Geometric element analysis of fretting in a model of a modular femoral component of a hip implant.

The study utilized the geometric element analysis method to investigate the effect of three variables (head diameter, d; head material; and neck material) on the y-direction displacement, due to fretting (delta), in a model of the head-neck connection in a modular version of the femoral component of a hip implant, subjected to a resultant hip joint force only. It was found that while d and neck material exerted a strong effect on delta, the head material had practically no such effect. The implications of this finding for design and materials selection issues for this connection are discussed.