Pelvic and Femoral Morphology in Developmental Dysplasia of the Hip

A recent epidemiological study showed that the prevalence of hip osteoarthritis (OA), defined as grade ≥ 3 based on the Kellgren and Lawrence classification system, was 1.34% in men and 2.54% in women in Japan [1]. The epidemiological feature of OA in Japan is characterized by the high prevalence of OA secondary to developmental dysplasia of the hip (DDH), 81% of which are reported to be secondary OA caused by DDH [2]. DDH is currently used as a generic term for a broad spectrum of conditions, including complete dislocation of the hip, subluxation, and acetabular dysplasia. This section will focus primarily on the morphological abnormality in adult acetabular dysplasia, which should be considered when reconstructing the adult hip.