Congenital bowing of long bones: Prenatal ultrasound findings and diagnostic dilemmas

Objective: Bowing of the long bones can be easily detected on antenatal ultrasound screening, but it is a nonspecific sign that can be associated with a variety of conditions, each denoting a different prognosis. Among these conditions, three well-differentiated bone dysplasias share bowed long bones as a main clinical manifestation. Campomelic dysplasia and Stuve-Wiedemann syndrome are characterized by a poor prognosis. Conversely, the overall prognosis of children affected with kyphomelic dysplasia is good, the intelligence and motor development are normal and the radiological abnormalities tend to improve and regress with age. Case Report. We report a case of prenatal detection of short and bowed femora at the 22nd week of gestation. Careful US examination as well as in utero X-ray of the skeleton allowed the exclusion of campomelic dysplasia. In the absence of an unambiguous diagnosis, the pregnancy was continued. At birth, the child presented with clinical and radiological features consistent with a diagnosis of kyphomelic dysplasia. Conclusion: This case illustrates the difficulties in making an accurate diagnosis and consequently giving a prognosis when isolated femoral bowing is found on fetal ultrasound examination. Copyright (C) 2002 S. Karger AG, Basel.