Thoracolumbar Spine Fractures

The Thoracolumbar Injury Classification and Severity Score (TLICS) is the most widely used classification for guiding treatment decisions. It adds three components, morphology, PLC status and neurological status, and the total points to the treatment.

Morphology (1-4 points)

Posterior ligamentous complex (0-3 points)

Neurological status (0-3 points)

Reading the neurology score. A complete cord or conus injury scores lower than an incomplete one, because there is less neural tissue left to protect; salvageable cord is the strongest argument for decompression, and it earns the highest neurological score. Cauda equina injury is scored as its own category at 3, alongside incomplete cord injury. It is not an extra point added to another row, and the maximum for this component is 3.

The AO Spine thoracolumbar system is the worldwide standard for T1-L5 injuries, built by international consensus to replace the cumbersome Magerl/AO 3-3-3 scheme. It grades three axes separately: morphology, neurology and modifiers. The morphology has three types of increasing severity.

Neurology is graded separately: N0 intact, N1 transient deficit, N2 radiculopathy (nerve root), N3 incomplete cord or any cauda equina injury, N4 complete cord, and NX not assessable. The case modifiers are M1, an indeterminate PLC on MRI, and M2, a patient or comorbidity factor such as an ankylosing spinal disorder.

Which image decides the type. The posterior wall on CT separates an A1 wedge from an A3/A4 burst; plain films show height loss and kyphosis but cannot assess it reliably. The PLC on MRI STIR separates Type A from Type B. A Type C is defined by displacement, and even a modest listhesis on the lateral means complete bony and/or ligamentous disruption. A burst fracture with translation is a C, not an A.

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Using it to decide. Neurology drives the decision. Any deficit of N2 or above, or a Type B or C injury, is a strong-to-near-absolute operative indication. Most Type A injuries (A0-A2, and A3/A4 when neurologically intact with acceptable alignment) are managed non-operatively, and a complete cord injury (N4) at the thoracolumbar level still warrants decompression and stabilisation to facilitate rehabilitation.

TL AOSIS. The TL AO Spine Injury Score integrates all three axes: 3 or less conservative, 4-5 surgeon's choice, over 5 surgical.

AO or TLICS. AO provides excellent morphological description, but TLICS is more practical for treatment decisions as it directly incorporates neurological status and the PLC into a scoring system.

Denis's historical classification is based on mechanism and column involvement.

Compression fractures are anterior column failures:

• Type A: both endplates
• Type B: superior endplate
• Type C: inferior endplate
• Type D: anterior cortex buckling

Burst fractures are anterior and middle column failures:

• Type A: both endplates
• Type B: superior endplate
• Type C: inferior endplate
• Type D: burst-rotation
• Type E: lateral burst

Seat-belt injuries are middle and posterior column failures in tension, and fracture-dislocations fail all three columns. In Denis's scheme a compression fracture is stable and a burst fracture potentially unstable.

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Who. TLICS 0-3: compression fractures with an intact PLC and some burst fractures with TLICS less than 4, in a neurologically intact patient with a stable fracture pattern.

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The osteoporotic compression fracture. The other half of the bimodal distribution is the osteoporotic vertebral compression fracture (VCF), where the problem is bone quality rather than high-energy instability. Most are managed conservatively with analgesia, early mobilisation and a brace if needed, and, crucially, with osteoporosis treatment: calcium and vitamin D, antiresorptives or anabolics, and a fracture-liaison referral.

Cement augmentation. For the subgroup with severe, persistent pain and an unhealed fracture, with marrow oedema on STIR confirming acuity, cement augmentation of the vertebral body is an option:

• Vertebroplasty - cement injected directly
• Balloon kyphoplasty - a balloon creates a cavity and partly restores height before low-pressure cement

The evidence is genuinely contested. Early sham-controlled trials (INVEST, Buchbinder) showed no benefit over placebo, whereas VAPOUR (early, severely painful acute fractures) and the VERTOS trials suggested faster pain relief in carefully selected acute cases. Augmentation is therefore reserved for the acutely painful, non-healing fracture, not routine use. Always exclude a pathological or malignant cause before augmenting, and remember that augmentation treats the pain, not the underlying osteoporosis.

Absolute indications

• TLICS 5 or more
• Neurological deficit with ongoing compression
• Fracture-dislocation (translational injury)
• Progressive kyphosis
• Polytrauma requiring early mobilisation

Relative indications

• TLICS 4 (if PLC questionable)
• More than 30 degrees kyphosis
• More than 50% canal compromise (controversial)
• Unable to brace (body habitus, burns)
• Patient preference

Timing. An incomplete neurological deficit with compression is urgent. Most unstable injuries are operated on early, at 24-72 hours, and stable injuries needing surgery for other reasons are less urgent.

Posterior pedicle screw fixation is the most common approach for thoracolumbar fractures. It is used for burst fractures with PLC injury, distraction/flexion injuries, fracture-dislocations and most TLICS 5+ injuries.

The short-segment trend. Short-segment fixation, one level above and one below, is the current trend because it preserves motion segments. Adding screws in the fractured vertebra, the index level, improves kyphosis control and reduces implant failure.

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Indications for anterior corpectomy and reconstruction

• Significant anterior column deficiency (more than 50% body loss)
• Retropulsed fragment for direct decompression
• Failed posterior approach
• Kyphosis correction

Approach by level

• Thoracotomy for T10-L1
• Retroperitoneal (flank) for L1-L4
• Thoracoabdominal for the thoracolumbar junction

Technique. Corpectomy of the fractured vertebra with removal of the discs above and below, direct decompression of the canal, a structural graft or cage, and anterior plate fixation.

The trade-off. It is more morbid than a posterior-only approach but gives good kyphosis correction. It may be combined with a posterior approach if instability is severe, and is worth considering in younger patients with significant anterior column loss.

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Consent. Neurological injury is rare if there is no deficit before surgery. Consent also covers infection, hardware failure, the need for revision or additional levels (5-10%), adjacent segment disease as a long-term risk, and DVT/PE; their rates are in the complications table.

Equipment

• Imaging - fluoroscopy or navigation
• Pedicle screws - appropriate sizes, polyaxial heads
• Rods - pre-contoured or malleable
• Decompression instruments - if laminectomy is planned
• Cell saver - for major reconstructions

Indications for direct decompression

• Neurological deficit with canal compromise
• Fragment not reducible with ligamentotaxis
• Ongoing compression on post-reduction imaging

Direct or indirect. Direct decompression is a laminectomy at the fractured level with removal of the retropulsed fragments. The alternative is indirect reduction by distraction.