An Investigation on Contact Stresses of New Jersey Low Contact Stress (NJLCS) Knee Using Finite Element Method

Abstract

The contact stress on the articulating surface of an artificial knee is one of the major evaluation parameters of the potential wear resistance of replacement joints. The objective of this paper is to investigate the types of contact stresses and their distribution on the plastic bearing platform of the New Jersey Low Contact Stress (NJLCS) Knee under loads and during a walking cycle. The bearing component of the NJLCS knee is made of Ultra-High Molecular Weight Polyethylene (UHMWPE) with the Young's Modulus of 600 MPa at body temperature. Peak contact stress generated was due to both factors, the magnitude of compressive load and the flexion angle. Finite Element Analysis (FEA) results indicated that the more congruent the contact surfaces, that is the more “area contact”, the less the contact stress will generate. With the same boundary conditions, FEA results, with a load of 2,200N, are confirmed with the previous experimental results.