Lymphocyte transformation testing (LTT) or lymphocyte proliferation testing (LPT) for hip or knee arthroplasty

In 2009-2010, 15,935 hip replacements and 22,545 knee replacements were reported in the Canadian Joint Force Registry. There are various combinations of liner material that were used for prostheses, but the most common bearing surface was metal-on-plastic (mainly polyethylene) which are replacing metal-on-metal liner. Allergy or hypersensitivity to corrosion products released to the blood from metal prosthetic implants is well documented in patients undergoing hip or knee arthroplasty, and could contribute to delayed hypersensitivity symptoms such as eczema, as well as aseptic loosening and failure of implanted prostheses. Immune response to metal ions such as nickel (Ni), chromium (Cr), and cobalt (Co) in the liner material of metal prostheses involves lymphocytes which upon contact with allergens are activated, forming the basis of the lymphocyte transformation test (LTT) and the lymphocyte proliferation test (LPT) for the detection of systemic hypersensitivity to metals. This study aims to review the clinical and cost benefits of LTT and LPT in patients undergoing hip or knee arthroplasty, and the evidence-based guidelines for their use.