Ultrasonographic predictors of residual acetabular dysplasia in high-risk infants

Developmental dysplasia of the hip (DDH) encompasses a spectrum of hip abnormalities that, if undiagnosed and untreated, can lead to long-term complications. While ultrasound is the gold standard for early diagnosis, the criteria for recommending radiographic follow-up remain unclear. This prospective cohort study investigated the predictive validity of ultrasonographic parameters at five months of age for residual acetabular dysplasia at one and two years of age in untreated high-risk infants. A total of 278 high-risk infants underwent ultrasound at the initial visit and at five months, with radiographic follow-up at one and two years. The findings indicate that femoral head coverage (FHC) < 50% at five months is significantly associated with an acetabular index (AI) ≥ 30° at one and two years, whereas Graf classification at five months did not reliably predict long-term dysplasia. These results suggest that FHC < 50% may be a more effective indicator for selecting infants who require radiographic follow-up, potentially reducing unnecessary imaging. Further studies are warranted to refine follow-up protocols and optimize DDH management strategies to balance early intervention with the risk of overtreatment.