Abstract

Purpose

Due to the high perforation rate of cervical pedicle screw placement, we have designed four different types of rapid prototyping navigation templates to enhance the accuracy of cervical pedicle screw placement.

Methods

Fifteen human cadaveric cervical spines from C2 to C7 were randomly divided into five groups, with three specimens in each group. The diameter of pedicle screw used in this study was 3.5 mm. Groups 1–4 were assisted by the two-level template, one-level bilateral template, one-level unilateral template and one-level point-contact template, respectively. Group 5 was without any navigation template. After the surgery, the accuracy of screw placement in the five groups was evaluated using postoperative computed tomographic scans to observe whether the screw breached the pedicle cortex.

Results

A total of 180 pedicle screws were inserted without any accidents. The accuracy rate was 75%, 100%, 100%, 91.7%, and 63.9%, respectively, from Groups 1 to 5. All the template groups were significantly higher than Group 5, though the two-level navigation template group was significantly lower than the other three template groups. The operation time was 4.72 ± 0.28, 4.81 ± 0.29, 5.03 ± 0.35, 8.42 ± 0.36, and 10.05 ± 0.52 min, respectively, from Groups 1 to 5. The no template and point-contact procedures were significantly more time-consuming than the template procedures.

Conclusion

This study demonstrated that four different design types of navigation templates achieved a higher accuracy in assisting cervical pedicle screw placement than no template insertion. However, the two-level template’s accuracy was the lowest compared to the other three templates. Meanwhile, these templates avoided fluoroscopy during the surgery and decreased the operation time. It is always very challenging to translate cadaveric studies to clinical practice. Hence, the one-level bilateral, unilateral, and point-contact navigation templates designed by us need to be meticulously tested to verify their accuracy and safety.

中文翻译：

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四种不同设计的快速原型导航模板对颈椎椎弓根螺钉置入的准确性：一项人体尸体研究

摘要

目的

由于颈椎椎弓根螺钉置入的穿孔率较高，我们设计了四种不同类型的快速成型导航模板，以提高颈椎椎弓根螺钉置入的准确性。

方法

取C2～C7的15具人体颈椎，随机分为5组，每组3个标本。本研究中使用的椎弓根螺钉直径为 3.5 mm。第 1-4 组分别由二级模板、一级双边模板、一级单边模板和一级点接触模板辅助。第 5 组没有任何导航模板。手术后，通过术后计算机断层扫描评估5组螺钉置入的准确性，观察螺钉是否突破椎弓根皮质。

结果

总共插入了180颗椎弓根螺钉，没有任何意外。1~5组的准确率分别为75%、100%、100%、91.7%和63.9%。所有模板组均显着高于第5组，但二级导航模板组显着低于第5组比其他三个模板组。第 1 组至第 5 组的手术时间分别为 4.72 ± 0.28、4.81 ± 0.29、5.03 ± 0.35、8.42 ± 0.36 和 10.05 ± 0.52 分钟。模板程序。

结论

本研究表明，与不插入模板相比，四种不同设计类型的导航模板在辅助颈椎椎弓根螺钉置入方面实现了更高的准确性。但是，与其他三个模板相比，二级模板的准确度是最低的。同时，这些模板避免了手术过程中的透视，减少了手术时间。将尸体研究转化为临床实践总是非常具有挑战性的。因此，我们设计的单级双边、单边、点接触式导航模板需要经过精心测试，以验证其准确性和安全性。