MSK Pt 2

Question 1

What are 4 types of skeletal dysplasia? Which one is most common lethal? Which one is not?

Answer 1

Thanatophoric dysplasia (most common lethal)
achondrogenesis
ostegenesis imperfecta
achondroplasia (most common nonlethal)

Question 2

_______________, ______________, and ________________ dwarfism are caused by the different mutations in the fibroblast growth factor receptor 3 gene

Answer 2

achondroplasia, hypochondroplasia, and thanotophoric

Question 3

Achondroplasia:

Answer 3

most common nonlethal

autosomal dominant

Question 4

What can we see with achondroplasia? (9)

Answer 4

rhizomelic shortening
mild limb bowing
exaggerated lumbar lordosis
macrocephaly
trident hands
frontal bossing
mid face hypoplasia
flattened nasal bridge
broad mandible

Question 5

Which type of SD is lethal within the first 2yrs of life?

Answer 5

homozygous achrondroplasia

Question 6

Heterozygous achondroplasia:

Answer 6

compatible with normal life + intellectual development
rhizomelic shortening
large head + prominent forehead
flattened nasal bridge
spinal kyphosis or lordosis
varus or valgus deformities
ear infections
sleep apnea
hydrocephalus

Question 7

What is spinal kyphosis vs. lordosis

Answer 7

kyphosis- convex curvature (hunchback looking spine)

lordosis- concave curvature (sticking butt out like a try hard looking spine)

Question 8

What is varus and vagus deformities

Answer 8

varus- bowlegged

valgus- knock knee

Question 9

What GA can we see the shortened limbs/disparity between head size and FL?

Answer 9

21-27 wks

Question 10

What do we see with heterozygous achondroplasia?

Answer 10

macrocephaly
kyphoscoliosis
thoracic dysplasia
polyhydramnios
micromelia

Question 11

What do we see with thanatophoric dwarfism?

Answer 11

extremely short limbs
extra skin folds
narrow chest
short ribs
underdeveloped lungs
enlarged head w/ large forehead
prominent, wide shaped eyes

Question 12

What are the 2 types thanatophoric dwarfism?

Answer 12

Type I- distinguished by the presence of curved thigh bones and flattened bones of the spine (platyspondyly)
Type II- straight thigh bones and a moderate to severe skull abnormality (cloverleaf skull)

Question 13

What do we see with thanatophoric dysplasia:

Answer 13

severe micromelia
severe thoracic dysplasia
polyhydramnios
cloverleaf skull 
also: ventriculomegaly, macrocranium, cerebellar hypoplasia, prominent forehead, saddle nose, hypertelorism, short ribs, platyspondyly, bowed legs

Question 14

What is platyspondyly

Answer 14

radiographic feature and refers to flattened vertebral bodies throughout the axial skeleton
most common spinal abnormality in the axial skeleton

Question 15

What’s a sign of thanatophoric dysplasia? (this was on a slide by itself so ?important)

Answer 15

significant narrowing of the chest and prominent abdomen

Question 16

Achondrogenesis:

Answer 16

2nd most common lethal skeletal dysplasia, most severe degree of limb shortening
trident fingers and frontal bossing

Question 17

Achondrogenesis type I vs. type II

Answer 17

type I- inherited autosomal recessive
most severe form. Characterized by: inadequate ossification of the skull, spine + pelvis, extensive shortening of tubular bones, multiple rib fractures
type II- various degrees of calcifications of the pelvis, skull, and spine. Without rib fractures. Mostly sporadic (new autosomal dominant mutations)

Question 18

What are the characteristics of achondrogenesis type I (9):

Answer 18

autosomal recessive
severe micromelia
thoracic dysplasia
short ribs with multiple fractures
short trunk
macrocrania
focal bone hypomineralization, especially of the spine
calvarium demineralized
polyhydramnios

Question 19

What are the characteristics of achondrogenesis type II (5):

Answer 19

autosomal dominant
lack of mineralization to vertebral bodies, sacrum and ischium
enlarged calvarium w/ normal ossification
shortening of ribs
absence of fractures

Question 20

What is a useful measurement when looking for achondrogenesis?

Answer 20

FL to BPD

often below 5th percentile

Question 21

Hypophospatasia is an inherited condition that affects:

Answer 21

bones + teeth

Question 22

Infants with hypophosphatasia are born with:

Answer 22

short limbs, an abnormally shaped chest and soft skull bones

spine is usually hypomineralized whereas with osteogenesis type II, the spine is not affect

Question 23

What two conditions are most commonly associated with hypomineralization of the spine?

Answer 23

achondrogenesis type I and hypophosphatasia

skull is not affected with achondrogenesis type I

Question 24

Osteogenesis imperfecta:

Answer 24

congenital bone disorder characterized by brittle bones that are prone to fracture

Question 25

What are the two types of osteogenesis imperfecta:

Answer 25

Type 1- blue sclera, hyperlaxity of ligaments and skin. Hearing impairment. No prenatal deformities Type 2- lethal, no ossification of the skull, beaded ribs, shortened and crumpled long bones, multiple fractures, thorax short but not narrow

Question 26

What condition is most commonly associated with fetal fractures?

Answer 26

osteogenesis imperfecta

Question 27

Caudal regression syndrome:

Answer 27

impairment of the development of the lower half of the body--lower back/limbs/GU and GI tract bones of lower spine are frequently misshapen or missing (same with corresponding spinal cord) incomplete closure of spine breathing problems

Question 28

There's a lot of shit on this PPT

Answer 28

too much info for these cards

Question 29

What are the genital abnormalities seen in females + males with caudal regression?

Answer 29

males- urethral opening on underside of penis (hypospadia) + cryptorchidism females- rectovaginal fistula *both can lack genitalia all together in severe cases

Question 30

What are the GI abnormalities seen with caudal regression?

Answer 30

malrotation of large intestine imperforated anus inguinal hernias

Question 31

What are the urinary abnormalities seen with caudal regression?

Answer 31

unilateral renal agenesis horseshoe kidney ureteral duplication bladder exstrophy

Question 32

What is sirenomelia?

Answer 32

legs are fused together | usually fatal bc of abnormal kidney + bladder developmet

Question 33

What causes sirenomelia?

Answer 33

failure of a normal vascular supply from lower aorta in utero

Question 34

Amniotic band syndrome:

Answer 34

spectrum of abnormalities which results from entrapment of various fetal parts from a disrupted amnion

Question 35

Radial ray anomaly:

Answer 35

large spectrum of upper limb anomalies which range from partial to complete deficiency of the radius w/ or w/o accompanying deficiency of the thumb

Question 36

Polydactyly:

Answer 36

foot/hand w/ more than 5 digits | a/w tri-13, Meckel Gruber Syndrome (encephalocele, polydactyly + renal cystic dysplasia)

Question 37

Clinodactyly is what? What is it most a/w?

Answer 37

inward curvature of 5th digit of the hand due to hypoplasia of the mid phalanx tri-21 - 61%

Question 38

Persistently clenched hand with overlapping fingers is a/w?

Answer 38

``` aneuploidic: tri-18 (edwards syndrome) tri-13 (patau syndrome) non-aneuploidic: Pena-Shokei syndrome Smith-Lemli-Opitz syndrome ```

Question 39

What is Pena-Shokeir syndrome?

Answer 39

autosomal recessive non aneuploidic condition with some clinical features similar to tri18. Lethal

Question 40

What is Smith-Lemli-Opitz syndrome?

Answer 40

lack of cholesterol production as well as build up of potentially toxic by-products of cholesterol production which accumulates in the blood and other tissues

Question 41

Trident fingers:

Answer 41

short stubby fingers with a separation b/w middle and ring fingers a/w various chondrodysplasias

Question 42

Syndactyly:

Answer 42

congenital fusion of 2 or more digits. Can be soft tissue or bone tends to affect 3rd + 4th digits

Question 43

Clubfoot:

Answer 43

abnormal deviation of the foot in relation to the tib + fib majority of the cases the sole is turned medially mostly isolated can be caused by abnormal bone formation, spina bifida + muscular defects

Question 44

Rocker bottom feet:

Answer 44

convex curvature of the pedal arch (like a rocking chair) + is most commonly a/w tri-18

Question 45

Sandal foot:

Answer 45

increase in space b/w great toe and second toe can be normal, but also a soft marker a/w tri21

Question 46

Which form of achondroplasia is incompatible with normal life?

Answer 46

heterozygous

Question 47

Which type of thanatophoric dysplasia is distinguished by curved femurs and a flattened spinal column?

Answer 47

type I

Question 48

What condition is likely indicated if you find fractured bones and a region of irregular thickening at the area of the fracture?

Answer 48

hypophosphatasia

Question 49

Which type of skeletal dysplasia has the most severe degree of limb shortening?

Answer 49

achondrogenesis

Question 50

What skeletal disorder is sometimes referred to as “brittle bone disease/syndrome”?

Answer 50

osteogenesis imperfecta

Question 51

Misshapen lower spinal vertebrae and absent spinal cord below L2 would be characteristic of what condition?

Answer 51

caudal regression