Elevation of Serum Cobalt and Chromium Levels in Patients With Metal-On-Metal Resurfacing Hip Prostheses: A 3-Year Follow-up

This prospective study was designed to monitor serum cobalt (Co) and chromium (Cr) levels in patients after hip resurfacing with the Cormet 2000 device. Serum samples were obtained from subjects at 6 months and 1, 2, and 3 years after surgery. Co/Cr levels were determined by high-resolution inductively coupled plasma mass spectrometry. The study group consisted of 20 men and 15 women with a mean age of 51 years (range, 33-66). Levels after device implantation were increased at all follow-up time points when compared with controls. Peak levels were observed at 1 year, with the elevations at 3 years trending down; but this decrease was not statistically significant. Long-term elevations of serum Co/Cr levels after implantation with the Cormet 2000, as well as other hip resurfacing devices, are of concern and will require additional studies to assess the potential long-term health risks of these levels in this patient population.