Total knee arthroplasty in patients with hypersensitivity to metals

Int Orthop. 2014 Feb;38(2):329-33. doi: 10.1007/s00264-013-2229-2. Epub 2014 Jan 4.

Abstract

Purpose: We evaluated the risk of hypersensitivity to metals in a population of consecutive subjects undergoing a total knee arthroplasty (TKA). We also proposed a diagnostic pathway to address any sensitivity to metals. We finally presented the mid-term outcomes of a full non allergenic knee implant.

Methods: We developed a protocol based on the medical history, patch testing, and on specific laboratory assays, in order to assess a sensitization to metals. Twenty-four patients (25 knees) with referred or suspected allergy to metals were found in more than 1,000 treated patients, with a mean age of 72.9 years. We proceeded to a radiologic study, a clinical evaluation by the visual analogic scale (VAS), and Knee Society rating system (KSS). In all cases a full anallergic cemented implant with an oxidized zirconium femoral component and an all-polyethylene tibial baseplate was chosen.

Results: Four (16.6%) of the 24 patients were considered to be hypersensitive to metals. The mean follow-up was 79.2 months. No patient reported any reaction related to hypersensitivity or complications after TKA. The VAS improved from a mean preoperative value of 7.2 to 1.8 postoperatively; the KSS and the functional score increased from 38 to 91 points and from 39 to 88 points, respectively.

Conclusions: We consider careful research of medical history for metals hypersensitivity crucial, and we perform patch testing and lab assays in case of doubtful sensitization. The choice of a modern hypoallergenic implant may prevent any kind of potential reactions.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Arthroplasty, Replacement, Knee / instrumentation*
  • Female
  • Follow-Up Studies
  • Humans
  • Hypersensitivity / epidemiology*
  • Knee Prosthesis / adverse effects*
  • Male
  • Metals / adverse effects*
  • Middle Aged
  • Osteoarthritis, Knee / surgery*
  • Polyethylene
  • Prevalence
  • Retrospective Studies
  • Risk Factors
  • Treatment Outcome
  • Zirconium / adverse effects

Substances

  • Metals
  • Polyethylene
  • Zirconium