Children's Orthopaedics Flashcards
Is a child’s skeleton the same as an adults?
No, it is not just a mini skeleton it is structurally different
How many bones are there in a child’s skeleton?
270
What is the other name for physis?
Growth plates
What happens at the physis?
Bone growth, it is the zone of elongation
By what process do flat bones develop?
Intramembranous ossification
By what process do long bones develop?
Endochondral ossification
What is the difference between intramembranous and endochondral ossification and when is each used?
With endochondral ossification the mesenchymal cells become cartilage before they become bone but in intramembranous there is no cartilage involvement
Endochondral= long bone development Intramembranous= flat bone development
Describe intramembranous ossification
Condensation of mesenchymal cells which differentiate into osteoblasts and an ossification centre forms
Secreted osteoid traps osteoblasts which become osteocytes
Trabecular matrix and periosteum form
Compact bone develops superficial to cancellous bone.
Crowded blood vessels condense into red bone marrow
Where does endochondral ossification occur
Occurs at both the primary and secondary ossification centres
What happens at primary ossification centres in endochondral ossification
Sites of pre-natal bone growth from the central part of the bone
What happens at secondary ossification centres in endochondral ossification
Post-natal growth after the primary ossification center and long bones often have several (the physis)
Describe the process of endochondral primary ossification
There is mesenchymal differentiation at the primary centre
The cartilage model of the future bony skeleton forms
Capillaries penetrate cartilage.
There is calcification at the primary ossification centre – spongy bone forms. Perichondrium transforms into periosteum
Cartilage and chondrocytes continue to grow at ends of the bone
Secondary ossification centres develop
Describe the process of endochondral secondary ossification
Long bone lengthening
Where does secondary endochondral ossification occur?
At the physis
What happens on the epihyseal side of the physis?
Hyaline cartilage is active and dividing to form hyaline cartilage matrix
What happens on the diaphyseal side of the physis?
Cartilage calcifies and dies and then replaced by bone
How does elasticity differ between children and adult bone?
Children’s bone can bend and are more elastic than adult
This is due to increased density of haversian canals
What is plastic deformity and why is it common in children?
When the bone bends before it breaks
It is common as children have more elastic bones
What is Buckle fracture and why is it common in children?
It is an incomplete fracture (aka torus fracture) where one side of the bone buckles in on itself but the other side is fine. It is more common in children as their bones are more elastic
What is greenstick fracture and why is it common in children?
When side of the bone bends and the other side snaps (like a twig), more common in children as they have more elastic bones
When does bone growth in children stop?
When the physis close
What factors affect when a child’s physes close?
Puberty
Menarche
Parental height
When does an average girl’s and boy’s physis close?
Girls=15-16
Boys=18-19
Why are physeal fractures more serious?
They can lead to growth arrest
How does speed and remodelling in children’s bones differ to adults?
It a lot faster and children can undergo a lot more deformity and angulation in comparison to adults
What is developmental dysplasia of the hip? When does it occur?
Group of disorders of the neonatal hip where the head of the femur is unstable or incongruous in relation to the acetabulum, occurs in utero.
What does normal hip development require that is disrupted in developmental dysplasia of the hip?
Concentric reduction and balanced forces through the hip
What are the types of developmental dysplasia of the hip? What kind is the most common?
Dysplasia (this is the most common)
Sublaxation
Dislocation
What are some risk factors for developmental dysplasia of the hip?
Female First born FH Breech Native americans/laplanders (due to habit of swaddling hip) Oligohydroamnios
How is developmental dysplasia of the hip usually picked up?
Baby check (there is screening in the UK)
How is developmental dysplasia of the hip treated?
Reducible hip and < 6months= pavlik harness
Failed harness or 6-18 months= MUA, closed hip reduction and spica
What is club foot? When does it occur?
Congenital deformity of the foot that occurs in utero
What population is club foot most common in?
Hawaiians
What gender is club foot more common in?
Twice as common in men as in women
Is club foot genetic?
Yes, 50% genetic
What gene is involved in risk for club foot?
PITX1
What pneumonic is used to identify club foot?
CAVE Cavus foot with high arch Adductus of foot Varus Eqinous
How is club foot treated?
Ponseti method which is a primary series of casts to correct the deformity then surgery if needed later
What is achondroplasia?
The most common skeletal dysplasia
What is the pattern of inheritance for achondroplasia?
Autosomal dominant
What gene is involved in achondroplasia?
G380 mutation of FGFR3
Briefly describe the pathophysiology of achondroplasia
There is inhibition of chondrocyte proliferation in the proliferative zone of the physis
This results in defects in endochondral bone formation
What results from achondroplasia?
Rhizomelic dwarfism
What are the characteristics of rhizomelic dwarfism in those with achondroplasia?
Humerus shorter than forearm Femur shorter than tibia Normal trunk Adult height of approx. 125cm Significant spinal issues
What is osteogenesis imperfecta?
Brittle bone disease
How is osteogenesis imperfecta inherited?
Autosomal dominant or recessive
What type of collagen is reduced in osteogenesis imperfecta? Why?
Type 1 because there is decreased secretion and production of abnormal collagen
What happens to osteoid production in osteogenesis imperfecta?
It is insufficient
What are the effects on bone of osteogenesis imperfecta?
Fragility fractures
Short stature
Scoliosis
What are non orthopaedic manifestations of osteogenesis imperfecta?
Heart problems Blue sclera Dentinogenesis imperfecta – brown soft teeth Wormian skull Hypermetabolism
What pneumonic is used to describe fractures?
PAID Pattern Anatomy Intra/extra articular Displacement
What are the different fracture patterns?
Transverse Oblique Spiral Comminuted Avulsion Torus Greenstick
What are the different anatomy catagories when describing fractures?
Proximal, middle or distal 1/3rd of the bone
What are the different fracture displacements?
Displaced
Angular
Shortened
Rotated
What classification method is used for physeal fracture?
Salter Harris
What pneumonic is associated with the Salter Harris classfication and what does it stand for?
SALT
Physeal Separation
Fracture traverses physis and exits metaphysis (Above)= most common
Fracture traverses physis and exits epiphysis (Lower)
Fracture passes Through epiphysis, physis, metaphysis
Crush injury to physis
Going down the SALT pneumonic for Salter Harris classification what happens to risk of growth arrest?
Risk of growth arrest
What happens if the whole physis is affected in a fracture?
There is limb length discrepancy
What happens if only part of the physis is affected in a fracture?
Angulation as the non-affected side keeps growing
What are the 2 aims in treating fracture affecting the physis?
Minimise angular deformity
Minimise limb length difference
How can limb length be corrected in physeal fracture?
Shorten the long side
Lengthen the short side
How can angular deformity be corrected in physeal fracture?
Stop growth on the unaffected side
Reform the bone (osteotomy)
What pneumonic/phrase is used in fracture management?
Resuscitate
Reduce
Restrict
Rehabilitate
What common method of closed reduction is used for children?
Gallows traction which involves holding the skin so long bones of the lower limb can be reduced
What is restriction in fracture management?
Maintainence of the fracture reduction
What are external methods of fracture restriction?
Splints
Plaster
What are internal methods of fracture restriction?
Plate and screws
Intra medullary device
When operating on fracture in children what should be considered?
Ongoing growth at the physis
Metalwork that may need to be removed in the future
What is a good rehabilitator for kids in relation to fractures?
Play
What is the main differential in a limping child?
Septic arthritis
How do children with septic arthritis usually present?
Previously well
Gone off food in past 24 hrs
Doesn’t want to put weight on their knee and hip
Why must you exclude septic arthritis in a limping child?
Because its a medical emergency and can cause irreversible long-term problems in the joint
What classification can be used to help score the probability of a child have septic arthritis?
Kocher’s classification
What does Kocher’s classification for scoring probability of septic arthritis include?
Non-weight bearing
ESR >40
WBC >12,000
Temperature >38
What is transient synovitis?
An inflamed joint in response to a systemic illness
How is transient synovitis treated?
Supportive treatment with antibiotics is the treatment
What is Perthe’s disease?
Idiopathic necrosis of the proximal femoral epiphysis
How is Perthe’s disease treated?
Supportive treatment
What is SUFE?
Slipped upper femoral epiphysis where the proximal epiphysis slips in relation to the metaphysis
Who does SUFE mainly affect?
Usually obese adolescent male
What conditions is SUFE associated with?
Hypothyroidism and hypopituitrism
How is SUFE treated?
Operative fixation with screw to prevent further slip and minimise long term growth problems
What are the differentials in a limping child?
Septic arthritis
Transient synovitis
SUFE
Perthe’s disease
