Paediatric hip--ultrasound screening for developmental dysplasia of the hip: a review.

This paper will try to deal with the following questions: Which is the correct screening model for the developmental dysplasia of the hip (DDH)? What is the clinical significance of "sonographic" DDH? Can overtreatment produced by ultrasound (US) screening cause a waste of resources and eventually morbidity? We reviewed the literature since January, 1996 through December, 2000. To compare our experience with the literature, we analysed the results of the US examinations of the hip performed in our Institute. Over 4 years of US screening 11326 infants (22652 hips), aged 3 days to 4 months, were examined consecutively. Sonographic hip findings were abnormal in 531 infants (4.7%). The screening showed 381 subjects (3.36% of the population) with a type IIa hip (bilateral or unilateral); 65% of these infants were normal at follow up and only 35% worsened. On the whole we treated 282 infants (2.5%). No open reduction was performed. Avascular necrosis appeared in 2/282 treated cases (1.06%). We support the routine generalised US screening of neonatal hips. The excess of doubtful cases and, consequently, of the extra referrals may be limited, and the overtreatment decreased to the lowest rates reported by optimisation of everyone's approach.