Issues concerning possible cobalt-chromium carcinogenicity: a literature review and discussion

Recently, questions have been raised concerning the stability and biocompatibility of metallic orthopaedic implants. Concerns have been expressed regarding cobalt-based alloys and the possibility of a future realization of a gross carcinogenic reaction from chrome-cobalt alloy implants. In this report, selected issues are reviewed and categorized for independent analysis to stimulate more comprehensive future research and theory formulation. Issues examined include those relating to metallic corrosion and potential local and systemic carcinogenic effects. The ionic valences of constituent materials, the electrochemical properties of the implant, and the proposed pathophysiological pathway of ions reportedly released from implants are traced. Tables listing 20 cases of primary neoplasia associated with total joint arthroplasty and seven cases reported in a 1975 study are discussed, compared, and contrasted. Finally, a selected bibliography is provided as a foundation for future study and research. In the author's opinion, the 50-year clinical experience and history of the use of cobalt-chromium as an implant material in orthopaedics, dentistry, and plastic surgery more than adequately establish its safety and effectiveness.