Increased chromosome translocations and aneuploidy in peripheral blood lymphocytes of patients having revision arthroplasty of the hip

The long-term biological effects of wear debris are unknown. We have invest igated whether there is any evidence of cumulative mutagenic damage in peri pheral blood lymphocytes of patients undergoing revision arthroplasty of pr edominantly metal-on-plastic total hip replacements compared with those at primary arthroplasty. There was a threefold increase in aneuploidy and a twofold increase in chro mosomal translocations which could not be explained by the confounding vari ables of smoking, gender, age and diagnostic radiographs. In the patients w ith TiVaAl prostheses there was a fivefold increase in aneuploidy but no in crease in chromosomal translocations. By contrast, in patients with cobalt- chrome prostheses there was a 2.5-fold increase in aneuploidy and a 3.5-fol d increase in chromosomal translocations. In six patients with stainless-st eel prostheses there was no increase in either aneuploidy or chromosomal tr anslocations. Our results suggest that future epidemiological studies of the putative lon g-term risks of joint replacement should take into account the type of allo y used in the prosthesis.