Short communication: quantitative macroradiography with biochemical correlation of children with renal osteodystrophy.

Abstract

Renal osteodystrophy is a common complication of chronic renal failure in children. Its radiological appearances include those of hyperparathyroidism, namely subperiosteal bone resorption and ungual tuft erosion and rickets (Meema et al, 1978; Genant & Resnick, 1988). Subperiosteal resorption has been considered the most sensitive radiographic sign of renal osteodystrophy (Sundaram, 1989) and as such, its extent has been assessed as an indicator for disease activity (Meema et al, 1978). Accurate measurements of its extent have been made using high definition magnification radiographs (Buckland-Wright et al, 1989; 1990). They showed that the extent of percentage subperiosteal resorption (i.e. subperiosteal resorption expressed as a percentage of the total subperiosteal bone length) and its change over time correlated with the level of serum parathyroid hormone (PTH). Thus a high PTH level was associated with extensive subperiosteal resorption. These findings were confirmed by a semiquantitative study employing conventional radiographic techniques, again showing a good correlation betwen PTH levels and the intensity of radiological change (Tratting et al, 1990). Both these studies involved patients who had severe renal osteodystrophy; children in the first study and an adult population in the second. Using the quantitative method devleloped for microfocal radiography, this study examined the extent of subperiosteal resorption in a group of children with controlled renal osteodystrophy, as reflected by their lower PTH levels. Two further questions were addressed.