Overdiagnosis of congenital dislocation of the hip.

In a retrospective study of 548 cases of CDH diagnosed and treated immediately after birth in the city of Malmo, 90 per cent may not have developed manifest dislocation even without treatment when the expected incidence is taken into account. It could, however, be demonstrated from variables such as sex ratio, birth rank, fetal presentation and the size of the capital epiphyses that the entire group indeed had characteristics relating them to CDH. These characteristics were more obvious in coses with a firmly established diagnosis. Cases in whom the diagnosis could not be confirmed radiologically deviated less or not at all from the general population.