The epidemiology and etiology of perthes’ disease
Despite over a century elapsing since the fi rst descriptions of Perthes’ disease, the etiological determinants remain unknown. Clues are emerging to help identify these determinants, such as intriguing geographic disease patterns and unexpected longitudinal incidence trends. While genetic tendencies are now generally sought as the answer to unexplained diseases, the absence of concordance in twins and lack of familial clusters suggest that the role of genetics is minimal. Large geographic variations in incidence with “pockets” of disease apparent even within small communities suggest that a major environmental risk factor is likely. The process of identifying the risk factor(s) and mechanism of action continues.