Orthopedic metal immune hypersensitivity.

For many patients, the metals used in contemporary joint replacement surgery produce little or no reaction from the immune system. In a small but significant percentage of patients, however, a very rapid, T cell-mediated, allergic response may occur. If untreated, this reaction may ultimately lead to implant failure. Diagnosis may be complicated, and no effective treatments are available. Fortunately, alternative materials show great promise.