Computational modeling of debonding behavior at the bone/cement interface with experimental validation

Both clinical examinations and in vitro physical experiments have shown that the fixation interfaces of cemented components are actually critical sites affecting the long-term stability and survival of prosthetic implants after implantation. This study aims to investigate the interfacial debonding behavior of bone/cement composite structures and attempts to establish an analysis model for clinical applications involving cemented prosthetic components. The mechanical properties of the bonded interface were characterized by interfacial strength, interfacial stiffness, and fracture toughness; the measured values of tensile strength, shear strength, and fracture toughness were 4.94 MPa, 5.94 MPa, and 0.34 MN/m3/2, respectively. The measured strengths of the different configurations from this study are in good agreement with the experimental results available in the literature. In addition, we generated a finite element model with the same geometry as that of the experimental specimen used in the fracture test. The extent of interfacial debonding was further determined by means of the surface damage criteria and the fracture characteristics of the interface crack. The finite element model with an elastic interface predicted that the stress intensity factor (SIF) at the bone/cement interface crack varies nonlinearly with the applied load, which shows that the interface disintegrates at the load level, as was measured in the fracture experiments. It was possible to verify that the proposed simulation model was capable of describing the interfacial mechanical behavior of cemented components.