Biomechanical Finite Element Analysis Of The PCL Meniscus Scaffold

ObjectiveReconstruction of the hunman knee three-dimensional model.Analyzing biomechanical changes in the replacement of the PCL Tissue engineering meniscus Scaffold in the hunman knee.MethodsThe MRI images of the volunteers were acquired by scanning the knee joint.The complete three-dimensional geometric model of the knee joint(including the femur,tibia,articular cartilage of the femoral condyle and tibial plateau,medial and lateral menisci and ligaments)was established by Mimics.The three-dimensional finite element model of knee joint is established by giving material properties,boundary setting and load loading by using Abaqus.The validity of the model was verified by comparing the contact area of the tibial plateau with previous literature.The biomechanical testing machine was used to test the PCL material properties.The PCL material was a numerical replacement of the meniscus material properties in the finite element model.The model of the PCL meniscus was established and the change of meniscus displacement and contact pressure under the axial compression of 1400 N femur was calculated.By removing the normal medial meniscus units and nodes,a three-dimensional finite element model of the knee joint after medial meniscectomy was established.To calculate and compare the compressive stress changes of three kinds of knee joint models under the axial compression of 1400 N femur in the articular cartilage of femoral condyle articular cartilageand tibial plateau.ResultsA three-dimensional finite element model of complete knee joint(including the femur,tibia,articular cartilage of the femoral condyle and tibial plateau,medial and lateral menisci and ligaments)was established.Validating the model by calculating the contact area of the tibial plateau joint under 200 N,400N,700 N axial compression compared with the previous literature.The medial and lateral meniscus displacements were 0.83 mm and 1.76 mm for the 1400 N femoral axial compressive load,and 1.15 mm and 2.20 mm for the medial and lateral meniscus in the PCL model.The maximum contact pressure of tibial plateau articular cartilage were 4.20 MPa and 4.14 MPa,respectively.The maximum contact pressure of articular cartilage in tibial plateau and femur plateau in PCL meniscus model was 4.63 MPa and 4.55 MPa.In the healthy knee joint,the maximum compressive stress in the medial and lateral articular cartilage of tibial plateau were 2.5MPa and 1.7MPa,respectively.The maximum compressive stress in the medial and lateral articular cartilage of the femoral condyle were 2.7Mpa and 2.1Mpa,respectively.In the complete medial meniscus resection model,the maximum compressive stress on the medial and lateral articular cartilage of the tibial plateau was 9.0MPa and7.0MPa,respectively,which increased by 260.0% and 311.7% compared with the healthy model respectively.The maximal compressive stress on the medial and lateral articular cartilage of the femoral condyle were 8.5Mpa and 7.8Mpa.Respectively,than the normal model of normal growth of 214.8% and 271.4%.When the medial meniscus was replaced by PCL,the maximum compressive stress on the medial and lateral tibial plateau articular cartilage were 2.7MPa and 1.8MPa,respectively,which were 8.0% and 5.9% higher than the healthy knee model.In the femoral condyle articular cartilage,maximum compressivestress were 3.0Mpa in the medial and 2.2Mpa in the lateral.Respectively,than the normal model increased by 11.1% and 4.8%.ConclusionsPCL scaffold in the three-dimensional finite element model of the knee can be achieved with good biomechanical ability,and can greatly reduce the meniscus femoral condyle and tibial plateau articular cartilage stress,to protect the purpose of articular cartilage for PCL tissue engineering Further studies of the meniscus provide a biomechanical basis.