Disorders of growth

Question 1

What are some factors that cause disorders of growth?

Answer 1

• Growth plate injury or arrest
• Growth plate over stimulation
• Lack of nutrition
• Vitamin deficiency
• Skeletal dysplasia
• Hormonal

Question 2

What are some causes of growth plate arrest?

Answer 2

Trauma
Infection
Tumours
Irradiation
Surgery
Compression
These can all partially or fully destroy the growth plate, leading to malformation or lack of growth of bone

Question 3

Describe the Salter Harris classification of physeal trauma

Answer 3

• S - Straight - The injury occurs straight through the physis
• A - Above - The injury comes from above physis and moves into the physis
• L - Lower - The injury comes from below the physis and moves into the physis
• T - Through - The injury comes from either above or below and passes straight through the physis
• R - cRush - The physis is crushed by the trauma

Question 4

Dys -

Answer 4

Abnormal

Question 5

• plasia

Answer 5

Growth

Question 6

Campto -

Answer 6

Bent

Question 7

Acro-

Answer 7

Peripheral

Question 8

Meso-

Answer 8

Middle

Question 9

Rhizo-

Answer 9

Root/Central

Question 10

Phoco-

Answer 10

Seal like

Question 11

-melia

Answer 11

Relating to limbs

Question 12

Thanato-

Answer 12

Death

Question 13

Diatrophic

Answer 13

Twisting

Question 14

Brachy-

Answer 14

Short

Question 15

Spondylo-

Answer 15

Relating to the spine

Question 16

Meta-

Answer 16

After or behind

Question 17

-Petrosis

Answer 17

Stone like

Question 18

What are the 4 main categories of skeletal dysplasia?

Answer 18

• Chondrodysplasias - Cartilage
• Tumour-like conditions
• Altered bone density conditions
• Storage disorders

Question 19

What are some examples of chondrodyspasias?

Answer 19

• Achondroplasia
• Pseudoachondroplasia
• SED
• MED
• Metaphyseal chondrodysplasia
• Diastrophic dysplasia

Question 20

What are some examples of tumour-like skeletal dysplastic conditions?

Answer 20

• Multiple hereditary exostoses
• Ollier’s disease
• Fibrous dysplasia
• Trevor’s disease

Question 21

What are some conditions that alter bone density?

Answer 21

Osteogenesis imperfecta
Osteoporosis

Question 22

What are some examples of skeletal dysplastic storage disorders?

Answer 22

Mucopolysaccharidoses:
- Morquio’s syndrome
- Hunter’s syndrome
- Hurler’s syndrome

Question 23

What is achondroplasia?

Answer 23

Achondroplasia is a spontaneous autosomal dominant condition, and is the most common form of skeletal dysplasia

It is the medical term for short stature (Dwarfism is no longer used)

Question 24

Describe the pathophysiology of achondroplasia

Answer 24

It causes rhizomelic dwarfism, affecting the proliferative zone of physis, leading to reduced longitudinal growth but normal circumferential growth

Question 25

What are some presentations of achondroplasia?

Answer 25

- Short stature - Foramen magnum stenosis - Adenotonsillar hypertrophy - Hyperlordosis of the lumbar spine - Macrocephalt - Trident hands - Brachydactyly - Champagne glass pelvis

Question 26

What causes multiple hereditary exostoses?

Answer 26

Multiple hereditary exostoses is caused by an EXT gene mutation

Question 27

Describe the pathophysiology of multiple hereditary exostoses?

Answer 27

In this, benign cartilage-covered bony lesions form from the metaphyses, which can put pressure on local structures, cause reduced range of movement and distort growth The lesions usually stop growing when the physes fuse

Question 28

What is a possible risk of multiple hereditary exostoses?

Answer 28

These lesions, if the cartilage cap thickens, can undergo malignant transformation

Question 29

What is osteogenesis imperfecta?

Answer 29

Osteogenesis imperfecta, also known as brittle bone disease, is a rare group of genetic disorders mainly affecting bone

Question 30

What causes osteogenesis imperfecta?

Answer 30

Oestogenesis imperfecta is caused by a defect in the maturation and orginisation of type I collagen, which accounts for most of the organic composition of bone The majority of cases are autosomal dominant, however, there are some rarer, autosomal recessive types

Question 31

How will autosomal dominant osteogenesis imperfecta present?

Answer 31

- Multiple fragility fractures in childhood - Short stature with multiple deformities - Blue sclera - Scoliosis - Coxa vara - Mitral valve prolapse - Dentinogenesis imperfecta (Disorder of tooth development)

Question 32

How will autosomal recessive osteogenesis imperfecta usually present?

Answer 32

Autosomal recessive osteogenesis imperfecta is usually either fatal during the perinatal period or is associated with spinal deformity

Question 33

How is osteogenesis imperfecta usually diagnosed?

Answer 33

Diagnosis is usually made using x-ray which will show thin bones with thin cortices The bones will be osteopenic In mild cases, x-rays may be relatively normal woth a history of low energy fractures

Question 34

How is osteogenesis imperfecta usually managed?

Answer 34

There is no cure for osteogenesis imperfecta, however, biphosphonates can be used to inhibit osteoclast activity Most management is conservative with fracture fixation, deformity correction surgeries and splintage to aid healing and prevent callus formation as fracture heal abnormally

Question 35

What are muscopolysaccharidoses?

Answer 35

These are a group of conditions, in which there is an accumulation of glycosaminoglycan (GAG) breakdown products in multiple organs

Question 36

What are GAGs?

Answer 36

GAGs are carbohydrates used in connective tissue formation

Question 37

What are some examples of mucopolysacharidoses?

Answer 37

- Morquio’s syndrome - Hunter’s syndrome - Hurler’s syndrome

Question 38

What are some signs and symptoms of mucopolysaccharidoses?

Answer 38

- Proportionate dwarfism - C1-2 cervical instability - Abnormal epiphyses - Bullet shaped phalanges - Genu velgum (Bow legs) - Orgaomegaly - Cardiac disease - Deafness - Reduced IQ