Prenatal ultrasonographic diagnosis of posteromedial bowing of the leg: two case reports.

Congenital posteromedial bowing of the leg was prenatally detected in two pregnancies, at 20 and 31 weeks of gestation. Posteromedial bowing is a rare anomaly of unknown etiology. The prenatal course, monitored by ultrasonography, and the postnatal clinical and radiographic outcomes are discussed and show a complex differential diagnosis. The initial postnatal therapy is conservative. Leg length discrepancy can eventually be treated by lengthening or epiphysiodesis on the contralateral side.