Fracture of a ceramic liner in a total hip arthroplasty with a sandwich cup.

摘要

Alumina ceramic-on-ceramic total hip arthroplasty (THA) has been widely used due to its advantages such as low wear, scratch resistance, wettable surface and relatively low biological reactivity of the wear particles. Nevertheless, this material in THA still persists to be one of the major concerns about the risk of fracture, due to its brittleness. Many authors have reported a fracture of the ceramic head but few reported a fracture of the ceramic acetabular insert. In order to reduce the rigidity of the ceramic-on-ceramic coupling and prevent an impingement between the rim of the ceramic liner and the metal neck of the femoral stem, a modular acetabular component with a sandwich insertion (alumina/polyethylene/titanium) was proposed. We report the fracture of the ceramic acetabular liner of such a ceramic sandwich cup due to a slightly retroverted position of the cup that causes an impingement between the femoral stem and the rim of the insert. The fracture occurred 3 years after the operation without trauma. At revision the entire cup was replaced using a polyethylene liner without inner ceramic liner.