[New development in bisphosphonate treatment. Effect of bisphosphonate on structural property]

Bisphosphonate is highly potent antiresorptive agent with an effect to preserve bone structure. Structural property is evaluated using bone imaging techniques. Hip Structure Analysis (HSA) program based on 2D hip DXA data, estimates 3D geometrical properties such as cross-sectional area (CSA) , subperiosteal width and average cortical thickness. From these geometrical parameters, biomechanical indices can be derived. HSA shows BP has an effect to prevent of endocortical resorption and to increase cortical thickness, and finally to increase biomechanical strength. Micro-CT visualizes and measures 3D trabecular microarchitecture, which shows that BP prevents osteoporotic microstructural deterioration, such as trabecular disconnectivity, decrease of trabecular number, and transformation from plate-like structure to rod-like structure. These changes are considered to be related to increase biomechanical strength.