Based on Magnetic Resonance Imaging*

ABSTRACT: In seven children in whom congenital dislocation of the hip was diagnosed after they began to walk, magnetic resonance imaging provided important information for treatment. In five children, it revealed adhesion of the capsule to the ilium, an inverted limbus, and a displaced transverse ligament; these findings in-dicated a need for open reduction. In the other two children, magnetic resonance imaging demonstrated that the capsule was redundant and appeared to have been stripped from the posterosuperior part of the ace-It has been generally accepted that treatment is easier and results are belier when congenital dysplasia of the hip is diagnosed and treated early than when it is diagnosed after the child begins to walk. In some patients, instability ofthe hip at birth may progress to subluxation or dislocation. The continuing growth of the child aggravates any defor-mation of bone in and around the hip, and the persistent abnormal position of the femoral head leads to contractures of soft-tissue structures. Persistent displacement of the femoral head causes a Figs. 1-A through 1-I: A twenty-three-month-old girl who had congenital dislocation of the left hip. Fig. 1-A: Roentgenogram made on admission. tabular rim; this allowed closed reduction. Repeat mag-netic-resonance imaging in these two hips suggested that the capsule gradually shrank after several months. The findings in these two patients suggested a long-standing Grade-I congenital dislocation of the hip, as described by Dunn and by Ogden. Children who have this type of congenital dislocation can be treated with closed reduc-tion, provided there is prolonged immobilization of the hip * No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject ofthis article. No funds were received in support of this study