| Objective: To investigate the biomechanical properties of hollow lag screw with inverted type and diamond type in the treatment of femoral neck fracture by using finite element model.Methods: 1.3D CT image datas of normal volunteers with a thickness of0.6258 mm were stored in Dicom format and imported into Mimicsl 15.0 medical image processing software.After threshold segmentation,region growth,threshold editing and 3D reconstruction,and established the 3D model of femur.Then import the above files into the Geomagic12.0 software and complete the construction of the surface model by grid processing,curve extraction,surface establishment,grid establishment and surface fitting,etc.Then the surface model was imported into ProEngineer5.0 software to build a 3D solid model.Finally,the document was entered into SolidWorks software,and 30°,50° and 70° were selected for three simulated osteotomy operations.2.The cannulated screw model was built in ProEngineer5.0software,and then the "inverted triangle" and "diamond" shapes were selected in Solidwork to perform Boolean operation on the cannulated screw and the femur model as required to complete the assembly of each model.Then mesh division and material attribute assignment are carried out in Hypermesh software to obtain nodes and cells.Finally,the file is imported into Ansys13.0 to analysis.The stress distribution,peak value and proximal displacement of femur and internal fixation were recorded.Results: The stress of the hollow pressure screw was concentrated in the middle region near the fracture end,and the stress distribution of the proximal femur and internal fixation in the rhomboid-fixed fracture model was more dispersed,the peakvalue was smaller,and the femur displacement was minimal.Conclusions: The results showed that the displacement is smaller,the stress dispersion is more significant and the biomechanical stability is better. |
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