[The growth of the juvenile hip joint. A planimetric study of x-ray films (author's transl)].

A total of 1.779 X-ray films of the pelvis done with the same technic in children and adolescents was divided into 8 different age groups between 5 and 20 years. Several planimetric parameters for the evaluation of pelvic growth were measured and statistically analysed. A growth quotient was found showing periods of limited intensive growth efforts of the human hip joint. Such growth periods were found in both sexes between 5 and 8 years, and again for girls between 9 and 12 years, for boys between 11 and 14 years. In pathologic hip joints the triradiate cartilage closes sooner. The development of the pelvic roof and the closure of the triradiate cartilage show a close relationship. By evaluating 802 normal hip joints, an acetabular form index useful for all age groups was found.