Selective ultrasound screening for developmental hip dysplasia: effect on management and late detected cases. A prospective survey during 1991-2006.

BACKGROUND: Early treatment is considered essential for developmental dysplasia of the hip (DDH), but the choice of screening strategy is debated. OBJECTIVE: We evaluated the effect of a selective ultrasound (US) screening programme. MATERIALS AND METHODS: All infants born in a defined region during 1991-2006 with increased risk of developmental dysplasia of the hip, i.e. clinical hip instability, breech presentation, congenital foot deformities or a family history of DDH, underwent US screening at age 1-3 days. Severe sonographic dysplasia and dislocatable/dislocated hips were treated with abduction splints. Mild dysplasia and pathological instability, i.e. not dislocatable/dislocated hips were followed clinically and sonographically until spontaneous resolution, or until treatment became necessary. The minimum observation period was 5.5 years. RESULTS: Of 81,564 newborns, 11,539 (14.1%) were identified as at-risk, of whom 11,190 (58% girls) were included for further analyses. Of the 81,564 infants, 2,433 (3.0%) received early treatment; 1,882 (2.3%) from birth and 551 (0.7%) after 6 weeks or more of clinical and sonographic surveillance. An additional 2,700 (3.3%) normalised spontaneously after watchful waiting from birth. Twenty-six infants (0.32 per 1,000, 92% girls, two from the risk group) presented with late subluxated/dislocated hips (after 1 month of age). An additional 126 (1.5 per 1,000, 83% girls, one from the risk group) were treated after isolated late residual dysplasia. Thirty-one children (0.38 per 1,000) had surgical treatment before age 5 years. Avascular necrosis was diagnosed in seven of all children treated (0.27%), four after early and three after late treatment. CONCLUSION: The first 16 years of a standardised selective US screening programme for developmental dysplasia of the hip resulted in acceptable rates of early treatment and US follow-ups and low rates of late subluxated/dislocated hips compared to similar studies.

Newborns with sonographically dysplastic and potentially unstable hips: 6-year follow-up of an RCT.

OBJECTIVE: To examine the long-term outcome of early abduction splinting versus active sonographic surveillance in newborns with mildly dysplastic hips. PATIENTS AND METHODS: Between 1997 and 2003, 128 newborns with mildly dysplastic and potentially unstable hips on ultrasound (43° ≤ α-angle < 50°) were randomly assigned to immediate abduction treatment or sonographic surveillance. All were invited for a radiographic follow-up at 6 years. The radiographs were analyzed by a single radiologist masked to the randomization allocation, and markers of hip dysplasia (acetabular index, center-edge angle of Wiberg) and avascular necrosis were reported. RESULTS: Eighty-three participants (65%) agreed to participate in the follow-up (42 participants from the treatment group). The mean acetabular index was 14.7° (SD: 5.6°) for the treatment group and 13.9° (SD: 3.9°) for the control group (mean difference: -0.8° [95% confidence interval: -2.9° to 1.3°]). Values were within normal ranges for age for all participants except for 1 female subject from the treatment group. The mean center edge was 26.6° for those treated and 26.4° for the active surveillance group (mean difference: -0.3° [95% confidence interval: -2.5° to 2.0°]). None had markers suggestive of avascular necrosis. CONCLUSIONS: We found no difference in radiographic outcome at 6 years of age between children allocated to initial splintage for 6 weeks and those offered active sonographic surveillance. The delayed acetabular ossification or persistent dysplasia seen in a third of infants from both groups at 1 year of age had completely resolved in all but 1 of the female subjects from the treatment group.