  We studied the elastic properties of bone to analyze its mechanical behavior.
The basic principles of ultrasonic methods are now well established for varying
isotropic media, particularly in the field of biomedical engineering. However,
little progress has been made in its application to anisotropic materials. This
is largely due to the complex nature of wave propagation in these media. In the
present study, the theory of elastic waves is essential because it relates the
elastic moduli of a material to the velocity of propagation of these waves
along arbitrary directions in a solid. Transducers are generally placed in
contact with the samples which are often cubes with parallel faces that are
difficult to prepare. The ultrasonic method used here is original, a rough
preparation of the bone is sufficient and the sample is in rotation. Moreover,
to analyze heterogeneity of the structure we measure velocities in different
points on the sample. The aim of the present study was to determine in vitro
the anisotropic elastic properties of cortical bones. For this purpose, our
method allowed measuring longitudinal and transversal velocities (CL and CT) in
longitudinal (fiber direction) and radial directions (orthogonal to the fiber
direction) of compact bones. Young's modulus E and Poisson's ratio &#61550;,
were then deduced from the velocities measured considering the compact bone as
transversely isotropic or orthotropic. The results are in line with those of
other methods.
