NEW YORK (Reuters Health) – Sonographic surveillance of newborns with mild hip dysplasia can reduce the need for early abduction splinting without increasing the risk of persistent or more severe dysplasia, a randomized study indicates.

For many years, clinical screening of newborns for hip dysplasia resulted in a splinting rate of 2%. More recently, newborns are often screened for hip dysplasia with ultrasound, which produces splinting rates of 5 to 7%. “This increase in abduction splinting treatment is partly due to the initiation of treatment of infants in whom mild, stable hip dysplasia has been identified,” the investigators write in the January issue of Pediatrics.

But splinting is not necessarily benign, lead investigator Dr. Karen Rosendahl of the Great Ormond Street Hospital for Children, London, UK and colleagues point out. Among its risks is avascular necrosis, reported in roughly 2% of babies treated in their first two months of life.

But, the researchers continue, “Although the justification for such treatment has recently been questioned, randomized trials to inform clinical practice have been lacking.”

Dr. Rosendahl and her associates therefore conducted a trial in 128 newborns, all with ultrasound evidence of mild dysplasia in one or both hips (sonographic inclination angle of 43 to 49 degrees). In all cases, the hip was stable and could not be dislocated.

Half of the infants were randomized to immediate abduction treatment using a Frejka pillow splint, with fittings, adjustments and sonographic follow-up at 6 weeks and 3 months (with splinting discontinued when indicated by improvement). The other babies were assigned to receive only sonographic surveillance at 6 weeks and 3 months.

Active surveillance “halved the number of children requiring treatment, did not increase the duration of treatment, and yielded similar results at 1-year follow-up,” the researchers report.

In the surveillance group, no infant underwent abduction splinting before 6 weeks of age. Abduction splinting was initiated in at 6 weeks in 12 infants in whom the alpha angle was 2 standard deviations above the mean. All 5 infants had stopped treatment by their 1st birthday.

Overall, 47% (29 infants) in the surveillance group received treatment compared with 100% in the immediate-treatment group.

The researchers note that while early splinting led to more rapid and consistent improvement, active surveillance and treatment of infants who did not improve spontaneously did not increase the proportion of children with delayed acetabular ossification or persistent dysplasia at 1 year of age.

“Our results may have important implications for families as well as for health care costs,” they conclude.

Reference:

Pediatrics 2010;125:e9-e16.