Distal Tibial Guided Growth for Anterolateral Bowing of the Tibia: Fracture May Be Prevented

Background: Congenital pseudarthrosis of the tibia is a rare and challenging pediatric condition. The pre-fracture state, called congenital tibial dysplasia or anterolateral bowing of the tibia, presents a high fracture risk due to underlying bowing and dysplasia. After fracture, there is a substantial risk of nonunion. Any union achieved may be complicated by refracture, deformity, leg-length discrepancy, stiffness, pain, and dysfunction. We present the results of using distal tibial growth modulation to improve tibial alignment and to decrease fracture risk in this condition. To our knowledge, this is the first report of isolated distal tibial growth modulation as the primary surgical treatment for this condition. Methods: This is a retrospective study of 10 patients with congenital tibial dysplasia who presented prior to pseudarthrosis and underwent distal tibial growth modulation as a primary treatment. The medical records and radiographs were reviewed for age at the times of diagnosis and treatment, fracture, secondary procedures, complications, residual deformity, cystic changes, and leg-length discrepancy. Results: Ten patients had a mean follow-up (and standard deviation) of 5.1 +/- 1.9 years. No patient sustained a tibial fracture, and no patient developed a tibial pseudarthrosis after guided growth was initiated. The mean age at the initiation of growth modulation was 2.6 +/- 1.3 years. Six patients required a plate exchange. The mean residual tibial diaphyseal angular deformity at the most recent follow-up was 4.3 degrees +/- 3.2 degrees of varus and 8.4 degrees +/- 5.8 degrees in the sagittal plane. Only 1 patient had a clinically important leg-length discrepancy, with the affected leg being longer. Conclusions: In this series of 10 patients with congenital tibial dysplasia, distal tibial growth modulation delayed or possibly prevented fracture, decreased tibial malalignment, improved radiographic appearance of bone quality, and preserved leg length. No patient developed tibial fracture or pseudarthrosis after the initiation of guided growth treatment. Although early results are promising, follow-up to maturity is required to define the exact role of this simple outpatient procedure in congenital tibial dysplasia.