The incidence and distribution of Legg–Calvé–Perthes' disease in Liverpool, 1982–95

AIMS To determine the incidence and distribution of Legg–Calvé–Perthes' disease in Liverpool, in the period 1982–95. METHODS Examination of information in a register, analysing the patients' addresses by indices of deprivation. RESULTS A total of 122 white children were diagnosed as having Perthes' disease during the study, whereas black and minority groups form 5.8% of the population. The incidence rate in inner Liverpool had decreased to 10.5 in the period 1990–95. Simple Spearman correlations revealed an association between the disease incidence in electoral wards and deprivation. Regression analysis showed that for the period 1990–95 the most powerful effects on incidence were increases in ward deprivation since 1976, the percentage free school meals in 1986, the ward Health Index in 1981, and the percentage low birth weight in 1981. CONCLUSIONS We suggest that environmental influences may come into play some years before a child presents with pain in the hip. There may be a genetic predisposition to the disease.