Ultrasound compared with radiographic assessment in developmental dysplasia of the hip.

Two hundred and seventy-two patients 'at risk' for hip dislocation underwent ultrasound examination. From this group 60 patients had ultrasound evidence of DDH (developmental dysplasia of the hip). Thirty-eight of these were also assessed radiographically. The diagnosis of dislocation was more accurate with sonography, where there was only one scan showing an equivocal dislocation (not dislocated on arthrography). On radiographic evaluation there were six cases of equivocal dislocation, and one case which was wrongly diagnosed as dislocation (dysplastic on sonography and arthrogram). A high level of agreement was found between the two methods in the diagnosis of dysplastic and normal hips (88 and 86% respectively). In view of the advantages of sonographic evaluation of the dislocated and dysplastic hip: safe (no ionizing radiation), dynamic and static assessment, accurate (prior to femoral epiphysis ossification) and non-invasive (compared with arthrogram), radiographic and arthrographic assessment of the hip has been largely abandoned in our practice.