Skeletal Immaturity, Rostral Sparing, and Disparate Hip Morphologies as Biomechanical Causes for Legg-Calve-Perthes’ Disease

Legg-Calvé-Perthes’ (Perthes’) disease is a developmental disease of the hip joint that may result
in numerous short and long term problems. The aetiology 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, summarising 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.