Cracks Emanating From a Fluid Filled Void Loaded in Compression: Application to the Bone-Implant Interface

Abstract

Loosening of orthopedic implants is believed to be caused, in part, by fracture at the bone-cement interface. This loosening occurs even in regions where the interfacial load is primarily compressive. A model is developed whereby cracks can radiate from an elliptical fluid filled void. The incompressible fluid is allowed to penetrate into the cracks when the system is loaded compressively. The mode I stress intensity factor is calculated to test the feasibility of crack growth, and a numerical scheme which uses piecewise quadratic polynomials is used to solve the resulting singular integral equations. The results show the combinations of parameters for which cracks are likely to grow.