A probabilistic damage model for acrylic cements. Application to the life prediction of cemented hip implants

In this paper, we propose a new model to predict the reliability function of the fatigue life of the cement of cemented hip implants. With this purpose, we compute the first moments of the relevant mechanical variables, using probabilistic finite elements (PFEM) and construct a B model to follow the evolution of the cumulative damage process. Two families of random variables have been considered, the muscle and joint contact forces at the hip associated to different activities (walking, stair climbing and a combination of both) and the fatigue material properties of the cement. This model predicts similar failure probability results to those observed experimentally. Its application to the Exeter Total Hip Replacement predicts areas of high damage very similar to those observed in clinical tests, allowing us to predict the failure probability (reliability) of the cement under cyclic loads with enough accuracy.