Embryology, diagnosis, and evaluation of congenital hand anomalies.

Although congenital hand anomalies are rare, musculoskeletal clinicians should have a basic understanding of their clinical manifestations and the possibility of concurrent anomalies and syndromes. In this review, we provide a brief overview of the embryology of limb development and the molecular pathways involved. We also summarize the clinical manifestations, diagnostic evaluation, and principles of surgical treatment for radial longitudinal deficiency, thumb hypoplasia, ulnar longitudinal deficiency, central deficiency, syndactyly, polydactyly, and amniotic constriction band. Although one of the main goals of treatment is to provide a functional upper extremity, musculoskeletal clinicians should be aware of the clinical findings that should trigger referral to evaluate for life-threatening syndromes.