The effect of osteoporosis on the mechanical properties of bone structures.

Since experimental data on the mode of failure of the lumbar vertebral body and the femoral neck scarce, a model predicting their fracture mechanisms under a representative loading is needed. This model should be ask to describe the inference of osteoporosis on the mechanical strength, and should use BMC-measurement date as an input. A simple mechanical model for both structures, composed of a thin-walled cylindrical cortual shell, filled with a trabecular bone core is used. We find that the BMC evaluated as the mineral content in a 1 cm thick section (expressed in g/cm) is a good predictor for the strength of the vertebral body, while for the femoral neck, additional information on the cortical wall thickness is needed.