Anomalies of Limbs
Limb anomalies can either be minor or major. The Minor limb anomalies are relatively common and can usually be corrected surgically. But the major ones are mostly caused by genetic factors or environmental factors.The following are the common types of limbs anomalies.
Other form of limb anomalies involves an increase or decrease in the number of digits.
(b)Osseous syndactyly- fusion of the bones-synostosis)
Limb anomalies can either be minor or major. The Minor limb anomalies are relatively common and can usually be corrected surgically. But the major ones are mostly caused by genetic factors or environmental factors.The following are the common types of limbs anomalies.
- Amelia,
is a complete absence of a limb (fig. 24)
- Meromelia, is a partial absence of a limb, or absence of part of the limb (fig. 24).
- Micromelia, is the shortness of the segment of the extremities.
- Phocomelia, the long bones are absent and the rudimentary hands and feet are attached to trunk by small irregularly bone.
Other form of limb anomalies involves an increase or decrease in the number of digits.
- Polydactyly, is the presence of an extra fingers or toes. The extra digit is incompletely formed and lacks normal muscular development (fig. 24).
- Ectrodactyly, is the absence of a digits, such as thumb.
- Syndactyly, is the abnormal fusion of the digits, it is mostly observed between the third and fourth fingers and between the second and third toes and has different form.
(b)Osseous syndactyly- fusion of the bones-synostosis)
- Brachydactyly, is the shortness of the digits due to the reduction in the length of the phalanges. It is often associated with shortness of stature
Cleft Hand and Cleft Foot: In these deformities, there is absence of one or more central digits, resulting from failure of development of one or more digital rays. The hand or foot is divided into two parts that oppose each other like lobster claws.
Congenital Absence of the Radius: In this condition, the radius is partially or completely absent and the hand deviates laterally. The ulna bows with the concavity on the lateral side of the forearm. It results from failure of the mesenchymal primordium of the radius to form. Absence of the radius is usually caused by genetic factors.
Clubfoot: Is a deformity of the foot involving talus. The sole of the foot is turned medially and the foot is adducted and plantar flexed. Abnormal positioning of the legs in utero may cause clubfoot, but in some cases is hereditary.
Congenital Dislocation of the Hip: This consists of underdevelopment of the acetabulum of the hip bone and the head of femur. The joint capsule is very relaxed at birth and the dislocation almost always occurs after birth.
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(Copyright © 2011 by U. Bala)