Effect of different defect areas of medial femoral condyle cartilage on Meniscal articular Cartilage stress: three-dimensional finite element analysis

Background: The present-day three-dimensional finite element analysis (FEM) is widely used in human biomechanics research, but there are few studies on the effect of cartilage defect of medial femoral condyle on meniscus stress of knee in full extension. OBJECTIVE The purpose of this study was to explore the changing trend of meniscus stress during the changing process of femoral medial condyle cartilage defect,to provide the simulated biomechanical insights into femoral condyle cartilage defect on meniscus,in order to provide the theory reference value for femoral condyle cartilage repair and clinical prevention of meniscus injury.) Methods One healthy male volunteer was chosen to obtain the three-dimensional digital finite element model. The material mechanical properties were input into the model with divided grids in the Abaques software. Using the boundary conditions and the loads to the model, the structural nonlinear finite element was calculated. Firstly, the stress distribution of the normal knee cartilage meniscus was observed under the condition of load, and then the stress distribution of the meniscus was observed under the condition of load when the medial femoral condyle cartilage was in different defects (0, 6, 8, 10, 12, 14, 16, 18 and 20 mm). The stress changing on the meniscus was analyzed when the defect of the femoral condyle cartilage happened. Results When the diameter of femoral medial condyle cartilage defect was no less than 10 mm, the stress distribution of the meniscus was statistically different (the value of P is less than 0.05). When the medial femoral condyle cartilage defect occurred in different areas(d), the stress peak was mainly concentrated in the body part and posterior corner of the meniscus. Moreover, we found that the maximum, minimum and average stress of meniscus increased with the increased defect area. We also found that the increased defect area can lead to the increases of stress of the meniscus.