Revision Total Knee Arthroplasty for Implant-Related Metal Allergy

Between 20 and 25% of individuals undergoing total knee arthroplasty (TKA) acquire hypersensitivity to metals, but only less than 1% display symptoms. For individuals presenting with painful TKA, metal hypersensitivity is a diagnosis of exclusion where skin patch test, lymphocyte transformation test, and synovial biopsies are useful adjuncts prior to revision surgery is undertaken to hypoallergenic implants. In individuals in whom a primary conventional TKA fails due to metal hypersensitivity, a “hypoallergenic” revision TKA should be recommended. However, before performing it, it is advisable to carry out knee arthroscopy to get tissue for microbiological and histopathological studies to exclude infection.