The relationship between the presence of metallosis and massive infection in metal-on-metal hip replacements.

With the increased use of metal-on-metal as a bearing surface, complications and side effects are being recognised more frequently. We present a small series of a previously unreported complication, which appears specific to metal-on-metal bearing surface arthroplasties: three cases of infection in the presence of local metal debris and histological features of aseptic lymphocytic vasculitis associated lesions (ALVAL). Each case is associated with significant soft tissue loss and bone destruction to such an extent that pelvic discontinuity has occurred. We postulate that the combination of metal debris, ALVAL and tissue necrosis provides a unique environment for peri-prosthetic bacterial growth and rapid spread of infection.