[Gout, hyperuricemia and femur head osteonecrosis (FHON)].

The authors report on 14 cases of osteonecrosis of the femoral head (ONFH) in patients suffering from gout. The cases of association were discovered over a period of 10 years among 232 patients with ONFH and 651 with gout. The necrosis had no particular characteristics except that there was a clear preponderence in males and a slight tendency to be bilateral; it occurred, perhaps, at a slightly earlier age. The patients with gout did not show any special clinical features ; the gout always preceded the necrosis, on average by 7 1/2 years. There was no obvious history of painful crises in the hip that could be attributed to the acute gout, except in one case. The excess of urate was detected by the baseline level of uricaemia (91 mg/litre on average), by the frequency of tophus (4 out of 14), and by the frequency of urinary lithiasis (2 out of 14), and did not appear to be any greater in the patients with gout and ONFH than it was in the whole of the population of gout patients. In those patients in whom it was estimated, the lipid analysis showed most frequently an increase in total lipids, in triglyceridaemia, and in cholesterolaemia. In the 5 patients in whom the investigations were sufficiently detailed, the dyslipidaemia was of Frederickson type II + IV (mixed hyperlipidaemia according to de Gennes' classification). Different physiopathological hypotheses are discussed by the authors, notably those concerned with micro-particulate fatty emboli (lipomicrons), which may obstruct, among others, the terminal arteries of the femoral head. Of the 6 patients for whom it was possible to obtain information, for an average period of 10 years since the onset of the necrosis, 2 had presented with untreated hyperlipidaemia and a severe general vascular illness (myocardial infarction in one case and regressive hemiplegia in the other). These findings lead to the conclusion that correction of the hyperlipidaemia by diet is indispensable to ensure the long-term survival of these patients.