[Bone quality, strength, and turnover]

Skeletal integrity is maintained by remodeling, a sequential process of bone resorption and formation. Bone mass and quality depends on a dynamic equilibrium between resorption and formation during a remodeling process. Bone strength, or its ability to resist to fractures, is determined by both mass and quality of bone. Recent clinical studies indicate that activity of remodeling, i.e., bone turnover, is not only a predictor of future changes in bone mass but also a determinant of the future fracture risk independent of bone mass and that fracture prevention by anti-resorptives cannot be solely explained by increased bone mass but is more closely associated with improved bone quality, especially, suppression of bone turnover. This review will focus on the impact of bone turnover on bone quality and fracture risk and its clinical relevance.