Prediction of reduction in developmental dysplasia of the hip by magnetic resonance imaging

The acetabular rim of 33 hips in 29 patients with developmental dysplasia of the hip was evaluated using magnetic resonance imaging (MRI). The hips were classified into the following three groups according to the shape of the acetabular rim: 12 hips with sharp acetabular rim (group 1), 13 hips with dysplastic and round acetabular rim (group 2), and eight hips with inverted acetabular rim (group 3). The position of the femoral head with the hip flexed and abducted was also recorded, according to the criteria proposed by Suzuki. They were all treated initially with the Pavlik harness. All group 1 hips were successfully reduced with the Pavlik harness, whereas in group 2 hips, all but three hips were reduced. In all group 3 hips, reduction was not successful. MRI provided useful information regarding the probability of reduction with the Pavlik harness.