Hypersensitivity to metallic implants remains relatively unpredictable and poorly understood. Although 20-25 % of total joint arthroplasty patients develop metal sensitivity, only a few highly susceptible persons (<1 %) exhibit symptoms. We present a case report of a fifty-two-year-old woman with a preoperatively documented metal allergy who underwent bilateral total knee arthroplasty using a titanium-niobium-coated implant on one side and a chrome-cobalt implant on the other side because of a logistics problem. At 2-year follow-up, no clinical symptoms of allergy or loosening of the implant were observed. Level of evidence IV.