Upper-extremity congenital anomalies

Embryogenesis of the upper extremity occurs between the fourth and eighth week of gestation and is guided by signaling centers within the developing limb bud. Certain upper-limb anomalies are associated with concomitant systemic disorders, whereas others occur in isolation or in combination with other musculoskeletal problems. Radial deficiency is associated with Holt-Oram syndrome, thrombocytopenia-absent-radius syndrome, VACTERL association (vertebral abnormalities, anal atresia, cardiac abnormalities, tracheoesophageal fistula, esophageal atresia, renal defects, radial dysplasia, lower-limb abnormalities), and Fanconi anemia. A chromosomal challenge test is currently available to detect Fanconi anemia prior to the onset of aplastic anemia, which allows additional time to search for a suitable bone-marrow donor. Postaxial polydactyly is frequently inherited in an autosomal dominant pattern but has a variable penetrance pattern. A small nubbin or rudimentary postaxial element can be safely removed by tying its base in the nursery.