1b// Children's Orthopaedics Flashcards
How many bones are there in a child’s skeleton?
270
What are growth plates called, and what do they do?
physis
they are the areas from which long bone growth occurs postnatally
What are the types of bone development?
intramembranous mesenchymal cells» bone
endochondral mesenchymal» cartilage» bone
What type of bone do intramembranous mesenchymal cells lead to?
flat bones (cranial bones and clavicle)
What type of bone do endochondral mesenchymal cells make?
long bones (all other long bones)
What is the process called of making cranial bones and the clavicle?
intramembranous ossification
What is the process called of making all other long bones?
endochondral ossification
Describe the process of intramembranous ossification.
- Condensation of mesenchymal cells which differentiate into osteoblasts – Ossification centre forms
- Secreted osteoid traps osteoblasts which become osteocytes
- Trabecular matrix and immature periosteum form
- then angiogenesis between woven bone and trabecular, forming bone marrow
- Compact bone develops superficial to cancellous bone. Crowded blood vessels condense into red bone marrow
Where does endochondral ossification occur?
both primary and secondary ossification centres
What are primary ossification centres? And what part of the bone are they located?
Sites of pre-natal bone growth through endochondral ossification from the central part of the bone
What are secondary ossification centres?
Occurs post-natal after the primary ossification centre and long bones often have several (the physis)
What are the 2 types of endochondral ossification?
primary and secondary
e.g., endochondral primary ossification
Describe the process of endochondral primary ossification.
pre-natal growth through primary ossification centres
a) Mesenchymal Differentiation at the primary centre
b) The cartilage model of the future bony skeleton forms
c) Capillaries (via angiogenesis) penetrate cartilage.
Calcification at the primary ossification centre – spongy bone forms
Perichondrium transforms into periosteum
d) Cartilage and chondrocytes continue to grow at ends of the bone
e) Secondary ossification centres develop
Where are primary ossification centres?
middle of diaphysis (shaft of bone)
Where do secondary ossification centres develop? And how are they developed?
at proximal and distal ends of long bone with their own blood supply
blood supply calcifies the previously uncalcified matrix into immature spongy bone, so cartilage at ends of bone become sites of secondary ossification
What is endochondral secondary ossification for?
long bone lengthening
post bone growth through secondary ossification centres
“the physis”
Describe endochondral secondary ossification.
- where does it occur
- what zone and where
- what does it contain
- and sides
Happens at the physis (physeal plate)
Zone of elongation in long bone
Contains cartilage
Epiphyseal side – hyaline cartilage active and dividing to form hyaline cartilage
matrix
Diaphyseal side – Cartilage calcifies and
dies and then replaced by bone
What are the epiphyseal and diaphyseal sides?
the diaphysis (shaft or primary ossification centre), metaphysis (where the bone flares), physis (or growth plate) and the epiphysis (secondary ossification centre).
Do these make sense?
How does a child’s skeleton differ to that of an adult? (4)
more elasticity
physis (constantly growing)
speed of healing is much faster (due to continuous growth)
remodelling potential
What does it mean by a child’s bone elasticity? And why is it more elastic?
Children’s bone can bend – more elastic than adult
due to increased density of haversian canals
What can increased density of haversian canals lead to? (3)
Plastic deformity:
– bends before breaks
Buckle fracture:
– Tarus like the column
Greenstick:
– like the tree
One cortex fractures but does not break the other side
Why do children have more haversian canals?
as their bones are more metabolically active
Describe growth of bones in children, e.g., where and speed? And when does growth stop?
Growth occurs at varying rates at varying sites
Growth stops as the physis closes
When does physeal closure occur?
Complete at girls: 15-16
boys= 18-19
What does physeal closure depend on?
puberty
menarche
parental height
gradual physeal closure
How are physeal injuries categorised?
salter-harris
What can physeal injuries lead to? And what can that lead to?
growth arrest
leads to deformity
What is the speed of remodelling and healing dependent on?
The speed of healing and remodeling potential is dependent on the location and the age of the patient
Who heals bones more quickly in the general population?
younger child
Which physis grows the most?
at the knee and at the extreme of upper limb
What the stages of healing/ remodelling? (3)
inflammation
repair/ callus
remodelling
What are common children’s congenital conditions (that you need to know)? (4)
Developmental Dysplasia of the Hip
Club Foot
Achondroplasia
Osteogenesis Imperfecta
What is developmental dysplasia of the hip? And what type of disorder is it?
Group of disorder of the neonatal hip where the head of the femur is unstable or incongruous in relation to the acetabulum.
A ‘Packaging Disorder’
What is a packaging disorder?
occurs in utero, due to the way a child sits
What is the normal development of the hip dependent on?
the concentric
reduction and balanced forces through the hip
What is the spectrum of developmental dysplasia of the hip? (3)
dysplasia
or
subluxation
or
dislocation
Dysplasia 2: 100 Dislocation 2:1000
What are risk factors for developmental dysplasia of the hip? (6)
Female 6:1
First born
Breech
FHx
Oligohydramnios
Native American/Laplanders – swaddling of hip
How is developmental dysplasia of the hip examined?
Usually picked up on baby check – screening in UK
Range of motion of hip
- Usually limitation in hip abduction
- Leg length (Galeazzi)
In those 3 months or older Barlow and Ortalani are non-sensitive
What are the investigations for developmental dysplasia of the hip?
Ultrasound – birth to 4 months
- After 4 months X-ray
- If prior to 6 weeks needs to be age adjusted
Measures the acetabular dysplasia and the position of hip
What is the treatment for developmental dysplasia of the hip?
Reducible hip and <6 months
- Pavlik harness 92% effective
Failed Pavlik Harness or 6-18 months
- Secondary changes- capsule + soft tissue
- MUA (manipulation under anaesthetic) + Closed reduction and Spica
What is clubfoot?
Congenital deformity of the foot
packaging disorder
What is the epidemiology of clubfoot?
1:1000
Highest in Hawaiians
M2:1F
50% are bilateral
What is the risk factor of clubfoot?
Genetic…
Approx. 5% likely of siblings
Familial in 25%
PITX1 gene
CAVE
What causes CAVE deformity?
due to muscle contracture
What is CAVE deformity?
deformity of Clubfoot
Cavus –high arch: tight intrinsic, FHL, FDL
Adductus of foot: Tight tib post and ant
Varus: Tight tendoachillies, tib post, tib ant
Equinous: tight tendoachilles
What is the treatment for clubfoot?
Ponseti Method
Gold standard
- First a series of casts to correct deformity
- Many require operative treatment
- Soft tissue releases or tendon transfers (more extreme is tendon) - Foot orthosis brace
- Some will require further operative intervention to correct final deformity.
What is achondroplasia?
The most common skeletal dysplasia
What is the pathophysiology of achondroplasia?
Autosomal Dominant
- G380 mutation of FGFR3
- inhibition of chondrocyte proliferation in the proliferative zone of the physis
- results in defect in endochondral bone formation
affects secondary ossification
What does achondroplasia lead to?
rhizomelic dwarfism
What is a part rhizomelic dwarfism?
Humerus shorter than forearm
Femur shorter than tibia
Normal trunk
Adult height of approx.125cm
Normal cognitive development
Significant spinal issues
What is osteogenesis imperfecta?
brittle bone disease
decreased type 1 collagen
Why is there decreased collagen in osteogenesis imperfecta? And what does that lead to?
Decreased Type I Collagen due to:
- Decreased secretion
- Production of abnormal collagen
leading to insufficient osteoid production
How do you get osteogenesis imperfecta?
hereditary- autosomal dominant or recessive
What are the manifestations of osteogenesis imperfecta on bones? (3)
Fragility fractures
Short stature
Scoliosis
What are the non-orthopaedic manifestations of osteogenesis imperfecta? (5)
Heart
Blue Sclera
Dentinogenesis imperfecta – brown soft teeth
Wormian skull
Hypermetabolism
What is wormian skull?
abnormal fusion of cranial sutures
What should you consider with paediatric fractures? (5)
Pattern
Anatomy
Intra/Extra-articular Displacement
Salter-Harris
What does the pattern of the fracture reflect?
reflects the way the energy is dissipated
What are the types of patterns in fracture?
comminuted= high E, more than 1 part fractured
What should you consider with anatomy and fractures?
where on the bone the fracture is
What are the 2 methods of bone healing?
primary and secondary bone healing
Which method of healing is prefered for intra-articular fractures?
primary bone healing is the preferred healing pathway in intra-articular fracture as minimises risk of post traumatic arthritis
What is primary bone healing?
heals by direct union
no callus formation
What is secondary bone healing?
bone healing by callus
*but remember…
- if the fracture affects the physis it affects growth
What are the steps of secondary bone healing?
- haematoma formation
- fibrocartilaginous callus formation
- bony callus formation
- bone remodelling
What are the types of displacements in fractures? (4)
*remodelling potential gives more allowance for displacement for children
*rotated is not well tolerated
*can be multiple at the same time
How are physeal injuries classified?
Salter Harris
How does Salter Harris classify physeal injuries?
Classification of physeal injuries (SALT)
- Physeal Separation
- Fracture traverses physis and exits metaphysis (Above)
- Fracture traverses physis and exits epiphysis (Lower)
- Fracture passes Through epiphysis, physis, metaphysis
- Crush injury to physis
Risk of growth arrest increases from 1 -5
Which type of physeal injury is most common and least common?
2 most common
5 least common
What do injuries to the physis possibly lead to?
growth arrest
What is key in growth arrest>
the location and timing
how much potential growth is affects
diff parts of the skeleton grow at diff rates
What are the types of physeal injuries? (2)
Whole physis – limb length discrepancy
Partial – angulation as the non affected side keeps growing
What are the aims of treatment for growth arrest?
Aim is to correct the deformity
Minimise angular deformity
Minimise limb length difference
How can you treat limb length?
shorten the longer side or lengthen the shorter side
How can you treat angular deformity?
stop the growth of the unaffected side
or
reform the bone (osteotomy)
What are the 4 Rs for fracture management?
Resuscitate Reduce Restrict Rehabilitate
What does it mean by reduce, for fracture management?
Correct the deformity and displacement
Reduce secondary injury to soft tissue / NV structures
What are the 2 types of reduction?
closed and open
What is a closed reduction?
Reducing a fracture without making an incision
Such as traction and manipulation in A&E
What is an open reduction?
Making an incision
The realignment of the fracture under direct visualisation
Give an example of closed reduction.
gallows traction
- commonly used for long bone fractures
holding the skin, the long bones of the lower limb can be reduced
What is restriction for?
Maintain the fracture reduction
Provides the stability for the fracture to heal
What do children rarely have issues with when it comes to bone fractures? And what can they have issues with?
with bone not healing
- however can have issues with too much healing
What are the 2 broad categories of restriction?
external and internal
What are examples of external and internal restriction? (2 each)
What type of restriction is commonly used in paeds? And why?
external
plasters and splints
Remodeling and huge healing potential means that operative internal fixation often can be avoided
What do you do when operative intervention may be required for restriction?
Do you have to rehabilitate children?
Children generally rehabilitate very quickly
Play is a great rehabilitator
Stiffness not as major issue as in adults
Use it, Move it and Strengthen!
Is operation more or less likely in children?
less as children have quicker healing
What are causes of the limping child? (4)
Septic Arthritis
Transient Synovitis
Perthes
SUFE
What is septic arthritis? And what is so important about it?
presence of infection in intra-articular space
child orthopaedic emergency
- can cause irreversible long term problems in the joint (therefore needs surgical washing of the joint to clear the infection)
What is the score used to find out the probability of a child having septic arthritis, and what is in it?
Kocher’s classification
- Non weight bearing
- ESR >40
- WBC >12,000
- Temperature >38
What is the diagnosis if septic arthritis has been excluded?
Transient synovitis is a diagnosis once septic arthritis has been excluded
Is a inflamed joint in response to a systemic illness
Supportive treatment with antibiotics is the treatment
What is key in septic arthritis? (3)
the history…
- duration
- other recent illness
- associated joint pain
What is Perthes disease?
Idiopathic necrosis of the proximal femoral epiphysis
With who is perthes disease most common?
usually in those 4-8
male 4:1
What must be done before diagnosis of Perthes and what is the treatment?
Septic arthritis needs to be excluded first
Treatment is usually supportive in the first instance
- once diagnosed they are referred to a specialist
What would you not expect to see in Perthes, that you would see in septic arthritis?
raised temp and inflamm markers
What is SUFE?
Slipped upper femoral epiphysis
The proximal epiphysis slips in
relation to the metaphysis
In who is SUFE most common in?
Usually obese adolescent male
- 12-13 years old during rapid growth
What is the treatment for SUFE?
Treatment is operative fixation to prevent further slip and minimise long term growth problems
- Septic arthritis needs to be excluded
first
