Crash Injury Analysis of Knee Joint Considering Pedestrian Safety

Background: Lower extremity injuries are frequently observed in car-to-pedestrian accidents and due to the bumper height of most cars, knee joint is one of the most damaged body parts in car-to-pedestrian collisions. Objective: The aim of this paper is first to provide an accurate Finite Element model of the knee joint and second to investigate lower limb impact biomechanics in car-to-pedestrian accidents and to predict the effect of parameters such as collision speed and height due to the car speed and bumper height on knee joint injuries, especially in soft tissues such as ligaments, cartilages and menisci. Materials and Methods: In this analytical study, a 3D finite element (FE) model of human body knee joint is developed based on human anatomy. The model consists of femur, tibia, menisci, articular cartilages and ligaments. Material properties of bones and soft tissues were assumed to be elastic, homogenous and isotropic. Results: FE model is used to perform injury reconstructions and predict the damages by using physical parameters such as Von-Mises stress and equivalent elastic strain of tissues. Conclusion: The results of simulations first show that the most vulnerable part of the knee is MCL ligament and second the effect of speed and height of the impact on knee joint. In the critical member, MCL, the damage increased in higher speeds but as an exception, smaller damages took place in menisci due to the increased distance of two bones in the higher speed.