Congenital amputation is a congenital disorder

Congenital disorder

A congenital disorder, or congenital disease, is a condition existing at birth and often before birth, or that develops during the first month of life , regardless of causation...

 that can be caused by fibrous bands of the amnion

Amniotic band syndrome

Amniotic band syndrome is a congenital disorder caused by entrapment of fetal parts in fibrous amniotic bands while in utero.-Epidemiology:Amniotic banding affects approximately 1 in 1,200 live births...

 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

Amelia (birth defect)

Amelia is the birth defect of lacking one or more limbs. It can also result in a shrunken or deformed limb. For example, a child might be born without an elbow or forearm. The term may be modified to indicate the number of legs or arms missing at birth, such as tetra-amelia for the absence of all...

).

Causes

Congenital amputations can result from a number of causes. One common cause is amniotic band syndrome

Amniotic band syndrome

Amniotic band syndrome is a congenital disorder caused by entrapment of fetal parts in fibrous amniotic bands while in utero.-Epidemiology:Amniotic banding affects approximately 1 in 1,200 live births...

, which occurs when the inner fetal membrane (amnion

Amnion

The amnion is a membrane building the amniotic sac that surrounds and protects an embryo. It is developed in reptiles, birds, and mammals, which are hence called “Amniota”; but not in amphibians and fish , which are consequently termed “Anamniota”. The primary role of this is the protection of the...

) ruptures without injury to the outer membrane (chorion

Chorion

The chorion is one of the membranes that exist during pregnancy between the developing fetus and mother. It is formed by extraembryonic mesoderm and the two layers of trophoblast and surrounds the embryo and other membranes...

). Fibrous bands from the ruptured amnion float in the amniotic fluid and can get entangled with the fetus, thus reducing blood supply to the developing limbs to such an extent that the limbs can become strangulated, the tissues die and are absorbed into the amniotic fluid.
Amnion ruptures can be caused by:

• teratogenic drugs (e.g. thalidomide
  Thalidomide
  Thalidomide was introduced as a sedative drug in the late 1950s that was typically used to cure morning sickness. In 1961, it was withdrawn due to teratogenicity and neuropathy. There is now a growing clinical interest in thalidomide, and it is introduced as an immunomodulatory agent used...
  
  , which causes phocomelia
  Phocomelia
  Phocomelia is an extremely rare congenital disorder involving the limbs . Étienne Geoffroy Saint-Hilaire coined the term in 1836....
  
  ), or environmental chemicals
• ionizing radiation (atomic weapons, radioiodine, radiation therapy
  Radiation therapy
  Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
  
  )
• infections
• metabolic imbalance
• trauma
  Physical trauma
  Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
  
  

Treatment

In rare cases, if diagnosed in utero, fetal surgery

Fetal surgery

Fetal surgery is any of a broad range of surgical techniques that are used to treat birth defects in fetuses who are still in the pregnant uterus.* Open fetal surgery involves completely opening the uterus to operate on the fetus....

 may be considered to save a limb which is in danger of amputation

Amputation

Amputation is the removal of a body extremity by trauma, prolonged constriction, or surgery. As a surgical measure, it is used to control pain or a disease process in the affected limb, such as malignancy or gangrene. In some cases, it is carried out on individuals as a preventative surgery for...

.

See also

The term "congenital amputation" is sometimes used loosely to mean "congenital absence".

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
  PubMed
  PubMed is a free database accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics. The United States National Library of Medicine at the National Institutes of Health maintains the database as part of the Entrez information retrieval system...
  
  , 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
• Kyle Maynard is an American motivational speaker and athlete. He is a former college award-winning wrestler and amateur mixed martial artist born with congenital amputation of the forearms and lower legs.