[Bone remodeling: evaluation methods].

Bone tissue undergoes continual renewal in order to keep the mechanical competence of the bone matrix. This is performed by two cells: osteoclasts which resorb the calcified matrix and osteoblast which synthetize a new bone matrix. Biochemical markers of bone remodelling allow the evaluation of the activity of each type of bone cells. An unbalance in this process induces modifications of the amount of calcified tissue and of the bone microarchitecture. Several technics based on X-ray and ultrasound allow a non invasive evaluation of these modifications.