Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device
November 8th, 2024
The sagittal adjusting screw (SAS) system has been widely used for thoracolumbar (TL) spinal trauma. Percutaneous options and specialized trauma reduction devices are also available for the SAS system. We describe a technique for reducing TL burst fractures using an SAS system and a newly introduced trauma reduction device.
This procedure is used to treat thoracolumbar fractures. With this technique, surgeons can achieve effective reduction and stable fixation in a minimally invasive manner. We believe the most significant recent advancement in thoracolumbar fracture surgery is non-fusion fixation using percutaneous pedicle screws.
This technique is less invasive and preserves segmental motion after implant removal. There are two widely used techniques for thoracolumbar fracture fixation. The first is the Schanz screw system, which offers significant advantage in reducing burst fractures, but its implant too bulky for minimally invasive percutaneous use.
The second is the multiaxial pedicle screw system, which has the disadvantage of limited fracture reduction due to its mobile head. The SAS technique effectively addresses both of these limitations. We are currently investigating the relationship between mid to long-term outcomes in spine fracture patients and disc degeneration.
It is also known that postoperative spinal malalignment is associated with disc conditions. Our goal is to identify the patient group with suboptimal prognosis prior to fixation surgery, as these patients may require fusion. After positioning the patient prone and making the skin incision, place the needle at the intersection of the facet and transverse process, ensuring the vertebra is not rotated.
Gently tap the needle tip into the bone using a mallet. As the needle advances, confirm on the anterior-posterior image that the tip approaches the medial margin of the pedicle. Obtain a lateral image to confirm the needle tip is located anterior to the posterior wall of the vertebra and close to the intersection point.
Insert the guidewire through the cannulated hole of the needle. Ensure that the wire does not breach the anterior cortex. Next, using a one-millimeter undersized cannulated tap, tap into the vertebrae.
After assembling the tab extenders and cap onto the sagittal adjusting screws, insert the screws into the vertebrae. Position the inner guides of the reduction device onto the extenders, then attach the distractor module onto the extender posts, ensuring it is fully seated. After placing the lordosis modules in a neutral position, turn the distraction key to distract and obtain ligamentotaxis.
Stretch the posterior longitudinal ligament and reposition the vertebral body segments back into the vertebral body from the spinal canal to restore vertebral body height. Next, squeeze the handles to restore lordosis. Monitor the correction of lordosis under fluoroscopy and verify the final correction.
Measure the rod lengths using a rod ruler placed on the screw heads. For fractures at or below the mid thoracic level, insert the rods through the uppermost incision. Finally, apply set screws to fix the rod in position.
After treatment, the mean regional kyphotic angle improved by 5.0 degrees in the conventional SAS group and by 3.3 degrees in the new trauma device group. The percent anterior vertebral body height was increased in both groups.
Overview
This article discusses a technique for treating thoracolumbar fractures using the sagittal adjusting screw (SAS) system. The method allows for effective reduction and stable fixation in a minimally invasive manner.
Key Study Components
Area of Science
- Neurosurgery
- Orthopedic surgery
- Trauma management
Background
- Thoracolumbar fractures are common injuries that require effective surgical intervention.
- The SAS system is a widely used tool for managing these types of fractures.
- Minimally invasive techniques are preferred for reducing recovery time and preserving motion.
- Recent advancements include non-fusion fixation methods.
Purpose of Study
- To describe a new technique for reducing thoracolumbar burst fractures.
- To highlight the benefits of using the SAS system in conjunction with trauma reduction devices.
- To improve surgical outcomes for patients with thoracolumbar injuries.
Methods Used
- Utilization of the SAS system for fracture reduction.
- Incorporation of a newly introduced trauma reduction device.
- Minimally invasive surgical techniques.
- Comparison with traditional methods of fracture fixation.
Main Results
- The SAS system allows for effective reduction of burst fractures.
- Minimally invasive techniques lead to stable fixation.
- Non-fusion fixation preserves segmental motion post-implant removal.
- Surgeons can achieve better outcomes with less invasive methods.
Conclusions
- The SAS system is a valuable tool in thoracolumbar fracture surgery.
- Minimally invasive techniques enhance patient recovery.
- Future research may focus on optimizing these methods further.
Frequently Asked Questions
Executive Industry Relevance
Minimally invasive fixation for thoracolumbar burst fractures using sagittal alignment screws and trauma reduction devices addresses a critical need for effective, motion-preserving stabilization in spinal trauma. This technique enables precise anatomical restoration while reducing surgical morbidity, supporting improved long-term patient outcomes and portfolio differentiation in device innovation. The approach is strategically positioned at the intersection of surgical innovation and translational impact for orthopedic and neurosurgical R&D pipelines.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables quantitative assessment of spinal alignment restoration and vertebral body height as objective endpoints.
- Supports mechanistic de-risking by isolating the impact of sagittal correction on disc degeneration and long-term outcomes.
- Facilitates identification of patient subgroups with suboptimal prognosis for targeted intervention strategies.
Screening & Assay Development
- Provides standardized radiological metrics such as regional kyphotic angle and vertebral height loss for reproducible outcome measurement.
- Establishes validated imaging endpoints for device performance benchmarking and comparative studies.
- Enables scalable evaluation of new trauma reduction devices across diverse patient cohorts.
Translational & Preclinical Research
- Aligns radiological outcomes with clinically meaningful endpoints for translational continuity.
- Supports risk-adjusted advancement decisions by correlating anatomical correction with disc health and functional recovery.
- Offers a platform for preclinical modeling of spinal trauma interventions and device optimization.
Pipeline & Workflow Integration
This minimally invasive fixation method integrates into the continuum from device concept validation through clinical translation and post-market surveillance.
- Discovery Biology: Quantitative imaging and anatomical restoration metrics inform hypothesis testing on device efficacy and biological impact.
- Screening: Standardized radiological endpoints enable reproducible device evaluation and cross-study comparability.
- Analytics: Radiographic measurements provide actionable data for statistical analysis and outcome prediction.
- Translational Research: Links device performance to patient-centric outcomes, supporting regulatory and clinical advancement.
- Enterprise Reuse: The workflow and endpoints are adaptable for future device iterations and broader trauma applications.
Operational & Enterprise Impact
- Scientific Value: Enhances predictive confidence in device-mediated anatomical correction and functional preservation.
- Operational Value: Promotes standardization, reproducibility, and scalability in surgical device evaluation.
- Strategic Value: Informs go/no-go decisions and supports capital-efficient device development.
- Portfolio Impact: Enables risk-adjusted prioritization of trauma device candidates and supports evidence-based advancement.
Implementation Considerations
- Requires expertise in minimally invasive spinal instrumentation and radiological assessment.
- Demands access to fluoroscopic imaging and specialized reduction devices for intraoperative guidance.
- Necessitates cross-team standardization of radiological measurement protocols.
- Adaptation may be needed for different spinal levels or patient anatomies.
- Limitations include the need for careful patient selection and monitoring for postoperative alignment and disc health.
