Ultrasonography in congenital dislocation of the hip. Simultaneous imaging of both hips from in front.

We describe a new technique for examining the infant hip using ultrasound. Both hips are imaged simultaneously via an anterior approach. The examination can be done with the hip either extended or flexed and abducted. The method has three advantages: 1) since both hips are imaged simultaneously, lines can be drawn to assist in determining the relationship between the femoral head and the pelvis; 2) proximal, anteroposterior and lateral displacement of the femoral head can all be demonstrated; 3) the method is applicable to the infant in a harness or a plaster cast to demonstrate maintenance of reduction of a dislocated hip. The usual direction of dislocation of the femoral head was anterior and lateral. Proximal migration was also observed in cases with more severe dislocation. In flexion, the dislocated head of the femur often moved posterior to the acetabulum. Of 1276 hips, in 638 infants aged from three weeks to one year, 49 showed congenital dislocation. The accuracy of our anterior method of sonography in diagnosing congenital dislocation of the hip compared well with the method of Graf and with radiography.