Association between histological findings and whole blood metal ion levels with pseudotumor characteristics indentified in MRI

Abstract

Clinical manifestation of adverse soft tissue complications related to metal-on-metal (MoM) implants is variable [1-4]. Intracapsular findings include metallosis, synovitis, synovial hypertrophy, effusion, and capsular necrosis [2, 5, 6]. In some patients adverse reaction to metal debris (ARMeD) may manifest as an aggressive pseudotumor. Microscopic findings may include massive perivascular lymphocyte infiltration with fibrin exudates or even synovial necrosis. This type of histological reaction has been termed ALVAL (aseptic lymphocytic vasculitis-associated lesion), and it has been proposed to be a specific type of reaction seen around MoM hips [7]. The term ARMeD has been proposed as an umbrella term to include all previously described adverse wear related to soft tissue complications [8].