Understanding Bone Strength Determinants and Treatment Effects

摘要

Bone mineral density (BMD) is currently the gold standard for the diagnosis of osteoporosis and is a surrogate measure of bone strength However, BMD provides information regarding only the quantity of mineral in bone and does not directly quantify risk of fracture. Indeed, evidence suggests that there are several factors beyond BMD that affect bone strength and susceptibility to fracture For example, patients with a normal bone density are at increased risk of fracture when treated with glucocorticoids. Also, changes in BMD seen with antiresorptive drugs account for only a small proportion of the observed reduction in vertebral fracture risk, and this reduction occurs before large increases in BMD are realized Other factors that contribute to bone strength include bone turnover, geometry, microarchitecture, and mineralization,. Although no clinical tool is currently available to measure these other components of bone strength, noninvasive imaging techniques are on the horizon that show promise for comprehensive individual assessment of fracture risk and treatment efficacy.