Metal-on-metal hip implants: do they impair renal function in the long-term? A 10-year follow-up study.

INTRODUCTION

The aim of our study was to investigate a potential influence of elevated serumcobalt and serumchromiumlevels on renal function at minimum 10 years after implantation of a metal-on-metal hip.

MATERIALS AND METHODS

Between November 1992 and June 1994 98 patients (44 m, 54 f) with an average age of 56 (22-79) years received a metal-on-metal bearing Metasul. At the time of the 10-year follow-up, 15 patients had died and 8 were lost to follow-up. The remaining 75 patients had laboratory analysis including serumcreatinine and full blood cell count as well as chromium and cobalt serum levels.

RESULTS

Ten years postoperatively the median serumcreatinine level was 0.86 (0.55-1.51) mg/dl, the serumcreatinine clearance Ccr was in the normal range. The hemogram did not differ from that measured at the time of surgery. The median serumcobalt concentration was 0.75 (0.3-50.10) microg/l and the serumchromium concentration was 0.95 (0.3-58.6) mug/l, 10 years postoperatively.

CONCLUSION

Our long-term data do not show any influence of serum cobalt or chromium concentrations on renal function following total hip arthroplasty.