Imaging And Clinical Study Of New Localization Of Lower Lumber Pedicle Screw Entry Points

Background and Purpose:After years of development,the pedicle screw system has been widely used in the operation of spinal degeneration,trauma,deformity,inflammation,tuberculosis and tumor.Risk of immobilization failure and potentially severe neurovascular injury due to pedicle screws placed in the wrong position.Therefore,improving the accuracy of pedicle screw becomes the key.At present,a variety of technologies that rely on advanced equipment have been developed,including X-ray assist technology and navigation aid technology.However,these technologies have the disadvantages of complex operations,radiation exposure,or high cost compared with free-hands technology.Traditional free-hands technology is still indispensable,but there are also problems such as low accuracy of placement and long learning curve.Therefore,it is particularly important to find a free-hands technology with simple operation and high accuracy.The purpose of this study is to explore the feasibility of positioning the lumbar pedicle screw entry point with the crest of lumbar vertebrae and the lateral edge of the articular process.Methods: Thirty patients with lumbar spinal stenosis,lumbar disc herniation,or lumbar spondylolisthesis who underwent single-segment posterior lumbar internal fixation(PLIF)were measured the Intersection of point of the Crest of lumbar vertebrae and the lateral margin of articular process by CT coronal position.To determined whether the point is located in the section in the sagittal and transverse,as the basis of clinical validation.Of the first 15 patients,the entry points of the left pedicle screw are locatedusing the horizontal line between the midpoint of the transverse process and the articular process joint.On the right side,the intersection of the lumbar lamina extension line and the perpendicular line of the lateral margin of the superior joint process is used as the entry point.The last 15 patients did the opposite.The time and the accuracy of placement,the amount of bleeding,and the size of the wound were compared between the two groups.Results:(1)Of the 180 entry points,174 were located in the vertebral pedicle section at the corresponding transverse position and sagittal position,while the 6 entry points were slightly deviated or located at the edge.The imaging positioning accuracy was about 96.67%.(2)In the traditional method,53 Marks were located in the pedicle cortical,and 7 Marks were located outside the pedicle cortical,with an accuracy of88.34%.In the new method,55 Marks were located in the pedicle cortical,and 5 Marks were located outside the pedicle cortical,with an accuracy of 91.67%.The average time was 6.79±1.06 min.The accuracy of the new method is slightly higher than that of the traditional method,and the difference is not statistically significant(P=0.625),and results are moderately consistent(?=0.586).The determination time of the new method was significantly shorter than that of the traditional method,and the difference was statistically significant(t=11.844,P<0.001).(3)In the traditional method,among the 60 pedicle screws,13.33%(8/60)of the pedicle screws had cortical rupture,and the degree of pedicle cortical rupture was all within 2mm,with an accuracy of 86.66%(52/60).In the new method,among the 60 pedicle screws,10%(6/60)of the pedicle screws had cortical rupture,and the degree of pedicle cortical rupture was all within2 mm,with an accuracy of 90.00%(54/60).The accuracy of the new method is slightly higher than that of the traditional method,and the difference is not statistically significant(P=0.687),and results are moderately consistent(?=0.444).Conclusion: The new method is proved to be safe and effective through imaging and clinical practice.The time to determine the entry point is significantly shorter than traditional methods.The exposure is simple.The accuracy of entry point determination and pedicle screw placement accuracy can reach the classic traditional method.Itprovides a simple,easy to operate and effective positioning method for determining the entry point of the lower lumbar pedicle screw.