Early Screening for Developmental Dysplasia of the Hip: Sonographic Reference Values, Risk Factors, and Treatment Considerations.

Developmental dysplasia of the hip (DDH) is a common neonatal musculoskeletal disorder. In Germany, sonographic screening is recommended at 1-10 days of life for neonates with specific risk factors. This study aims to determine reference values for early sonographic screening and to evaluate associated risk factors. Between 2007 and 2022, 3383 neonates (6766 hips) underwent hip ultrasound according to Graf. Of these, 967 neonates were screened universally (2007-2015) and 1900 based on predefined risk factors (2015-2022). DDH was defined as ≥type IIc, according to Graf. A subgroup of 20 neonates with borderline alpha angles (51-52°) was followed up after 3-6 weeks. The mean alpha angle was 61.2° ± 5.3° (range 50.5-71.9°), and beta angle 70.8° ± 8.6° (range 53.6-88.0°). DDH prevalence was 2.5% in the universal and 3.2% in the risk-based cohort (p = 0.350). Logistic regression revealed associations with abnormal birth presentation (OR = 3.09, p < 0.001) and female sex (OR = 3.77, p < 0.001), not with Cesarean section or familial predisposition. In the follow-up subgroup, all hips showed a sufficient maturation to an alpha angle of 61.0° (range 57-66°). This study provides reference values for early DDH screening and confirms abnormal birth presentation and female sex as relevant risk factors.