Distal Tibial Articular Surface Defect Finite Element Model And Biomechanical Analysis

Background: With the rise of digital medicine, the development ofcomputer technology, the use of finite element analysis has been widely usedfor research of bone and joint biomechanics, but about distal tibial articularsurface defect finite element analysis, there is no such reports at home andabroad.Objective: Establish ankle three-dimensional finite element model,produced a different area of the defects of the distal tibial articular surface,andsimulated the distal tibial articular surface deformation and displacementunder the different phases.Predict distal tibial articular surface defectmaximum allowable degree and the pathogenesis of the ankle traumaticarthritis about mechanics,provide a theoretical basis for clinical application.Methods: Continuous tomographic images is obtained by multi-slicespiral CT scan of a normal adult male ankle,and import the Mimics Medicinemodeling software to generate a entity model, the application of largegeneral-purpose finite element analysis software ANSYS13.0meshing, andmaterial property assignment generate a finite element model. Constraintboundary conditions, simulation ankle distal end axial force, and drawn thefinite element model of the articular surface of the distal tibial stressdistribution and displacement results in different phases.Results and Conclusion: The total number of units of the establishedfinite element model of the ankle is157,990, and the total number of nodes is193,801. On three phase,with the increase of the distal tibial defect area, thecontact area gradually decreases, especially in10degrees of the plantarflexion, the most obvious changes in the area of the defect diameter13mm;The contact area on the three phase, contact area of the neutral position is thelargest; the neutral position and10degrees of the dorsiflexion with the distal tibial defect area increasing, the peak stress gradually increasing, the peakstress is significantly increased after11-13mm; and the peak stress is mainlyconcentrated in the posteromedial and posterolateral quadrants;more complexchanges,11-13mm in10degrees of the plantar flexion, with the defect areaincreasing the peak stress changes significantly increased to13mm peak stressreaches a maximum. Therefore, the distal tibial articular surface maximumdefect diameter is11-13mm.Circular area of articular cartilage and bone beddefects more than11-13mm in diameter, joint function will be affected,patients walking pain and joint dysfunction and other symptoms, one of themain reasons for the eventual development of ankle traumatic arthritis.