Mechanical multiscale characterisation of vertebral trabecular bone for the prediction of vertebral fracture risk
LicenseStandard (Fassung vom 01.10.2008)
A world wide annual prevalence of 1.7 million osteoporosis-related, vertebral fractures constitutes a major clinical challenge. The ability to predict vertebral fracture risk using CT based, patient specific finite element simulations of whole vertebral bodies would be very useful for the management of patients with osteoporosis. Numerical models depend critically on the used material properties for bone tissue. Due to its hierarchical structure, the macroscopic material properties of bone depend on material properties on length scales several orders of magnitude below a clinically relevant length scale. To provide input for those numerical models and to investigate multiscale mechanical material properties this thesis addressed the following research questions: i) It is known that the spatial orientation of vertebral trabecular bone is the second critical independent variable characterising its mechanical behaviour. Is it possible to detect the trabecular orientation from clinical CT datasets? ii) The macroscopic mechanical behaviour may be influenced by the microscopic mechanical properties such as stiffness. How big is the stiffness of the bone material of single trabeculae, how is it distributed and how big are the directional differences? iii) How big is the micromechanical stiffness of vertebral trabecular bone and their distribution in a hydrated more physiological setting? iv) Macroscopic stiffness of vertebral trabecular bone may be dominated by its microscopic stiffness. Using the experimental results on the microscale, large scale finite element models were set up. Can the macroscopic stiffness be simulated? v) Clinical research questions targeting the fracture load of vertebral bodies or the behaviour of implants and their effects on the affected vertebrae necessitate accurate knowledge about the macroscopic mechanical properties of the vertebral trabecular core. Does the accumulation of damage depend on loading mode and direction?
Subject HeadingsWirbelbruch [GND]
Spinal injuries [MeSH]
Finite element analysis [MeSH]