The Effect Of Discoid Meniscus On Cartilage Degeneration And Cartilage Biomechanics Changes After Meniscectomy

Chapter1:Clinical effect analysis of discoid meniscus on cartilage degenerationObjective:To investigate epidemiology of discoid meniscus, researching the effect of discoid meniscus on cartilage degeneration.Methods:Collecting adequate cases of discoid meniscus, recording the tear condition, pattern of meniscus and the degeneration progression of cartilage, ages of patients included.Results:The degeneration progression of cartilage is related to course of disease, and there is no difference of cartilage degeneration progression between tore and intact discoid meniscus, complete and in complete discoid meniscus.Conclusion:It’s better to get arthroscopy operation for patient with complete or asymptomatic discoid meniscus.Chapter two:The finite element biomechanical analysis of healthy human kneeObjective:To create finite element model of human knee and get the the biomechanical feature of healthy adults.Methods:Chose a healthy volunteer, using CT and MRI to get the images of DICOM form. Used the Mimics and ANSYS software to form3-diamensional geometric model and finite element model; then got the biomechanical feature of healthy adults with boundary condition.Results:This finite element model was checked with other studies, with coincident of peak contact pressure (3.12MPa on medial meniscus,2.39MPa on lateral meniscus); and the distribution feature was also similar.Conclusion:Based on DICOM document with CT and MRI scanning, used software of Mimics and ANSYS, we constructed a finite element model of knee joint, including bone, cartilage and main ligaments; the model was proved dependable by comparing with published data. Otherwise, the pressure mainly located at posterior medial part of knee with full extend. Chapter three:The finite element biomechanical analysis of discoid meniscus and meniscectomyObjective:To create finite element model of discoid meniscus and varies of meniscectomy based on model of Chapter two; approaching the biomechanical features of them.Methods:Enlarging and thickening the lateral meniscus by software of E-feature Recontruction3D to get model of discoid meniscus; stegnosis to4mm to mimesis partial meniscectomy and took off to mimesis total meniscectomy.Results:The lateral condyles of femur has greater pressure in discoid meniscus; and knee with partial meniscectomy has smaller cartilage contact area and less pressure on meniscus, which has lower risk of osteoarthritis compared with total meniscectomy.Conclusion:The lateral condyles cartilage of femur has greater risk of degeneration than other parts of knee with lateral discoid meniscus; and partial meniscectomy is better than total meniscectomy on biomechanical side.