Guided growth for tibia vara (Blount's disease)

Blount's disease is commonly attributed to an intrinsic, idiopathic defect in the posteromedial proximal tibial physis resulting in progressive bowing of the leg, intoeing, and lateral knee thrust. Treatment has historically included bracing, physeal stapling, or corrective osteotomy, and was determined primarily by age at presentation. As we feel the pathology is not necessarily age dependent, we have elected to use the technique of guided growth using a lateral tension band plate to correct limb alignment as a first-line treatment in all patients presenting to our clinic as long as they had growth remaining and no evidence of a physeal bar. We identified 17 patients with tibia vara (27 limbs) who were managed by means of guided growth of the proximal tibia, from age 1.8 years to 15.1 years. Clinical and radiographic parameters were followed pre- and postoperatively. The response to guided growth was documented as were any related complications. Twenty-one (78%) limbs had complete normalization of their mechanical axis (middle 50% of knee). Time to correction averaged 13.5 months (8–19 months). There were no peri-operative complications. We observed hardware failure in 3 patients; 2 with screw breakage and 1 patient with hardware migration, none requiring subsequent osteotomy or further treatment. Two patients had rebound varus: one is being observed and another has undergone a repeat procedure. Patients with pathologic tibia vara present at various ages and have historically undergone various treatments ranging from bracing to tibial osteotomy based on age at presentation. We have found that guided growth utilizing tethering plates can be used effectively as first-line treatment in all patients with growth remaining. This minimally invasive method is predictable and well tolerated. Recurrent deformity, though unlikely, is easily remedied by repeating the process and does not preclude osteotomy if eventually needed. Concomitant resolution of ligamentous laxity and inward torsion can be anticipated as the mechanical axis is restored to neutral. The only contraindications for guided growth include an unresectable physeal bar or skeletal maturity.