Review of Knee Models: 1996 Update

Abstract

This paper is an update on our previous review of knee models (Hefzy and Grood [30]). We find that progress was made in the area of dynamic modeling. Since 1988, a technique was developed to solve the system of differential algebraic equations describing the three-dimensional dynamic behavior of the knee joint. This technique allows to solve complex problems. However, not a single dynamic comprehensive anatomically based mathematical three-dimensional model of the knee joint that includes both tibio-femoral and patello-femoral joints has yet been developed. In the area of meniscal modeling, we find that only one three-dimensional model of the knee joint that includes the menisci is available in the literature. This quasi-static model includes menisci, tibial, femoral and patellar cartilage layers, and ligamentous structures. This model is limited since it solves only for one position of the knee joint: full extension. From this updated survey, we conclude that the development of a comprehensive three-dimensional anatomically based mathematical model of the knee joint (that solves the three-body contact problem at the tibio-femoral joint between the menisci, tibia and femur, and includes the patello-femoral joint) continues to present major challenge.