N-Acetyl-Cysteine Reduces Blood Chromium and Cobalt Levels in Metal-on-Metal Hip Arthroplasty

The most common reasons for revision of metal-on-metal hip arthroplasty are aseptic loosening and metal reaction. Failure of a metal-on-metal implant due to the aggressive destruction of periprosthetic tissues may require extensive reconstruction procedures. The aim of this case report is to describe the treatment in an asymptomatic patient with high levels of chromium and cobalt, using chelation therapy. The rational use of N-acetyl-cysteine (NAC) involves thiol groups to chelate sites for metals. More than 10 years after the metal-on-metal hip arthroplasty, the patient did not have to undergo revision surgery; the levels of the ions in the blood were considerably lowered (chromium from 4.51 mcg/L to 1.85 mcg/L; cobalt from 7.78 UG/L to 0.8 UG/L) after using NAC without adverse effects.