[Ultrasound screening of hip joints in newborn infants]

The aim of the present study was to assess the efficiency of ultrasonography in the screening of hip joints in newborn babies. In 1987, 2,531 newborns (92.4% of all liveborn babies) were examined clinically and with ultrasound. The coverage of the femoral head by the bony acetabular roof was measured on a longitudinal, coronal scan. The mean head coverage was 57% in boys and 55% in girls (p = 0.0001). Unstable hips, shown by both ultrasound and clinical examination, were found in 27 newborns (1.1%). The mean head coverage of unstable hips was 41%, significantly lower than for stable hips. No late hip dislocations were diagnosed in children with normal findings who were not included in the follow-up routines. In conclusion, the study indicated that ultrasonography measuring the femoral head coverage is an appropriate method of screening in newborns. It is useful for differentiating between a true and a false positive Ortolani sign. Moreover, ultrasound can show hip dysplasia that is not clinically demonstrable at birth.