Infantile Blount disease: long-term follow-up of surgically treated patients at skeletal maturity.

Seventeen patients with infantile Blount disease who were treated by surgical correction and followed up to skeletal maturity were reviewed by clinical and radiographic examination. Patients with symptomatic knees or significant ligament instability or both underwent further evaluation by magnetic resonance imaging (MRI) or arthroscopy or both. Average age at time of initial surgery was 5.5 years and at final follow-up was 20.5 years. Average length of follow-up was 15 years. Recurrence of the deformity requiring repeated osteotomy occurred more frequently in children who underwent initial osteotomy at > 4 years of age or at Langenskiöld stage > or = III or both. Patients who underwent a single osteotomy for correction of their deformity had significantly decreased pain in the affected knee at maturity. All patients who were symptomatic or had significant knee instability or both had abnormal ligamentous, meniscal, or bony changes (or more than one of these) on MRI, which were confirmed by arthroscopy. Early surgical intervention during initial stages of the disease process will result in a decreased incidence of recurrence of deformity and decreased symptoms and knee pathology at skeletal maturity.