EFFECTS OF MENISCECTOMY ON THE CONTACT CHARACTERISTIC OF THE TIBIOFEMORAL JOINT AT DIFFERENT FLEXION ANGLES
Aimed at the change of the contact characteristic of a tibiofemoral joint after meniscectomy,MRI images of the normal human knee at four flexion angles (0°/25°/60°/80°) were used to construct the normal,medial/lateral/bilateral meniscectomy finite element models of the tibiofemoral joint.In the experiment,the single compressive load and the compressive load with torque were applied to these models for the finite element simulation.The results show that: 1) For the tibiofemoral joint at different flexion angles,unilateral meniscectomy makes the axial load supported by the persistence meniscus and the maximum equivalent stress on the persistence meniscus increase,and the increment after lateral meniscectomy is higher than that after medial meniscectomy.2) For each flexion angle,after the meniscectomy,the axial load transmitted directly between tibial/femoral cartilage increases.The increment after bilateral meniscectomy is most,and unilateral meniscectomy influences the meniscus-removed side more than the meniscus-left side.Besides,the maximum equivalent stress on the tibial cartilage also increases in sequence: bilateral meniscectomy/lateral meniscectomy/medial meniscectomy.3) In the tibiofemoral joint,after lateral and bilateral meniscectomy,an obvious stress concentration occurs on the lateral tibial cartilage at 25° and 80°flexion angles.In a word,for the tibiofemoral joint at different flexion angles,when the meniscus injures is removed,the tibial/femoral cartilage bears more loading directly,and then the stress distribution changes and the maximum equivalent stress on the cartilage increases,which leads the degradation of the joint cartilage and other complex joints to disease.Furthermore,lateral meniscectomy changes the contact behavior of the tibiofemoral joint more serious than medial meniscectomy,which needs to be valued in meniscectomy.