The utility of MR in assessing Blount disease

Objective: To review the MR appearances of Blount disease. Design and patients: The MR examinations of six knees in four patients (ages 6-7 years) with Blount disease were reviewed. Results: All patients showed delay in ossification of the medial tibial epiphysis. A spectrum of changes was seen in and around the tibial growth plate including: widening and depression of the medial growth plate; small and deep intrusions of cartilage into the metaphysis; edema of the medial tibial epiphysis and medial and lateral metaphysis: varus deformity of the lower leg: widening of the lateral growth plate. osteochondral injury to the medial femoral condyle; hypertrophy of the medial meniscus, focal bone bridging. Conclusion: MR appearances are consistent with the primary abnormality in Blount disease, which is failure of endochondral ossification of the medial growth plate. MR examination is useful in surgical planning.