The effect of pulsed electromagnetic fields on the corrosion of a chromium-cobalt-nickel alloy orthopaedic implant

In order to assess whether pulsed electromagnetic fields influence the rate of corrosion of orthopaedic metal implants, an alloy, called MP-35N, was exposed for 3 wk to a pulsed electromagnetic field. The results demonstrated that while there was a progressive release of the major consituents of MP-35N, i.e. cobalt (32.5%), nickel (36%), and chromium (20%), with time, corrosion was not significantly higher in the presence of the pulsed electromagnetic field when compared to that of the non-exposed pins. There was a significantly higher release of cobalt by the control pins after 5,10, and 15 d incubation when compared with the pulsed pins. These findings were confirmed by SEM which demonstrated progressive surface corrosion with time and that the extent of corrosion was similar for both the control and pulsed pins. These results suggest that pulsed electromagnetic fields have no effect in promoting the surface corrosion of orthopaedic metallic implants.