Finite Element Analysis Of Biomechanical Study On Treatment Of Tibial Fracture With Fracture Reduction Fixator

Research purpose(1)A three-dimensional finite element model of the fracture reduction fixture was established,and the effectiveness of the model was verified by physical mechanics experiments;(2)Comparison of different needle diameters,materials,and proximal fixation needles of the fracture reduction fixture with respect to the tibia Displacement of proximal fracture fragments of fractures was evaluated to assess the mechanical stability of fracture reduction fixtures for tibial fractures.Research methods(1)Using the CAXA 3D solid design software to perform a 1:1 three-dimensional geometric modeling of the fracture reduction fixture and assemble it according to clinical practice.Use the Marc finite element analysis software to perform 50N,100N,150N,200N of the fracture reduction fixture model.Axial load;fix the fracture reduction fixture to mechanics universal testing machine and perform axial loading experiment;compare the relationship between finite element calculation and physical mechanics experimental force and displacement.(2)Using Mimics 10.0 medical image processing software,the tibial fracture model was initially established using the CT scan of the sacrum;the CAXA 3D solid design software was used to assemble the fracture reduction fixture to the tibial fracture model according to clinical practice,and a fracture reduction fixture was established.Treatment of tibial fractures with different fixed needle diameters(2.5mm,3.0mm,3.5mm,4mm),material(stainless steel,titanium alloy),and proximal fixation needle insertion point(flat tibial tubercle height,20mm after tibial tubercle,22.5 Models of mm,25mm,27.5mm,30mm,32.5mm,and 35mm were loaded with axial loads of 50N,100N,150N,and 200N on the medial and lateral tibial plateaus to simulate the force of the tibial plateau in the standing position,by observing the proximal fibula fracture.The displacement of the fracture block in the horizontal plane,sagittal plane,and coronal plane was evaluated to evaluate the mechanical stability of the fracture reduction fixture in the treatment of tibial fractures.Research result(1)The axial stiffness of the fracture reduction fixture was measured to be 85.4 N/mm,the axial stiffness of the FEM model was 88.5 N/mm,and the ratio between the finite element calculation and the measured results was 1.037.(2)At the same axial load,the larger the fixed needle diameter of the fracture reduction retainer,the smaller the displacement of the proximal humerus fracture block in the horizontal,sagittal,and coronal planes;The displacement of the proximal humerus fracture block in the horizontal plane,sagittal plane,and coronal plane is small.The closer the proximal puncture needle is to the posterior humerus,the smaller the displacement of the proximal humerus fracture block in the horizontal,sagittal,and coronal planes.Conclusion(1)The validity of the three-dimensional finite element model and calculation method of the fracture reduction fixture.This modeling and calculation method can be used for related research of fracture reduction fixture.(2)The diameter of different fixed needles in the fracture reduction fixture can affect the displacement of the proximal humerus fracture block.The larger the fixed needle diameter,the stiffness of the fracture reduction retainer.(3)The stainless steel material for fracture reduction retainer is more rigid than titanium alloy.(4)The position of the proximal transfixion of the fracture reduction retainer can affect the sagittal displacement of the proximal humerus fracture block.The proximal position of the transfixion needle is closer to the posterior edge of the humerus,and the displacement of the proximal humerus fracture block in the sagittal plane is smaller.