Assessing bone quality--animal models in preclinical osteoporosis research.

As new agents are developed for osteoporosis prevention and intervention, the need for reliable animal models becomes more pressing. At the same time, the necessity of not focusing on bone mass as the sole efficacy parameter has become apparent. Before accepting any agent for clinical osteoporosis trials, FDA now requires that it has proven its efficacy in a small animal model and also in a larger animal model with known intracortical bone remodeling. This efficacy should be proven both concerning bone mass and bone biomechanical competence. In this paper, methods for testing bone quality in small and large animal models are presented, and the necessity of testing several skeletal sites: vertebrae, long bones, and femoral necks is discussed.