The role of patch testing in the evaluation of orthopedic implant-related adverse effects: current evidence does not support broad use.

In recent years, there has been a growing interest in the use of skin patch testing to evaluate patients for orthopedic, implant-related adverse effects. This may be done preoperatively to avoid implanting a material to which an individual may be allergic or postoperatively to implicate sensitivity as a cause for implant failure. There is emerging evidence that patch testing might have utility in the workup of implant-related adverse events; however, the level of evidence at the present time is weak and based only on a collection of case reports, series, and retrospective cohort studies (level IV evidence as per United States Department of Health and Human Services guidelines); there are no randomized controlled trials (level I evidence) with which to guide medical decision making. Recent reports have advocated that patch testing be broadly used in the preoperative evaluation of all patients self-reporting a history of metal sensitivity. In addition, several authors have advocated that patch test results should guide preoperative implant selection and postoperative implant removal. It is the opinion of this author that these recommendations are premature, lacking robust clinical evidence, and unfeasible given the broad-reaching logistical impact and societal costs involved. More robust clinical data are needed, and thorough cost-benefit analyses must be performed before such far-reaching and costly systematic practices should be broadly implemented.