Answer to Question #235985 in Cell Biology for john luvis

Question

The combined effects of porosity and strain rate on bone strength have been expressed by the following equation: where is the relative density. If the fracture stress of compact bone at 10 −3 s −1 is equal to 120 MPa, what is the fracture strength of cancellous bone with 50 vol.% porosity at 10 s −1?

Answer 1

The porosity and pore size of cancellous bone is much greater than that of cortical bone: cancellous bone has 75 – 85 % porosity with 300-600 µm diameter pores and cortical bone has 5 – 10 % porosity with 10 – 50 µm diameter pores.