What follow-up is required for children with a family history of developmental dysplasia of the hip?

To determine what follow-up is needed for children with a family history of developmental dysplasia of the hip (DDH) but who have had a normal clinical and ultrasound examination at 6 weeks of age. A retrospective review of medical and imaging records of all children with a family history of DDH referred to the hip-screening clinic over a 5-year period. An absolute acetabular index value of greater than 30 degrees or gross asymmetry in acetabular index values was used as an indication of occult acetabular dysplasia. One hundred and eighty-one children were identified as having had a normal ultrasound scan with a positive family history of DDH. Two (1.1%) children had acetabular dysplasia on their radiograph performed at 9-12 months of age. The dysplasia, however, resolved in both cases with simple observation and both children have now been discharged from further follow-up. We do not feel that it is necessary for children with a positive family history of DDH to have a radiograph of their pelvis at 1 year of age if they have had a normal clinical and ultrasound examination at 6 weeks of age and such children can safely be discharged from further follow-up at that time.