Cartilaginous abnormalities and growth disturbances in Legg-Calvé-Perthes disease: evaluation with MR imaging.

Abstract

To evaluate the magnetic resonance (MR) imaging appearance of cartilaginous abnormalities in Legg-Calvé-Perthes (LCP) disease and their association with growth arrest. Twenty-seven MR images and radiographs of 25 hips in 23 patients were reviewed for epiphyseal, physeal, and metaphyseal abnormalities. Follow-up radiographs (mean time, 20.5 months) were evaluated for growth arrest. Epiphyseal abnormality seen in 74% of cases was not related to growth disturbances. Transphyseal bone bridging on MR images, the strongest predictor of abnormal growth (P < .01), was found in 63% of femurs. MR imaging helped detect physeal abnormalities with greater sensitivity (94%), specificity (89%), and positive predictive value (94%) than radiography. Metaphyseal extension of physeal cartilage seen in 81% of cases was associated with growth abnormality (P < .01), particularly when detected at radiography. Cartilaginous physeal and metaphyseal abnormalities in LCP disease are common and frequently result in growth arrest.