From a macroscopic point of view, human bone appears in two forms. The most obvious difference between these two types of bone is their volume fraction of solids or relative densities. The term cortical or compact is used to categorize bone with a volume fraction of solids greater than 70 percent. On the other hand, bone with a volume fraction of solids less than 70 percent is referred to as cancellous or trabecular. Typically, most bones within the human body possess both types: a core of spongy cancellous bone is surrounded by an outer shell composed of a dense compact bone. The constitutive properties of cancellous bone are of vital importance as it is this bone that is in direct contact with the implant or prosthesis.