Investigations on the galvanic corrosion of multialloy total hip prostheses

Publisher Website
Google Scholar
Abstract
Total hip prostheses combining cobalt and titanium alloys in direct physical contact are currently being used. The purpose of this paper was to investigate the possibility of an accelerated corrosion occurring due to the coupling of these alloys. Electrochemical corrosion studies based on mixed potential and protection potential theories were used to study thein vitroeffects of coupling the titanium and cobalt alloys. Verification of these studies was made by direct coupling experiments. Macroscopic examination of surface features of four retrieved total hip prostheses ranging from 0–6 years implantation were conducted. The electrochemical studies predicted coupled corrosion potentials of ‐0.22 V and low coupled corrosion rates of 0.02 μA/cm2. Direct coupling experiments verified these results. Cobalt‐titanium interfaces on the implants were macroscopically examined, and no instances of extensive corrosion were found. Overall, thein vitrocorrosion studies and the examination of retrieved prostheses predicted no exaggeratedin vivocorrosion due to the coupling of these cobalt and titanium alloys.