Rejected Total Joint

If you are a patient with a painful total joint with previous negative workups for infection or loosening, the next step may be an evaluation for an allergic reaction to byproducts of wear. Often patients with these allergies have been previously sensitized through the use of hardware which by the exposure of particulate matter cause repeated sensitization of the immunologic system. In rare instances, the first clue may be that the patient may have sensitivity to wearing inexpensive jewelry.

While the prevalence of metal sensitivity in adults is approximately 10-15% (#1), poorly functioning implants are six times more likely to have a metal allergy most likely because of a longer exposure to joint wear debris. Due to such prior sensitizations, a delayed type cell-mediated hypersensitivity can be produced by T-lymphocytes (# 2). These release various chemicals called cytokines which initiate an inflammatory cascade including activation of macrophages and other cytotoxic chemicals. The cumulative effect of the produced destructive enzymes and phagocytic cell action result in weakening of the soft tissues surrounding implants causing latent effects such as bone resorption, pain, stiffness, and eventual loosening and prosthetic failure.

Recent evidence suggests that an allergy to certain metals may result in the body "rejecting" the arthroplasty components, especially knee and hip replacements (# 3). Instead the cellular catabolic process may be two fold. There needs to be a critical volume of particulate wear debris in order to induce a reaction. Secondly these wear particles need to be of a particular size and geometry to trigger the T-cell immune activation (# 4). Still unknown at this time is a positive family history of previous skin hyper sensitization and metallic jewelry intolerance. After formal preoperative testing in terms of serum immunologic assays, a candidate for a total joint replacement may require the use of alternative prostheses which are hypoallergenic. These can be in the form of a zirconium coated implant or an all-poly articulating base without any exposure to nickel and/or chromium. An Oxinium femoral component mated to an all-poly tibial insert may also reduce the antigen load of wear debris.

While orthopedic surgeons are programmed to rule out loosening and/or infection, allergic reactions to metal wear byproducts are less understood and consequently frequently overlooked. Rarely does a metal allergy present with skin manifestations. Instead, the only presenting symptom may be pain. Higher percentages of patients experience allergies to wear and particulate debris if they are females, the implant is not functioning well, and it has been in place for over one year. The workup for T-cell-mediated sensitivity by the older skin contact tests have been recently challenged as inaccurate (# 3). The most sensitive test is the lymphocyte transformation test (LTT) and/or a T-cell migration inhibitory test. Newer research has begun using intra operative cell staining techniques which is currently being investigated by me at The Houston Methodist Hospital. Two labs in the country currently provide the LTT testing for a relatively healthy fee of $300-$600 depending on the amount of byproduct sensitizations that they are being tested for.

In situations where no definitive explanation for a symptomatic implant has been diagnosed, it is incumbent on orthopedic surgeons to exhaust all known explanations. While allergic reactions to total joint replacement may not be the answer to all unexplained painful total joints, allergies are receiving much more attention recently due to the plethora of complications associated with metal-on-metal hip replacements. Further testing and research one of which I am conducting at FSWOG research, will have to be undertaken to completely elaborate on this interesting phenomenon. Owing to the abundance of patients with these implants, it is likely that more information will be forthcoming in the years ahead.

References

1. Basketter DA, Briatico-Vangosa G, Kaestner W, Lally C, Bontinck WJ. Nickel, cobalt and chromium in consumer products: a role in allergic contact dermatis? Contact Dermatitis. 1993:28:15-25.
2. Yang J. Merritt K. Detection of antibodies against corrosion products in patients after CoCr total joint replacements. J Biomed Mater Res. 1994:28:1249-58.
3. Thomas RH, Rademaker M, Goddard NJ, Munro DD. Severe eczema of the hands due to an orthopaedic plate made of Vitallium. Br. Med J (Clin. Res Ed). 1987:294:106-7
4. Kwon YM. Z. Xia, S. Glyn-Jones, D.J. Beard, H. S. Gill, D. W. Murray. Dose-dependent cytotoxicity of clinically relevant cobalt nanoparticles and ions on macrophages in vitro. Biomedical Material 2009, 4 (2); 25018