Design of a Polycarbonate-Urethane Meniscal Implant: Finite Element Approach

The medial meniscus plays an important role in the knee joint [1]. Meniscus dysfunction due to tear is a common knee injury which leads to degenerative arthritis, attributed primarily to the changes in knee load distribution [2]. Clearly, there is a substantial need to protect the articular cartilage by either repairing or replacing the menisci. A “floating” Polycarbonate-Urethane (PCU) meniscal implant (Fig. 1a) is proposed as a solution for restoring the function of the missing meniscus and for the reduction of pain, through improved tibial and femoral pressure distribution. The implant is composed of PCU embedded with polyethylene reinforcement fibers (“Dyneema^®”, DSM), and its design is based on the geometry of the articulating surfaces of the femur and tibia. Our goal was to develop an optimal meniscal implant design (in terms of composition and geometry), whose contact pressure with the tibial plateau (TP) would be similar to that of the natural meniscus and be able resist mechanical failure of any of its components. We hereby present one aspect of the implant bench-tests, finite element (FE) analyses of the implant in the medial knee under physiological relevant loading conditions.