Finite Element Modeling And Mechanical Analysis Of Rabbit Patellar Tendon And Tendon Insertion Under Different Mechanical Conditions

Objective:To investigate the pathogenesis of patellar tendinopathy from the perspective of biomechanics by transforming the two-dimensional image of rabbit patella and tendon insertion into three-dimensional modeling and conducting finite element mechanical analysis under different loading conditions.Methods:One adult female New Zealand white rabbit(18 weeks of age,body weight 2.6±0.2kg)was selected as the object of study.After sampling treatment,the samples were scanned and preserved by Micro-CT.Using Mimics,Magics,Geomagic Studio,Solidworks and other software to transform two-dimensional images into threedimensional models,and then using ANSYS Workbench to carry out finite element static and transient mechanical analysis to obtain equivalent displacement,stress and strain cloud images.Set different load size and direction,different movement mode of loading conditions,detect the value of the target area,and get the final result.Results:(1)The change of load direction had a great influence on the overall distribution trend.With the increase of load Angle,the stress concentration effect at the insertion point of the patellar tendon was gradually weakened,while the insertion point of the fourth femoral tendon was gradually strengthened,and the effect on patella was not significant.(2)The change of load size has no influence on the overall distribution trend,but has a great influence on the magnitude of displacement,stress and strain.From a regional point of view,the influence of load changes on the insertion of patellar tendon and femoral fourth tendon is greater than that on patella.From the perspective of the patella itself,the contact area with the femur is most affected,and the contact area with the insertion of the fourth femoral tendon and the insertion of the patellar tendon is less affected.(3)From the perspective of the internal and external rotation and pronation of the knee joint,varus produced greater stress concentration at the insertion of the patellar tendon than valus,and internal rotation produced greater stress concentration at the insertion of the patellar tendon than external rotation.Conclusion:(1)Relative to the insertion of patellar tendon and quadriceps tendon,the size and direction of the tensile load,as well as the valvation and internal rotation of the operation mode have a greater influence on the insertion of patellar tendon.(2)From the perspective of patellar bone and the tendons connected at both ends,the occurrence of patellar tendinopathy is related to the stress concentration at the insertion of patellar tendon,and to the stress shielding of the insertion of patellar tendon by the insertion of quadriceps tendons and their extended joint within a certain range of movement.