基于3D打印的颈椎后路椎弓根螺钉精准置入研究

Accurate insertion of posterior cervical pedicle screw based on 3D printing

目的探讨基于数字化设计和3D打印导航模块辅助颈后路椎弓根螺钉精准置钉的方法。方法10例颈椎解剖标本术前以0.625 mm层厚进行CT扫描,将CT数据导入Mimics软件三维重建出颈椎模型。Mimics设计颈椎双侧椎弓根螺钉钉道,设计分别与双侧颈椎椎弓根后部解剖结构卡位的带钉道导航模块并3D打印。在颈椎标本上进行3D打印导航模块辅助的颈椎椎弓根螺钉置入手术,按术前设计的进针点、方向和长度置入椎弓根螺钉,术后进行CT扫描评价手术效果。结果全部解剖标本手术均按术前设计准确实施,螺钉位置与术前设计高度一致,术后效果与术前设计无明显差异。结论数字化设计及3D打印技术能良好地指导颈椎后路椎弓根螺钉精准置入,操作简便,具备较高的可行性、安全性、精确性。

Objective To explore the method of accurate fixation of posterior cervical pedicle screw based on digital design and 3D printing navigation module.Methods Preoperative computed tomographic(CT)scans of 0.625-mm slice thickness were obtained from whole surgical area of ten anatomical specimens.The CT data were imported into Mimics.We developed a 3-dimensional full-scale model of the patient's cervical spine.Molds of the left and right sides at each vertebra were also constructed.One hole was made in each mold for the insertion of a screw guide.We performed a simulated surgery on all specimens usind the 3D printing navigation mold.The proper insertion point,direction,and length of the guide were also confirmed on the anatomical specimens.The screw positions in the sagittal and axial planes were evaluated by postoperative CT scan to check for malpositioning.Results The screw insertion was done in the same manner as the preoperative design.With the aid of this guide the pedicle screws could be easily inserted even at the level where the pedicle seemed to be very thin and sclerotic on the CT scan.Postoperative CT scan showed that there were no critical breaches of the screws.Conclusion This method seems to be easy and safe to use.The technique may improve the safety of pedicle screw insertion even in difficult cases with narrow sclerotic pedicles.