🩻MSK🩻 - Children's Orthopaedics Flashcards
What is important to note about the paediatric skeleton?
NOT a miniaturised version of an adult
Has 270 bones and is a system that is in continuous change
What are the physes?
A physis is a growth plate
The area from which long bone growth occurs post-natally
Outline bone development for flat bones
Intramembranous ossification
Mesenchymal cells -> bone
Outline bone development for long bones?
Endochondral ossifications
Mesenchymal cells -> cartilage -> bone
What type of bone growth do cranial bones and the clavicle follow?
Intramembranous ossification
What are mesenchymal cells?
Type of stromal stem cell that can differentiate into various connective tissue cells like bone, cartilage, and fat
What is the first step of intramembranous ossification?
Condensation of mesenchymal cells
Differentiate into osteoblasts
Ossification centre forms
What occurs in intramembranous ossification after formation of the ossification centre?
Secreted osteoid traps osteoblasts
Trapped osteoblasts become osteocytes
Some osteoblasts further differentiate into osteoclasts
What occurs after the formation of osteocytes in intramembranous ossification?
Trabecular matrix forms
Mesenchyme forms the periosteum
Angiogenesis - blood vessels incorporated between the woven bonetrabeculae
What occurs after trabecular matrix and periosteum formation in intramembranous ossification?
Compact bone develops superficially to cancellous bone
Crowded blood vessels condense to form red bone marrow
Where does long bone formation take place?
At primary and secondary ossification centres
What are primary ossification centres?
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 Long bones often have several (the physes)
What are the first steps in primary/pre-natal endochondral ossification?
Mesenchymal differentiation at the primary centre
Cartilage model of the future bony skeleton forms
Capillaries penetrate cartilage
-Calcification at the primary ossification centre – spongy bone forms
Perichondrium transforms into periosteum
What occurs after capillaries penetrate the cartilage and the periosteum forms in primary/pre-natal endochondral ossification?
Cartilage and chondrocytes continue to grow at ends of the bone
Secondary ossification centres develop with its own blood vessel and calcification at the proximal and distal end – calcification of the matrix
Cartilage remains at epiphyseal (growth) plate and at joint surface as articular cartilage.
Where does secondary ossification occur?
The physis (physeal plate)
What is the physis?
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 is the significance of the physis in children?
Responsible for the skeletal growth of a child
Congenital malfunction or acquired insult to this area (traumatic, infective or otherwise) will have a subsequent impact of the growth of that child
How are children’s bones structurally and mechanically different to adult bones?
Children’s bones can bend
Increased density of Haversian canals in children - more porous bone than adults
Leads to more elastic bones than adults
Due to the nature of their bones, what injuries can children sustain to their bones that adults cannot?
Buckle fracture - tarus, like the column
Plastic deformity - bends before breaking
Greenstick - like a tree, one cortex fractures but doesn’t break the other side
How does growth at the physis change throughout life?
Growth occurs at varying rates at varying sites
Growth stops as the physis closes
Gradual physeal closure, Puberty, Menarche, Parental height
Complete at:
Girls 15-16
Boys 18-19
What can physeal injuries lead to?
Growth arrest
Growth arrest can lead to deformity
Which physes have the most growth?
Physis at extremes of upper limb (wrist and shoulder) grow more
Physis at the knee grows most of all
What are the common children’s congenital conditions (in the context of paediatric orthopaedics?
Developmental dysplasia of the hip
Club foot
Achondroplasia
Osteogenesis imperfecta
What is developmental dysplasia of the hip?
Group of disorders of the neonatal hip where the head of the femur is unstable or incongruous in relation to the acetabulum (socket for femur in the pelvis)
The normal development relies on the concentric reduction and balanced forces through the hip
Spectrum with dysplasia – subluxation – dislocation
What are the risk factors for developmental dysplasia of the hip?
Female 6:1
First born
Breech
FH
Oligohydramnios (having less amniotic fluid)
Native American/Laplanders – swaddling of hip
Rare in African/Asian
How is DDH picked up?
Usually picked up on baby check - screening in UK
Range of motion of hip - usually limitation in hip abduction, leg length (Galeazzi)
3 months or older - Barlow and Ortalani tests are non-sensitive (maneuvers used to test for hip instability/dislocation)
What investigation can be used to find DDH?
Ultrasound - birth to 4 moths
After 4 months - X-ray
Measures acetabular dysplasia and the position of hip
What is the treatment for DDH?
Reducible hip and <6months - Pavlik Harness 92% effective
When would a Pavlik harness not be suitable for DDH, and what is the alternative?
Failed Pavlik Harness or 6-18 months
Secondary changes- capsule + soft tissue
MUA + Closed reduction and Spica
What is clubfoot?
Congenital Talipes Equinovarus
Congenital deformity of the foot
1:1000
Highest in Hawaiians
Males 2:1
50% bilateral
Genetic component - PITX1 gene
What deformity is seen in clubfoot?
CAVE deformity due to muscle contracture
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
1. First a series of casts to correct deformity
2. Many require operative treatment
Soft tissue releases
3. Foot orthosis brace
4. Some will require further operative intervention to correct final deformity.
What is achondroplasia?
Most common skeletal dysplasia
Rhizomelic dwarfism
-Humerus shorter than forearm
-Femur shorter than tibia
-Normal trunk
-Adult height of approx. 125cm
Normal cognitive development
Significant spinal issues
Outline the pathophysiology behind achondroplasia
Autosomal Dominant
-G380 mutation ofFGFR3
-inhibition of chondrocyte proliferation in theproliferative zoneof thephysis
-results in defect in endochondral bone formation
What is osteogenesis imperfecta?
Brittle bone disease
Fragile bones due to insufficient osteoid production
How does the insufficient osteoid production occur in osteogenesis imperfecta?
Hereditary – autosomal dominant or recessive
-Decreased Type I Collagen due to:
-Decreased secretion
-Production of abnormal collagen
Leads to insufficient osteoid production
What effects does insufficient osteoid production have in osteogenesis imperfecta?
Bone malformation and fragility
Fragility fractures
Short stature
Scoliosis
What are the non-orthopaedic manifestations of osteogenesis imperfecta?
Increased risk of cardiovascular issues
Blue Sclera
Dentinogenesis imperfecta – brown soft teeth
Wormian skull
Hypermetabolism
What are the standard fracture patterns, and the additional ones only experienced by children?
Transverse
Oblique
Spiral
Comminuted - 3+ pieces
Avulsion - tendon or ligament pulls away a piece of bone
Children specific:
Plastic deformity
Greenstick
Buckle fracture
What are the anatomical categorisations of fractures?
What are the two types of bone healing?
How are fractures categorised by displacement?
How are physeal injuries classified?
Salter Harris scale
Risk of growth arrest increases from 1-5
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
Type 2 is the most common
How can growth arrest manifest?
Injuries to the physis can cause growth arrest
Location and timing is key
Whole physis - limb length discrepancy
Partial - angulations as the non-affected side continues to grow
What are the treatment goals for growth arrest?
Minimise angular deformity - Stop the growth of the unaffected side, reform the bone (osteotomy)
Minimise limb length difference - shorten the long side, lengthen the short side
What are “The 4 Rs” of fracture managements?
Resuscitate
Reduce
Restrict
Rehabilitate
What is “resuscitate”?
Initial step
Ensure patient is stable, DR ABC
What is “reduce”?
Correct the deformity and displacement
Reduce secondary issue to soft tissue / NV structures
What are the 2 types of reduction?
Closed
Reducing a fracture without making an incision
Such as traction and manipulation in A&E
Open
Making an incision
The realignment of the fracture under direct visualisation
Give a technique for closed reduction?
What is “restrict”?
Maintain the fracture reduction
Provides the stability for the fracture to heal
Children rarely have issues with bone not healing
(Can have issues with too much healing!)
But remember the child’s quicker fracture healing times and remodelling potential
What are the different forms of restriction?
What methods of restriction are commonly used in paediatric fracture?
Plasters and splints
Remodelling and huge healing potential means that operative internal fixation often can be avoided
Outline “rehabilitate” in the context of paediatric fractures?
Children generally rehabilitate very quickly
Play is a great rehabilitator
Stiffness not as major issue as in adults
Use it, Move it and Strengthen!
What are the causes of “the limping child”?
Septic arthritis (MOST IMPORTANT - AIM TO RULE OUT IMMEDIATELY)
Transient synovitis
Perthes
SUFE
Why is it so important to rule out septic arthritis in children presenting with a limp?
Septic arthritis in a child is a orthopaedic emergency!
Can cause irreversible long term problems in the joint - needs surgical washout of the joint
How can septic arthritis be diagnosed?
Kocher’s classification can help score probability
-Non weight bearing
-ESR >40
-WBC >12,000
-Temperature >38
The history is key
-Duration
-Other recent illness
-Associated joint pain
What is the treatment for septic arthritis?
Joint washout/lavage
IV Abx
What is transient synovitis?
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 Perthes disease?
Idiopathic necrosis of the proximal femoral epiphysis
Usually in those 4-8 years old
Male 4:1
Septic arthritis needs to be excluded first
Treatment is usually supportive in the first instance
Significant affect on QoL, comparable to childhood cancer
What is SUFE?
Slipped upper femoral epiphysis
The proximal epiphysis slips in relation to the metaphysis
Usually obese adolescent male
-12-13 years old during rapid growth
Septic arthritis needs to be excluded first
Treatment is operative fixation to prevent further slip and minimise long term growth problems
