Magnetic resonance arthrography in children with developmental hip dysplasia

Conventional and gadolinium enhanced magnetic resonance arthrograms were done on 14 hips in 10 children ages 7 to 24 months. The contralateral normal hips in those with unilateral disease were studied with unenhanced magnetic resonance imaging for comparison. By conventional arthrography, there were no well visualized structures. Visualized structures seen as filling defects were the labrum, ligamentum teres, and transverse acetabular ligament. By magnetic resonance arthrography, well visualized structures were the labrum, ligamentum teres, transverse acetabular ligament, and pulvinar. By unenhanced magnetic resonance imaging, well visualized structures were the labrum, ligamentum teres, and transverse acetabular ligament. The difference in visualization by magnetic resonance arthrography versus conventional arthrography was statistically significant with respect to all five structures: labrum, ligamentum teres, transverse acetabular ligament, pulvinar, and psoas tendon. The difference in visualization by magnetic resonance arthrography versus unenhanced magnetic resonance imaging was statistically significant with respect to the labrum and pulvinar. Magnetic resonance arthrography is indicated for assessing complete concentric reduction when it does not appear to be achieved by conventional arthrography, for confirming closed reduction immediately after manipulation, and potentially for preoperative planning for an open reduction.