COMPARING THE PRESSURES ON THE ARTICULAR CARTILAGE IN INTACT AND MENISCECTOMIZED KNEE JOINTS USING FINITE ELEMENT ANALYSIS
Shriram Duraisamy1, Gideon Praveen Kumar2, Subburaj Karupppasamy1
1Singapore University of Technology and Design, Singapore;
2Institute of High Performance Computing, A*STAR, Singapore
Injuries to the menisci are the second most common injury to the knee. The higher level of contact stresses on the articular cartilage after meniscectomy predisposes the knee to an increased risk of osteoarthritis (OA). Prevalence studies have shown that injuries are more common in the medial meniscus than the lateral meniscus due to its inherent anatomical disadvantage of being less mobile and having smaller articular surface. In this study, we investigated the effect of total meniscectomy (complete removal of medial meniscus) on the articular cartilage pressures using an experimentally validated 3D finite element (FE) model of the human knee joint. MRI extracted 3D geometric model of the knee joint, from the Open Knee project, was used to build the FE model. We have modeled the femur and tibia bones as rigid bodies, articular and meniscal cartilages as elastic materials, and ligaments as isotropic and hyperelastic materials. Three different conditions were considered: an intact tibio-femoral joint, a tibio-femoral joint after total meniscectomy with no pre-tension applied to the medial collateral ligament, and a tibio-femoral joint after total meniscectomy with pre-tension applied to the medial collateral ligament. The computed results showed that the cartilage pressure was significantly higher in tibio-femoral joints with total meniscectomy than in the intact tibio-femoral joint (8.11MPa Vs 7.70MPa vs 6.20MPa). When compared the two different conditions after total meniscectomy, the model with pre-tension applied to the medial collateral ligament provides balanced force distributions. These results could lead to understanding contribution of mechanical factors in cartilage degeneration after meniscectomy.
Keywords: cartilage pressure, finite element, knee joint, osteoarthritis