Li Jie, Zhao Liu-Jun, Zheng Min-Zhe, Gan Kai-Feng, Chen Yi-Lei, Feng Zong-Xian, Pan Ling-Xiao, Xu Jun-Xiang, Fan Teng-di, Chen Jing-Yang, Zhao Feng-Dong
Department of Orthopaedics, Sir Run Run Shaw Hospital Affiliated to Zhejiang University School of Medicine, Hangzhou 310016, Zhejiang, China.
Zhongguo Gu Shang. 2021 Jan 25;34(1):45-50. doi: 10.12200/j.issn.1003-0034.2021.01.009.
To compare accuracy of anterior cervical pedicle screws between assist of rapid prototyping 3D guide plate and free-hand insertion, and evaluate the safety of two methods.
Eight adult cervical cadaver specimens after formaldehyde immersion, including 4 males and 4 females, aged 32 to 65(40.3±5.6) years old. After X-ray examination to exclude bone damage and deformity, 4 of them (3D guide plate group) randomly selected were for CT scan to obtain DICOM format data, and the data was imported into Mimics software for model, designed the ideal entry point and nail path for anterior cervicaltranspedicular screw (ATPS). After obtaining the personalized guide plate of the nail channel, it was exported as STL data, and the individual guide plate was printed by rapid prototyping and 3D printing technology. In turn, with the assistance of 3D guide plates, one-to-one personalized ATPS screws were placed on the four lower cervical cadaver specimens. Another 4 (free-hand group) lower cervical cadaver specimens were implanted with ATPS screws using free-hand technique. All specimens were performed CT thin-layer scanning and three-dimensional reconstruction after operation. The Tomasino method was used to evaluate the safety of the screws on the CT cross-sectional and sagittal images, to determine whether there was a cortical puncture of the lower and inner edges of the pedicle. According to the CT rating results, gradeⅠandⅡwere safe, and grade Ⅲ- Ⅴ were dangerous.And the accuracy of screws was recorded and analyzed between two groups.
Two screws were inserted in each segment from C to C in 8 adult cadavers. A total of 80 screws were inserted, 40 in the 3D guide plate group, and 40 in the free-hand group. The Tomasino screw rating method was used to evaluate the safety of screw, 21 screws were gradeⅠ, 14 screws were gradeⅡ, 3 screws were grade Ⅲ, 1 screw was grade Ⅳ, 2 screws were grade Ⅴ in 3D guide plate group, while 14 screws were gradeⅠ, 8 screws were gradeⅡ, 8 screws were grade Ⅲ, 6 screws were grade Ⅳ, 2 screws were grade Ⅴ in free-hand group. The safety rate of 3D guide plate group was 87.5%, and 55.0% of the free hand group (=8.7, =0.003).
The 3D printing rapid prototyping guide plate assisted insertion of the anterior cervical pedicle screw can significantly improve the accuracy and safety, and provide a theoretical basis for further clinical application.
比较快速成型3D导板辅助下与徒手植入颈椎前路椎弓根螺钉的准确性，并评估两种方法的安全性。
8例经甲醛浸泡的成人颈椎尸体标本，男4例，女4例，年龄32至65岁（40.3±5.6岁）。经X线检查排除骨质破坏及畸形后，随机选取其中4例（3D导板组）行CT扫描获取DICOM格式数据，将数据导入Mimics软件进行建模，设计颈椎前路椎弓根螺钉（ATPS）的理想进钉点及钉道。获取个性化钉道导板后，导出为STL数据，采用快速成型及3D打印技术打印出个体化导板。依次在3D导板辅助下，对4例下颈椎尸体标本一对一植入个性化ATPS螺钉。另4例（徒手组）下颈椎尸体标本采用徒手技术植入ATPS螺钉。所有标本术后均行CT薄层扫描及三维重建。采用Tomasino法在CT横断面及矢状面上评估螺钉的安全性，判断椎弓根下内缘是否有皮质穿孔。根据CT分级结果，Ⅰ级和Ⅱ级为安全，Ⅲ - Ⅴ级为危险。记录并分析两组螺钉的准确性。
8例成人尸体颈椎每节段均植入2枚螺钉，共植入80枚螺钉，3D导板组40枚，徒手组40枚。采用Tomasino螺钉分级法评估螺钉安全性，3D导板组中21枚螺钉为Ⅰ级，14枚为Ⅱ级，3枚为Ⅲ级，1枚为Ⅳ级，2枚为Ⅴ级；徒手组中14枚螺钉为Ⅰ级，8枚为Ⅱ级，8枚为Ⅲ级，6枚为Ⅳ级，2枚为Ⅴ级。3D导板组的安全率为87.5%，徒手组为55.0%（χ² = 8.7，P = 0.003）。
3D打印快速成型导板辅助植入颈椎前路椎弓根螺钉可显著提高准确性及安全性，为进一步临床应用提供理论依据。
