Normal somatomedin-C activity measured by radioimmunoassay in Perthes' disease.

In recent years, the association between somatomedin and Perthes' disease has been investigated. Somatomedin activity measured by different methods (i.e., bioassay and radioreceptor assay) has generated variable results. The purpose of this study was to examine plasma somatomedin-C activity in Perthes' disease using radioimmunoassay. Somatomedin-C activity in affected boys and girls between six and 11 years of age was normal compared to the standard data on normal children. It is difficult to prove a functional pituitary somatomedin target axis. Therefore, caution is advisable before hypothesizing an etiology of Perthes' disease on the basis of results of plasma somatomedin concentration.