Sugawara Taku, Higashiyama Naoki, Kaneyama Shuichi, Sumi Masatoshi
Department of Spinal Surgery, Research Institute for Brain and Blood Vessels Akita, Akita, Japan.
Department of Orthopaedic Surgery, Kobe Rosai Hospital, Kobe, Japan.
Spine (Phila Pa 1976). 2017 Mar 15;42(6):E340-E346. doi: 10.1097/BRS.0000000000001807.
Prospective clinical trial of the screw insertion method for posterior C1-C2 fixation utilizing the patient-specific screw guide template technique.
To evaluate the efficacy of this method for insertion of C1 lateral mass screws (LMS), C2 pedicle screws (PS), and C2 laminar screws (LS).
Posterior C1LMS and C2PS fixation, also known as the Goel-Harms method, can achieve immediate rigid fixation and high fusion rate, but the screw insertion carries the risk of injury to neuronal and vascular structures. Dissection of venous plexus and C2 nerve root to confirm the insertion point of the C1LMS may also cause problems. We have developed an intraoperative screw guiding method using patient-specific laminar templates.
Preoperative bone images of computed tomography (CT) were analyzed using three-dimensional (3D)/multiplanar imaging software to plan the trajectories of the screws. Plastic templates with screw guiding structures were created for each lamina using 3D design and printing technology. Three types of templates were made for precise multistep guidance, and all templates were specially designed to fit and lock on the lamina during the procedure. Surgery was performed using this patient-specific screw guide template system, and placement of the screws was postoperatively evaluated using CT.
Twelve patients with C1-C2 instability were treated with a total of 48 screws (24 C1LMS, 20 C2PS, 4 C2LS). Intraoperatively, each template was found to exactly fit and lock on the lamina and screw insertion was completed successfully without dissection of the venous plexus and C2 nerve root. Postoperative CT showed no cortical violation by the screws, and mean deviation of the screws from the planned trajectories was 0.70 ± 0.42 mm.
The multistep, patient-specific screw guide template system is useful for intraoperative screw navigation in posterior C1-C2 fixation. This simple and economical method can improve the accuracy of screw insertion, and reduce operation time and radiation exposure of posterior C1-C2 fixation surgery.
采用患者特异性螺钉导向模板技术对C1-C2后路固定螺钉置入方法进行前瞻性临床试验。
评估该方法用于置入C1侧块螺钉（LMS）、C2椎弓根螺钉（PS）和C2椎板螺钉（LS）的疗效。
C1-LMS和C2-PS后路固定，也称为Goel-Harms法，可实现即刻坚强固定和高融合率，但螺钉置入存在损伤神经和血管结构的风险。解剖静脉丛和C2神经根以确定C1-LMS的置入点也可能引发问题。我们开发了一种使用患者特异性椎板模板的术中螺钉导向方法。
使用三维（3D）/多平面成像软件分析术前计算机断层扫描（CT）的骨图像，以规划螺钉的轨迹。使用3D设计和打印技术为每个椎板制作带有螺钉导向结构的塑料模板。制作了三种类型的模板用于精确的多步骤导向，并且所有模板都经过特殊设计，以便在手术过程中贴合并锁定在椎板上。使用该患者特异性螺钉导向模板系统进行手术，并在术后使用CT评估螺钉的置入情况。
12例C1-C2不稳定患者共置入48枚螺钉（24枚C1-LMS、20枚C2-PS、4枚C2-LS）。术中发现每个模板都能精确贴合并锁定在椎板上，螺钉置入成功完成，无需解剖静脉丛和C2神经根。术后CT显示螺钉未穿破皮质，螺钉与计划轨迹的平均偏差为0.70±0.42mm。
多步骤、患者特异性螺钉导向模板系统可用于C1-C2后路固定术中的螺钉导航。这种简单且经济的方法可提高螺钉置入的准确性，减少C1-C2后路固定手术的操作时间和辐射暴露。
3级。
