Objective: The study was undertaken to describe the magnetic resonance imaging (MRI) appearances of dysplasia epiphysealis hemimelica (DEH) of the knee and to determine whether MRI provides additional information concerning the anomaly compared with more traditional methods of diagnosis.
Design and patients: The subjects of the study were three children (one girl and two boys, aged 13 months, 3 years and 11 years) with DEH of the knee. All the patients had plain films of the knee and MRI scans.
Results and conclusion: Plain radiographs showed bone overgrowth and asymmetrical ossification centres with adjacent scattered calcifications which coalesced to form a lobulated irregular mass. MRI showed a definite cartilaginous or osteocartilaginous lesion. Its origin from the epiphysis was much more clearly defined. MRI showed the extent of the lesion non-invasively, as well as any potential cleavage plane between the epiphysis and the mass lesion. Abnormal surface nodularity and joint involvement could be determined. It is concluded that plain films supplemented with MRI provide the greatest amount of diagnostic information in cases of DEH. MRI is useful to show the exact location and extent of the lesion, any joint involvement and any potential cleavage between the epiphysis and the mass lesion.