IL-17A-Mediated Immune-Inflammatory Periarticular Mass and Osteolysis From Impingement in Ceramic-On-Ceramic Total Hip Arthroplasty.

We present a rare case of symptomatic adverse local tissue reaction in a 54-year-old female patient who had undergone total hip arthroplasty with ceramic-on-ceramic bearing. Inflammatory periarticular mass and osteolysis developed in the absence of cobalt chrome alloy interfaces and a modular neck component. On the pathologic images, there was no clear evidence of gross metal staining of tissues, metal corrosion, and ceramic or metal wear particles. However, there were impingement scars on the titanium alloy femoral neck and acetabular cup associated with a high combined anteversion angle of 75° (stem: 40° and cup: 35°), suggesting titanium debris release in vivo. Immunohistochemical staining proved a predominant infiltration of CD4+ T cells and the corresponding IL-17A response to metal. We conclude that neck-rim impingement may lead to the development of adverse local tissue reaction (periarticular mass and osteolysis) due to a metal hypersensitivity with the production of proinflammatory cytokines (IL-17A) by CD4+ T cells even in ceramic-on-ceramic total hip arthroplasty.