Of 212 patients undergoing total hip replacement who were tested
preoperatively for sensitivity to nickel, chromium, and cobalt, fourteen
showed sensitivity. No sensitivity to the bone cement was recorded. Of 173
patients who had never had a metal implant before, 5.8 per cent showed a
positive reaction. Two patients out of fifteen with a failed McKee-Farrar
prosthesis were found to be sensitive. Of six patients who had a stable
McKee-Farrar prosthesis in the other hip, none showed sensitivity to the
metal. In four of sixty-six patients, sensitivity to nickel or cobalt
developed after the implantation of a metal-to-plastic prosthesis. No
patients were sensitized to the cement. The consequences of proved
hypersensitivity in patients with metal-to-plastic prostheses, either
present prior to insertion of the prosthesis or evoked by the implant
material, are not known.