Classification of Osteodysplasias and Study Methodology

Skeletal dysplasias represent a heterogeneous spectrum of rare diseases involving the development and growth of the skeleton and can manifest as alterations in the shape, size, density, or integrity of the bones and present as anomalies of the limbs, skull, spine, thorax, and pelvis. The growth failure begins in the early stages of embryonic development and is perpetuated in all stages of prenatal and postnatal life. Skeletal dysplasias can be distinguished into osteochondrodysplasia and dysostosis. Osteochondrodysplasia includes generalized disorders of the skeleton, while dysostosis refers to abnormalities of a single bone or a group of bones. Every single skeletal dysplasia is relatively rare and is characterized by a considerable number of variants. Through a meticulous methodological study it is possible to answer questions and allow us to recognize many osteodysplasias. The sonographer must know fetal anatomy, clinical genetics, and be able to recognize normal pictures from pathological ones.