Background: DDH represents a spectrum of anatomical abnormalities in which the femoral head and the acetabulum are either in improper alignment or grow abnormally. Although screening leads to earlier identification, 60–80% of abnormal hips of newborns identified by physical examination resolve spontaneously by 2–8 weeks and 90% of the hips of newborns with mild dysplasia identified by ultrasound resolve spontaneously between 6 weeks and 6 months.
Aims: To assesses accuracy of ultrasound screening of neonatal hip by the static technique of Graf. We attempt to answer the question whether routine radiological follow up of these children are indicated.
Methods: Since 2001, we have performed selective ultrasound screening of over 600 neonates (1200 hips). The reasons for referral included, breech presentation, clicky hip, unstable hip, dislocation, foot deformity and family history of DDH. Clinical examination, followed by serial ultrasound examinations at presentation, 6 weeks and 3 months of age were carried out. A radiological examination and measurement of the acetabular index was performed at 6 months of age. Hips were classified according to the 4 Graf types. We compared the ultrasound findings with the acetabular index (AI) for individual patients.
Results: All children were followed up prospectively from presentation to discharge. For neonates without any family history of DDH and normal clinical examination (symmetrical skin creases, equal limb lengths, unrestricted abduction and no instability demonstrated on the Ortolani and Barlow manoeuvres) the ultrasound classification according to Graf co-related with the acetabular index on 6 month radiographs. 100% of hips with normal scan (Graf I) both at 6 weeks and at 3 months of age had a normal AI.
Discussion: The static technique of Graf is an accurate and reliable method of assessment of neonatal hips. In children with normal clinical examination, and no family history of dysplasia, scan findings are a good predictor of the AI. Routine radiological follow up in such patients is not necessary.
