9.3 Children's Orthopaedics Flashcards
How many bones does a child’s skeleton have?
270
Where does long bone growth occur postnatally?
the physis (growth plate)
What are the two types of ossification?
Intramembranous
Endochondral
What bones are formed from intramembranous ossification?
flat bones
What bones are formed from endochondral ossification?
long bones
What is the difference between intramembranous and endochondral ossification?
intramembranous:
mesenchymal cells –> bone
endochondral:
mesenchymal cells –> cartilage –> bone
What are the four stages of intramembranous ossification?
- In central ossification centers, differentiation of mesenchymal cells –> pre-osteoblasts, –> osteoblasts.
- osteoblasts synthesis and secrete osteoid. differentiation of osteoblasts –> osteoclasts
- cells become trabecular matrix and periosteum
- angiogenesis –> blood vessels incorporated and become red bone marrow. Compact bone develops superficial to cancellous bone
What two places does endochondral ossification occur?
primary and secondary ossification centers
What are the primary ossification centers?
Sites of prenatal bone growth at central part of the bone (through endochondral ossification)
What are the secondary ossification centers?
The physis
Long bones often have several and bone growth only occurs here postnatally, after the primary ossification centres.
What are the 5 stages of endochondral primary ossification?
- mesenchymal differentiation
- cartilage model of the future bony skeleton forms
- capillaries penetrate cartilage, calcification at primary ossification center - spongy bone forms, perichondrium transforms into periosteum
- cartilage and chondrocytes continue to grow at the end of the bone
- secondary ossification centers (the physis) develop
What are the two sides of the physis?
epiphyseal side and diaphyseal side
What happens at the epiphyseal side?
hyaline cartilage divides and grows to form hyaline cartilage matrix
What happens at the diaphyseal side?
cartilage calcifies and dies and then is replaced by bone
What are 4 ways that a children’s skeleton is different from an adults?
Elasticity
Physis
Speed of Healing
Remodeling
Why are childrens bones more elastic than an adults?
Increased density of haversian canals (microscopic tunnels)
Because of the increased elasticity in children’s bones, what are 3 types of fractures we see in children that we don’t usually see in adults.
Plastic deformity - bends before breaks
Buckle fracture - tarus like column
Greenstick - one cortex fractures but does not break other side
How does growth at the physis stop, when does this usually occur?
Growth stops gradually as the physis closes
Girls: 15-16
Boys: 18-19
Can be affected by parental height
What is the speed of healing and remodelling potential dependent on?
location and age of patient
younger children heal more quickly, different physis’ grows at different speed (knee more than hip etc.) but fractures near the physis heal more quickly
What is developmental dysplasia of the hip?
‘packaging’ disorder of the neonatal hip where the head of the femur is unstable or incongruous in relation to the acetabulum
What is required for normal development of the hip?
concentric and balanced forces through the hip
What is the difference between dysplasia and dislocation of hip?
on spectrum
dysplasia –> subluxation –> dislocation
dysplasia much more common than dislocation
What are the risk factors of developmental dysplasia of the hip?
female first born breech family history oligohydramnios - not enough fluid in amniotic sac native american/lapanders
How is developmental dysplasia of the hip screened and what do they check for?
usually picked up on baby check - screening in the UK
- range of motion
- usually limitation in hip abduction
- leg length discrepancy
How is developmental dysplasia of the hip investigated?
birth to 4 months: ultrasound
4 months +: x-ray
How is developmental dysplasia of the hip treated?
reducible hip and <6 months: pavlik harness
failed pavlik harness or 6-18 months: manipulation under anesthetic (MUA) and spica cast (this is because of secondary changes to the capsule and soft tissue)
What is congential talipes equinovarus?
club foot
What are the risk factors for congenital talipes equinovarus?
male
hawaiian
family history (there is a very large genetic component, 5% chance if siblings, familial cause in 25% of cases)
What gene is mutated in congenital talipes equinovarus?
PITX1 gene
How is clubfoot characterised?
congenital talipes equinovarus consists of four deformities (all four present) = CAVE Cavus Adductus of the foot Varus Equinous
What is the C in CAVE caused by ?
Cavus - high arch, tight intrinsic flexor hallucis longus, flexor digitorum longus
What is the A in CAVE caused by?
Adductus of foot - tight tib post, tib ant
What is the V in CAVE caused by?
Varus - tight tendoachillies, tib post, tib ant
What is the E in CAVE caused by?
Equinous: tight tendoachilles
How is clubfoot treated?
Ponseti Method - gold standard
- A series of casts to correct deformity
- Many require operative treatment - soft tissue releases
- Foot orthosis brace (skateboard)
- Some might require further operative intervention to correct final deformity
What is Achondroplasia?
An autosomal dominant condition that results in rhizomelic dwarfism.
Causes the inhibition of chondrocyte proliferation in the proliferative zone of the physis. –> Effects secondary endochondral ossification.
The most common skeletal dysplasia conditions
What is the mutation that causes Achondroplasia?
G380 mutation of FGFR3
What are the characteristics of rhizomelic dwarfism? (6)
humerus shorter than forearm femur shorter than tibia normal trunk adult height of approx. 125cm significant spinal issues normal cognitive development
What is oesteogenesis imperfecta?
Hereditary disease (AD or AR)
Decreased Type 1 collagen due to:
- decreased secretion
- production of normal collagen
which results in insufficient osteoid production.
What are the orthopaedic manifestations of OI? (3)
fragility fractures
short stature
scoliosis
What are the non - orthopaedic manifestations of OI? (5)
heart problems blue sclera dentinogenesis imperfecta - brown soft teeth wormian skull hypermetabolism
What are the 5 things we need to know about for paediatric fracture classification.
Pattern Anatomy Intra/Extra articular Displacement Salter - Harris
Give 5 examples of fracture pattern?
Comminuted Oblique Spiral Transverse Avulsion
=COSTA
What do we have to think about when classifying the anatomy of a fracture?
Where in the bone
proximal 1/3
middle 1/3 (diaphysis)
distal 1/3
What is an intra-articular fracture?
A fracture that crosses a joint surface. (could involve cartilage damage)
What is an extra-articular fracture?
A fracture that occurs outside or somewhere other than a joint
What is the difference between primary and secondary bone healing?
Primary - heals by direct union
Secondary - bone healing by callus formation
For intra-articular fractures, which type of bone healing is preferred?
Primary as this minimises risk of post-traumatic arthiritis
What are the four types of fracture displacment?
displaced
angulated
shortened
rotated
What is the salter harris classification, list all 5 types?
Classification of physeal injuries (SALT)
- Physeal separation
- Fracture transverses physis and exits metaphysis (above)
- Fracture transverses physis and exits epiphysis (lower)
- Fracture passes through epiphysis, physis, metaphysis
- Crush injury to the physis
According to the salter harris classification, which type has the highest risk of growth arrest?
5
Risk of growth arrest increases from 1-5
Which type of physeal injury according to the salter harris classification is the most common?
Type 2
What are the type types of growth arrest?
whole physis - limb length discrepancy
partial - angulation as the non affected side keeps growing
What two things affect the severity of growth arrest caused by injury to the physis?
location
timing (age)
How is growth arrest causing limb length discrepancy, treated?
shorten the long side
lengthen the short side
How is growth arrest causing angular deformity, treated?
stop the growth of the unaffected side
reform the bone (osteotomy)
What are the 4 things to consider in fracture management?
resuscitate
reduce
restrict
rehabilitate
what is reduce in fracture management?
correct the deformity and displacement
reduces secondary issue to soft tissue and neurovascular structures
What is closed reduction?
reducing a fracture without making an incision
such as traction and manipulation in A&E
What is open reduction?
making an incision
the realignment of a fracture under direct visualisation
What is gallows traction?
Type of closed reduction where that by holding the skin, the long bones of the lower limb can be reduced
What does restrict involve in fracture management?
maintain the fracture reduction
provides the stability required for the fracture to heal
What are the two types of restriction, give examples for both.
External - splints, plaster
Internal - plates, screws, intra-medullary device
What type of restriction is more commonly used in paediatric fractures, why?
External (plaster and splints) as remodelling and healing potential means that operative internal fixation can often be avoided
What are the two things to consider for paediatric internal fracture restriction (plates, screws)?
ongoing growth at the physis
metalwork may need to be removed in the future
What does rehabilitation involve for paediatric fractures?
play
children generally rehabilitate very quickly and don’t usually need physio, stiffness is also not as a major issue as in adults
When is Kocher’s classification used?
to help score probability of septic arthritis
What is Kocher’s classification?
Non-weight bearing
ESR >40
WBC >12,000
Temp >38
Why is septic arthritis an orthopaedic emergency?
because it can cause irreversible long term problems in the joint
How is septic arthritis treated?
surgical washout
antibiotics
What are other symptoms of septic arthritis?
24-48 hr off food and drink
last 12 hours is unwell
doesn’t want to move joint
What is transient synovitis?
Similar symptoms but only diagnosed once septic arthritis is excluded
Is an inflamed joint secondary to systemic (secondary) illness
Much more common
How is transient synovitis treated?
Antibiotics and supportive treatment
What is perthes diseases?
idiopathic necrosis of the proximal femoral epiphysis
What are the demographics of most perthes disease patients?
4-8 years old
male 4:1 female
What is SUFE?
Slipped upper femoral epiphysis
The proximal epiphysis slips in relation to the metaphysis
What does a typical SUFE patient look like?
obese adolescent male
12-13 years old during rapid growth
associated with hypothyroidism/hypopituitarism
What is the treatment for SUFE?
operative fixation with screw to prevent further slip and minimise long term growth problems
Before diagnosing Perthes disease, transient synovitis, SUFE what needs to be excluded first?
Septic arthritis
