Legg-Calvé-Perthes disease: imaging with MR.

Magnetic resonance (MR) imaging studies were obtained to evaluate the shape of the cartilaginous femoral head and the adequacy of femoral acetabular containment in 35 children with Legg-Calvé-Perthes disease (LCPD). MR results for 24 of the 35 children were compared with results at arthrography. The shape of the cartilaginous femoral head was well identified with MR imaging, but, with arthrography, less information could be obtained about the medial and lateral aspects of the cartilaginous capital epiphyses in nine and three cases, respectively. Thirteen children underwent surgery; remodeling and regained femoroacetabular congruity of the articular surfaces following derotation varus osteotomy was identified in seven of 10 who underwent repeat MR imaging. In addition, MR images and conventional radiographs of the hips were compared. The radiographically identifiable distribution of the bone necrosis of the capital epiphysis correlated well with that demonstrated on MR images. MR imaging is a valuable non-invasive procedure with which to obtain information about the status and treatment of the cartilaginous femoral head in children with LCPD.