Instantaneous Three-dimensional Kinematic Study Of Lumbar Disc Deformation Under Different Loads

Objective:In this study,the instantaneous three-dimensional kinematics characteristics of lumbar disc deformation under different load conditions in normal subjects were studied by means of biPlane fluorescence fluoroscoPy?dual fluoroscoPic imaging system,DFIS?combined with MRI/CT,and the height distribution of lumbar intervertebral disc in Chinese was obtained.The kinematic Parameters of a new tyPe of bionic artificial intervertebral disc design,3D Printed artificial cage and finite element model were established.the Pathogenesis of intervertebral disc degeneration was exPounded from the biomechanical Point of view.Methods:A total of 10 healthy volunteers,5 males and 5 females,aged 21?39years,with an average age of 32±5 years,were recruited.Using the combination of DFIS and CT,the sagittal images of L3-S1 segments scanned by CT were transformed into three-dimensional reconstruction models,and then matched to the instantaneous images of lumbar sPine motion taken by double fluorescent X-ray system under different loads.To reProduce the instantaneous motion state of lumbar vertebrae in different Postures?standing Position,flexion Position and extension Position?under different loads,assisted by comPuter related software,The kinematic data of lumbar disc height,lumbar intervertebral disc angle and intervertebral disc tension-comPression deformation and shear deformation were obtained.Results:The intervertebral disc angles of L3-4,L_4-5 and L₅-S₁ were the smallest in the anterior flexion Position and the largest in the Posterior extension Position under different loads and Postures,and the difference was statistically significant?P<0.05?.At the same time,with the increase of load,the angle of intervertebral disc also increased gradually.EsPecially in 10kg,it was the most obvious,but the statistical difference was not significant.The average height of L3-4 disc was 9.54±1.47mm,that of L_4-5 disc was 9.86±1.80mm,and that of L₅-S₁ disc was 9.25±2.80mm,the difference was statistically significant?P<0.05?.The distribution trend of lumbar disc deformation is different under different loads and Positions.with the increase of load,the comPression deformation increases and the tensile deformation decreases gradually.Conclusion:With the gradual aggravation of the load,the intervertebral disc height,intervertebral disc angle and intervertebral disc deformation of lumbar vertebrae in different Positions changed significantly,esPecially when the load reached 10kg.