ERU 26 - The Fetal Spine and MSK System Flashcards
What anomalies area represented in VACTERL association?
Vertebral anomalies Anorectal atresia Cardiac anomalies TrachEoesophaleal fistula Renal anomalies Limb anomalies
At what week does the fetal spine start to develop?
6-8
What are the components of the fetal vertebrae?
3 echogenic ossification centers: the centrum and 2 neural processes
Myelocele
Meningocele
Meningomyelocele
Spina bifida containing only spinal cord
Contains only meninges
Contains meninges and nerve root
spina bifida occulta vs aperta
Occulta is a closed defect (covered by skin)
Aperta is visible without imaging
What cranial sonographic finding is associated with spina bifida?
Lemon sign: scalloping of the frontal bones
Banana sign: Displacement of the cerebellum inferiorly and obliterated cisterna magna
Colpocephaly: Small frontal horns and enlarged occipital horns
Limb-Body Wall Complex
A rare group of fetal defects that include: Short/absent umbilical cord Ventral wall defects Limb defects Craniofacial defects - exencephaly (cerebrum outside skull) - encephalocele (protrusion of brain tissue through a defect) Scoliosis Elevated MSAFP
What are the 4 most common skeletal dysplasias?
Achondroplasia
Achondrogenensis
Osteogenesis imperfecta
Thanatophoric dysplasia
Heterozygous Achondroplasia
What physical findings are associated?
A type of dwarfism in which rhizomelia is present (proximal limbs much shorter than distal limbs)
The most common nonlethal skeletal dysplasia.
Difference in GA between BPD and FL, frontal mossing, trident hand
How does homozygous achondroplasia differ from heterozygous achondroplasia?
Homozygous achondroplasia is usually fatal within 2 years of life.
Achondrogenesis
What is a common associated finding?
A rare, lethal condition resulting in absent mineralization of the skeletal bones.
Polyhydramnios
What ultrasound findings are associated with osteogenesis imperfecta?
Malleable skull, multiple fractures, and bell-shaped chest
Thanatophoric Dysplasia
What are the common ultrasonographic findings?
Most common lethal skeletal dysplasia
Cloverleaf skull, hydrocephalus, long bones with “telephone receiver” shape, bell shaped chests, depressed nasal bridge, redundant soft tissue
Caudal regression syndrome
Sonographic findings
Common cause
Sacral agenesis
No sacrum or coccyx on US. Possible club feet
Uncontrolled pregestational DM
Sirenomelia
Associated with:
Often caused by:
Mermaid syndrome: Fusion of the lower extremities
Bilateral renal agenesis > oligohydramnios, genital absence, two-vessel cord
Poorly controlled pregestational DM
