[Prenatal bowing of the long bones]

A case of congenital angulation and bowing of the long bones is reported. The condition belongs to a group of bone pathologies which have as a common feature an abnormal bowing of the diaphysis. The cortex at the concave side shows a thickening while the convex side shows a cortical thinning, corresponding to a structural adaptation to external compressing forces at the site of the bowing of the bone. The angulation is a consequence of bowing of long bones over other foetal parts.