A new method to evaluate the elastic modulus of cortical bone by using a combined computed tomography and finite element approach

This study attempted to estimate the elastic modulus of cortical specimens directly from the computed tomography (CT) number (CT). Cubic specimens of fresh bovine femora were tested under compressive loading. The corresponding three-dimensional mesh models of these specimens were established with the aid of CT images. The elastic modulus of each element was determined using the following transfer formula: E=Ax(CT)(B). The A and B were determined by matching the simulation results with the experimental force-displacement curves. An optimization approach was used to match the entire specimen sets between simulations and experiments. The results indicated that the elastic modulus of cortical bone can be effectively estimated using a power relationship (E=1.26 x 10(-3) x (CT)(1.93)) directly from the CT number. This procedure eliminates the need to determine the bone density, and therefore reduces the computational time required to define mechanical properties in finite element methods.