Fretting Corrosion Testing of Total Hip Replacements with Modular Heads and Stems

Abstract

© 2017 Elsevier Inc. All rights reserved. Human hip joints with diseased cartilage and bone are commonly replaced using total hip replacements (THRs), which often have modular head and neck components that connect via matching taper, much like nested cones. Fretting corrosion occurs when subtle relative motion (i.e., micromotion) causes abrasion at the head-neck taper connection (i.e., fretting), thus allowing surrounding biofluids to degrade the material (i.e., corrosion). Corrosion then releases toxic metallic debris that causes local tissue lysis and painful inflammation, ultimately leading to revision surgery. However, concern with long-term systemic effects remains as the toxic debris diffuses throughout the body. Modular THRs are susceptible to fretting corrosion; however, they are important to allow intraoperative flexibility to reconstruct the joint with optimized biomechanics. Therefore, this chapter describes a procedure for investigating fretting corrosion of THRs, as well as how to analyze, present, and interpret results