Congenital hip dislocation and dysplasia in Southern Chinese.

In 1975 we carried out a survey in Hong Kong to locate Chinese children with congenital dislocation of the hip. Analysis of the available records between 1960 and 1975 gave an observed incidence which was at least 10 times less than found in Caucasians. The age and sex distribution, radiographic findings and the left-sided predominance were similar to Caucasians with congenital dislocation of the hip. However, unlike Caucasian children, the Chinese presented with dislocation and not dysplasia. The mothers of children with congenital dislocation of the hip were compared with a control group with normal children to assess their use of the "Hong Kong" position, in which the children are carried on the back of their mother with their hips in a position of wide abduction. Since only half of the children in either group were carried in this manner, other factors must be responsible for the low incidence of congenital dislocation of the hip in southern Chinese.