Two family studies on congenital dislocation of the hip after early orthopaedic screening Hungary

Two family studies involving 1767 and 379 index patients in Budapest and Bekes county, respectively, were undertaken to examine the effect of early orthopaedic screening on the recurrence risk of congenital dislocation of the hip. About 14%, 2.1-2.3%,1.2-1.4%, and 4.7-6% of sibs, parents, uncles and aunts, and cousins, respectively, had congenital dislocation of the hip in these two surveys. The recurrence risks were eight-fold and four-fold higher in brothers and sisters, four times higher in parents, 2.5-fold higher in uncles and aunts, and 2.0-2.5 times higher in cousins, respectively, than in the general population. This family pattern seems to fit best with a model of polygenic-multifactorial inheritance. In earlier studies higher recurrence risks were found. These may be explained by the change of diagnosis due to early orthopaedic screening which may increase the possibility of over diagnosis and the treatment of mild cases which previously recovered spontaneously.