Purpose: To analyze ultrasound findings and investigate the epidemiology, intervention efficacy, and associated factors of developmental dysplasia of the hip (DDH) in infants aged 0-6 months.
Methods: This retrospective study analyzed 6189 infants (3360 males, 54.3%) who underwent initial routine hip ultrasound at Shaoxing Maternal and Child Health Hospital (April 2022 to June 2024). Outcomes included DDH detection rate, Graf classification, laterality, and early intervention success rate (conversion to Graf Type I). Descriptive statistics summarized outcomes including detection rates, distributions, and intervention success rates while univariate and multivariate logistic regression identified influencing factors.
Results: The DDH detection rate was 3.2% (196/6189), primarily left-sided (64.73%), and Graf Type IIa/b (90.82%). The early intervention success rate was 98.95% (189/191). Female sex (aOR = 19.76, 95% CI: 11.91-32.81), breech delivery (aOR = 3.97, 95% CI: 2.47-6.39), family history (aOR = 1.54, 95% CI: 1.01-2.33), swaddling history (aOR = 2.44, 95% CI: 1.58-3.76), and gluteal fold asymmetry (aOR = 2.67, 95% CI: 1.86-3.84) were risk factors (all p < 0.05). First-born (aOR = 0.29, 95% CI: 0.20-0.42) and vaginal delivery (aOR = 0.25, 95% CI: 0.18-0.35) were protective.
Conclusion: This single-center study delineates the clinical profile of DDH, demonstrates a remarkably high success rate of early intervention, and identifies its independent influencing factors, providing evidence for risk-stratified screening while noting limited generalizability.