个体化导航模板辅助儿童下颈椎椎弓根螺钉置钉准确性实验研究﹡

Experimental study on screw insertion in lower cervical pedicle assisted by digital navigation template to lower cervical pedicle stereotaxy in child

目的利用计算机辅助设计与快速成形技术为儿童下颈椎椎弓根螺钉置入提供一种个性化、精确定位的方法。方法对6具颈椎尸体标本进行CT扫描,根据CT扫描资料,利用逆向工程原理及快速成型技术设计制造出个体化导航模板,利用个体化导航模板在尸体标本上辅助置入胸椎椎弓根螺钉,所有螺钉的置入由同一位具有腰椎椎弓根螺钉置钉经验但无颈椎椎弓根螺钉置钉经验的骨科医师进行操作,随后根据CT扫描评价椎弓根螺钉位置。结果共设计制作30个导航模板,辅助置入60枚颈椎椎弓根螺钉,CT扫描发现所有螺钉均准确置入相应椎弓根内。结论数字化导航模板辅助下颈椎椎弓根螺钉置钉准确性高,操作简单,为儿童下颈椎椎弓根螺钉的准确置入提供了一种新的、可行方法。

Objective To provide a new method in the accuracy of pedicle screw placement in lower cervical vertebraes of Child using computer-aided design.Methods A novel individual navigation template was developed by reverse engineering and rapid prototyping according to pre-operative CT data of 6 child cervical vertebraes.The templates were used for lower cervical vertebraes screw placement in the cadavers.All screws were implanted by an experienced orthopaedic surgeon in the lumbar spines but not in the cervical vertebraes.Subsequently,CT scan were performed to evaluate the screw orientation associated with the pedicle axis.Results 60 cervical pedicle screws assisted by 30 digital navigation templates were placed in lower cervical vertebras.CT scan findings showed all screws were accurately nailed into the corresponding pedicles.Conclusion Pedicle screw placement assisted by digital navigation templates is highly accurate and simple.It is a new alternative to lower cervical pedicle stereotaxy of child.