Application Of 3D Printing Technology In Preoperative Evaluation Of Small And Narrow Pedicle Internal Fixation

Objective: To design and apply 3D printing to individualized vertebral body,and its auxiliary application value before surgery in patients with thoracolumbar fracture accompanied by narrow vertebral pedicle.Methods: jilin province people’s hospital in October 2018 to June 2020 received hospital for hospitalized trauma patients with thoracic lumbar fracture clinical information,select the CT screening to determine the injured vertebra and adjacent vertebral body up and down at least one vertebral pedicle of narrow deformity,and conform to the application of nail fixation surgery patients with indications of rod system.The observation group included 25 patients,11 males and 14 females,with an average age of 51.52 years.After the original CT data were exported,the original data were imported into Mimics(3D modeling software)in DICOM format,and the 1:1 simulation model of the vertebral body was established using Mimics,which was sliced by the supporting software(CURA)in the 3D printing machine.The printed model was used as the simulated prosthesis for in vitro surgical design and surgical rehearsal.Among them,25 patients with thoracolumbar fracture who did not receive preoperative exercise assisted by this technique were enrolled as the control group.They were matched for age,sex,Cobb Angle and Frankel classification.Results: The observation group and the control group were treated by posterior screw rod system internal fixation.Before the operation,the 1:1 simulation reduction of the vertebral bodies of 25 patients using 3D printing showed no difference in the anatomical morphology of the vertebral bodies exposed during the real internal fixation,and the effect of screw placement was good.After surgery,CT,X ray and other auxiliary means were compared,and the position of pedicle screws was basically the same as that of the preoperative model,and the position of screw placement was accurate.The intraoperative comparison between the two groups was as follows: in the observation group,144 pedicle screws were placed,the average operative time was 96.40 min,the average intraoperative radiation was 12.32 times,the average intraoperative blood loss was 90.64 ml,and the accuracy of pedicle screws placement was 97.22%.In the control group,132 pedicle screws were placed,the average operation time was 136.80 min,the average intraoperative radiation was 17.80 times,the average intraoperative blood loss was 139.56 m L,and the accuracy of pedicle screws placement was 89.39%.The difference was statistically significant(P<0.05).The ratio of anterior vertebral height compression before and after operation was significantly lower in the control group than in the observation group.Cobb Angle of the observation group was still significantly better than that of the control group before and after treatment,the difference was statistically significant(P<0.05).Conclusion: 3D printing technology was used to print models of injured vertebrae and the upper two adjacent vertebrae,and personalized customized surgical plan and surgical simulation were performed before surgery.This assistive technology make in case of deformity,narrow pedicle cases through the posterior pedicle fixation more convenient and accurate finish nailing process,but also avoid the operation of the additional tissue damage,reduce intraoperative length nailing,avoid exposure to radiation edge time is too long and bled,etc,to ensure patient safety.