Finite Element Model Of The Lumbar Spine And Biomechanics Analysisy

Objective:1)To reconstruct the finite element model of L1-L5 motion segment with the Mimics and Hyper Mesh for the further study of biomechanical analysis. The results of the finite element model were matched to the results of the vitro experiment of biomechanics.2)The finite element model of the intact lumbar spine was modified to study the biomechanical changes as a result of surgical alteration for treatment of stenosis at L3-L4 and L4-L5 using three techniques.Methods:1)CT scanning was conducted to the spine (L1-L5) of the healthy volunteer with the layer of 0.75mm to get 129 images. The cross-section images were output JPG format. The three-dimensional finite elements model of L1-L5 vertebrae structure was constructed by the combination of Mimics and Hyper Mesh. Besides, endplates and joint cartilage intervertebral disc and ligament structure including were also simulated. Using appropriate material properties and unit types on the model of an intelligent finite element mesh. Between the high and the low articular process adopts the surface-surface contact theory to carry on processing. And The results of the finite element model were compared with the results of the vitro experiment of biomechanics.2)A validated finite element model was modified treatment of stenosis at L3-L4 and L4-L5 with the same boundary conditions and physical loads to study the motion and loading in the annulus changes at the surgical site as a result of surgical alteration for using three techniques.Results:1)The three-dimensional finite element model was built structure integrity, with good geometric similarity. The number of units and nodes were divided more than the previous model s. The results of the finite element model were matched to the results of the vitro experiment of biomechanics. Moreover, this model could be used for finite element mechanics analysis of various lumbar vertebrae. The introduction of contact theory finite element model can improve the reliability and auteenticity.2)The current study suggests that the removal of posterior lumbar spinal elements for the treatment of stenosis at L3-L4 and L4-L5 produces a graded increase in motion at the surgical site, with the greatest changes occurring in flexion-extension and axial rotation and that during lateral bending the amount of resection only slightly affected.Conclusion:1)Finite element model of lumbar motion segment can be rapidly, accurately established with Mimics and Hyper Mesh, and improve the results of the analysis of the reliability and accuracy. Throughout the reconstruction process to maximize the excluded man-made interference, and embodies the easy, efficient, accurate, and the height of the modeling advantages of automation. The introduction of contact theory finite element model can improve the reliability and auteenticity.2)The data show that for flexion-extension and axial rotation the increases in motion are correlated to the extent of posterior element removal. While a thorough decompression, the reservation should be the maximum posterior structure, can be a corresponding decrease postoperative intervertebral disc, facet structure of the stress, and delay the degenerative lumbar spine.