Paeds Ortho Flashcards
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?
osteogenesis imperfecta osteomyelitis / septic arthritis NAI rickets birth injury
What is included in a ‘bone profile’ blood test?
Ca, phos, alk phos, albumin
What investigations would you do to distinguish between osteogenesis imperfecta and NAI?
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?
What is the mode of inheritance for osteogenesis imperfecta?
Autosomal Dominant
A 2wk old neonate has had a fracture. What is appropriate analgesia at this age?
oramorph !
regular paraz + ibuprofen
What is vitamin D2 called and which food?
ergocalciferol
mushrooms
What is vitamin D3 called and which food?
cholecalficerol
egg yolk, oily fish
What is the precursor to vit D3 called, from sunlight?
7-dehydrocholesterol
Which form of vit D is stored in the liver?
25-hydroxy vit D
Which form of vit D is stored in the kidneys?
1,25-dihydroxy vit D
a.k.a. calcitriol , “activated vit D”
What is calcitriol?
1,25-dihydroxy vit D
What are the 3 ways that vitamin D makes calcium available?
- increase bone resorption (releases Ca)
- increase Ca absorption from gut
- increase Ca reabsorption from kidney (get rid of phos)
Vit D def can present as rickets, or more acutely as what?
hypocalcaemia
convulsions, tetany and cardiomyopathy
Define osteoporosis!
low bone density + microarchitectural destruction
… leading to …
increased fragility and risk of fracture
What is the diagnostic criteria for osteoporosis in kids?
one or more vertebral crush fractures
OR
low bone density PLUS long bone fractures
(2# by age 10 or 3# by age 15)
Give me two INHERITED causes of osteoporosis in children?
- osteogenesis imperfecta
- inborn errors e.g. galactosemia
Give me three ACQUIRED causes of osteoporosis in children?
- drugs (steroids)
- malabsorption (vit D, Ca)
- low weight bearing (cerebral palsy, JIA)
Osteogenesis imperfecta is a defect in ….?
Type 1 collagen
Name three key symptoms of osteogenesis imperfecta.
fragility fractures
blue sclerae
deafness - we’re not sure why
What is the classification of osteogenesis imperfecta?
“Sillence” classification - types of O.I. (mainly type 1, type 2)