Measuring bone quality.

Osteoporosis is defined as a reduction in bone mass and impairment of bone quality that lead to bone fragility and fracture risk. Bone quality includes a hierarchy of properties from macroscopic to nanoscale level. Several techniques have been developed in an attempt to measure these non-density properties. Densitometry, high-resolution images (radiography, CT scan), and MRI can measure the geometry and microarchitecture of bone. Tissue mineralization and composition can be assessed by use of microradiography, Fourier-transform infrared spectroscopy, or Raman microspectroscopy. Finite-element analysis is an image-based method that enables calculation of bone strength. More recently, microindentation has enabled direct estimation of bone material strength, measured in the cortical bone of the tibia. Most of these techniques are of limited use to clinics, although finite-element analysis and microindentation have high potential for clinical use and can enable more comprehensive and accurate evaluation of bone fragility and fracture susceptibility.