Blount disease refers to a local disturbance of growth of the medial aspect of the proximal tibial metaphysis and/or epiphysis that results in tibia vara. The condition is commonly bilateral.
There are infantile, juvenile and adolescent forms. The infantile type is 5x more frequent than the others and is seen particularly in early walkers. It appears to be the result of abnormal compressive forces inhibiting growth at the medial growth plate and not from avascular necrosis.
Treatment depends on the subtype and stage. As a general rule:
infantile or early stage: often conservatively managed
adolescent or late stage: a proximal tibial osteotomy is often considered