Autopsy analysis thirty years after metal-on-metal total hip replacement. A case report

Metal-on-metal bearings have demonstrated low wear after many years in vivo1,2. Consequently, there has been a resurgence of interest in metal-on-metal bearings. There are, however, concerns about potential adverse effects due to local accumulation and systemic distribution of cobalt-chromium wear moieties and ions, especially after several decades in situ3-5. Cobalt and chromium particles have been shown to induce carcinoma in animal models6, giving rise to the concern that such alloys could have the same effect in human tissue, if present in sufficient amounts for a sufficient length of time. Autopsy retrievals provide the opportunity to assess the distribution of wear products in the tissues immediately surrounding as well as at a distance from the implant7. The aim of this study was to assess the distribution and histological effects of wear particles from a McKee-Farrar metal-on-metal-bearing total hip replacement after nearly thirty years in situ. Amoderately obese, forty-seven-year-old woman fell and sustained a transcervical fracture of the right femur, which was treated initially with internal fixation and a spica cast. A subsequent nonunion was treated with a Judet prosthesis, which was eventually removed, leaving the patient with a Girdlestone resection of the right hip. In 1970, at the age of sixty-eight years, the patient underwent total hip arthroplasty of the left hip for the treatment of extensive osteoarthritis, and a metal-on-metal McKee-Farrar total hip prosthesis was implanted. In 1995, the patient was contacted by our research group, and she agreed to be evaluated as part of a long-term study of McKee-Farrar total hip replacements8,9. She also consented to join the “Willed Joint” program of the Joint Replacement Institute, thereby agreeing to donate her hip joints and to permit postmortem biopsies of her organs. The patient …