Neurosurg Focus. 2024 Dec 1;57(6):E13. doi: 10.3171/2024.9.FOCUS24431.
An increasing number of studies have shown that a robotic guidance system (RGS) can provide accurate cervical pedicle screw (CPS) placement. The accuracy of CPS placement with an RGS has mostly been evaluated according to the magnitude of pedicular cortical violation. However, an RGS assists in pedicle screw (PS) placement by directly indicating the preplanned trajectory in the operative field. Therefore, investigating how accurately the planned trajectory is executed is essential to determine the accuracy of CPS placement using an RGS, in addition to evaluating the clinical accuracy. Hence, this study aimed to evaluate the accuracy of CPS placement using an RGS by comparing the executed trajectory with the planned trajectory.
This prospective study analyzed 174 CPSs placed between C2 and C6 in 39 consecutive patients who underwent cervical fusion surgery using an RGS. The deviation of the executed CPS trajectory from the planned trajectory was measured at the entry point and at a depth of 20 mm in both the axial and sagittal planes on CT images. Additionally, its direction was noted (lateral or medial in the axial plane and cephalad or caudal in the sagittal plane). These measurements were analyzed according to spinal levels (C2 and C3-C6), laterality (right and left sides), and registration material (preoperative and intraoperative CT images). Furthermore, clinical accuracy was assessed using the Neo classification (grades 0-3).
Overall, the mean (± SD) deviations from the planned trajectory at the entry point and at a depth of 20 mm were 0.79 ± 0.65 mm and 0.86 ± 0.69 mm in the axial plane and 0.88 ± 0.81 mm and 0.82 ± 0.79 mm in the sagittal plane, respectively. When separately examining the deviations according to spinal level, laterality, and registration material, the mean deviations were < 1 mm at any point. Analysis of the deviation direction showed that the CPSs were placed divergently from the planned trajectory in the axial plane. In the sagittal plane, the CPSs were likely to be inserted parallel to the planned trajectory. However, at C2 the CPSs were placed in the caudal direction relative to the planned trajectory. Regarding clinical accuracy, the acceptable rates (grades 0 and 1) were 97.7% and 97.1% in the axial and sagittal planes, respectively, without any CPS-related complications.
This study suggests that an RGS can reliably execute planned trajectories, aiding accurate CPS placement in clinical settings.
越来越多的研究表明，机器人制导系统（RGS）可实现精确的颈椎椎弓根螺钉（CPS）置钉。CPS 置钉的准确性主要根据椎弓根皮质破坏的程度来评估。然而，RGS 通过直接在手术视野中指示预定的轨迹，辅助椎弓根螺钉（PS）置钉。因此，除了评估临床准确性外，研究如何精确执行计划轨迹对于确定使用 RGS 进行 CPS 置钉的准确性至关重要。因此，本研究旨在通过比较执行轨迹与计划轨迹，评估使用 RGS 进行 CPS 置钉的准确性。
本前瞻性研究分析了 39 例连续患者的颈椎融合手术中使用 RGS 进行的 174 例 CPS 置钉。在 CT 图像上，在入口点和 20mm 深度处，测量执行的 CPS 轨迹与计划轨迹在轴向和矢状面的偏差。此外，还记录了其方向（轴向平面中的外侧或内侧，矢状面中的头侧或尾侧）。根据脊柱水平（C2 和 C3-C6）、侧别（右侧和左侧）和注册材料（术前和术中 CT 图像）对这些测量值进行分析。此外，使用 Neo 分类（0-3 级）评估临床准确性。
总体而言，入口点和 20mm 深度处的计划轨迹偏差在轴向平面和矢状平面上分别为 0.79±0.65mm 和 0.86±0.69mm，0.88±0.81mm 和 0.82±0.79mm。分别单独检查脊柱水平、侧别和注册材料的偏差时，任何点的平均偏差均<1mm。偏差方向的分析表明，CPS 在轴向平面上偏离计划轨迹发散。在矢状面中，CPS 更倾向于沿计划轨迹平行插入。然而，在 C2 处，CPS 相对于计划轨迹朝向尾侧插入。关于临床准确性，在轴向和矢状平面上，可接受率（0 级和 1 级）分别为 97.7%和 97.1%，没有与 CPS 相关的并发症。
本研究表明，RGS 可以可靠地执行计划轨迹，有助于在临床环境中实现精确的 CPS 置钉。
