Paeds Ortho

Question 1

A 2wk old neonate is brought to A&E crying inconsolably. Right leg is not moving. No Hx of trauma.
FHx - mum had six fractures as child, most from trivial trauma. Grandad also had ‘a lot’ of fractures.
Differentials?

Answer 1

osteogenesis imperfecta
osteomyelitis / septic arthritis
NAI
rickets
birth injury

Question 2

What is included in a ‘bone profile’ blood test?

Answer 2

Ca, phos, alk phos, albumin

Question 3

What investigations would you do to distinguish between osteogenesis imperfecta and NAI?

Answer 3

bone profile, serum Vit D, PTH
genetic testing

NAI:
skeletal survey 
top to toe Ex.
CT head (to look for shaken baby)
clotting profile (if signs of bruising)
opthalm (for retinal haemorrhages)

involvement of social services / police?

Question 4

What is the mode of inheritance for osteogenesis imperfecta?

Answer 4

Autosomal Dominant

Question 5

A 2wk old neonate has had a fracture. What is appropriate analgesia at this age?

Answer 5

oramorph !

regular paraz + ibuprofen

Question 6

What is vitamin D2 called and which food?

Answer 6

ergocalciferol

mushrooms

Question 7

What is vitamin D3 called and which food?

Answer 7

cholecalficerol

egg yolk, oily fish

Question 8

What is the precursor to vit D3 called, from sunlight?

Answer 8

7-dehydrocholesterol

Question 9

Which form of vit D is stored in the liver?

Answer 9

25-hydroxy vit D

Question 10

Which form of vit D is stored in the kidneys?

Answer 10

1,25-dihydroxy vit D

a.k.a. calcitriol , “activated vit D”

Question 11

What is calcitriol?

Answer 11

1,25-dihydroxy vit D

Question 12

What are the 3 ways that vitamin D makes calcium available?

Answer 12

1. increase bone resorption (releases Ca)
2. increase Ca absorption from gut
3. increase Ca reabsorption from kidney (get rid of phos)

Question 13

Vit D def can present as rickets, or more acutely as what?

Answer 13

hypocalcaemia

convulsions, tetany and cardiomyopathy

Question 14

Define osteoporosis!

Answer 14

low bone density + microarchitectural destruction
… leading to …
increased fragility and risk of fracture

Question 15

What is the diagnostic criteria for osteoporosis in kids?

Answer 15

one or more vertebral crush fractures
OR
low bone density PLUS long bone fractures
(2# by age 10 or 3# by age 15)

Question 16

Give me two INHERITED causes of osteoporosis in children?

Answer 16

• osteogenesis imperfecta

- inborn errors e.g. galactosemia

Question 17

Give me three ACQUIRED causes of osteoporosis in children?

Answer 17

• drugs (steroids)
• malabsorption (vit D, Ca)
• low weight bearing (cerebral palsy, JIA)

Question 18

Osteogenesis imperfecta is a defect in ….?

Answer 18

Type 1 collagen

Question 19

Name three key symptoms of osteogenesis imperfecta.

Answer 19

fragility fractures
blue sclerae
deafness - we’re not sure why

Question 20

What is the classification of osteogenesis imperfecta?

Answer 20

“Sillence” classification - types of O.I. (mainly type 1, type 2)

Question 21

What happens in Type 2 osteogenesis imperfecta?

Answer 21

fractures in utero, IUGR, wormian bones. Usually die in utero.

Question 22

What might you notice about a child’s face in osteogenesis imperfecta?

Answer 22

Triangular face

Question 23

What is the treatment for osteogenesis imperfecta?

Answer 23

There’s no cure :(

• surgical correction of deformities (e.g. rod placement)
• physio
• mobility aids.

Question 24

brittle bone disease a.k.a

Answer 24

osteogenesis imperfecta

Question 25

What is the management of osteoporosis in children?

Answer 25

bisphosphonates e.g. pamidronate physio (correct vit D def)

Question 26

Genetic disease where bones are DENSE but brittle. Need bone marrow transplant.

Answer 26

Osteopetrosis

Question 27

Disease of high bone turnover and remodelling. Bone pain and deformity (skull, pelvis). What's this?

Answer 27

Paget's disease

Question 28

What is the difference between osteoporosis and osteomalacia?

Answer 28

They both cause weak bones. - In osteoporosis, there is decreased bone mass with a normal ratio of mineral to matrix. - In osteomalacia, there is less mineralization. osteoporosis - low bone density osteomalacia - failure of bone mineralization The catch-phrase of osteoporosis is "normal-enough bone, but not enough of it!"

Question 29

What is rickets?

Answer 29

osteomalacia in kids | failure of bone mineralization

Question 30

What is Fanconi syndrome?

Answer 30

loss of phosphate at kidney | it causes rickets rickets because cant swap phosphate for Ca reabsorption

Question 31

Which drugs can speed metabolism of vit D, causing rickets?

Answer 31

carbamazepine phenytoin phenobarbital

Question 32

vit D3 and vit D2 can be got from food. But 90% of ours comes from sunlight. In UVB, there is the vit D3 PRECURSOR, which is called...

Answer 32

7-dehydrocholesterol

Question 33

Give me some RISK FACTORS for vit D deficiency (--> rickets) | not including underlying conditions that cause secondary vit D def

Answer 33

``` dark skin living in northern latitudes EBF after 6months maternal vit D def being housebound or institutionalised (no sun) poverty, vegetarianism ```

Question 34

Vit D def can also be secondary to lots of different underlying conditions. Name some.

Answer 34

malabsorption - CF, coeliac | hepatic and renal disease (impaired vit D conversion)

Question 35

As well as Calcium (which you get via vit D), bones also need phosphate to mineralize. If they don't have enough phosphate, this can cause failure of bone mineralization. What's this called and what two genetic conditions can cause it?

Answer 35

HYPOPHOSPHATAEMIC RICKETS - Fanconi sydrome - X-linked hypophosphataemia

Question 36

What enzyme is defunct in X-linked hypophosphataemia causing rickets?

Answer 36

PHEX

Question 37

Kate, what is the actual difference between parenteral nutrition and enteral nutrition?

Answer 37

``` parenteral = IV enteral = NG, PEG, JEJ ```

Question 38

Give me 4 signs of rickets . | not the fancy ones

Answer 38

poor growth / short stature frontal bossing bowed legs widened wrists + bone and joint pain.

Question 39

Give me 3 fancy signs of rickets.

Answer 39

Rachitic rosary Harrisons sulcus Craniotabes

Question 40

What is Rachitic rosary in rickets?

Answer 40

palpable costochondral junction

Question 41

What is Harrisons sulcus in rickets?

Answer 41

indentation of soft lower ribcage where diaphragm inserts

Question 42

What is craniotabes in rickets?

Answer 42

soft skull bones, can press finger into them

Question 43

You have identified a child has low vitamin D levels. What is now required to diagnose rickets?

Answer 43

wrist X ray | definitive diagnosis of rickets requires X ray of a long bone

Question 44

Definitive diagnosis of rickets requires X ray of a long bone. What would it show?

Answer 44

cupping + fraying of metaphysis splaying of epiphyseal plate e.g. champagne glass wrist

Question 45

Describe the management of rickets.

Answer 45

oral cholecalciferol daily (vit D3) dietary advice encourage sunlight exposure treat any underlying condition treat pain ?ortho intervention

Question 46

What would vit D (25-hydroxy) level be in rickets?

Answer 46

low

Question 47

What would Ca level be in rickets?

Answer 47

low / normal

Question 48

What would phosphate level be in rickets?

Answer 48

low (getting rid at kidneys to increase Ca reabsorption)

Question 49

What would Alk Phos level be in rickets?

Answer 49

high - lots of bone turnover - because high resorption to increase serum Ca

Question 50

What would PTH level be in rickets?

Answer 50

high (PTH is busy trying to increase serum Ca)

Question 51

What does PTH try to do?

Answer 51

increase serum Ca