orthopaediatrics Flashcards
child vs adult bones
Child's has 270 bones - in continuous change Physis (growth plates) Elasticity greater Speed of healing faster Remodelling always
development of flat bones
intramembranous ossification
development of long bones
endochondral ossification
intramembranous ossification
formation of ossification centre - condensation of mesenchymal cells to osteoblasts
secreted osteoid traps osteoblasts – osteocytes
trabecular matrix and periosteum form
compact bone develops superficially, crowded blood vessels become red bone marrow
ossificaiton centres
primary ossification centres - pre-natal bone growth through endochondral oss from central part of bone
secondary ossification centres - post-natal after primary ossification centres, forms the physis
what ossification centre is there pre-natally
primary
endochondral primary ossification
mesenchymal differentiation creates a cartilage model in diaphysis
angiogenesis penetrates, primary centre forms and spongy bone
continues up the shaft, cartilage and chondrocytes form bone ends.
secondary ossification centres form at bone ends now
endochondral secondary ossification
centre calcifies and dies to immature spongy bone
epiphyseal side contains active hyaline cartilage which continues dividing to form hyaline cartilage matrix (epiphyseal growth plate)
What happens if the physis are faulty
Any congenital malfunction or acquired insult – traumatic/infective or otherwise will have impact on growth of the child
why are childrens bones more elastic
increased density of haversian canals (need blood supply for growing tissue)
dissipation of energy means it can bend more before breaking
importance of childrens bone elasticity
plastic deformations - bends before breaking
buckle fractures - pushes outwards like roman column
greenstick fractures - one cortex fractures but other side doesnt break
when does bone growth stop
when physis closes - puberty
what is physis closure dependent on
parental height
menarche
puberty
when are boys and girls’ physis closed
boys - 18/19
girls - 15/16
what is a physeal injury
Categorised by salter harris
May lead to growth arrest -> deformity
What 2 factors impact remodelling potential of children?
AGE: greater the younger they are LOCATION: Physis at knee grows more Pysis at extreme of upper limb grows more
common congenital ortho conditions
developmental dysplasia of the hip
club foot
achondroplasia
osteogenesis imperfecta
what is developmental dysplasia of the hip (DDH)
Group of disorders where head of femur unstable or incongruous with acetabulum
A ‘packing disorder’- depending on how child sits in womb impacts how hip sits in acetabulum
Normal development relies of concentric reduction and balanced forces in hip
risk factors for developmental dysplasia of hip
female 6:1
first born
breech
family history
oligohydramnios (lack of fluid in amniotic sac)
native american/ laplanders- swaddling of hip
Rare in african american/ asian
examination for DDH
baby check- screening usually picks it up
Hip RoM:
- usually limitation in hip abduction
- leg length (Galeazzi test)
In 3 months and older, Barlow and Ortolani test (to check for hip instability) are non-sensitive
investigation for DDH
ultrasound (birth- 4 months) - measure acetabular dysplasia and hip position
If aster 4 months, X-Ray
treatment of DDH
If reducible hip and <6 months old - pavlik harness- holds femoral head in acetabulum
If failed/irreducible or 6-18 months old - MUA + closed reduction and spica
what is club foot?
Epidemiology?
congenital deformity of foot
Highest in hawaiians
M:F 2:1
50% are bilateral
what does CAVE mean in relation to club foot
Cavus - high foot arch: tight intrinsic muscles, FHL, FDL
Adductus of foot - tight tibialis post and ant
Varus - tight tendoachilles, tib post tib ant
Equinous - tight tendoachilles
