Radiological Features of Skeletal Dysplasia

Prenatal Radiological Features

The American College of Obstetricians and Gynecologists recommends ultrasound as the primary imaging modality for prenatal diagnosis of skeletal dysplasia, with most severe cases detected at the routine 18-20 week anatomical survey 1, 2
Increased nuchal translucency at 10-14 weeks gestation accompanied by shortened/bowed limbs, abnormal chest/ribs, or undermineralized skull is highly suggestive of severe skeletal dysplasia 1, 3
The optimal time for detecting most skeletal dysplasias during routine anatomical screening is 18-20 weeks gestation 1, 2, 3
Earlier detection generally correlates with worse clinical phenotype and prognosis 1, 3
Short limb length, defined as femur or humerus length <5th percentile or >2 SD below mean, is a key ultrasound finding 1, 2
Angular deformities of long bones, such as bowing, are also a key ultrasound finding 1, 2
Abnormal chest configuration, including bell-shaped thorax, short ribs, or abnormal costochondral junctions, is a key ultrasound finding 1, 2

The American Academy of Pediatrics recommends plain radiography skeletal survey as the standard postnatal imaging modality for diagnosing skeletal dysplasia 2
Rachitic changes, including cupped and flared metaphyses, widened irregular physes, and cortical thickening, are characteristic of skeletal dysplasia 4
Bowing deformities, primarily affecting lower limbs, are a common feature of skeletal dysplasia 4
Vertebral body abnormalities, including irregular shape, flattening, and anterior beaking, are a key feature of skeletal dysplasia 2, 3
Scoliosis and kyphosis, resulting from anatomically different-sized vertebrae, are common in skeletal dysplasia 5, 7
Spinal canal stenosis, frequently observed in achondroplasia, can make regional anesthesia technically difficult or dangerous 5, 7

The American College of Medical Genetics and Genomics recommends offering prenatal next-generation skeletal panel gene sequencing or whole exome/genome testing to increase diagnostic yield 1, 2, 3
Retaining fetal DNA for further evaluation until a correct diagnosis is established is crucial 5
Performing postnatal skeletal survey on all terminated fetuses with suspected skeletal dysplasia is essential 5
Advanced anesthesia consultation is mandatory, not optional, due to the potential for spinal canal stenosis, craniocervical junction abnormalities, and nasopharyngeal narrowing 5, 7