Anomalies of Limbs
Amelia, meromelia and micromelia
Congenital Anomalies:These anomalies of the limb are rare and mainly hereditary due to chromosomal abnormalities. However, as al- ready discussed, thalidomide has been proved to be a teratogenic drug that causes gross limb deformities.
Amelia means absence of one or more of the limbs ( in Greek me/os =
Meromelia is an anomaly in which parts of one or more limbs are missing. Sometimes the proximal segment of a limb is normal but the distal portion is missing; such condition is known as hemimelia. In another condition, called phocomelia, the proximal segments of the limbs are missing and
the hands and feet are attached directly to the trunk like the flippers of a
seal (in Greek phoke = seal)
Cogenital Anomalies:is an anomaly in which all segments of the limbs are present but much shorter than normal.
2) Polydactyly, ectrodactyly, brachydactyly and syndactyly
Polydactyly, ie, the presence of extra fingers or toes is a common condition. ·Oftenly the extra digits are incompletely formed and lack proper muscular connections and, hence, are useless. This condition is usually bilateral. Polydactyly is inherited as a dominant trait.
Ectrodactyly means absence of a digit. This deformity is usually uni- lateral.
Brachydactyly means abnormal shortness of fingers or toes. This anomaly is usually inherited as a dominant trait and is generally associated with a short stature.
Syndactyly (fused digits) is the most frequent congenital anomaly of
the limbs. It is more frequent in the foot than in the hand. This condition is inherited as a simple dominant or simple recessive trait. In most of the cases this anomaly is present as cutaneous syndactyly in which adjacent digits are
fused simply by a skin’ web because this ‘web failed to break down during
development. Such digits can be easily separated surgically. http://www.jst-hosp.com.cn/:However, in a more severe form of syndactyly, called osseous syndactyly, the bones of adjacent digits are fused together.