Seasonal variations of congenital dislocation of the hip

Abstract

The distribution of the months of birth of children with congenital dislocation of the hip (CDH) in six countries in the Northern Hemisphere and in Victoria (Australia) were compared. The quarterly and monthly patterns of the six Northern Hemisphere countries were found to be in agreement: i.e. less children with CDH were born during the months of March through August than during September through February with peak incidence from the end of October till mid‐January. A reversed pattern of CDH births was noted in Victoria with maximum frequency in the second quarter of the year and a trough in the first quarter. Temperature per se could not be considered responsible for the variations in CDH births in both Hemispheres. Huntington ‘s hypothesis of a “basic animal rhythm” operating in man seems a reasonable explanation.