Perthes' disease in the very young child.

We report two cases of very young children who presented with irritable hips and in whom magnetic resonance imaging with gadolinium-enhancement revealed ischaemic changes affecting the capital ossific nucleus. Radiological changes consistent with Perthes' disease subsequently appeared. In the published literature Perthes' disease has been reported in children as young as 24 months. Gadolinium-enhanced magnetic resonance imaging has revealed Perthes' disease in younger children which can predate the appearance of radiographic changes by up to 3 months.