Orientation of materials
Ideally materials are isotropic and homogeneous.
- A material is called isotropic when its properties are the same in x-y-z direction.
- A material is said to be homogeneous if it is made of the same material throughout.
Bone and bone grafts however are anisotropic and non-homogeneous . Cancellous bone is actually extremely anisotropic and non-homogeneous. Cortical bone, on the other hand, is approximately linear elastic, transversely isotropic, and relatively homogenous.
Figure : Influence of tissue anisotropy on stress strain curves.