Skeletal changes through the lifespan—from growth to senescence

Both peak bone mass attained during childhood and adolescent growth, and bone loss associated with senescence are major determinants of bone mass and fracture risk late in lifeIncidence of distal forearm fractures increases markedly around the time of puberty and children who sustain these fractures in the setting of mild, but not moderate, trauma have systemic skeletal deficits that persist into young adult lifeWith ageing, cortical bone at multiple skeletal sites remains fairly stable in both sexes until mid-life, when estrogen deficiency in women and gradual sex steroid deficiency in men begins to drive cortical bone lossBy contrast, substantial trabecular bone loss occurs in both sexes during young adult life, in conditions of sex steroid sufficiencyCortical porosity is increasingly recognized as an important component of bone 'quality' that increases markedly with age; changes in cortical porosity are not captured by dual-energy X-ray absorptiometryAssessment of cortical porosity might help identify individuals at increased risk of fracture from the large group of patients with osteopenia, in whom assessment of fracture risk remains most ambiguous