The etiology of valgus angulation after metaphyseal fractures of the tibia in children.

We conducted a retrospective study of proximal metaphyseal fractures of the tibia in children who developed valgus deformities. We reviewed the cases in an effort to determine the most likely etiology of post-fracture tibia valga, which occurs despite careful treatment and follow-up. We reviewed seven major theories presented in the literature regarding the etiology of this problem. Our conclusion was that all the theories were not prerequisites for the development of valgus angulation, but rather may be secondary mechanisms. We suggest that the most likely primary mechanism is an increased vascular response causing an asymmetric growth stimulation of the medial metaphysis of the proximal tibia.