A, Congenital posteromedial bowing of tibia in 11-year-old girl. Although deformity largely corrected spontaneously, child is left with 6 cm of shortening and valgus angulation in midshaft of tibia. B, Double-level tibial lengthening. Lower corticotomy is made at apex of angular deformity in midshaft, and upper corticotomy could have been made more proximally in metaphyseal region. After distraction with appropriately placed hinge, more distal corticotomy not only opens up for elongation but also corrects valgus deformity. C, Final result after removal of fixator shows excellent regenerated bone in gaps. This 6-cm lengthening required 4 ½ months in fixator. Premature consolidation of proximal fibular osteotomy resulted in spontaneous proximal fibular epiphysiolysis. SEE TECHNIQUE 29.46.