Hip sonography in the "Graf technique" is an important tool to detect early DDH cases and dysplastic hips in the German speaking countries, although hip sonography is still controversially discussed in the English speaking countries. The reason may be different techniques with different classification and outcome. Exact anatomical identification, measurement technique, typing, difference between instability and elasticity with a reproducible "standard plane" is absolutely necessary to make hip ultrasound (US) comparable and reliable. US screening had reduced open reductions in Germany to 1:4000, in Austria to 0.23 per thousand. Because of the early screening and earlier less aggressive treatment, the overall costs could be reduced by 1/3 in comparison to the pre-ultrasound area. US screening seems to prevent many, but not all operations and can be recommended as an important tool for prevention.