An Application Basic Study On Atlanto-axial Vertebral Pedicle Screw Individualization Placement Of Medical Three Dimensional Reconstruction Combined With 3D Printing Technology

Objective:1、To summarize and discuss the morphology changes by measuring national people’s atlanto-axial vertebrae parameters of three-dimensional reconstruction.2 、 Using computer-aided design,reversal engineer theory and 3D printing technology,to design a digital navigation templates,which could be assistant to atlanto-axial vertebrae pedicle screw fixation,and to find a relatively simple and accurate method for atlanto-axial vertebrae pedicle screws fixation.Method:1、Cervical CT tomography data of national people are collected to reconstruct an atlanto-axial vertebrae 3D model by using the software of mimics.Measuring atlanto-axial vertebrae pedicle screw parameters of three-dimensional anatomical in the computer,to collect and analysis those datas,whether they have statistical significant.2、On the basis of anatomical study,using computer-aided design,reversal engineer theory,designing atlanto-axial vertebrae pedicle screw digital navigation template,and using 3D printing technology to produce atlanto-axial vertebral models and their matched pedicle screw navigation templates.Surgical simulation pedicle screw is fixed on the model,to make sure accuracy and feasibility of digital navigation simple template.Result:1 、 Making atlanto-axial three-dimensional digital model of 60 patients successfully,measuring and collecting the parameters of both sides of atlanto-axial vertebral pedicle screw,and comparing them with each other.If P values>0.05,no significant difference between the left and right side.Adding each side datas respectively,and calculate the average and standard deviation of both sides.Atlas pedicle nail is 27.72 ± 2.35mm;the point of nail is away from post-midline about20.46 ± 1.51mm;the width of atlas pedicle was 11.03 ± 0.72mm;the atlas pedicle adjacent to vertebral artery groove,the thinnest height is 4.74 ± 1.32 mm,the thickestheight is 5.24 ± 1.20mm;the atlas pedicle on vertebral artery pressure trace,the thickness of pedicle is 3.83 ± 1.17mm;the optimal screws entry into atlas pedicle,the internal inclination angel is about 8.4 ± 2.0 °;the elevation angle is about7.8 ±1.7 °.The optimal length of nail into axis pedicle is about 27.17 ± 2.10 mm,narrowest pedicle height is 9.84 ± 1.27 mm,a width of axis pedicle is7.54 ± 1.44 mm,the optimal screws entry into atlas pedicle,the internal inclination angel is about 17.0 ±1.2 °,the elevation angle is about 37.0 ± 2.7 °.2 、 Designing and producting 10 kinds of personalized atlanto-axial vertebral pedicle screw navigational template,navigational templates march with print three-dimensional model to simulate surgical pedicle screw implantation.The navigational templates are marched with the corresponding surface of the model accurately.Opening the pedicle model along the pedicle nails,the direction、angel and entry piont of pedicle screws are correct,measured parameters are consistent between pre-operation and pos-operation.The result of scientific application shows that navigational template design is simple and practical.Conclusion:1 、 The study is based on using CT scan data to reconstruct atlanto-axial vertebrae’s three-dimensional model,and measuring those atlanto-axial pedicle anatomical data in the software of Mimics,which includes three-dimensional measurement technology.There are important significances for researching the upper cervical anatomy;and we could make sure those datas of the implantation of pedicle screw before surgery;the technology has a guiding function for the surgical procedure.2 、 Using computer-aided design,reverse engineering theory,3D printing technology to produce atlanto-axial vertebral models and their matched pedicle screw navigational template.Aided by the atlanto-axial pedicle screw navigational template,the implantation of pedicle srew is high accuracy and simple.Although there are still a lot of deficits,the prospect of orthopedic surgery is bright.