Arthrographic evaluation of developmental dysplasia of the hip. Outcome prediction.

Arthrograms of 35 hips in 33 children less than 2 years of age with typical development dysplasia of the hip were reviewed. After arthrograms were repeated for 11 hips 6 weeks following the initial test, results were classified into 6 types based on medial pooling ratio and morphology of the acetabular limbus. Using modified Severin's criteria for outcome evaluation, 7 of the 11 hips had been upgraded in type. All hips that were classified as Type I by arthrogram had Severin I results. The relation of arthrographic type and radiographic results was statistically significant. Immediate open reduction is recommended in hips classified as Type VI at first arthrogram or Type III and above at repeat arthrogram.