Children's Orthopaedics Flashcards
Child skeleton vs adult skeleton bone no.
270 bones
subject to continuous change
What is the physis
Growth plates
Areas in which long bone growth occurs post-nataly
located at the proximal/distal ends
What are the two types of bones in the body?
Flat bones and Long bones
What is the process of forming flat bones called?
Intramembranous Ossification
e.g. clavicle + cranium
What is the process of forming long bones called?
Endochondral Ossification
Describe the process of intramembranous ossification
Mesenchymal (stem) cells condense and differentiate to osteoblasts.
Secreted osteoid (ECM) traps osteoblasts forming osteocytes. (calcify osteoid)
Trabecular matrix and periosteum forms
Compact bone forms superficial to cancellous bone
Angiogenesis - vessels form red bone marrow
Describe the process of endochondral ossification
Hyaline cartilage laid down
Bone forms w/in it at the centre -> 1º ossification centre
Pushes cartilage to the ends of the bone -> 2º
What are the primary ossification centres in endochondral ossification?
Pre-natal bone growth from the centre part of bone
What are the secondary ossification centres in endochondral ossification?
Post-natal - physis (physeal plate)
Lengthens long bones
Describe bone growth at 1º ossification centres
(endochondral)
Mesenchymal differentiation into chondrocytes
Cartilage model forms
capillaries penetrate cartilage, calcification occurs at the 1º causing the formation of spongey bone
perichondrium -> periosteum
cartilage and chondrocytes grow at end of bone
Describe bone growth at 2º ossification centres
(endochondral)
Zone of elongation containing cartilage
Epiphyseal side: Active cartilage division to form matrix
Diaphyseal side: Cartilage calcifies and is replaced by bone
What type of growth occurs at the physis?
Interstitial growth (long bone lengthening)
How does a child’s skeleton differ to that of an adult
- More elastic
- Active physis, constantly growing and developing
- Increased speed of healing
- Greater opportunity for bone remodelling
Why are children’s bones less dense than adults?
More haversian canals in children - more porous and decreased bone density
Allows for increased flexibility
What is a haversian canal
Tubes containing blood vessels, nerves and lymphatics
Why do children have more haversian canals
Their bone is more metabolically active as they are still growing
What three types of injuries can children’s bones get?
Plastic deformity,
buckle fracture,
greenstick fracture
Explain plastic deformity
Bones have elasticity .: bend before breaking. Unless an extreme bend, children with bent bones will usually straighten out without intervention
Explain how a buckle fracture works
Pressure on both sides of a bone, bone is not strong enough to hold pressure so buckles
Explain what a greenstick fracture is
Bones break like a tree branch - one sides tears but not all the way through
What happens to bones to stimulate growth arrest?
Physis closes
What affects when the physis closes
Puberty
Menarche
Parental height
At what age does the physis close
Girls 15-16 / Boys 18-19
What is the impact of trauma induced growth arrest
Physis injured
Lead to deformity, the uninjured area will continue ton grow
What is healing speed and remodelling potential dependent on?
The age of the child - younger child heals quicker
The location of injury
Which bony parts of the child’s body heals more quickly?
The more active areas - knees, extremes of upper limb (shoulder/wrist)
Common children’s congenital conditions
Developmental dysplasia of the hip
Club foot
Achondroplasia
Osteogenesis Imperfecta
What is developmental dysplasia of the hip
Congenital group of disorders where head of femur is unstable in relation to acetabulum (socket)
Why does hip dysplasia arise
The normal development relies on the concentric reduction and balanced forces through the hip. When this is absent it means the socket doesn’t form correctly due to lack of pressure.
What is the spectrum of symptoms of developmental dysplasia?
Dysplasia, - head of femur not placed correctly in socket
Subluxation - Hip pops in and out due to shallow socket
Dislocation - Hip develops outside of socket
What are risk factors for developmental dysplasia?
Female,
breech position
family history,
oligohydramnios - lack of amniotic fluid
some native american groups
What feature of examination can you identify developmental dysplasia?
Limited hip abduction, leg length
What treatment is there for developmental dysplasia?
Pavlik harness,
closed reduction if the harness fails
Investigations for developmental dysplasia?
Ultrasound 0-4mths
What is the technical name for club foot?
Congenital Talipes Equinovarus
congenital deformity of the foot
What acronym describes the symptoms of club foot?
CAVE -
Cavus (high arch),
Adductus of foot,
Varus (tight tendoachillies),
Equinous (same as varus)
Risk factors for club foot
Male
Hawaiian
PITX1 gene
What is the treatment for clubfoot?
Ponseti Method - series of casts,
operative treatment for soft tissue release,
foot orthosis brace
What is the most common skeletal dysplasia?
Achondroplasia (Rhizomelic dwarfism)
What genetic inheritance pattern is achondroplasia?
Autosomal dom
What is the technical name for brittle bone disease?
Osteogenesis Imperfecta
What happens in achondroplasia?
Inhibited chondrocyte proliferation in physis, defect endochondral bone formation
What molecule is decreased in OI and why?
Decreased Type 1 Collagen because of decreased secretion or abnormal production
What are the symptoms of achondroplasia?
Humerus shorter than forearm,
femur shorter than tibia,
spinal issues,
normal trunk/skull,
normal cognition
What is the relevance of the A in PAIDS?
Location of the fracture
proximal, middle (diaphysis) or distal third
Levels of displacement in the bone
Displaced
Angulated
Shortened
Rotated - not tolerated well
What structure does OI lead to an insufficiency of?
Osteoid (ECM)
OI effect on the bone
Fragile bones, short stature, scoliosis
What does it mean by intra/extra-articular?
Intra-articular fracture extends into the joints - 1º healing. Requires direct union and no callus
2º healing is by callus formation
Haematoma -> fibrocartilaginous callous -> bony callous -> remodelling
Non-orthopaedic OI effects
Blue sclera,
dentinogenesis imperfecta (brown soft teeth), hypermetabolism - PTH
cardiac abnormalities
What mneumonic do you use to assess paediatric fractures?
PAIDS -
Pattern,
Anatomy,
intra/Extra-articular,
Displacement,
Salter-Harris Classification
What are the different types of fracture patterns?
TOSCA -
Transverse,
Oblique,
Spiral, - rotational torque pattern of injury
Comminuted (multi pieces), - high energy trauma
Avulsion - bone pulled off ligament
child specific - plastic deformity, greenstick, buckle
What is the Salter Harris Staging?
Way of classifying physeal injury
Stages in Salter Harris SALTS
- physeal Separation, through the physis
- Above physis into metaphysis fracture
- beLow physis into epiphysis
- Through all of physis, metaphysis and epiphysis
- physis cruShed (growth arrest)
How does risk of growth arrest change with each salter harris stage
Risk of growth arrest increases
stage 2 is most common
What can happen if partial injury occurs to physis?
Angulation of growth - non affected keeps growing whilst affected side has arrested
What can happen if complete injury occurs to physis?
Limb length discrepancy
What are the treatment aims with growth arrest?
Fix limb length discrepancy or minimise angular deformity
How to correct limb length discrepancy
Shorten long side
Lengthen short side
How to correct an angular deformity
Stop growth of unaffected side
Reform the bone via osteotomy
What are the four Rs of fracture management?
Resuscitate,
Reduce,
Restrict,
Rehabilitate
What system do you use for resuscitation?
ATLS - Advanced Trauma Life Support
Meaning of fracture reduction
Correct deformity and displacement
types of fracture reduction
Closed - w/o incision e.g. using traction/manipulation
Open - incision, realign fracture w/ surgery
Why do we restrict fractures
provides stability for fracture to heal
Types of fracture restriction
External - Splints, plaster (more commonly used)
Internal - plates, screws, intra-medullary device (may need to remove once healed)
Why do children generally rehabilitate quicker?
Play is a good rehabilitator - testing weight bearing and movement
.: physiotherapy not usually rq
What are the four most common diagnoses for a limping child?
Septic Arthritis,
Transient Synovitis,
Perthes,
SUFE
Which of those four diagnoses is the most serious and should be investigated first?
Septic Arthritis
What is septic arthritis
infection w/in intra-articular space
Medical emergency in children
Can cause irreversible long term jt problems due to necrosis and ^ pressure due to oedema
management of septic arthritis
Surgical washout of the joint
What classification can you use to identify if it is septic arthritis?
Kocher’s Classification:
Non-weight bearing,
ESR > 40,
WBC > 12,000,
Temp > 38
Important points of history that help with classification of septic arthritis
duration - acute
recent illness
associated joint pain
What is transient synovitis?
Inflamed joint due to a systemic condition
Diagnosed once septic arthritis is excluded
How do you treat transient synovitis?
Supportive with antibiotics
What is Perthes disease?
Idiopathic necrosis of proximal femoral epiphysis
diagnosed with plain film radiograph
Who is perthes disease most common in?
Age 4-8, Male:Female 4:1
What does SUFE stand for and what does it mean?
Slipped Upper Femoral Epiphysis - proximal epiphysis slips out of place
usually during a period of rapid growth
Who is SUFE most common in?
obese adolescent (12-13) male, associated with hypothyroid/pituitary problems
What is the treatment for SUFE?
Operative fixation with a screw inbetween bone and epiphysis. Minimise further growth problems
