Stresses at the meniscofemoral joint: elastostatic investigations on the applicability of interface elements

Stress distributions at the meniscofemoral joint were analysed and the applicability of nonlinear interface elements in a finite element model (FEM) were tested. Centred and 70% off-centre load cases with a complete, a partially removed or a totally removed medial meniscus were evaluated in two dimensions. Interface width was assumed to increase linearly from almost zero to 1 mm at the inner and outer border of the femoral condyles. Maximum interface forces were found at the centre of the condyles, decreasing to zero at the peripherical and intercondylar femoral border. Simulation data concerning a removed medial meniscus or medial 70% off-centre load with complete meniscus indicated higher medial contact forces in the first case. A decrease in the elastic modulus of the articular surface tissues caused two small force transfer peaks (femoral centre and intercondylar border), which were strongly influenced by the predefined gap width.