Revisiting the concept of inflammatory cell-induced corrosion.

A peculiar type of surface pitting damage to revised joint replacement implant metal surfaces has been attributed to cellular activity and termed inflammatory cell-induced-corrosion. We visually examined 1859 explanted metal implants to document the presence and extent of these features. The data was used to examine correlations between these features and the implant material, and modularity as well as clinical variables. The features were observed in approximately 77% of modular and 30% of monobloc hip implants in a variety of metals, as well as to some degree in various other implants. To test the possibility that these features were an artefact of electrocautery damage during revision surgery, a cleaned, flat, polished, CoCr disk was exposed to a variety of electrocautery interactions. This led to the production of pits and markings comparable to the published damage and to the damage found on the explants we examined. It is concluded that electrocautery damage rather than cellular activity is the cause of these features. Although rarely reported, this damage may be associated with femoral neck fracture. (c) 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1148-1155, 2018.