Late-developing acetabular dysplasia following normal infant hip ultrasound in breech and family-history cohorts: A systematic review

Purpose: This systematic review evaluates the reported incidence of late-developing acetabular dysplasia in infants with breech presentation or a positive family history of developmental dysplasia of the hip following normal early ultrasound. Methods: MEDLINE, Embase, and the Cochrane Library were searched for studies of breech or positive family-history cohorts who underwent early ultrasound and subsequent radiographic follow-up for late-developing acetabular dysplasia. Two reviewers independently screened studies, extracted data, and assessed methodological quality. Results: Ten studies met inclusion criteria. Across these studies, radiographic follow-up after normal infant ultrasound was incomplete and variably reported, with several cohorts demonstrating substantial attrition. Among infants with a positive family history who underwent radiographic assessment ( n = 520), no cases of late-developing acetabular dysplasia were reported. In breech cohorts with available follow-up ( n = 727), reported late-developing acetabular dysplasia rates ranged from 0% to 29%, with higher estimates generally observed in studies with earlier follow-up or more permissive diagnostic thresholds. Management was predominantly observational, and operative treatment was described in one case only. Conclusions: Persistent acetabular dysplasia after a normal screening ultrasound was not identified in the included family-history cohorts with post-screening imaging. In breech cohorts, reported rates of late-developing acetabular dysplasia vary widely and appear to be influenced by timing of assessment and diagnostic criteria. Methodological heterogeneity and incomplete cohort ascertainment limit interpretation, underscoring the need for prospective studies with standardised definitions and child-level incidence reporting. Significance of Study: This review highlights critical gaps in the evidence informing management of developemental dysplaisa of the hip following screening and provides a framework for designing definitive prospective studies to guide surveillance practices. Level of Evidence: Level III.