Department of Orthopaedic Surgery, National Hospital Organization, Murayama Medical Center, 2-37-1 Gakuen, Musashimurayama, Tokyo, 208-0011, Japan.
Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Neurosurg Rev. 2020 Aug;43(4):1135-1142. doi: 10.1007/s10143-019-01140-1. Epub 2019 Jul 3.
Cortical bone trajectory (CBT) can facilitate both minimum invasiveness and strong screw fixation; however, ensuring the ideal cortical trajectory is challenging due to the narrow corridor, necessitating high-level surgical skill. A patient-specific template guide for CBT screw placement may be a promising solution to improve accuracy and safety. Little has been reported on the use of a CBT screw guide in clinical practice. The aim of the present study was to evaluate the accuracy of CBT screw placement using the template guide. This study was a retrospective clinical evaluation of prospectively collected patients. Forty-three consecutively enrolled patients who underwent posterior lumbar spinal fusion using the guide system were included. First, three-dimensional planning of CBT screw placement was performed using computer simulation software. The trajectory was directed in a more anterior position of the vertebral body, compared with the original CBT, and the standard size was set as 5-6 mm in diameter and 40-45 mm in length. Then, screw guides were created for each vertebra preoperatively and used. The safety and accuracy of a total of 198 inserted screws (L1 to L5) were analyzed using postoperative computed tomography by evaluation of pedicle perforation and measurement of screw deviations between the planned and actual screw positions. A total of 193 screws (97.5%) were placed completely inside the pedicle and there was no incidence of neurovascular injuries. The mean screw deviation from the planned trajectory on the coronal plane at the midpoint of the pedicle was 0.62 ± 0.42 mm, and the mean angular deviations in the sagittal and transverse planes were 1.68 ± 1.24° and 1.27 ± 0.77°, respectively. CBT screw placement using a patient-specific template guide was accurate enough for clinical application. This technique could be an effective solution to achieve both correct screw insertion and a reduction of complications.
皮质骨轨道 (CBT) 既能实现最小的侵入性，又能增强螺钉固定；然而，由于狭窄的通道，确保理想的皮质骨轨道具有挑战性，这需要高水平的手术技能。针对 CBT 螺钉放置的患者特异性模板导向器可能是提高准确性和安全性的有前途的解决方案。关于在临床实践中使用 CBT 螺钉导向器的报道很少。本研究旨在评估使用模板导向器进行 CBT 螺钉放置的准确性。本研究是一项对前瞻性收集的患者进行的回顾性临床评估。纳入了 43 例连续接受导板系统后路腰椎融合术的患者。首先，使用计算机模拟软件对 CBT 螺钉放置的三维规划进行。该轨迹位于椎体的更前位置，与原始 CBT 相比，标准尺寸设定为 5-6mm 直径和 40-45mm 长度。然后，术前为每个椎骨创建螺钉导向器并使用。通过术后 CT 评估椎弓根穿孔和测量计划与实际螺钉位置之间的螺钉偏差，分析总共 198 个（L1 到 L5）插入螺钉的安全性和准确性。总共 193 个螺钉（97.5%）完全置于椎弓根内，没有发生神经血管损伤。在椎弓根中点的冠状面，螺钉偏离计划轨迹的平均值为 0.62±0.42mm，矢状面和横断面的平均角度偏差分别为 1.68±1.24°和 1.27±0.77°。使用患者特异性模板导向器进行 CBT 螺钉放置的准确性足以用于临床应用。该技术可以作为一种有效的解决方案，实现正确的螺钉插入和减少并发症。
