Introduction: There is concern that cobalt and chromium ions released from metal on metal (MOM) bearing surfaces may have an adverse effect on renal function over time.

Aim: The aim of this study was to assess renal function in patients who have had MOM hip resurfacing at between two and seven years follow up.

Methods and Materials: Seventy seven patients had MOM hip resurfacing performed in our unit between 1st March 2001 and 28th February 2006. All patients were invited to present for an up to date renal profile. Of these, 59 patients volunteered a sample (76%). Forty-eight were male and eleven were female. Ages ranged from 33 to 63 years (mean 59 years). Nine patients had hypertension pre-operatively. No other risk factors for renal dysfunction were present in our patient population.

Results: Pre-operative urea and creatinine levels ranged from 2.9 to 10.6mmol/L (mean 6.4mmol/L) and 50 umol/L to 121umol/L (mean 77.2umol/L) respectively. Post-operative urea and creatinine levels ranged from 5.3mmol/L to 6.3mmol/L (mean 5.3mmol/L) and 62umol/L to 75umol/L (mean 67umol/L) respectively. Two patients who had normal serum creatinine profiles pre-operatively showed mildly elevated serum creatinine levels at most recent follow up.

Conclusion: Medium term follow up of patients following MOM hip resurfacing does not suggest evidence for the development of renal impairment in this patient population.