Legg-Calvé-Perthes' (Perthes') disease is a developmental disease of the hip 
joint that may result in numerous short and long term problems. The etiology of 
the disease remains largely unknown, but the mechanism is believed to be 
vascular and/or biomechanical in nature. There are several anatomical 
characteristics that tend to be prevalent in children with Perthes' disease, 
namely: skeletal immaturity, reduced height, and rostral sparing. We present an 
overview of the literature, summarizing the current understanding of the 
pathogenesis, particularly related to how the formation of the vasculature to 
the femoral epiphysis places children aged 5-8 at a higher risk for Perthes' 
disease, how skeletal immaturity and rostral sparing could increase the 
probability of developing Perthes' disease, and how animal models have aided our 
understanding of the disease. In doing so, we also explore why Perthes' disease 
is correlated to latitude, with populations at higher latitudes having higher 
incidence rates than populations closer to the Equator. Finally, we present five 
hypotheses detailing how Perthes' disease could have a biomechanical cause. 
Clin. Anat. 29:759-772, 2016. © 2016 Wiley Periodicals, Inc.