilateral end-plate involvement, large retropulsed fragment, high canal compromise (>50%), high neurological deficit risk; surgical treatment frequently needed
Criteria
Burst fracture with additional posterior ligamentous complex injury — transition to AO B2 class
Distinct Features
PLC injury addition increases instability; TLICS score ≥5 surgical indication; interspinous edema/rupture on STIR, facet subluxation, spinous process fracture may accompany
Distinguishing Feature
In compression fracture only anterior column is fractured — intact posterior wall, no retropulsion, no vertical fracture line, normal interpedicular distance. In burst fracture, anterior + posterior column fracture, retropulsed fragment, sagittal split, and increased interpedicular distance are present.
Distinguishing Feature
In pathologic burst fracture, underlying metastatic lesion should be investigated. In metastatic fracture, diffuse T1 hypointensity, diffusion restriction, epidural soft tissue mass, and multiple vertebral involvement favor malignancy. In traumatic burst fracture, acute edema pattern, trauma history, and absence of diffusion restriction support benign etiology.
Distinguishing Feature
In Chance fracture (flexion-distraction), horizontal fracture line passes through posterior elements (spinous process, lamina, pedicles) — compression anteriorly, distraction posteriorly. In burst fracture, axial loading is the dominant mechanism with characteristic vertical (sagittal) fracture line. Chance fracture may be accompanied by seatbelt sign and abdominal organ injury.
Urgency
emergentManagement
surgicalBiopsy
Not NeededFollow-up
specialist-referralBurst fracture is an unstable fracture type requiring emergency evaluation. Treatment decision is based on TLICS score and AO classification: TLICS <4 conservative, ≥5 surgical, 4 controversial. Surgical indications: neurological deficit, >50% canal compromise, PLC injury, progressive deformity. Surgical options include posterior stabilization (pedicle screw-rod system), anterior corpectomy + cage, or combined approach. Conservative treatment involves TLSO brace for 8-12 weeks. In patients with neurological deficit, urgent surgical decompression (<24 hours) improves neurological recovery chances. Long-term complications include post-traumatic kyphosis, chronic pain, and adjacent segment degeneration.
Burst fracture is an unstable fracture type with risk of neurological deficit. Spinal canal compromise and PLC integrity influence surgical decision. TLICS (Thoracolumbar Injury Classification and Severity) score is used for treatment guidance. Retropulsed fragment >50% canal compromise strongly indicates surgery. Urgent surgical decompression is needed if neurological deficit is present.