The Analysis Of The Effect Of Shape Of Bone Graft On Adjacent Segment Stress After Anterior Cervical Decompression And Fusion

The cervical injury is more and more,but also is fatal in recent years.For the cervical spondylitis myelopathy,most clinicians use the anterior decompression and fusion.The surgery is regard as the gold standard for the treatment of such diseases.However,adjacent segments degeneration is a long-term complication in clinical treatment operation.There are many factors affecting the degeneration of adjacent segments.ASD is also hot issue in the current medical research.The main purpose of this paper is to analyze the effect of height of bone graft on adjacent segment degeneration after anterior cervical decompression and fusion.In this paper,X-ray films were obtained by CT scanning and saved as point cloud files.The reverse modeling method was used to obtain the three-dimensional model based on the patient's X-ray film.Software was used to deal with point cloud files to generate an initial surface file of the cervical C3-C6 contour.A real three-dimensional geometric surface was generated by surface reverse processing software.The surface was imported into finite element preprocessing software to get the finite element model.Finally,Ansys was used for the finite element calculation after dividing the grid,defining the boundary conditions and other steps.The anterior cervical fusion was simulated by changing the material and shape of the C4-5 intervertebral disc.The change of the stress distribution in the adjacent intervertebral disc after the operation was analyzed.In case I,the height of intervertebral space was severely lost before surgery,only about 2.2 mm.We found the minimum stress on the adjacent disc with the intervertebral height of 8mm in simulation surgery.The anteroposterior height difference of C4-5 before operation in case II and III was very sick.Calculated and found that the minimum stress showed on the adjacent disc when intervertebral height difference is about 0-1mm.Therefore,according to the results of this article,for patients with severe loss of intervertebral height,intervertebral height should eventually be restored to about 8mm.For patients with abnormal intervertebral height difference,anteroposterior height difference should be maintained at about 0-1mm.Finite element method can be used to analyze the effect of different surgical treatment on adjacent segments stress by simulation surgery.Different patient symptoms should be taken a different shape of the bone graft to reduce the adjacent segment disc stress.The effect of operation on the adjacent segment disc degeneration was reduced to lowest.This conclusion can provide some reference for the actual operation.