ABSTRACT

Objective

To explore the corridor for atlas pedicle screw placement perpendicular to the coronal plane and to develop patient-specific navigation templates for pedicle screw placement.

Methods

This study is a retrospective analysis. A total of 71 patients (41 males and 30 females) were involved in this study from June 2016 to June 2018, and they were divided into a template group (39 patients) and a conventional group (32 patients). The CT-based 3D reconstruction models were analyzed in the template group. From the perspective of the 3D atlas in a coronal view, the pedicle corridor was obtained. Taking the center of the tangential circle of the pedicle as the entry point, we simulated screw placement perpendicular to the coronal plane. Then, the individual navigation template was designed and used in surgery. In the conventional group, free-hand pedicle screw placement was performed perpendicular to the coronal plane. The diameter of the maximum tangential circle and screw length of the pedicle corridor were measured in the template group. The surgical time, radiation exposure time, screw grading criteria and so on were evaluated and compared between the two groups after surgery.

Results

;The diameter of the maximum tangential circle and the distance between the entry point and posterior tubercle were significantly greater in males than in females. The operation was successfully completed in all patients, without aggravation of nerve injury, and the follow-up was 12-20 months, with an average of 15.6 months. A total of 78 screws were inserted in the template group, and 64 screws were inserted in the conventional group. The surgical times in the template group and conventional group were 76.47±24.44 min and 125.63±36.41 min, respectively. The radiation exposure times in the template group and conventional group were 3.51±1.77 and 10.15±4.95, respectively, and there was a significant difference between the two groups. In the template group, the deviation in the screw entry point and screw angle were 1.92±1.67 mm and 2.08±1.98°, respectively. The medial angle deviation between the left and right sides was 2.71±1.88° in the template group, which was significantly less than the deviation of 3.76±2.22° in the conventional group.

Conclusion

A pedicle screw trajectory perpendicular to the coronal plane can be quickly obtained based on the perspective of 3D models. The technique of screw placement perpendicular to the coronal plane assisted by navigation templates has a shorter operative time, lessintraoperative fluoroscopy and a higher safety of screw placement than traditional surgery.

中文翻译：

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C1椎弓根螺钉垂直于冠状面置入的三维解剖分析和导航模板：一项回顾性研究

摘要

客观的

探索垂直于冠状面的寰椎椎弓根螺钉置入通道，并开发针对患者的椎弓根螺钉置入导航模板。

方法

本研究为回顾性分析。2016年6月至2018年6月共纳入71例患者（男性41例，女性30例），分为模板组（39例）和常规组（32例）。在模板组中分析了基于 CT 的 3D 重建模型。从冠状位 3D 图谱的角度，获得了椎弓根走廊。以椎弓根切线圆的中心为切入点，模拟垂直于冠状面的螺钉放置。然后，设计了个人导航模板并在手术中使用。在常规组中，徒手椎弓根螺钉放置是垂直于冠状面进行的。在模板组测量椎弓根通道的最大切圆直径和螺钉长度。术后对两组手术时间、辐射暴露时间、螺钉分级标准等进行评价比较。

结果

;最大切圆的直径和入口点与后结节之间的距离男性明显大于女性。所有患者均顺利完成手术，无神经损伤加重，随访12～20个月，平均15.6个月。模板组共插入螺钉 78 颗，常规组插入螺钉 64 颗。模板组和常规组的手术时间分别为76.47±24.44 min和125.63±36.41 min。模板组和常规组的辐射暴露时间分别为3.51±1.77和10.15±4.95，两组比较有显着性差异。模板组螺钉进入点和螺钉角度的偏差分别为1.92±1.67 mm和2.08±1.98°，分别。模板组左右内侧角偏差为2.71±1.88°，明显小于常规组3.76±2.22°的偏差。

结论

基于3D模型的视角，可以快速获得垂直于冠状面的椎弓根螺钉轨迹。与传统手术相比，导航模板辅助冠状面垂直置钉技术手术时间短，术中透视少，置钉安全性更高。