The reliability of modern alumina bearings in total hip arthroplasty—Update to a 2006 report

Ceramic components׳ clinical fractures in total hip arthroplasty (THA) are a rare but, nonetheless, serious complication. As a result of continued improvements in ceramic material quality, manufacturing methods, and implant design made over the last 30 years, the incidence of such failures has been drastically reduced. In this report, the frequency of these ceramic components׳ clinical failures in THA will be examined. In addition, some information regarding the contribution that can be made by the surgeon to enhance the reliability of ceramic components will also be presented. In order to get a broad view, the largest supplier of these components, CeramTec Medical Products (Plochingen, Germany), was contacted, and they agreed to share their most recent data. In the year 2000, the largest supplier of alumina–ceramic bearings for orthopedic applications (CeramTec GmbH, Plochingen, Germany) began a rigorous program of collecting clinical fracture data for all of its ceramic components. The clinical fracture data for the period of January 2000–June 2013 are reported here, with a review of the material properties, historical component fracture trends, and relative risk of fracture associated with alumina THA bearings. The data reported is divided into two separate groups. The first one is the incidence of clinical fracture of the Biolox®forte material. This is their original material developed in the 1970s and is still available today and optimized over the years. The overall clinical fracture rate of these alumina components was 0.021%, or 21 in 100,000, during the January 2000–June 2013 time period. The second group is composed of components manufactured from their Alumina Matrix Composite, Biolox®delta. The overall clinical fracture rate for these components is 0.0001% or 1 in 100,000. Almost 80% of these alumina bearing failures occurred within 36 months following surgery. Using the latest material and increasing femoral head diameter were associated with a substantially reduced risk of fracture. Alumina bearings used in modern THA implants are safe and reliable, with a very low risk of failure. Improvements in the materials, developments in the manufacturing, the introduction of the Alumina Matrix Composite, and the trend to utilize larger-diameter ball heads are likely to continue to reduce the concerns that have been in the mind of surgeons using ceramics in THA.