Introduction

Total hip replacement failure due to fretting-corrosion remains a clinical concern. We recently described that damage within CoCrMo femoral heads can occur either by mechanically-dominated fretting processes leading to imprinting (via rough trunnions) and surface fretting (via smooth trunnions), or by a chemically-dominated etching process along preferential corrosion sites, termed “column damage”. These corrosion sites occur due to banding of the alloy microstructure. Banding is likely caused during thermo-mechanical processing of the alloy and is characterized by local molybdenum depletion. It was the objective of this study to quantify material loss from femoral heads with severe corrosion, identify the underlying damage modes, and to correlate the damage to the alloy's microstructure.