A comparative study of histology in Perthes' disease and idiopathic avascular necrosis of the femoral head in adults (IANF).

Thirty-seven femoral heads in idiopathic avascular necrosis of adults and fifty-seven biopsy specimens of the capital nucleus of Perthes' disease were studied histologically. Although the early pathological changes in these two diseases are very similar, in the intermediate and late (advanced) stages they gradually take differing courses. Although the initiating causes in both diseases are still obscure both are probably produced by repeated episodes of infarction of the femoral head.