Twelve-week standard of care protocol longer than median time to normalization among IIc hips treated with Pavlik harness

Best treatment protocols for infants with developmental dysplasia of the hip (DDH) are poorly defined. This study estimates the time to normalization among Graf IIc hips undergoing Pavlik harness treatment. Following institutional review board approval, patients referred for DDH evaluation at a pediatric institution between 2009 and 2018 (n = 1424 hips/712 patients) were identified. We isolated all Graf IIc hips that underwent Pavlik harness treatment (n = 132 hips/n = 106 patients). Demographic and outcome measures were collected. Normalization was defined as alpha angle greater than or equal to 60 degrees and femoral head coverage greater than or equal to 50%. Kaplan-Meier and Cox proportional hazards regression analyses modeled time to normalization and identified factors associated with earlier normalization. Median time to normalization was 7.0 weeks. At 12 weeks standard treatment, 85.8% [95% confidence interval (CI): 80.2-91.9%] had normalized. Greater femoral head coverage [hazard ratio (HR) per 1% increase: 1.03; 95% CI: 1.01-1.05; P = 0.0068] and hip stability at treatment initiation (HR unstable vs. stable: 0.64; 95% CI: 0.44-0.93; P = 0.0192) were associated with longer time to normalization. Some patients may not need 12 weeks of Pavlik bracing, particularly those with stable presentation who normalize before week 12. Shorter treatment lengths offer benefit without sacrificing long-term outcomes. Findings reinforce growing evidence that femoral head coverage should be a more significant consideration during diagnosis and instability is a concerning finding on examination.