Experimental Study Of Pedicle Screw Implantation With 3D Printed Guide Plate For Upper Cervical Vertebra Deformity

Objective:Reverse engineering software and 3D printing technology were used to design personalized screw placement guide templates for patients with upper cervical deformities to assist in the implantation of upper cervical pedicle screws,and to evaluate the safety,accuracy and effectiveness of 3D printed guide plates in the implantation of pedicle screws with upper cervical deformities.Methods:The preoperative CT data of 13 patients with upper cervical deformity in the Imaging Center of the Second Affiliated Hospital of Bengbu Medical College from January 2019 to January 2021 were selected to design and print the individualized solid cervical model and guide plate of patients with upper cervical deformity in equal proportions.Experimental group: pedicle screw implantation assisted by 3D printing guide plate;Control group: Pedicle screws were implanted by hand with fluoroscopy.CT three-dimensional reconstruction was used to evaluate the safety and accuracy of the implanted screw.According to whether lateral perforation occurred,screws were divided into four categories: Class Ⅰ(not penetrated),Class Ⅱ(≤1mm)as safe placement,class Ⅲ(> 1mm,≤2mm),class Ⅳ(> 2mm)as unsafe placement.Results:64 pedicle screws were implanted in the two groups,respectively.The experimental group designed and printed 13 cases of 3D printing guide plate.56 class Ⅰ screws(87.50%),7 Class Ⅱ screws(10.94%),and 1 class Ⅲ screws(1.56%)were implanted by the guide template,and no class Ⅳ screws were placed.Nail safety rate of(98.44%);The average time of single screw insertion was(11.66±1.17)min.Average screw length(21.67±1.33)mm;The mean X-ray fluoroscopy was(2.69±0.61)times.The control group underwent pedicle screw implantation by hand under C-arm X-ray.Implanted Ⅰ class screw 41(64.06%),Ⅱ screw 14(21.88%),screw Ⅲ class 7(10.94%),class Ⅳ screw 2(3.13%).Safety rate of nail placement(85.94%);The average implantation time of single screw was(23.19±0.43)min.Average screw length(21.70±1.14)mm;The mean X-ray fluoroscopy was(8.66±0.72)times.The safety rates of the experimental group and the control group were 98.44%and 85.94%,respectively(P < 0.05).The fluoroscopy times and time of single screw implantation in the experimental group were better than those in the control group(P< 0.05).There was no significant difference in the length of single screw implantation between the two groups(P > 0.05).Conclusion : Mimics17 software can use the CT image data of patients with upper cervical deformity to clearly,accurately and intuitively reflect the complex structure of the upper cervical atlantoaxial vertebra,so as to facilitate the construction of the best nail entry channel and design and print the nail placement guide template with bilateral guide sleeve.Experimental studies have proved that the use of 3D printed guide plate for pedicle screw implantation in patients with upper cervical deformity significantly improves the safety,accuracy and effectiveness of screw placement.It also reflects that the effect of pedicle screw implantation in the cervical spine model of patients with upper cervical deformity by designing 3D printed guide plate to simulate the surgical process is worthy of recognition and completely feasible.Compared with manual screw placement,3D printing guide plate is safer,more efficient and more accurate for pedicle screw implantation in patients with upper cervical deformity.It breaks the original limitations of operation and is worthy of clinical promotion.