The limbs are a particularly important part of the fetus to evaluate in great detail even though, until recently, the examination of all four limbs was not part of the standard guidelines for a screening obstetrical ultrasound.
The examination of the limbs should include the measurements of the humerus and femur in the second trimester as well as the evaluation of the distal arm and distal leg and the hands and feet. The skeletal examination also includes the spine and ribs to detect any skeletal dysplasia or vertebral body abnormality. Specific abnormalities such as polydactyly, syndactyly, clenched hands, clubbed feet, and rocker bottom feet are all part of syndromes that can be detected if other parts of the syndrome are specifically sought. Examinations of these syndromes will be demonstrated in this lecture.
The detection of skeletal syndromes depends on the recognition of specific patterns of these malformations