No physiologic age-related increase of circulating somatomedin-C during early stage of Perthes' disease: a longitudinal study in 21 boys.

Perthes' disease was originally viewed as a local ischaemic necrosis of the femoral head. Several authors, however, have presented data suggesting that children with this disease also suffer from a general disorder of skeletal maturation. Hormonal changes in the hypothalamus-pituitary-growth plate axis have been discussed as a possible underlying cause and contradictory results reported on the role of the somatomedins in this process. In this report for the first time sequential data are presented on plasma somatomedin-C (Sm-C/insulin-like growth factor I) levels in 21 boys with Perthes' disease. Values were compared with data from 105 control subjects. The physiologic increase with age of plasma Sm-C levels in the control group was either absent or diminished in children with early-stage Perthes' disease (P less than 10(-6), signs test). The Sm-C values in affected children were low. Our data correlate well with reports from others of retarded skeletal maturation in children with Perthes' disease and support the hypothesis of an accompanying disorder of the synthesis or release of Sm-C/IGF-I or its binding proteins.