Department of Orthopedics, Xi'an Jiaotong University Second Affiliated Hospital, Xincheng District, Shannxi, People's Republic of China.
Comput Assist Surg (Abingdon). 2021 Dec;26(1):49-57. doi: 10.1080/24699322.2021.1919210.
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.
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.
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.
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.
由于颈椎椎弓根螺钉置钉的穿孔率较高，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钉的准确性。
将 15 具 C2 至 C7 的人尸体颈椎随机分为 5 组，每组 3 个标本。本研究使用的螺钉直径为 3.5mm。第 1-4 组分别使用双层面板、单层面板双侧、单层面板单侧和单层面板点接触模板辅助。第 5 组没有任何导航模板。手术后，通过术后 CT 扫描评估五组螺钉放置的准确性，观察螺钉是否穿透椎弓根皮质。
共置入 180 枚螺钉，无任何意外。准确性分别为第 1 至 5 组的 75%、100%、100%、91.7%和 63.9%。所有模板组均明显高于第 5 组，而双层面板导航组明显低于其他三组模板组。手术时间分别为第 1 至 5 组的 4.72±0.28、4.81±0.29、5.03±0.35、8.42±0.36 和 10.05±0.52 分钟。无模板和点接触程序明显比模板程序耗时更长。
本研究表明，四种不同设计类型的导航模板在辅助颈椎椎弓根螺钉置钉方面的准确性均高于无模板置入。然而，与其他三种模板相比，双层面板的准确性最低。同时，这些模板在手术过程中避免了透视，并缩短了手术时间。将尸体研究转化为临床实践一直具有很大的挑战性。因此，我们设计的单层面板双侧、单侧和点接触导航模板需要经过精心测试，以验证其准确性和安全性。
