Design And Biomechanical Analysis Of New Type Internal Fixation Of The Zygomatical Arch Fracture

Objective To establish the3D solid model of zygomatic arch with the method offinite element model based on the date scanned by Spiral-CT.Simulating bone sectionand designing a new kind of Ni-Ti SMA material type internal fixation device ofzygomatic arch fracture.Plan to establish a finite element model of the zygomatic archfracture fixation and make a simulation test of the stability of the model.To provide aproof and experimental foundation for researching this new type fixation device in thefuture.Methods One heathy adult volunteer was chosen. Get the DICOM data rang fromsupraorbital margin to inferior border of mandible scanned by Spiral-CT.The data wasused to establish zygomatic arch3D model after some edit such as Threholding、EditeMasks、 Region Growing and Morphological operation by Mimics10.01;Thenre-constructed to the NURBS surface with the soft of Geomagic studio9.0;The3D solidmodel of zygomatic arch which can be separated from cortical bone and spongy bonewas obtained by the use of UG NX5.0;To design a new type fixation device andestablish a fracture model on the basis of the3D solid model of zygomatic arch,then putthe fixation device placed in predetermined positions.A finite element model of thezygomatic arch fracture fixation was established after meshing and define the materialproperties.to define contact and constraint the degree of freedom of the model,loadsimulation experiment,simulating concentrated force loading experiment on the finiteelement model,the size of the force points10N、30N、60N、90N、120N、150N six level,recording the displacement and stress distribution of the model in differentconditions.Results The model of the new type fixation device was established,the devicecomprises a support plate and8fixing claws,fixed in the zygomatic arch inner side andwrapped around the upper end and lower end; a finite element model of zygomatic archfracture fixation was established and it conclude52977elements and87116nodes;Thestress and displacement were obvious linear distribution with the gradually increase ofthe concentrated force loaded on the most lateral of the finite element model, but thestress concentration area and maximum displacement position of the finite elementmodel did not vary with the size of stress chang,the stress mainly concentrated in thesupport plat and fixing claws,the maximum displacement of zygomatic model is locatedthe the lower edge of the intermediate bone, the maximum displacement of the modeldoes not exceed1mm when the load is less then50N, the force loaded on the model ishigh up near100N while the force effect point displacement is1mm.Conclusion The result of the biomechanical analysis about the stability of the newtype fixation device was satisfy.It provide a effective and feasible foundation for furtherresearch.