Hip morphology on initial ultrasound predicts hip morphology at one year in developmental dysplasia of the hip

PURPOSE: This study aimed to determine whether point-of-care ultrasound performed during the Pavlik method treatment of developmental dysplasia of the hip predicts acetabular morphology at 12 months of age. METHODS: We reviewed the medical records, ultrasounds, and radiographs of patients treated successfully with the Pavlik method between 2017 and 2019. We performed sonographic measurements on point-of-care ultrasound at the initial presentation, the Pavlik discontinuation, and an additional sonographic follow-up. We measured the acetabular index on a plain anteroposterior radiograph of the pelvis obtained at a minimum of 12 months of age. Spearman’s rank correlation coefficient was used to analyze for correlation between sonographic measurements and the acetabular index. RESULTS: A total of 72 patients were included in the final analysis. There were no residual or late dysplasia cases at the last radiographic follow-up (mean age = 14.8 ± 2.7 months). Sonographic parameters at the initial presentation significantly correlated with the acetabular index at the final radiographic follow-up (p < 0.001). Patients with worsening degrees of developmental dysplasia of the hip based on stability on sonographic testing (stable, unstable, or dislocated) had higher acetabular indices at the final radiographic follow-up (p < 0.05). CONCLUSION: Point-of-care ultrasound at initial presentation and the Pavlik discontinuation significantly correlate with acetabular morphology at 1–1.5 years of age. At initial presentation, hips that were unstable or dislocated on point-of-care ultrasound had significantly greater acetabular indices than stable hips at the final follow-up. LEVEL OF EVIDENCE: level IV case series.