The pubo-femoral distance decreases with Pavlik harness treatment for developmental dysplasia of the hip in newborns.

Abstract

To evaluate the evolution of the ultrasonographic pubo-femoral distance (PFD) before and after Pavlik harness treatment for developmental dysplasia of the hip (DDH) in newborns. Twenty-five patients (16.7±10.4days; 19 females, six males) diagnosed with DDH and treated using the Pavlik harness were included. Eighteen patients had bilateral, and seven unilateral DDH, with a total of 43 dysplastic hips. The seven non-dysplastic hips in unilateral cases were used for comparison. The PFD was measured in the coronal and axial planes with the hip flexed to approximately 90°, before and after an average of 93days of treatment. The femoral head coverage was assessed in the coronal plane, and correlated with PFD values. In dysplastic hips, the mean PFD decreased from 6.1±1.8mm to 3.0±0.7mm in the axial (adjusted difference, 2.9mm; p<0.01), and from 5.9±2.0 to 3.0±0.6mm in the coronal plane (adjusted difference 2.7mm; p<0.01). The femoral head coverage increased from 30.8 to 62.1%, and the mean differences of femoral head coverage and PFD were significantly correlated (p<0.001). There was no difference between treated dysplastic and non-dysplastic hips. There was high intra- and inter-observer agreement for PFD measurements. The PFD decreased significantly after DDH treatment using the Pavlik harness in newborns, and showed significant correlation with the femoral head coverage improvement. PFD might be a reliable tool for monitoring DDH treatment in newborns treated using the Pavlik harness.