[The natural history of developmental dysplasia of the hip. A meta-analysis of the published literature].

Assessment of the natural history of developmental dysplasia of the hip (DDH) is indispensable for age-dependent treatment of these patients. Based on a systematic meta-analysis of the published literature, this study gives an overview of the spontaneous course of DDH in different age decades. Furthermore, these results are discussed in the context of physiologic development of the hip. The data were compiled by a systematic literature search of medical databases from 1975 through 2007. For this evaluation, only papers that presented as high a level of evidence as possible were included. In early childhood, DDH with subluxation or dislocation necessitates treatment; otherwise, the spontaneous course leads invariably to osteoarthritis of the hip. However, a stable, well-centered dysplastic hip has a high potential of developing as a physiologic joint. In the analyzed data, an association between mild or moderate DDH after the end of growth and the development of osteoarthritis could not be demonstrated. The level of evidence of existing data is not sufficient to determine that persisting mild dysplasia is a relevant ethiopathological factor for osteoarthrosis of the hip. Therefore, prospective epidemiological studies are required.