[Malformations of the lower extremities].

Malformations with deficiencies of the lower extremities are rare. They are usually caused by toxic influences during pregnancy between the 4th and the 12th week of gestation. Some malformations have a genetic origin. The total incidence of congenital deficiencies of the lower extremities is approximately 18 in 100,000 newborns. The most common deficiencies are fibular hemimelias, followed by congenital femoral deficiencies and tibial hemimelias. Hemimelias are often associated with deficient toes or ray defects. Congenital pseudarthrosis of the tibia is less common, but this diagnosis is underestimated in epidemiological studies in neonates, because the fracture usually only occurs at walking age. Other deficiencies such as bladder exstrophy with pelvic defects, split feet and defects in association with hereditary skeletal dysplasias (Apert syndrome, constriction band syndrome) are extremely rare. Various treatment options are available, including shoe elevation, orthotic or prosthetic devices, realignment osteotomy, arthrodesis, rotationplasty, amputation and surgical leg lengthening. Complex deformities should be treated by a team of specialists such as orthopedic surgeons, orthotists, physiotherapists, psychologists and possibly other surgeons too.