developmental dysplasia of the hip (ddh) is the most frequent developmental disorder of the locomotor system. it is detected among 0.1–5.2% of newborns (1, 2). this might be the reason, that there is a high interest to detect ddh cases as early as possible. undetected or late cases lead to catastrophes for the patient and family. limping, leg length discrepancy, pain, frequent operations and so...