The Duration of Pavlik Harness Wear Following Successful Reduction of Dislocated Hips Does Not Play a Role in Determining Radiographic Dysplasia at 2 Years.

BACKGROUND: Though the Pavlik harness is often used to reduce dislocated hips in infants with developmental dysplasia of the hip (DDH), residual acetabular dysplasia may occur following reduction. It is unclear whether patient or treatment-related factors, including Pavlik wear duration, are associated with residual dysplasia. As a result, there is considerable variability in treatment practices using the harness. The purpose of this study was to determine whether the duration of Pavlik wear predicts radiographic success at 2-year follow-up for newborns with successfully reduced hips. METHODS: Consecutive newborns referred to a single tertiary academic center for concerns of idiopathic DDH were prospectively enrolled between 2008 and 2019. Patients with an Ortolani-positive or fixed dislocated hip reduced with a Pavlik harness were included. Residual acetabular dysplasia was defined as an acetabular index (AI) at 2-year follow-up greater than or equal to the 90th percentile of the normative AI value for age. Associations were investigated between baseline clinical characteristics, including duration of Pavlik wear, and residual dysplasia. RESULTS: Fifty-five patients (64 hips) were included. Forty-seven were female, 35 first-born, 21 born breech, and 8 with a family history of DDH. Age at initiation of harness was 3.8±4.8 weeks, with average duration of wear of 11.8±4.4 weeks. At 2-year follow-up, 7 patients (8 out of 64 hips) had residual dysplasia with an average AI of 30.0±3.0 degrees. There was no significant difference in duration of wear between hips that developed residual dysplasia and normal hips at 2-year follow-up (13.2±4.9 vs. 11.9±4.4 wk, P=0.45). None of the traditional risk factors for DDH (female sex, first-born, breech presentation, and family history of DDH) were found to be associated with residual dysplasia. CONCLUSIONS: In a cohort of primarily Ortolani-positive and fixed dislocated hips (n=5) reduced with a Pavlik harness, duration of Pavlik wear was not found to be associated with residual dysplasia at 2-year follow-up. A total of 12 weeks in the harness was associated with a relatively low rate of dysplasia. Traditional risk factors for DDH were not associated with residual dysplasia. LEVEL OF EVIDENCE: Level III-retrospective cohort study.