Cobalt and chromium concentrations in patients with metal-on-metal and other cementless total hip arthroplasty.

We measured the cobalt and chromium concentrations in the serum and urine of 32 patients with current designed metal-on-metal total hip arthroplasty and 43 patients with conventional metal on ultrahigh molecular weight polyethylene (UHMWPE) cementless total hip arthroplasty. The results of our study showed that the serum and urine chromium concentrations increased in 37.5% and 90.6%, respectively, of 32 patients with well-fixed metal articulation (the mean values were 0.09 microg/dl and 2.2 microg/l, respectively) and also increased in 28.6% and 85.7%, respectively, of 7 patients who received metal-on-UHMWPE articulation with loosened acetabular component or stem made of Co/Cr alloy (the mean values were 0.06 microg/dl and 1.6 microg/l, respectively). On the other hand, the serum and urine cobalt concentrations were below the detection limit in all patients.