Embryology of the upper limb.

An increased understanding of embryogenesis has advanced our fundamental knowledge of limb anomalies. Animal models with similar limb patterning have been used to dissect and manipulate crucial signaling centers that affect limb development and orientation. Experimental embryologists can produce limb anomalies that are similar to the human phenotype encountered in clinical practice. The evaluating physician must possess a basic comprehension of embryogenesis and limb formation to comprehend congenital limb anomalies and to communicate relevant knowledge to the family. This Current Concepts article is intended to provide an update of limb development that is germane to the clinical scenario.