Lateral Proximal Physeal Tethering As An Alternative To Epiphysiodesis Used With Hemiplateau Elevation Osteotomy To Treat Infantile Blount Disease
INTRODUCTION: Infantile Blount disease, or bow-legging in children, is caused by decelerated growth of the proximal posteromedial tibial physis leading to tibia vara. Obesity related pressure on the tibial physis increases risk of Infantile Blount disease. Obesity rates are increasing in young children thus, Blount disease will continue to present treatment challenges. For advanced disease, surgical treatment is indicated to realign the limb and joint surface with a hemiplateau elevation osteotomy of the tibia. Typically, surgery involves closure of the growth plate to prevent recurrent deformity, leading to loss of growth, a problem for very young children.
CASE DESCRIPTION: An obese 5-year-old boy with Langenskiöld stage IV infantile Blount disease presented with significant medial tibial plateau depression and recurrent tibia vara despite previous surgical correction at age 3-years. Due to his young age, a novel surgical technique was performed to prevent recurrent deformity while preserving future growth potential. The technique combined a medial hemiplateau elevation osteotomy to correct the articular surface and unload the medial proximal tibial physis with lateral proximal physeal tethering, rather than the traditional epiphysiodesis. The left tibia showed proper alignment of the tibial plateau, appropriate growth from the medial aspect of the proximal tibia, and slight valgus alignment 21-months following surgery warranting tether removal. The patient continues to grow without recurrence of the left tibial varus one year after tether removal.
DISCUSSION: Used together these procedures allowed for correction of alignment in infantile Blount disease while preserving future growth potential, essential for very young patients.