Updated 10/1/2014 R. Lass, MD; A. Grübl, MD2; A. Kolb, MD1; S. Domayer, MD; C. Csuk, MD; B. Kubista, MD; A. Giurea, MD; R. Windhager, MD March 05, 2014 Read Original Study by Clicking Here http://jbjs.org/article.aspx?articleid=1832017 Background: Second-generation, metal-on-metal bearings were introduced in 1988, to reduce wear and avoid polyethylene particle-induced osteolysis from total hip arthroplasty. In 2007, we reported the long-term results of ninety-eight patients (105 hips) who underwent primary cementless total hip arthroplasty involving the use of a prosthesis with a high-carbide-concentration, metal-on-metal articulating surface between November 1992 and May 1994. … The cumulative rate of implant survival, with aseptic failure as the end point, was 93.0% at 18.8 years. The median serum cobalt concentration in patients whose hip implant was the only source of cobalt was 0.70 μg/L (range, 0.4 to 5.1 μg/L), showing no increase in the value as noted at a minimum of ten years of follow-up. The clinical and radiographic results of our study, which, to our knowledge, represent the longest duration of follow-up for a series of cementless total hip arthroplasties with use of a 28-mm metal-on-metal bearing, continue to be comparable with the results observed for other hard-on-hard bearings.