Blount's disease: classification and treatment.

Forty-three tibia vara in 27 patients were analyzed retrospectively in two centers. The criteria for diagnosis of the child form are discussed. A simple classification is suggested to facilitate the choice of treatment. In stage 0 (possible Blount's disease), the patient is younger than 2 1/2 years, and an observation period is indicated for gathering data. In stage 1 (confirmed Blount's disease and absence of medial metaphyseal bony bridge), known as physis+, a valgization osteotomy is proposed. In stage 2 (evidence of a medial metaphysoepiphyseal bony bridge) known as physis-, valgization osteotomy with lateral epiphysiodesis and treatment of the lower limb discrepancy is proposed. For stages 1 and 2, there are two possibilities: normal medial tibial plateau or sloping of the medial tibial plateau, indicating a transphyseal elevation osteotomy. When one-step correction is proposed for stage 2 disorder, external fixators such as Orthofix or Ilizarov devices are useful.