Anterior Cervical Fusion And Artificial Disc Replacement Of Three-dimensional Finite Element

Purpose:1. To build a set of valid three dimensional finite element model for C3-C7cervicalvertebra.2. Based on the built cervical vertebra three dimensional finite element model, applythree dimensional finite element method to analyze the internal fixingbiomechanics property of the two different operations of cervical vertebraanterior fusion and non-fusion.Method：1． To do CT scan of the cervical vertebra for a healthy male adult and gain theDICOM format tomographic images, then import them into Mimics softwareto generate the IGS format point cloud model, And import the cloud model tothe Geomagic software to generate higher precision geometric model, andthen import the IGS formate geometric model into Hypermesh software to dogrid division and give the materials characteristics of each part of the cervicalvertebra, and generate the three dimensional finite element model, And thendefine the boundary condition and loading mode, and calculate in theLSDYNA software. Apply the same boundary condition and load as theprevious records research to built three dimensional finite element model,give single or multiple torque load of front flexion, back extension, sideflexion, axial rotation, calculate the range of motion of each segment, andcompare the calculated results with the previous research to verify the validityof the model.2． Apply two sets of different operation embedding fixer into the built C3-7cervical vertebra model, One set with C5&C6vertebras cut completely,embedding iliac bone between C4-C7, titanium plate fixed in the front ofC3-C7vertebras, then excise C3/C4intervertebral disk and implantintervertebral fusion cage; the other set with C5&C6vertebras cut completely, iliac implantation titanium plate fixing, C3/4intervertebral disk excise andartificial cervical vertebra disk implantation. Apply the same boundarycondition and loading to the two sets of models separately so as to bettercompare the biomechanics properties of the two different implants of cervicalartificial disk implantation and Cage implantation.Results:1.2. As for each loading directions for fusion&non-fusion operation methods’three dimensional finite element model, the cervical artificial disk’s motionrange decreased remarkably comparing to comparing normal cervical vertebra,especially at the front flexion and back extension loadings; between the Cageteam and the cervical artificial disk replacement group, the C3, C4and C7vertebras’ back structure appeared obvious stress concentration. Comparingwith the two different groups of Cage implantation and cervical artificialdisk replacement,the C3appeared obvious stress concentration. Cervicalartificial disk replacement appeared much more obvious stress concentrationto the normal group.Cage implantation appeared increased stress than cervicalartificial disk displacement in front anteflexion, axial rotation,sideflexion,and cervical artificial disk appeared decreased stress than cageimplantation,only a small increase in back extension.Conclusion:1. Built C3-C7three dimensional finite element model for normal person, whichcan be used for the biomechanics research and evaluation.2. The cervical corpectomy combined with artificial cervical vertebra diskreplacement group possess better biomechanics properties than Cagegroup,reserves better range of motion,and delays adjacent joint degenerationin the treatment of long segment cervical spondylotic myelopathy...