Environmental tobacco and wood smoke increase the risk of Legg-Calvé-Perthes disease.

Background: The etiology of Legg-Calvé-Perthes disease (LCPD) remains unknown. A few studies have suggested passive smoke inhalation may be a risk factor, although the association is not confirmed and a causal relationship has not been established.

Questions/purposes: We therefore undertook this study to confirm an association between environmental tobacco smoke, firewood smoke, and socioeconomic status and the risk of LCPD.