Instrumentation at the Fracture Level for Burst Fractures
Instrumentation at the fracture level provides significantly greater biomechanical stability in burst fractures compared to traditional short-segment fixation without fracture-level screws. 1, 2, 3
Biomechanical Advantages of Fracture-Level Instrumentation
Fracture-level screw placement offers several key advantages:
- Enhanced construct stiffness: Adding screws at the fracture level improves overall construct stability by approximately 68% compared to conventional short-segment posterior fixation 3
- Better kyphosis correction: Fracture-level screws provide superior intraoperative correction and maintenance of sagittal alignment 1, 2
- Improved height restoration: Studies show significantly better compression ratio of anterior vertebral height when fracture-level screws are incorporated 2
- Comparable to longer constructs: Fracture-level screw reinforcement provides stability comparable to long-segment fixation but preserves more motion segments 3
Clinical Outcomes with Fracture-Level Instrumentation
Research demonstrates significant clinical benefits:
- Better radiographic parameters: Statistically significant improvements in sagittal index (p<0.001), local kyphosis angle (p=0.006), and compression ratio of anterior vertebral height (p=0.002) when fracture-level screws are used 2
- Maintained correction: Fracture-level screws help maintain the correction achieved intraoperatively over time, which is particularly important in short-segment constructs 1
- Reduced hardware failure: The additional point of fixation decreases stress on adjacent-level screws, potentially reducing hardware failure rates
Practical Application
For thoracolumbar burst fractures:
- Short-segment fixation with fracture-level screws is preferable to traditional short-segment fixation (one level above and below without fracture-level screws)
- Consider fracture severity:
- Stable burst fractures: Short-segment with fracture-level screws may be sufficient
- Unstable burst fractures: Fracture-level screws can make short-segment constructs viable, potentially avoiding the need for long-segment fixation
Important Considerations and Caveats
- Pedicle integrity: Ensure the pedicles at the fracture level are intact enough to accept screws
- Vertebral body comminution: Extreme comminution may limit the effectiveness of fracture-level screws
- Alternative augmentation: For severely unstable fractures, consider additional anterior column support through vertebroplasty/kyphoplasty 4 or anterior approaches
- Rehabilitation concerns: Overly aggressive physical therapy should be avoided in the early postoperative period to prevent fixation failure 5
Fracture-level screw placement represents a valuable technical advancement in the treatment of thoracolumbar burst fractures, offering improved biomechanical stability while preserving motion segments compared to traditional long-segment constructs.