|Abstract / Summary
Background and Purpose: It is unclear whether delayed type hypersensitivity reactions against implanted metals play a role in the etiopathogenesis of malfunctioning total knee arthroplasties. We therefore evaluated the association between metal allergy, defined by a positive patch test reaction against common metal allergens, and revision surgery in patients who underwent knee arthroplasty.
Methods: The nationwide Danish Knee Arthroplasty Register, including all knee implanted patients and revisions in Denmark after 1997 (n=46,407), was cross-linked with a contact allergy patch test database from the capital area of Copenhagen (n=27,020).
Results: A total of 327 patients were registered in both databases. The prevalence of contact allergy to nickel, chromium and cobalt was comparable among patients with and without revision surgery. However, in patients with two or more episodes of revision surgery, the prevalence of cobalt and chromium allergy was markedly higher. Metal allergy diagnosed prior to implant surgery appeared not to increase the risk of implant-failure and revision surgery.
Interpretation: While we could not confirm that a positive patch test reaction to common metals is
63! associated with complications and revision surgery following knee arthroplasty, metal allergy might in selected cases be a contributor to the multifactorial pathogenesis of implant-failure. In those with multiple revisions, cobalt and chromium allergy seem to be more frequent.