children's orthopaedics

Question 1

how are flat bone developed -just name

Answer 1

intramembranous mesenchymal cells-> bone

Question 2

how are long bone developed- just name

Answer 2

endochondral mesenchymal -> cartilage -> bone

Question 3

steps of intramembranous ossification

Answer 3

1. condensation of mesenchymal cells-> differentiate into osteoblasts and form ossification centre
2. secreted osteoid traps osteoblast which becomes osteocytes
3. trabecular matrix and periosteum form
4. compact bone develops superficial to cancellous bone. Blood vessels condense into red bone marrow

Question 4

what is primary ossification centres of long bone formation- and when does it occur

Answer 4

pre-natal bone growth through endochondral ossification from central part of bone

Question 5

what is secondary ossification centres of long bone formation

Answer 5

post-natal after primary ossification centre.

Question 6

steps of endochondral primary ossification

Answer 6

1. mesenchymal differentiation at primary ossification centre (POC) (in middle of bone diaphysis)
2. cartilage model of future bony skeleton forms
3. capillaries penetrate cartilage
   a)calcification at POC form spongy bone
   b)perichondrium transforms into periosteum
4. cartilage and chondrocytes continue to grow at bone ends
5. secondary ossification centre develops

Question 7

secondary endochondral ossification steps

Answer 7

Long bone lengthening at physis

Epiphyseal side – hyaline cartilage divide, forming hyaline cartilage matrix

Diaphyseal side – Cartilage calcifies+ dies. Then replaced by bone

Question 8

difference between children’s and adults skeleton

Answer 8

elasticity
physis
healing speed
remodelling

Question 9

3 issues with elasticity

Answer 9

Plastic deformity
– Bone deformity persists after force removed.- no cortices fractured

Buckle fracture
– One side of the bone bends, raising a little buckle, without breaking the other side of the bone.

Greenstick
One cortex fractures but does not break the other side

Question 10

cause of increased elasticity

Answer 10

Increased density of haversian canals

Question 11

age of girl and boy when growth stops and physis closes

Answer 11

Girls 15-16
Boys 18-19

Question 12

what can physeal injuries lead to

Answer 12

growth arrest and deformity

Question 13

what is developmental dysplasia of the hip

Answer 13

head of the neonatal femur is unstable to the acetabulum

Question 14

risk factor of DDH

Answer 14

female
first born
breech

Question 15

DDH:
Examination and investigation

Answer 15

baby check

US-0-4month
x-ray-after 4 months

Question 16

DDH treatment

Answer 16

pavlik harness 6months

if failed/6-18months:
MUA+ closed reduction and spica

Question 17

proper name for clubfoot and cause

Answer 17

congenital talipes equinovarus

deformity from muscle contracture

Question 18

gene cause and commonest ethnicity to have club foot (congenital talipes equinovarus)

Answer 18

PITX1 gene
Hawaiians

Question 19

symptoms of clubfoot

Answer 19

CAVE
Cavus –high arch
Adductus of foot: Tight tib post and ant
Varus: Tight tendoachillies,
Equinous(toe pointing down): tight tendoachilles

Question 20

clubfoot treatment

Answer 20

ponseti method- series of casts to correct deformity

Question 21

what is achondroplasia

Answer 21

G380 mutation ofFGFR3 gene

inhibition of chondrocyte proliferation in physis

defect in endochondral bone formation

Question 22

signs of achondroplasia

Answer 22

Rhizomelic dwarfism

Humerus shorter than forearm
Femur shorter than tibia
Normal trunk
Adult height of approx. 125cm

Question 23

osteogenesis imperfecta (brittle bone disease)
cause

Answer 23

decrease T1 collagen
-less secretion/abnormal collagen production

leading to insufficient osteoid production

Question 24

effects of osteogenesis imperfecta on bone and non-ortho symptoms

Answer 24

Bones
Fragility fractures, Short stature, Scoliosis

Non-orthopaedic
Blue Sclera, brown soft teeth
Hypermetabolism

Question 25

paediatric fractures checklist

Answer 25

PAID
pattern
anatomy
intra/extra-articular
Displacement

salter-harris

Question 26

5 types of pattern in PAID

Answer 26

transverse
oblique
spiral
comminuted
avulsion

green stick
plastic deformity
buckle fracture

Question 27

anatomy in PAID

Answer 27

Ie. name of bone, proximal third, middle third or distal third

Question 28

intra/extra-articular of PAID–what kind of bone healing is preferred and why

Answer 28

Primary bone heading
-preferred in intra-articular fracture as minimise risk of post traumatic arthritis

secondary bone healing
-healing by callus

Question 29

4 types of displacement in PAID

Answer 29

displaced
angulated
shortened
rotated

Question 30

salter Harris classification for physeal injuries

Answer 30

1. Physeal Separation
2. Fracture traverses physis and exits metaphysis (Above)
3. Fracture traverses physis and exits epiphysis (Lower)
4. Fracture passes Through epiphysis, physis, metaphysis
5. Crush injury to physis

Question 31

growth arrest risk in relation to salter harris and most common type

Answer 31

risk increases from 1 to 5

type2 = most common

Question 32

growth arrest of whole physis vs partial

Answer 32

Whole physis – limb length difference

Partial – angulation as the non affected side keeps growing

Question 33

growth arrest treatment

Answer 33

limb length correction
a) shorten long side
b) lengthen short side

angular deformity
a)stop growth of unaffected side
b) reform bone (osteotomy)

Question 34

reduce- example of closed reduction

Answer 34

gallows traction - holding skin- long bone of lower limb can be reduced

Question 35

preferred restrict method

Answer 35

external -splints/plaster are preferred over internal

as kids have a great healing potential

Question 36

septic arthritis treatment

Answer 36

surgical washout of the joint to clear the infection

Question 37

septic arthritis- kocher’s classification

Answer 37

non weight bearing
ESR 40+
WBC 12,000+
Temp 38+

Question 38

transient synovitis diagnosis and treatment

Answer 38

1. exclude septic arthritis

Is a inflamed joint in response to a systemic illness

antibiotics

Question 39

perthes disease

Answer 39

Idiopathic necrosis of the proximal femoral epiphysis

Usually 4-8 years old boys.
doesn’t affect 10+

Question 40

SUFE- commonest in? Associated with?
Treatment?

Answer 40

Obese adolescent male
10+ (12-13 y.o)

associated with hypothyroidism/hypopituitarism

treat: operative fixation to prevent further slip and minimise LT growth issues