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.
