Skeletal dysplasia

Question 1

Definition of rhizomelia

Answer 1

small proximal bones - femur, humerus Examples - Thanatophoric dysplasia and achondroplasia

Question 2

Definition of mezomelia

Answer 2

small intermediate bones - ulna, radius

Question 3

Definition of acromelia

Answer 3

shortening of distal bones - hands and feet

Question 4

Definition of micromelia

Answer 4

shortening of all segments of the extremities

Question 5

Definition of campomelia

Answer 5

bowing of the long bones

Question 6

Definition of preaxial

Answer 6

lateral (radius/tibia) Example of preaxial polydactyly: short-rib polydactyly syndrome type 2 , carpenter syndrome

Question 7

Definition of post axial

Answer 7

medial (ulna/fibula) Example of postaxial polydactyly: short-rib polydactyly syndrome type 1 and 3

Question 8

Definition of syndactyly

Answer 8

digits stuck together, webbed or fused example : Carpenter syndrome, Jarcho-Levin syndrome

Question 9

Definition of hemivertebrae

Answer 9

partially formed vertebral body

Question 10

Poor prognostic signs

Answer 10

• FL/AC - less than 0.16
• CC/AC - less than 0.8
• Small thorax (bell-shaped)
• Marked bowing
• Cloverleaf skull

Question 11

Achondroplasia:

Answer 11

-Limb shortening (after 22 weeks) -Macrocephaly -Frontal bossing -Normal intelligence and life expectancy

Question 12

Steps to assess for skeletal dysplasia on ultrasound:

Answer 12

Bone length - is it short and what part is short? Bone quality - is it curved, fractured, demineralized? Chest - is it long and narrow or short? Face - is there a small jaw, cleft, abnormal telorism? Head - is it abnormally shaped (cloverleaf), is it large? Hands and feet - are there extra digits, short, deformed? is it clubbed? Spine - is there abnormal curvature

Question 13

Poor ossification of the skull is associated with what skeletal dysplasia:

Answer 13

Osteogenesis imperfecta Hypophosphatasia

Question 14

Poor ossification of the spine is associated with what skeletal dysplasia:

Answer 14

Achondrogenesis

Question 15

Bowed lower extremity with normal upper extremity is associated with what skeletal dysplasia:

Answer 15

Camptomelic dysplasia

Question 16

Hitchhicker thumb is associated with what skeletal dysplasia:

Answer 16

Diastrophic dysplasia

Question 17

Telephone receiver femur is associated with what skeletal dysplasia:

Answer 17

Thanatophoric dysplasia

Question 18

Third trimester shortening of bones is associated with what skeletal dysplasia:

Answer 18

Achondroplasia

Question 19

Trident hand and association with skeletal dysplasia:

Answer 19

When the last four fingers are the same length. It can be seen in various chondrodysplasias

Question 20

Femur to foot length:

Answer 20

Femur to foot length ratio of less than 1 is associated with skeletal dysplasia

Question 21

Short rib polydactyly syndrome

Answer 21