Investigation of the fracture characteristics of the interfacial bond between bone and cement: experimental and finite element approaches

This study integrated the finite element method, fracture mechanics, and three-point bending test to investigate the fracture characteristics of the interfacial bond between bone and cement. The fracture tests indicated that the interfacial fracture toughness of the bone/cement specimens was 0.34 MN/m^3/2, with a standard deviation of 0.11 MN/m^3/2, which was in good agreement with the experimental data available in the literature. A finite element model of the experimental testing specimen was used to predict the critical stress intensity factor (SIF) at the fracture load by the proposed fracture analysis method. The critical SIF of the opening mode of the interface crack was 0.392 MN/m^3/2, which was slightly higher than the fracture toughness obtained in the experiment. Additionally, considering the coupled effects of the crack opening mode and shearing mode, the critical effective SIF was 0.411 MN/m^3/2, with a phase angle of 17.2°. Comparisons of the results obtained from the bending test and numerical analysis made it obvious that the fracture characteristics of the bonded interface between the bone and cement could be accurately predicted by the proposed model. With this analysis model, a realistic investigation on the debonding behavior of cemented artificial prosthetic components is highly expected.