The Finite Element Simulation Research On The Stability And Biomechanics Of The Endoscopic Transoral-transpharyngeal Approach To Atlanto-axis

Objective:Then a normal C0-C1 spine model was established by using of the scanning data.(Established by a senior). pathology models was established basing on that normal model. And it was used to studied on stability and biomechanics of cervical spine.Methods:(1) The coordinate data was got by SCT. Then the picture data was converted to ASCII cloudy point. The point data was deal with CATIA software. GEOMAGIC STUDIO and CATIA were used to establish geometry model. The pre-post was carried out by HYPERMESH and LS-DYNA. The finite model was loaded and validated by some test data.(2) Establish two pathology models basing on the validated normal model according to the two operations which are the prior fusion of the atlas and axis with a removal dens and the posterior fusion of the atlas and axis with a removal dens.(3) The underside of C2 was fixed, and the movement of neck was simulated such as pitching, lateral curvature, circumgyration.Results: 1) According to the operation method, the elements of normal model were deleted corresponding to the removal parts in the operation. Then two pathology models were established which were the prior fusion of the atlas and axis with a removal dens and the posterior fusion of the atlas and axis with a removal dens. Boundary conditions were loaded into model to simulate some motions of cervical spine. The results show that the excision of dens leads to augment of facet territory, and fusion reconstructs the stability of cervical vertebra, but the facet territory is lack. The contours of stress shows that the two pathology models' stress are both increased. The prior fusion of the atlas and axis's stress was increased obviously in lateral flexion, and the posterior fusion of the atlas and axis' stress was increased obviously around lateral block in extension.Conclusion: two pathology models were established basing on the normal model, two pathology models were used to simulate the motions of cervical spine and helped study on stability and biomechanics of cervical spine.; it provided the theory for cervical operations...