What are the indications for short versus long segment fixation surgery in thoracolumbar fractures?

Short Versus Long Segment Fixation for Thoracolumbar Fractures

For thoracolumbar burst fractures requiring surgical stabilization, short-segment fixation including screws in the fractured vertebra is the preferred approach, as it achieves equivalent clinical and radiological outcomes to long-segment fixation while reducing operative time, blood loss, and preserving motion segments. 1, 2, 3

Indications for Short-Segment Fixation

Short-segment fixation (one level above and one level below, WITH screws in the fractured vertebra) is indicated for:

• Burst fractures with McCormack Load-Sharing Classification (LSC) score ≤6 1
• Fracture-dislocations at the thoracolumbar junction (T11-L2) 1
• Patients where motion segment preservation is a priority 4, 3

The critical technical modification is inclusion of pedicle screws in the fractured vertebra itself, which provides superior biomechanical stability compared to traditional short-segment fixation that skips the fracture level 2. This technique has been validated even for severe unstable fractures (LSC ≥7), contradicting older recommendations that required anterior column reconstruction for high LSC scores 2.

Clinical Outcomes with Short-Segment Fixation Including Fracture Level

• Kyphosis correction: Mean improvement from 26.8° preoperatively to 4.3° postoperatively, with only 2.4° loss at final follow-up 1
• Operative efficiency: Mean operative time 58-94 minutes with blood loss 394-451 mL 1, 3
• Low complication rates: Infection in 4% and implant failure in 2% of cases 1
• Functional outcomes: Mean ODI of 17.5% and VAS of 1.6 at 2-year follow-up 1, 2

Indications for Long-Segment Fixation

Long-segment fixation (two or more levels above and below) is indicated for:

• Extremely unstable injuries requiring circumferential reconstruction 5
• Fracture-dislocations with severe posterior ligamentous complex disruption 5
• When short-segment fixation with fracture-level screws is technically not feasible 4

However, the evidence demonstrates that long-segment fixation offers no clinical or radiological advantage over properly executed short-segment fixation with fracture-level screws 4, 3. Long-segment constructs result in significantly increased operative time (81.5 vs 58.4 minutes) and blood loss (690 vs 451 mL) without improving kyphosis correction or functional outcomes 3.

The Fusion Question

Arthrodesis should be omitted from instrumented fixation for thoracolumbar burst fractures (Grade A recommendation). 6, 7

• Fusion does not improve clinical outcomes 6, 7
• Fusion does not improve radiological outcomes 6, 7
• Fusion increases operative time and blood loss without benefit 6, 7

This represents a paradigm shift from traditional teaching. The Congress of Neurological Surgeons provides Grade A evidence that instrumentation alone is sufficient for thoracolumbar burst fractures 6.

Surgical Approach Selection

The posterior approach is preferred for most thoracolumbar fractures, as anterior, posterior, and combined approaches yield equivalent clinical and neurological outcomes (Grade B recommendation) 6, 8. The posterior approach offers:

• Greater surgeon familiarity and lower complication rates 8, 7
• Ability to perform both decompression and stabilization through single incision 5
• Option for percutaneous technique with equivalent outcomes to open surgery (Grade B) 6, 7

Common Pitfalls to Avoid

• Skipping the fractured vertebra in short-segment constructs: Traditional short-segment fixation without fracture-level screws has high failure rates and progressive kyphosis 1, 2
• Overreliance on McCormack LSC for surgical planning: Even fractures with LSC ≥7 can be successfully managed with short-segment fixation including the fracture level, questioning the relevance of LSC in modern practice 2
• Unnecessary fusion: Adding arthrodesis increases morbidity without improving outcomes 6, 7
• Excessive segment inclusion: Long-segment fixation sacrifices motion segments without clinical benefit when short-segment fixation with fracture-level screws is properly executed 4, 3

Practical Algorithm

1. Confirm surgical indication (neurological deficit, instability, or progressive deformity)
2. Plan short-segment posterior fixation (one level above, fracture level, one level below)
3. Include pedicle screws in the fractured vertebra for load-sharing
4. Omit fusion unless specific contraindications exist
5. Consider percutaneous technique for reduced blood loss and operative time 6, 7
6. Reserve long-segment fixation only for extreme instability not amenable to short-segment technique