Hypoplasia, Brachydactyly, and Other Failures of Formation

Abstract

Congenital anomalies affect 1–2 % of newborns, and approximately 10 % of these children have upper extremity abnormalities. Congenital anomalies of the limb are second only to congenital heart disease in the incidence of birth malformations (Bamshad et al. Pediatr Res 45:291–299, 1999). The clinical manifestations of these anomalies in children are extremely variable, and as such, classifying specific patterns of deformities remains an ongoing challenge. However, approximately 10–15 % of these congenital upper extremity anomalies can be grouped into a broad category that represents underdevelopment and/or failure of formation within portions of the upper limb. The deformities represented in this category can range anywhere from a smaller than normal digit (hypoplasia) to a complete absence of the extremity (amelia).

To the medical provider who is unaccustomed to evaluating and caring for these children, describing these anomalies can be difficult, and formulating potential treatment plans is often a difficult task. Therefore, the goals of this chapter are to (1) present accepted terminology used to define specific conditions, (2) discuss the common clinical features, and (3) provide treatment recommendations for some particular diagnostic subtypes seen in this category of deformities.