Congenital amputation

Congenital amputation is a congenital disorder caused by fibrous bands of the amnion that constrict foetal limbs to such an extent, that they fall off due to missing blood supply. The child is born without one or more limbs or without parts of limbs (amelia).

Causes
The inner fetal membrane (amnion) ruptures without injury to the outer membrane (chorion). Fibrous bands from the ruptured amnion float in the amniotic fluid and can entangle the fetus, reducing blood supply of limbs to such an extent, that they fall off and get absorbed in the amniotic fluid. Amnion ruptures might be caused by:
 * teratogenic drugs (e.g. thalidomide, which causes phocomelia), or environmental chemicals
 * ionizing radiation (atomic weapons, radioiodine, radiation therapy)
 * infections
 * metabolic imbalance
 * trauma

Treatment
In rare cases, if diagnosed in utero, fetal surgery may be considered to save a limb which is in danger of amputation.

Literature

 * Gabos PG. (Department of Orthopedic Surgery, Alfred I. duPont Hospital for Children, Wilmington, DE 19899, USA) Modified technique for the surgical treatment of congenital constriction bands of the arms and legs of infants and children Orthopedics. 2006 May;29(5):401-4
 * Walter JH Jr, Goss LR, Lazzara AT. (Department of Orthopedics, Pennsylvania College of Podiatric Medicine, Philadelphia 19107, USA.) Amniotic band syndrome J Foot Ankle Surg. 1998 Jul-Aug;37(4):325-333
 * Light TR, Ogden JA. (Dept. of Orthopaedic Surgery, Loyola University School of Medicine, Maywood, Illinois 60153, USA) Congenital constriction band syndrome. Pathophysiology and treatment Yale J Biol Med. 1993 May-Jun;66(3):143-155
 * Further literature available e.g. via PubMed, free medical literature database of the US health authority (search for: congenital amputation or amniotic band or congenital constriction bands or other synonyms) via http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed