Skeletal System

Question 1

Skeletal dysplasias can be caused by

Answer 1

Genetic mutations, or teratogens

Question 2

Rhizomelic

Answer 2

Shortening of the proximal segment of an extremity such as femur or humerus

Question 3

Mesomelic

Answer 3

Shortening of distal segment of an extremity

Such as radius, ulna, tib, fib

Question 4

Micromelia

Answer 4

Shortening of both proximal and distal limb segments

Question 5

Acromelia

Answer 5

Shortening of distal segments in hands and feet

Question 6

Amelia

Answer 6

Absence of extremity

Question 7

Polydactyl and Syndactyly

Answer 7

More than 5 digits

Or webbed hands/feet

Question 8

Most common lethal dysplasia

Answer 8

Thanatophoric Dysplasia

Question 9

Lethal Dysplasia is characterized by

Answer 9

• Severe Micromelia, small thoracic circumference with pulmonary hypoplasia
• Associated with polyhydramnios and thickened skin

Question 10

Types of lethal dysplasias

Answer 10

Thanatophoric Dysplasia
Achondrogenesis
Osteogenesis Imperfecta
Short rib polydactyly

Question 11

Thanatophoric Dysplasia

Answer 11

Rhizomelia
Bowed long bones 
Cloverleaf head 
Horseshoe Kidney 
ASD 
Holoprosencephaly 
Large abd
Hypertelorism

Question 12

Achondrogenesis

Answer 12

Short limbs due to abnormal bone formation and hypomineralization

Question 13

Sono of achondrogenesis

Answer 13

• Large cranium (macrocranium)
• Short limbs (micromelia)
• Short trunk length and thoracic cavity

Question 14

2 types of achondrogenesis

Answer 14

Type 1: parenti-fraccaro

Type 2: Langer-Saldino

Question 15

Type 1 of achondrogenesis

Answer 15

Less common BUT more severe
Autosomal Recessive
Partial/complete skull lack of ossification

Question 16

Type 2 of achondrogenesis

Answer 16

More common BUT less severe
Spontaneous
No ossification of spine

Question 17

Osteogenesis Imperfecta type 2!

Answer 17

Rare disorder of collagen forming factors causing fragile bones

Sono will show many fx, bowing and short limbs

Question 18

Hypophospatasia Congenita

Answer 18

Diffuse hypomineralization caused by ALP deficiency

Auto recessive

Question 19

How do you dx hypophospatasia congenita

Answer 19

Fetal blood sample, CVS, DNA analysis

Question 20

Camptomelic dysplasia

Answer 20

Hypoplastic or completely absent fibula

Club foot, scoliosis, heart disease, other abnormalities

Question 21

Bent limb dysplasia

Answer 21

Camptomelic Dysplasia

Question 22

Short rib polydactyly dysplasia

Answer 22

Auto recessive

Short ribs, limbs and polydactyly

Question 23

Non lethal dysplasias

Answer 23

Heterozygous achondroplasia
Diastrophic dysplasia
Chondroectodermal dysplasia
Osteogenesis imperfecta 1,3 and 4

Question 24

What is the most common NON lethal dx

Answer 24

heterozygous achondroplasia

Question 25

Heterozygous achondroplasia

Answer 25

Spontaneous OR auto dominant Neuro complications Sono: rhizomelia, frontal bossing, small nasal bridge

Question 26

Asphyxiating thoracic dysplasia

Answer 26

``` Narrow thoracic cavity Pulmonary hypoplasia Micromelia Renal dysplasia Polydactyly ```

Question 27

Jeune’s Syndrome

Answer 27

Asphyxiating thoracic dysplasia

Question 28

Diastrophic dysplasia

Answer 28

Rare! Talipes, Cleft Pal, micrognathia, scoliosis Normal life but under 4ft tall Sono: hitchhiker thumb, club foot, dislocations

Question 29

Ellis-can creveld syndrome

Answer 29

Chondroectodermal dysplasia - disorder of bone growth leading to dwarfism - common with inbred communities - 50% have heart defects

Question 30

Miscellaneous limb deformities

Answer 30

``` Amelia Phocomelia Oligodactyly Polydactyly Sirenomelia Radial Ray Defects Asso. with aneuploidy ```

Question 31

Phocomelia

Answer 31

Absence of PART of the limb

Question 32

Caudel Regression

Answer 32

Partial/total sacral a genesis | Sirenomelia is most severe form

Question 33

Sirenomelia

Answer 33

Mermaid Syndrome Bilateral renal agenesis Oligohydramnios Single umbilical artery

Question 34

ABS

Answer 34

-Amniotic band breaks away from amnion and sticks to fetus, entangles and can cause amputations

Question 35

Radial Ray Defects

Answer 35

- Absence of radius with a weird thumb | - Asso. T18, T13, VACTERL, Faconi’s, pancytopenia

Question 36

Arthrogyropsis Multiplex Congenita

Answer 36

Joint Contractures Fetal Akinesia Limb Ptyergium Talipes and clinched hands

Question 37

Possible causes for Arthrogyrposis Multiplex Congenita

Answer 37

Oligo Twinning (extrinsic) Uterine masses Neuromuscular disorder Skeletal disorder Connective tissue disorder (intrinsic)

Question 38

Limb Pterygium

Answer 38

Webbing of skin

Question 39

Hand and Foot Deformities

Answer 39

``` Hitch Hiker thumb Ectrodactyly Clinodactyly Camptodactyly Syndactyly ```

Question 40

Hitch Hiker thumb

Answer 40

Suggestive diastrophic dwarfism | Asso with aqueducts stenosis

Question 41

Ectrodactyly

Answer 41

Lobster Claw | Split hand and foot

Question 42

Clinodactyly

Answer 42

Permanent curvature of 5th digit | Asso with trisomy 13, 15, 18, 21

Question 43

Camptodactyly

Answer 43

Permanent flexion of digit

Question 44

Syndactyly

Answer 44

Fusion of digits | Asso with IUGR and triploidy

Question 45

Talipes equinovirus

Answer 45

Fancy name for club foot

Question 46

Rocker bottom foot

Answer 46

-Prominent calcaneus and convex plantar surface

Question 47

Sandal Toe

Answer 47

Large gap between 1st digit and the rest of the toes | Asso. with T21