Ultrasound screening for developmental dysplasia of the hip after 4 weeks increases exam accuracy and decreases follow-up visits.

Background: Developmental dysplasia of the hip (DDH) is a preventable and treatable disorder in children. Hip ultrasound is recommended for early detection of affected hips. The timing of the initial hip ultrasound and the frequency of subsequent ultrasounds are controversial topics when considering costs and efficiency.

Methods: Registry data from the Taiwanese Screening and Audit System for Developmental Dysplasia of the Hip were obtained for biometry of hip ultrasounds using the Graf classification and relevant demographic data from 2016. Initial screening results and final case management outcomes were compared to determine screening accuracy and the number of visits needed to determine final outcomes.

Results: In total, we screened 1683 newborns in 2016. Of the initial cases screened within 28 days (n = 1168), 86.6% were negative, 10.1% positive, and 3.3% intermediate, while of the cases screened after 28 days (n = 515), 97.3% were negative, 0.8% positive, and 1.9% intermediate. Screening of the newborns' final hip outcomes revealed that 1641 (97.6%) were negative, treatment was administered in 8 cases (0.4%), and 34 (2.0%) cases were lost to follow-up. When comparing screening times, screening after 28 days improved specificity (89%-97%), and later screenings were associated with fewer visits needed to confirm hip outcomes (aOR = 0.19, CI95% = 0.10-0.38, p < 0.001) and improved accuracy (aOR = 13.84, CI95% = 4.23-45.26, p < 0.001).

Conclusion: This study provides evidence of the benefits of screening for DDH after 28 days, namely: reduced false positives, improved screening accuracy, and a reduced requirement for follow-up visits. Delaying screening can also potentially reduce unnecessary parental anxiety, eliminate unnecessary healthcare burdens, and reduce costs. We recommend performing hip ultrasound screening for newborns after 28 days.