Paper 3: Materials and the Design of Artificial Weight-Bearing Joints

Abstract

In this paper the choice of design and materials for artificial human joints is considered as an engineering design problem, and some possible solutions which result from this approach are discussed. Various types of plain bearing design are examined and the use of flexible connecting members is suggested as an alternative possibility. It is considered that the plain bearing designs must be based on the requirement that they should operate with a full fluid film of synovial fluid, and possible designs and materials are discussed from this point of view. The effect of fixation problems on the total design is also examined, and designs which appear to offer a rational solution are proposed. It is concluded that for bearing engineers to make any major contribution to the design problem requires more information on the variation of joint load in both magnitude and direction in relation to the timing of joint movement. Research into the performance of plastic on plastic bearings is also desirable with more information on which plastic materials are biologically acceptable.