In-Vivo Corrosion and Fretting of Modular TI-6AL-4V/CO-CR-MO Hip Prostheses: The Influence of Microstructure and Design Parameters

• Main Author: Gonzalez, Jose Luis, Jr
• Format: Others
• Published: FIU Digital Commons 2015
• Subjects: Total Hip Prosthesis; Cobalt-Chrome; Ti-6al-4v; Biomaterials; Corrosion; Metallosis; Applied Mechanics; Biomedical Devices and Instrumentation; Metallurgy; Other Materials Science and Engineering; Tribology
• Online Access: http://digitalcommons.fiu.edu/etd/1756; http://digitalcommons.fiu.edu/cgi/viewcontent.cgi?article=3027&context=etd

The purpose of this study was to evaluate the incidence of corrosion and fretting in 48 retrieved titanium-6aluminum-4vanadium and/or cobalt-chromium-molybdenum modular total hip prosthesis with respect to alloy material microstructure and design parameters. The results revealed vastly different performance results for the wide array of microstructures examined. Severe corrosion/fretting was seen in 100% of as-cast, 24% of low carbon wrought, 9% of high carbon wrought and 5% of solution heat treated cobalt-chrome. Severe corrosion/fretting was observed in 60% of Ti-6Al-4V components. Design features which allow for fluid entry and stagnation, amplification of contact pressure and/or increased micromotion were also shown to play a role. 75% of prosthesis with high femoral head-trunnion offset exhibited poor performance compared to 15% with a low offset. Large femoral heads (>32mm) did not exhibit poor corrosion or fretting. Implantation time was not sufficient to cause poor performance; 54% of prosthesis with greater than 10 years in-vivo demonstrated none or mild corrosion/fretting.