The Fracture of Femoral Components — An Act of God?

Abstract

In previous work a probability model for the fracture of femoral components was presented. This model was based on the assumption that the components were defect-free and that they fractured by a process involving metal fatigue. The model predicted the probability of fracture as a function of the patient's body weight and as a function of the time elapsed since operation (Dobbs, 1977). The present work is an extension of the model taking into account the patient's age and decreasing activity. It predicts the time dependence of the incidence of fracture and of the conditional failure rate. These predictions are compared with recently published survey data tending to support the view that the fracture of these components is a wearing-out process.