Chromosomal changes after surgery for joint replacement.

Joint replacement has alleviated the suffering of millions of patients who would otherwise be crippled by arthritis. Whatever the uncertainties about the effects of this procedure , the benefits are very real. This is of paramount importance when evaluating any risks from surgery. Uncertainties arise because all foreign materials produce a tissue reaction when they are implanted in the body. The swelling caused by a thorn is a typical example. Orthopaedic materials are not exempt from a reaction by the host. This becomes most pronounced when wear of a replacement arthroplasty generates huge numbers of particles of metal, cement (polymethylmethacrylate and additives) and poly-ethylene as well as soluble metal. These particles provoke an inflammatory reaction, which in turn contributes to local tissue destruction and aseptic loosening. The particles are also disseminated systemically in the body at lower concentrations to local and distant lymph nodes, the liver and the spleen. 1 The soluble metal is released into the circulation and excreted in the urine. 2 Since wear debris can elicit a local reaction is it possible that its systemic dissemination could induce a systemic effect, especially in the long term? A systemic effect caused by lower concentrations of particles may take time to become manifest. This was therefore not a relevant issue in the past, since Sir John Charnley initially insisted that joint replacement surgery be restricted to the elderly. However, because of its success, increasingly younger patients have been treated. Approximately one-third of those now undergoing joint replacement are less than 60 years old 3 and a tenth are under 40. A minority of patients may therefore be exposed to ortho-paedic materials for up to 60 years. The wear debris includes metals such as chromium, nickel, cobalt, aluminium , titanium and vanadium which may have allergic, toxic and mutagenic effects in other situations. There is therefore concern that there may be long-term risks associated with joint replacement either to the patient or, in theory, to any children which they may conceive. In industry the exposure of workers or the environment to the same metals is regulated by biomonitoring 4 and by law, 5 respectively. In orthopaedic surgery the priority for the treatment of a young patient is the use of a prosthesis which is associated with the least amount of aseptic loosening, at least in the short term. There has, however, been a plethora of new joint replacements of many …