The Fetal Skeleton

Question 1

Aplasia

Answer 1

Absence of bone

Question 2

Hypoplasia

Answer 2

Incomplete development

Question 3

Amelia

Answer 3

Absence of one or more limbs

Question 4

Hemimelia

Answer 4

Absence of one or more extremities below the elbow or knee

Question 5

Acheiria

Answer 5

Absence of one or more hands

Question 6

Apodia

Answer 6

Absence of one or more feet

Question 7

Adactyly

Answer 7

Absence of one or more digits from the hands of feet

Question 8

Phocomelia

Answer 8

Absence of the proximal portion of an extremity with the hand or foot attached to the trunk

Question 9

Meromelia

Answer 9

Absence of part of a limb

Question 10

Aplasia or hypoplasia of what bone is common in many skeletal syndrome?

Answer 10

Radius

Question 11

What abnormality can be described as a linear density attached from the uterine wall?

Answer 11

ABS

Question 12

What abnormality is known as mermaid syndrome?

Answer 12

Sirenomelia

Question 13

Prognosis for sirenomelia is usually poor due to?

Answer 13

Renal agenesis

Question 14

What is known as a rare form of short limbed dwarfism?

Answer 14

Camptomelic dysplasia

Question 15

What is an inherited rare disease of defective bone mineralization?

Answer 15

Congenital hypophosphatasia

Question 16

Apert syndrome is a type of what?

Answer 16

Craniofacial dysotosis

Question 17

In what abnormality is trident hand seen in?

Answer 17

Achondroplasia

Question 18

A persistently clenched hand with an overlapping index finger is strongly associated with?

Answer 18

Trisomy 18

Question 19

Pre-axial polydactyly affects?

Answer 19

Radial side

Question 20

Post-axial polydactyly affects?

Answer 20

Ulnar side

Question 21

Achondroplasia sonographic features:
Ready
For
Little
Tiny
Men

Answer 21

Rhizomelic limbs
Frontal bossing
Low nasal bridge
Trident hand
Macrocephaly/hydrocephaly

Question 22

How early can limb buds be visualized?

Answer 22

8 weeks

Question 23

When do the bones in hands and feet form?

Answer 23

11-13 weeks

Question 24

When can fetal long bones be accurately measured?

Answer 24

12 weeks

Question 25

Femoral length varies according to what factors?

Answer 25

1. Maternal weight 2. Ethnicity 3. Height

Question 26

T or F? The fetal femur grows 2mm per week in the third trimester?

Answer 26

FALSE: It grows 3mm per week from 14-27 weeks and 1mm per week in the third trimester

Question 27

Features of bones in skeletal dysplasia?

Answer 27

1. Shortened 2. Thinned 3. Deformed

Question 28

What abnormality is associated with craniosynostosis/ or cloverleaf deformity?

Answer 28

Thanatophoric Dysplasia

Question 29

Lethal skeletal dysplasias are often accompanied by?

Answer 29

Pulmonary hypoplasia

Question 30

What type of TD is most common?

Answer 30

Type I

Question 31

In what abnormality do the limbs have a "telephone receiver appearance"?

Answer 31

TD - Type I

Question 32

What is the most common form of lethal skeletal dysplasia?

Answer 32

TD

Question 33

What abnormality is seen with platyspondyly?

Answer 33

Type I TD

Question 34

Most common skeletal dysplasia to result in stillbirth?

Answer 34

TD

Question 35

What abnormality is seen with a "champagne cork appearance" of a narrow thorax with protruding abdomen?

Answer 35

TD

Question 36

Two types of Achondrogenesis?

Answer 36

Type I - Parenti Fraccaro Type II - Langer Saldino

Question 37

OI may present with what three things:

Answer 37

Long bone and rib fractures Blue sclera Hearing impairment

Question 38

What type of OI is caused by an abnormal decrease in collagen?

Answer 38

Type I

Question 39

When do most rib fractures occur in Type I osteogenesis imperfecta?

Answer 39

After birth

Question 40

What is the most mild and most severe form of OI?

Answer 40

Type II - most severe Type IV - most mild

Question 41

In what type of OI do infants die shortly after birth?

Answer 41

Type II

Question 42

In what abnormality may you see a bell-shaped appearance of the thorax?

Answer 42

Type II OI and Camptomelic Dysplasia

Question 43

What type of OI do you see limb bowing in utero?

Answer 43

Type III

Question 44

What type of OI is not detected in utero?

Answer 44

Type IV

Question 45

Characteristics of Camptomelic Dysplasia:

Answer 45

Short bowed limbs Short trunk Large head Bell-shaped chest Hypoplastic scapule

Question 46

In what abnormality might the skull be easily compressed and spurs are seen in the middle of long bones?

Answer 46

Congenital hypophosphatasia

Question 47

What type of congenital hypophosphatasia is detected in utero?

Answer 47

Type I - decreased ossification with short, bent bones

Question 48

What abnormality is known as abnormal ossification?

Answer 48

Dysostosis

Question 49

What abnormality is associated with widening of the cranial fontanelles?

Answer 49

Cleidocranial dysostosis

Question 50

What abnormality is associated with absent or hypoplastic clavicles?

Answer 50

Cleidocranial dysostosis

Question 51

"Mitten hand" is seen in what abnormality?

Answer 51

Apert syndrome

Question 52

When can the fetal hands be best visualized? (trimester)

Answer 52

Late first or mid-second

Question 53

Has poly or oligo been reported in fetuses with VACTERL?

Answer 53

Polyhydramnios

Question 54

Clubfoot is most commonly due to?

Answer 54

Oligohydramnios

Question 55

In what abnormality will you see an overall reduction in ossification with short-bent bones?

Answer 55

Congenital hypophosphatagia

Question 56

T or F? Type 2 congenital hypophosphatasia is lethal

Answer 56

False: Type 1 is detected in utero and is lethal

Question 57

What abnormalities can VACTERL Association possibly simulate? (3)

Answer 57

Trisomy 13 Trisomy 18 Sirenomelia