[Thirty-four years follow-up of a bilateral Mac Kee-Farrar arthroplasty without loosening or osteolysis].

We report the case of a 93-year-old patient with bilateral Mac Kee-Farrar hip arthroplasties implanted 34 years ago. The patient was seen in 2005 for a type B1 periprosthetic fracture on the right prosthesis implanted in 1973. There was no loosening and the fracture was treated by plate fixation. Before the fracture, the Postel-Merle d'Aubigné (PMA) score was 16 on both sides, with a Devane activity score grade 2. At last follow-up, the PMA score was 13 for both hips, with a Devane activity score grade 1. Serum cobalt level was 1.36 microg/L (normal <1 microg/L). This exceptional case is to our knowledge the longest observed with this implant without clinical or radiographic signs of loosening. The serum cobalt level, rarely assayed after more than 30 years, was within the limits accepted for a metal-on-metal hip bilateral arthroplasty. We discuss the causes of failure and success of the Mac Kee-Farrar implant as reported in the literature and remark that long survival of the metal-on-metal bearing can occasionally be observed without signs of wear. Recent works on the metal-on-metal bearing merit attention.