Effects of metal-on-metal wear on the host immune system and infection in hip arthroplasty

BACKGROUND AND PURPOSE: Joint replacement with metal-on-metal (MOM) bearings have gained popularity in the last decades in young and active patients. However, the possible effects of MOM wear debris and its corrosion products are still the subject of debate. Alongside the potential disadvantages such as toxicity, the influences of metal particles and metal ions on infection risk are unclear. METHODS: We reviewed the available literature on the influence of degradation products of MOM bearings in total hip arthroplasties on infection risk. RESULTS: Wear products were found to influence the risk of infection by hampering the immune system, by inhibiting or accelerating bacterial growth, and by a possible antibiotic resistance and heavy metal co-selection mechanism. INTERPRETATION: Whether or not the combined effects of MOM wear products make MOM bearings less or more prone to infection requires investigation in the near future.