Section of Neurosurgery, Department of Neuroscience, University of Turin, Turin, Italy.
Section of Neurosurgery, Department of Neuroscience, University of Turin, Turin, Italy.
World Neurosurg. 2019 Jun;126:e1468-e1474. doi: 10.1016/j.wneu.2019.03.121. Epub 2019 Mar 20.
Pedicle screw instrumentation is a standard procedure in lumbar spinal fusion. The cortical bone trajectory (CBT) screw is an alternative technique, less invasive but harder to perform. The identification of the entry point and the appropriate direction can be tricky especially to the surgeons just at the beginning. Therefore, the aim of this study is to evaluate the reliability of preoperative computed tomography (CT) planning in the CBT screw placement.
We retrospectively evaluated 82 patients who underwent a single-level posterior lumbar arthrodesis with CBT screws. The correct entry point and the best trajectory were identified on a 3-dimensional (3D) multiplanar reconstruction CT view. The concordance between achieved and planned trajectories was assessed on a postoperative CT.
A total of 328 screws was positioned. The average entry point distance from the target was 1.1 mm (standard deviation, ±0.15 mm). In 301 screws (91.8%), the obtained trajectory differed no more than 2° from the planned one. No screws misplaced or new neurological deficit was recorded.
The CBT screw placement is a great alternative to the pedicle screw. Accurate preoperative 3D planning is useful to predict the entry point and the direction with accuracy similar to navigation systems, avoiding its costs and technical difficulties. The 3D CT planning is helpful in the customization of spine surgery, and the results underline the radiological reliability of this technique.
椎弓根螺钉固定是腰椎融合术的标准程序。皮质骨轨迹（CBT）螺钉是一种替代技术，侵入性较小但更难操作。尤其是对于刚开始的外科医生来说，确定进钉点和合适的方向可能很棘手。因此，本研究旨在评估 CBT 螺钉放置的术前计算机断层扫描（CT）规划的可靠性。
我们回顾性评估了 82 例接受单节段后路腰椎融合术的患者，使用 CBT 螺钉。在三维（3D）多平面重建 CT 视图上确定正确的进钉点和最佳轨迹。在术后 CT 上评估实际轨迹与计划轨迹的一致性。
共定位 328 枚螺钉。平均进钉点距离目标 1.1 毫米（标准差 ±0.15 毫米）。在 301 枚螺钉（91.8%）中，获得的轨迹与计划轨迹相差不超过 2°。未发生螺钉移位或新的神经功能缺损。
CBT 螺钉固定是椎弓根螺钉的理想替代方法。准确的术前 3D 规划有助于准确预测进钉点和方向，其准确性可与导航系统相媲美，同时避免其成本和技术难度。3D CT 规划有助于脊柱手术的定制，其结果强调了该技术的放射学可靠性。
