ABSTRACT
Differences in bone size, shape, microstructure and material composition account for differences in bone strength between individuals, sexes and races. The variance in bone morphology is established during the first 2 years of life and does not vary much subsequently. During growth, an increasing volume of bone matrix is assembled with varying medullary and cortical canal void volumes establishing bone's external dimension and differing configuration of its matrix forming the compact bone, the transitional compartment and porous trabecular compartment. Growth in height is the result of appendicular and axial growth. As longitudinal growth is more rapid in the appendicular than axial skeleton before and in early puberty, illness may produce greater deficits in appendicular morphology. For example, disease affecting radial growth before puberty, compromises the gain in bending strength. Skeletal fragility in advanced age has its antecedence in growth because the variance in bone traits achieved during growth is an order of magnitude greater than rates of loss during aging.
