[Natural course of mild hip dysplasia from young childhood into adulthood].

For radiometric evaluation of hip development in children, Hilgenreiner's acetabular index is one of the most important parameters. In order to assess the prognostic value of the acetabular index to separate healthy from pathologic hip joints, follow-up studies of untreated mildly dysplastic hips were undertaken. When 48 hips classified as mildly dysplastic at the age of 1-4 years were followed up when the patients were adult, 90% had normal hip scores according to Tönnis, 81% a normal acetabular angle according to Ullmann and 71% a normal acetabular coverage according to Wiberg. From the data presented there is no clear-cut delineation between healthy and pathologic hips during childhood. Therefore, the developmental dynamics of the hip during longer time intervals have to be taken into consideration.