Secondary osteoporosis.

Secondary osteoporosis is more difficult to define in children than in adults but clearer definitions have recently been provided by the International Society for Clinical Densitometry. Whereas in adults, osteoporosis is defined on the basis of reduced bone density on scanning, in children the definition requires additional clinical parameters to be fulfilled. Secondary osteoporosis may arise either as a result of the effects of underlying disease or as a result of the treatment of such diseases (e.g. with glucocorticoids). The normal balance of bone formation and removal, both by bone modelling and remodelling, is disturbed in such a way as to alter the normal accumulation of bone that occurs during childhood. A multitude of intrinsic and extrinsic factors contributes to these processes. The underlying principles of treatment of secondary osteoporosis is, where possible, to remove the underlying cause. Where this is not possible, minimising the effects of treatment with drugs that adversely effect bone may be sufficient to eliminate any deterioration in bone quality. If this is not possible, the use of bone sparing drugs such as the bisphosphonates may be necessary whilst ensuring that attention is paid to optimising calcium and vitamin D intake and encouraging exercise and mobility.