  The minimal invasive procedure of vertebroplasty is a surgical technique to
treat compression fractures of vertebral bodies. During the treatment, liquid
bone cement gets injected into the affected vertebral body and therein cures to
a solid. In order to investigate the treatment and the impact of injected bone
cement, an integrated modelling and simulation framework has been developed.
The framework includes (i) the generation of microstructural computer models
based on microCT images of human cancellous bone, (ii) computational fluid
dynamics (CFD) simulations of bone cement injection into the trabecular
structure and (iii) non-linear finite element (FE) simulations of the
subsequent bone cement curing. A detailed description of the material behaviour
of acrylic bone cements is provide d for both simulation stages. A non-linear
process-depending fluid flow model is chosen to represent the bone cement
behaviour during injection. The bone cements phase change from a highly viscous
fluid to a solid is described by a non-linear viscoelastic material model with
curing dependent properties. To take into account the distinctive temperature
dependence of acrylic bone cements, both material models are formulated in a
thermo-mechanically coupled manner. Moreover, the corresponding microstructural
CFD- and FE-simulations are performed using thermo-mechanically coupled
solvers. An application of the presented modelling and simulation framework to
a sample of human cancellous bone demonstrates the capabilities of the
presented approach.
