Release of hexavalent chromium from corrosion of stainless steel and cobalt—chromium alloys

Abstract

Experiments were undertaken to determine whether hexavalent chromium was released during corrosion of orthopedic implants. Uptake of chromium (Cr) by cells and separation using amberlite resin were the methods used to determine that hexavalent Cr was present. We used salts of chromium as trivalent chromium (chromic chloride) and hexavalent chromium (potassium dichromate) to verify that the amberlite separation technique separates hexavalent Cr into the upper phase and trivalent Cr into the lower phase. The use of the salts also verified that only the hexavalent Cr became red blood cell-associated and that most of this was intracellular rather than membrane bound. The use of the amberlite separation technique demonstrated that the hexavalent Cr in the red blood cells was rapidly reduced to trivalent Cr. Cellular uptake of chromium was documented in red blood cells following corrosion of stainless-steel and cobalt-chromium implants in vivo, in the red blood cells of patients undergoing total joint revisions, and in fibroblasts subjected to products of fretting corrosion of stainless-steel and cobalt-chromium implants. Thus, corrosion of implants can lead to the release of the biologically active hexavalent chromium into the body. This chromium is rapidly reduced to trivalent chromium in cells.

Trivalent and Hexavalent Chromium Issues in Medical Implants

“…The corrected redox potentials for all the reaction pathways listed in Reference [23] are all less than the redox potential of the oxygen reduction reaction, indicating that it is thermodynamically possible for these reactions to occur in the body. These basic calculations are consistent with the published findings of Merritt and Brown [26,27] who reported Cr +6 could be produced through corrosion of CoCr and stainless steel implants in the body. These authors concluded Cr +6 released from the implant is rapidly reduced to Cr +3 in red blood cells (RBC).…”

“…Merritt and Brown conducted experiments to determine whether Cr +6 was released during corrosion of orthopedic implants [27]. Uptake of Cr by cells, and separation using amberlite resin, were the methods used to determine whether Cr +6 was present.…”

Management of metal-on-metal hip implant patients: Who, when and how to revise?

“…Metal particulate and ionic wear debris from the hip is released into the peri-prosthetic tissues and transported systemically throughout the body [15,16] . Studies have demonstrated a peak in blood cobalt levels at 6-mo post implantation and chromium levels at 9-mo, followed by a steady decline over time [17,18] .…”

Bio-Corrosion Behavior of Ceramic Coatings Containing Hydroxyapatite on Mg-Zn-Ca Magnesium Alloy

“…However, metallic materials may cause the release of toxic corrosion products [2,3] and allergens [4,5]; it need a second surgery for implant removal after the healing of damaged tissues. As a result, biodegradable implants for biomedical application have attracted great attention in recent years [6][7][8].…”