The epidemiology of diseases of the hip: a review of the literature.

Diseases of the hip are significant public health problems. Fractures and osteoarthrosis of the hip are common in older age-groups, while congenital dislocation of the hip, Legg-Calvé-Perthes disease, and slipped epiphysis affect a certain proportion of infants, children, and adolescents. The distribution of these five common hip diseases in the population is reviewed, aetiological hypotheses are discussed, and gaps in knowledge identified. Particular attention is focused on the roles of mechanical stress and hormones, since there is evidence for the involvement of one or both of these factors in the aetiology of each of the diseases. Many characteristics of their descriptive epidemiology have still to be explained, however, and it is clear that more research is needed.