Course Director

September 28-30, 2018

Evaluation of the FetalSkeletal System

Carol B. Benson, MD No Disclosures

2D & 3D Ultrasound

Ultrasound Assessmentof Fetal Skeletal System

Extremities

Spine

Calvarium

Long Bone Development

Ossify by the end of the first trimester

Late third trimester2° ossification centers visible

distal femurproximal tibiaproximal humerus

Tole 41w epiphysis

Epiphysis41 weeks

Drachman & Rousseau nlSpine 3D

ExtremitiesAssess To Exclude

Size Skeletal dysplasia

Presence Absent limbAmniotic band

syndrome

Bones of forearms Radial hypoplasia

Hand position Clenched fists

Foot position ClubfootRockerbottom foot

Michel arm 3 bones

Caraballo nl hand

Reed 3D Foot

Foot

Femur Length

Normal for gestational age= Mean ± 2 SD

Femur length falls 2 - 4 SD below meanMost are growth restrictedWithout skeletal dysplasia

Femur length falls > 4 SD below meanUsually a skeletal dysplasiaBones appear abnormal by US

Steimle Femur length

Long Bones are Too Short

Skeletal dysplasia

Dysotosis

Malformation

Deformationamniotic band syndromerestrictive uterine environment

Ultrasound assessment

Degree of shortening of long bonestypically > 4 SD below mean for GA

Distribution of involved bonesextremities, spine, calvarium, ribs

Bony abnormalities

↓ mineralization, fractures, bowing

Polydactyly

Skeletal Dysplasias

Lethal Skeletal Dysplasias

Neonate cannot surviveusually due to respiratory failure

Ultrasound diagnosis typicallymade in 2nd trimester

Thanatophoric dysplasia Osteogenesis imperfecta Type 2 Achondrogenesis Congenital hypophosphatasia Short rib – polydactyly syndrome

Nonlethal Skeletal Dysplasias

Infants typically surviveUltrasound diagnosis typically

not made in 2nd trimestersometimes made in 3rd trimester

Heterozygous achondroplasia Osteogenesis imperfecta Types 1&4 Asphyxiating thoracic dystrophy

Thanatophoric Dwarf

Most common lethal skeletal dysplasiaSevere rhizomelia

(proximal shortening)Bowed long bonesNarrowed thorax – short ribsFlattened vertebral bodiesCloverleaf skullMegalencephaly – temporal lobe

with excess sulcation/fissures

Cole thanatophoric dwarf

Thanatophoric dysplasia

Kristian 19wthanatophoric

Thanatophoric dysplasia

Kristian 19wthanatophoric

FEM

Osteogenesis ImperfectaType 2

Type 2 — Autosomal recessiveLethal

Ultrasound findings — Type 2FracturesDeformitiesPoor mineralizationSoft skull

Types 1, 3, & 4 — Autosomal dominantNonlethal

Lopez OI

Osteogenesis Imperfecta Type 2

Lopez OI

Osteogenesis Imperfecta Type 2

Astacio OI 3D

Osteogenesis Imperfecta Type 2

Wang OI

OsteogenesisImperfecta

Type 2

Osteogenesis ImperfectaType 1 & 4

Type 1 & 4 — Autosomal dominantNonlethal

Ultrasound findings — Type 1 & 4Lagging growth of long bones

3rd trimesterBowing of long bonesMild deformitiesPoor mineralizationSoft skull

McBride OI type 4

Osteogenesis Imperfecta Type 1

Al-Owfi OI type 4

Osteogenesis Imperfecta Type 4

Arthrogryposis

Multiple joint contracturesEtiologies

Limitation to movementOligohydramniosMultiple gestationBicornuate uterus

Abnormal nerve function Abnormal musculature Defective connective tissue

ArthrogryposisMultiplex Congenita

Ultrasound findingsContracturesFetal growth restrictionPolyhydramniosHydrops

Beausoleil arthrogryposis

Arthrogryposis

McGuiganarthrogryposis

Banerjee Larsen synarthrogryposis

Arthrogryposisfrom

Larsen syndrome(rare genetic syndrome)

Zaiats clubfeet CMV

Clenched Hands – Cytomegalovirus

VentriculomegalyIntracranial calcifications

Zaiats clubfeet CMV

Clubfeet – Cytomegalovirus Abnormal Hands & Forearms

Isolated

Part of multiple anomalies or syndrome

Radial ray anomaliesOrofacial malformationsBlood dyscrasiasCongenital heart disease

Radial Ray AnomaliesAssociated with

SyndromesCornelia de LangeFanconi anemiaHolt-OramRadial aplasia-ThrombocytopeniaPoland syndromeNager acrofacial dysostosisVACTERL

Trisomies 13 & 18

Colon absent radius tri 18

Absent radius – Trisomy 18

Martins hypoplradius VACTERL

Hypoplastic radiusAbnormal thumb

VACTERL

Limb Reduction Defects

Terminal transverse deletions(e.g., absent hands)

Isolatedsporadic, unilateralamniotic band syndromevascular accident

SyndromesOrofacial (e.g., Poland)Amniotic bands

Penney absenttoes ABS Osgood absent hand

Osgood absent hand 3D bones

Galloabsent forearm

Right hand Left arm

Nager Acrofacial Dysostosis

CharacteristicsMandibulofacial dysostosis

Hypoplastic mandibleExternal ear abnormalities± Auditory canal atresia

Upper extremity reduction defectsRadial ray defects

Alshamsi Nager’s

PolydactylySupernumerary fingers or toesSkeletal dysplasias

Short-rib polydactylyChondroectodermal dysplasiaAsphyxiating thoracic dysplasia

Trisomy 13Meckel-Gruber syndromeAutosomal dominant polydactyly

usually post-axial

MacGowan polydactyly withMeckel Gruber

Polydactyly with Meckel-Gruber

Hand Foot

Silkinapolydactyly

Polydactyly

Malenko dup thumbpolydactyly

Duplicated thumb

Ectrodactyly

V-shaped defect (cleft) in middle ofhands &/or feet with missing digits

± Syndactyly Associated

Genetic syndromes, e.g.Split-hand-foot malformationSilver-RussellCornelia de Lange

Ligibel cleft handmissing finger

Clefthand

Dowd ectrodacthands & feet

Appleton absent finger

Clinodactyly &Overlapping Digits

Deviation or deflection of finger(s)

Curving of 5th finger towards 4th

Trisomy 21

Overlapping digitsTrisomy 13Trisomy 18

Paolini tri 21 clinodactyly

Clinodactyly – Trisomy 21

Sin abnl hands

Powell tri 18clinodactyly

Clenched hands – Trisomy 18

Ferrouilletclinodactyly

Clenched hands – Trisomy 18

Clubfoot

EtiologyGenetic

A variety of syndromesChromosomal defects

EnvironmentalSevere oligohydramniosUterine anomalies

Ultrasound findingsBones of the foot lie in parallel

to bones of lower leg

Lashley clubfeet

Clubfoot

21 weeks

13 weeks

Rockerbottom Foot

EtiologyTrisomy 18Skeletal dysplasia

Ultrasound findingsRounded bottom of foot

Woodlandrockerbottom feet

Rockerbottom feet

Proximal FocalFemoral Deficiency

Partial absence of proximal femur

Unilateral (90%)

Associated with other skeletal anomalies

Michailidis PFFD 3D

ProximalFocal

FemoralDeficiency

Janvier PFFDpostnatal

ProximalFocal

FemoralDeficiencyPostnatal

Amniotic Band Syndrome

Early rupture of amnion

Fibrous bands entrap or adhere to fetus

Limb amputations or deformities

EncephalocelesFacial clefts

Ventral wall defectsEctopia cordis

Allien ABS

Amniotic BandSyndrome

13 weeks

20 weeks

28 weeks

Dailey ABS anomalous hand

Amniotic BandSyndrome

Meyers 17w ABS

Amniotic Band Syndrome

Spinal Abnormalities

Meningomyelocele

Hemivertebra

Scoliosis

Diastomatomyelia

Caudal regression / sacral agenesis

Sacrococcygeal teratoma

Meningomyelocele

Normal

Meningomyelocele

Davis 18w Meningomyelocele

Meningomyelocele18 weeks

Mayameningomyelocele

Meningomyelocele

19 weeks

Mayameningomyelocele

Meningomyelocele – 25 weeks

Meningocele

Spina bifida

Protrusion of membranes & fluid

No protrusion of nerve roots

Often skin covered

Ultrasound findingssplaying of posterior elementscystic mass protruding

Cabral 19w 3DMeningocele

19 weeks

Reif 20w Meningocele

Hemivertebrae

Associated with a variety of syndromes

Ultrasound findingsKink in spineMismatch of posterior

ossification centers

Johnson hemivertebrae

Hemivertebrae

Hazen Hemivert

Hemivertebrae

1

5

10

13

Rossman hemivert

Diastomatomyelia

Bony, cartilaginous or fibrous spur bisecting spinal canal and spinal cord

Causes tethered cord

Widened spinal canal

Sometimes associated withneural tube defect

Pecci diastomatomyelia& Meningomyelo

Diastomatomyelia with meningomyelocele

Pecci diastomatomyelia& Meningomyelo

Diastomatomyelia with meningomyelocele

Pecci diastomatomyelia& Meningomyelo

Diastomatomyeliawith meningomyelocele Sacral Agenesis

Hypoplasia / absence2 or more sacral vertebrae

In fetuses of diabetic motherswith poor glucose control

MacDougall sacral agen

Sacral agenesis

Bensonsacral agenesis

Sacral agenesis

Sacrococcygeal Teratoma

Germ cell tumor arisingin presacral area

Ultrasound findingsMass arising from lower sacrumExtending posteriorly and inferiorly± Hydrops± Extension anteriorly into pelvis

Bonica SCT

Sacrococcygeal TeratomaSacral erosion

Cranial Anomalies

Craniosynostosis Trigonocephaly (Trisomy 13) Cloverleaf skull (Thanatophoric

dysplasia)

Lemon sign (Chiari II malformation)

Strawberry skull (Trisomy 18)

Craniosynostosis

Premature closure of one or morecranial sutures; Male:Female = 2:1

Complications:Abnormal head shapeAbnormal facesNeurologic deficits

e.g., hearing lossPrenatal diagnosis

Typically not possible before 3rd trimester

Duprey Aperts craniosyn

Apert SyndromeCraniosynostosis

27 weeks

Trigonocephaly

Craniosynostosis with premature

fusion of metopic suture

(anterior midline, forehead)

Associated with Trisomy 13

Britt tri 13trigonoceph

Trigonocephaly – Trisomy 13

35 weeksSemilobar

Holoprosencephaly

Cloverleaf Skull

Craniosynostosis causing

trilobed shape

prominent forehead

Associated with

Thanatophoric dysplasia

Cole thanat skull

Cloverleaf skull – Thanatophoric dysplasia

20 weeks

Cole thanat skull

Cloverleaf skull – Thanatophoric dysplasia

29 weeks

Lemon-Shaped Cranium

Associated with Chiari II malformationMeningomyelocele Victoria

lemon sign

Lemon Sign withMeningomyelocele

Strawberry-Shaped Cranium

Associated with Trisomy 18 Schindlerstrawb sk

Strawberry-Shaped CraniumTrisomy 18 – 15 weeks