Breakage of an intramedullary rod after bone union in congenital pseudoarthrosis of the tibia: a report of two cases.

We report 2 patients with congenital pseudoarthrosis of the tibia who underwent intramedullary Rush rod transfixation through the ankle joint following refracture and nonunion of vascularised fibular grafting 6 and 8 months earlier. After 9 and 5 years, both Rush rods were broken at the level of the ankle joints, while the reconstructed area was solidly united. The growth of the distal tibia increased the distance of the tips of the broken rod and hence the ankle joint motion. The broken tips may damage the articular cartilage and result in valgus deformity of the ankle and limb length discrepancy.