Fractures and bone healing Flashcards
At what age are fractures most common
Men: <45
Women: >45
What type of fracture is most common if aged <70
Colles
What type of fracture is most common if aged >70
Hip
What is a closed fracture vs open
Closed- bone fragments don’t pierce the skin
Open- they do
What is a transverse fracture
- A fracture where the fracture line is perpendicular to the shaft of the bone
- Usually caysed by direct applied force to fracture site
What is a spiral fracture
aka oblique
Caused by violence transmitted through limb from a distance such as twisting
What is a compression factor
Fracture in cancellous bone as result of compression
What changes to the trabecular bone occur during ages 30-80
Elasticity of trabecular bone <64%
Strength decrease by 68
Toughness by 70
What is a burst fracture
Compression of the vertebrae
Where are burst fractures most common
Thoracic-lumbar junction
What is an avulsion fracture
Fracture that occurs where tendon/ ligament attaches to bone
Bony fragment usually torn off by tendon/ ligament
What is fracture dislocation/ subluxation
Fracture involving a joint which results in mal-alignment of joint surfaces
What is an impacted fracture
Bone fragments impacted into each other
What is a comminuted fracture
2 or bone pieces involved
High energy trauma
What is a stress fracture
Abnormal stress on normal bone (fatigue)
Normal stress on abnormal bone (insufficiency)
What is a torus fracture
Occurs in softer bones
Axial loading causing trabecular compression causing one side of the bone to buckle and the cortex heals
What is a greenstick fracture
Children
Bones soft and bend without fracturing completely
What complications may arise from a epiphyseal growth plate fracture
Interference with growth
What is the first stage of bone healing
Fracture haematoma
Blood from broken vessels forms a clot
Swelling and inflammation to dead bone cells at fracture site
What is the time scale for formation of fracture haematoma
6-8 hours post injury
What is a fracture haematoma characterised by
Hypoxia
Low ph
Pro-inflammatory and anti-inflammatory cytokines with inflammatory cells from peripheral cells
What happens during the initial inflammation phase of bone healing
Immune cells rapidly recruited
Neutrophils first, then macrophages then lymphocytes
What is the second stage of bone formation
Fibrocartilaginous callus
What happens during the formation of a fibrocartilaginous callus
New capillaries organise fracture hamatoma into granulation tissue called procallus
Fibroblasts and osteogenic cells invade procallus
Make collagen fibres which connect ends together
Chondroblasts begin to produce fibrocartilage
When is fibrocartilaginous callus formed until
3 weeks
What happenes during soft callus formation
- inflammatory cells
- organisation and resorption of clot
- fibroblass enter and differentiate as chondrocytes
- chondrocytes produce collagen that bridgets fracture site cartilage and trabecular bone laid down
When does bony callus happen
3 weeks-3/4 months
What happens in bony callus formation
Osteoblasts make woven bone
How does bone remodelling work
- Osteoclasts remodel woven into compact and trabecular bone
- Often no trace of fracture line
Consequences of fracturing epiphyseal growth plate
Interference with growth
Describe stage 1 of bone healing
Fracture hematoma
- blood from broken vessels forms a clot
- Swelling and inflammation to dead bone cells at fracture site
How long does stage 1 of bone healing take to happen
6-8 hours post injury
