Trauma Flashcards
Are the majority of fractures due to direct or indirect trauma?
indirect e.g. twisting/bending forces
What is primary bone healing?
There is a minimal fracture gap, and bone simply bridges gap with new bone from osteoblasts
When does primary bone healing occur?
healing of hairline fractures
when fractures are fixed with compression screws and plates
What is secondary bone healing?
there is a gap at the fracture site, needs to be filled temporarily to act as scaffold for new bone
What does secondary bone healing involve?
inflammatory response with recruitment of pluropotential stem cells, which differentiate into different cells during healing process
Describe the process of secondary bone healing.
- fracture occurs
- haematoma with inflammation
- macrophages and osteoclasts remove debris and resorb bone ends
- granulation tissue forms from fibroblasts and new vessels
- chrondroblasts form cartilage
- osteoblasts lay down bone matrix (collagen type 1 - endorchondral ossification)
- calcium mineralization produces immature woven bone (hard callus)
- remodeling occurs with organization along lines of stress into lamellar bone
Give the 4 main steps of secondary bone healing.
inflammation
soft callus
hard callus
remodelling
When is the soft callus usually formed?
by 2nd to 3rd week
When is hard callus usually formed??
6-12 weeks
What may result in atrophic non union?
lack of blood supply, no movement e.g. internal fixation with fracture gap, too big a fracture gap or tissue trapped in gap
What can smoking do to fracture healing?
severely impair it due to vasospasm
Why do hypertrophis non unions occur?
too much movement
List the 5 basic fracture patterns.
transverse, oblique, spiral, comminuted, segmental
Describe transverse fractures.
pure bending force causes one side to fail in compression and the other to fail in tension
Describe oblique fractures.
shearing force e.g. fall from height causes oblique fracture pattern
What are oblique fractures able to be fixed with?
interfragmentary screw
Do oblique fractures tend to shorten~??
yes
Describe spiral fractures.
occur due to torsional forces (twisting)
What are communuted fractures?
fractures with 3 or more fragments
suggests higher energy injury, very unstable
What is a segmental fracture?
bone is fracture in two different places. very unstable - need rods or plates
What is displacement?
direction of translation of distal fragment (e.g. can be anteriorly or posteriorly displaced and medially or laterally displaced)
What does angulation describe?
direction which the distal fragment points towards
What is different about children’s fractures?
periosteum in children is much thicker, tends to remain intact
Fractures heal more quickly
Can remodel more easily
Tend to buckle/partially fracture or splinter
At what age does a child’s fractures tend to be treated as an adult’s?
12-14 start of puberty