数字化导航模板辅助儿童胸椎椎弓根螺钉置钉的准确性

背景：目前国内外学者已将椎弓根螺钉内固定技术应用于儿童脊柱损伤治疗中，儿童胸椎椎弓根细小，解剖结构变异大、毗邻关系复杂，如将以成人数据为依据的椎弓根螺钉技术简单地应用于处于不断生长发育的儿童，手术风险极大，提高置钉的准确性和降低失误率成为儿童椎弓根内固定技术能否深入开展的关键所在。 目的：利用计算机辅助设计与快速成型技术为儿童胸椎椎弓根螺钉置入提供一种个性化、精确化的定位方法。 方法：对4例儿童尸体标本CT 扫描后将原始数据利用软件进行三维重建，将标本随机分为2组：一组采用传统椎弓根内固定法，另一组采用逆向工程原理及快速成型技术设计并制造出个体化导航模板，利用个体化导航模板在标本上辅助置入腰椎椎弓根螺钉，随后分别根据CT 扫描评价椎弓根螺钉置钉位置。 结果与结论：传统椎弓根内固定法置钉准确率为58%；而个体化数字导航模板法的置钉准确率为81%，置钉成功率优于传统手术组，且经过卡方检验两者之间差异有显著性意义(P < 0.05)。提示个体化导航模板辅助儿童胸椎椎弓根螺钉置入具有较高的准确率，充分体现了置钉个体化原则，为儿童胸椎椎弓根螺钉的准确置入提供了一种新的可行的方法。中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程全文链接：

Accuracy of screw placement in child’s thoracic pedicle assisted by digital navigation template

BACKGROUND:Many scholars at home and abroad have already attempted to apply the technique of the internal fixation pedicle screw placement to cure children’s spinal injuries in recent years, because the children’s thoracic pedicle is more small, anatomical structure variation is big and adjacent relationship is complicated, so the application of adult’s pedicle screw technology simply to children who was in a continuous growth and development can increase operation risk greatly. Above this, improving the accuracy of nailing and reducing error rate become keys for further development of cervical pedicle fixation. OBJECTIVE:To provide an individualized and accurate positioning method for screw placement in thoracic  pedicle of children by computer aided design and rapid prototyping technology.  METHODS:After computed tomography scan of four cases of child specimens, the original data were made for three-dimensional reconstruction by the software, then the specimens were randomly divided into two groups: one group used the traditional pedicle internal fixation method, and the other group, first created the individual navigation template using the principle of reverse engineering and rapid prototyping technology. The lumbar pedicle screws were put into the samples by the individual navigation template. The position of the pedicle screws was evaluated according to the computer tomography scan. RESULTS AND CONCLUSION:The accurate rate of screw placement of the traditional pedicle internal fixation method was 58%; and the accurate rate of screw placement of the individual digital navigation template method was 81%. The success rate was better than the traditional surgery group. Furthermore, chi square test showed that there was a significant difference between two groups (P < 0.05). These findings suggested that there has a high accuracy of the screw placement in thoracic pedicle of children assisted by the individual navigation template, fully reflects the principle of individualization of screw placement, and provides a new feasible method for accurate screw placement in thoracic pedicle of children.