Childrens Orthopaedics Flashcards
What is the paediatric skeleton?
the paediatric skeleton and musculoskeletal system is NOT a miniaturised version of an adult
How many bones are in a child’s skeleton?
- 270 bones
- a system that is in continuous change
What are the physis?
- (growth plates) are the areas from which long bone growth occurs post-natally
- Most long bones have 2 physis one proximally and one distally
What are the 2 types of bone development?
- Intramembranous
2. Endochondral
What is intramembranous bone development?
- mesenchymal cells -> bone
- flat bones
What is endochondral bone development?
- mesenchymal -> carilgae -> bone
- long bones
What is intramembranous ossification?
- Condensation of mesenchymal cells which differentiate into osteoblasts – 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
When does intramembranous ossification happen?
-Development of Flat Bones -cranium and clavicle
Where does long bone formation happen?
the 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
- middle ofdiaphysis of the bone - prenatal
What are secondary ossification centres?
Occurs post-natal after the primary ossification centre and long bones often have several (the physis)
What happens to the tissue during endochondral ossifcation?
the tissue that will become bone is firstly formed from cartilage
What are the stages of endochrondral primary ossifcation?
- Mesenchymal Differentiation at the primary centre
- The cartilage model of the future bony skeleton forms
- Capillaries penetrate cartilage
- 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
What happens at secondary ossification centres?
- Post bone growth through Secondary ossification centres
“The Physis’ - Long bone lengthening
Where does long bone lengthening happen?
at the physis (physeal plate)
What is the physis?
- Zone of elongation in long bone
* Contains cartilage
What happens at the epiphyseal side?
hyaline cartilage active and dividing to form hyaline cartilage matrix
What happens at the disphyseal side?
Cartilage calcifies and dies and then replaced by bone
What can children bones do?
-Children’s bone can bend – more elastic than adult
•Increased density of haversian canals
What does this elasticity mean?
- Plastic deformity
- Buckle fracture
- Greenstick
What is plastic deformity?
bends before breaks
What is buckle fracture?
Tarus like the column
What is a greenstick fracture?
- like the tree
- One cortex fractures but does not break the other side
How does growth vary?
- Growth occurs at varying rates at varying sites
- Growth stops as the physis closes
- Gradual Physeal closure, Puberty, Menarche, Parental height
When does physis closure complete for girls?
15-16
When does physis closure complete for boys?
18-19
How are physeal injuries categorised?
by Salter-Harris
What can physeal injuries lead to?
growth arrest
What can growth arrest lead to?
deformity
What is the speed of healing and remodelling potential dependent on?
- The speed of healing and remodeling potential is dependent on the location and the age of the patient
- Younger child heals more quickly
Which physis grow more?
- Physis at the knee grows more
* Physis at extreme of upper limb grows more
What are some commin children’s congenital conditions?
- Developmental dysplasia of the hip
- Club foot
- Achondroplasia
- Osteogenesis imperfecta
What is developmental dysplasia of the hip?
- 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’ (IN UTERO)
- The normal development relies on the concentric reduction and balanced forces through the hip
What is the spectrum with dysplasia?
- Spectrum with dysplasia – subluxation – dislocation
- Dysplasia 2: 100 Dislocation 2:1000
- progressive
What are the risk factors in developmental dysplasia of the hip?
- Female 6:1
- First born
- Breech
- FH
- Oligohydramnios
- Native American/Laplanders – swaddling of hip
- Rare in African American/Asian
What is the examination for developmental dysplasia of the hip?
-Usually picked up on baby check – screening in UK
1. RoM of hip
•Usually limitation in hip abduction
•Leg length (Galeazzi)
2. In those 3 months or older Barlow and Ortalani are non-sensitive
What is the investigation 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 if there is reducible hip and <6 months?
Pavlik harness 92% effective
What is the treatment for developmental dysplasia of the hip if failed Pavlik Harness or 6-18 months?
- Secondary changes- capsule + soft tissue
2. MUA + Closed reduction and Spica
What is congenital talipes equinovarus?
- Congenital deformity of the foot (clubfoot)
1. 1:1000
2. Highest in Hawaiians
3. M2:1F
4. 50% are bilateral
What are the causes of congenital talipes equinovarus?
- Genetic
- Approx. 5% likely of siblings
- Familial in 25%
- PITX1 gene
What is the 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
What is the ponseti method?
Gold standard
- First a series of casts to correct deformity
- Many require operative treatment
- Soft tissue releases - Foot orthosis brace
- Some will require further operative intervention to correct final deformity
What is achondroplasia?
- The most common skeletal dysplasia
- Autosomal Dominant
What is the cause of achondroplasia?
- G380 mutation ofFGFR3
- inhibition of chondrocyte proliferation in theproliferative zoneof thephysis
- results in defect in endochondral bone formation
What are the symptoms of rhyzomelic 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
What are the causes of osteogenesis imperfecta?
Hereditary – autosomal dominant or recessive
Why is there decreased type 1 collage in osteogenesis imperfecta?
•Decreased secretion
•Production of abnormal collagen
-leads to Insufficient osteoid production
What are the effects of osteogenesis imperfecta on the bones?
- Fragility fractures
- Short stature
- Scoliosis
What are the non-orthopeadic manifestations of osteogenesis imperfecta
•Heart •Blue Sclera •Dentinogenesis imperfecta – brown soft teeth •Wormian skull -hypermetabolism
How does a children’s skeleton differ to that of an adult?
- Elasticity
- Physis
- Speed of healing
- Remodelling
