Fractures Flashcards
Before 75 years, which fracture is most common? [1]
After 75 years, which fracture is most common? [1]
Before 75: wrist fracture (colle’s or colles like)
After 75: Hip fractures
Difference between open / closed fracture? [1]
Displacced v undisplaced? [1]
Closed: bone fragments do not pierce skin
Open/compound: do pierce skin
Displaced: not in anatomical position
Compression force is most likely to cause what type of fracture? [1]
Impacted fracture
Transverse fracture is usually caused by what type of force? [1]
Usually caused by directly applied force to fracture site (e.g. object dropped on you)
Name two places that have retrograde blood supply
Scaphoid
Head of femur
What happen to blood spply if fracture scaphoid in waist? [1]
Waist: becomes avasuclar and dies
what type of force cause a spiral or oblique fracture? [1]
Caused by violence transmitted through limb from a distance (twisting movements)
Can create sharp edges that lacerate tissue / vasculature
Which disease increases the likilihood of crush / compression fractures? [1]
osteoporosis
Which type of bone is compressed in a crush injury? [1]
Where in the body do these occur? [1]
A compression fracture is a type of broken bone that can cause your vertebrae to collapse, making them shorter.
Cancellous / trabeculae bone
How does a burst fracture occur? [1]
E.g. if jump of a building
Occurs in short bones e.g. vertebra from strong direct pressure such as impaction of disc
Force transmitted from lower limb into vertebral column
Burst fractures are most common in which vert layers? [2]
Why are burst fractures so problematic? [1]
Most common at thoracic/lumbar junction
Broken bone can impinge vertebral column and damage spinal cord
Burst fractures are most common in which vert layers? [2]
Why are burst fractures so problematic? [1]
Most common at thoracic/lumbar junction
Broken bone can impinge vertebral column and damage spinal cord
What type of force causes an avulsion fracture? [1]
What are avulsion fractures characterised by? [1]
Avulsion fracture: caused by traction; when a piece of bone attached to a tendon or ligament gets pulled away from the main part of the bone.
Describe charactersitics of a fracture dislocation/subluxation [1]
Fracture involves a joint: results in mal-alignment of joint surfaces
A complete dislocation happens when the bones in your joint are totally separated and pushed out of place
A colles fracture is what type of fracture? [1]
Impacted
Describe the characteristics of an impacted fracture [1]
Bone fragments are impacted (forced, pushed) into each other
What are characteristics of a comminuted fracture [2]
Two or more bone pieces - high energy trauma
What are characteristics of a stress fracture [2]
Abnormal stress on normal bone (fatigue fracture - e.g. too much walking)
OR
Normal stress on abnormal bone (insufficiency fracture) - e..g Pagets disease
Stress fractures are difficult to assess on an x-ray. State 3 other imaging techniques used to assess a stress fracture [3]
Bone scintigraphy becomes positive at same time or sooner than plain films
Low false positive
CT and MRI scans
Describe characteristics of torus fracture [2]
In children
Children have lots of woven bone
Axial loading causing trabecular compression; bulging of the cortex
Incomplete fractures of the shaft of a long bone that is characterised by bulging of the cortex. They result from trabecular compression due to an axial loading force along the long axis of the bone
Describe characteristics of greenstick fracture [2]
Occurs in children: bones soft and bend without fracturing completely
Salter-Harris fractures are used to classify which type of fractures? [1]
Fractures of the epiphyseal growth plate
Why are fractures of the epiphyseal growth plate problematic? [1]
Can cause growth plate to ossify early; particularly bad if have two bones in parralel (e.g. tibia and fibula)
Describe the mechanism of bone healing after a fracture [5]
Fracture hematoma:
* Blood from broken vessels forms a clot 6-8 hours after injury
* Creates hypoxia; low pH
* Dead cells present cause pro-inflam cytokines
* Swelling
Fibrocartilaginous callus
* Angiogensis occurs (due to previous hypoxia)
* Fibroblasts and osteogenic precursors invade procallus
* Chondroblasts makes fibrocartilage
Inflammatory, granulation and soft callus
* Organisation and resorption of clot as new capillaries form
* Fibroblasts enter and differentiate as chondrocytes
* Chondrocytes produce collagen that bridges fracture site cartilage and trabecular bone laid down
Bony callus
* osteoblasts make woven bone
* Excess bone can form and create a bridge or a pseudo-arthrosis especially in the foot
Bone remodelling
* Osteoclasts remodel woven bone into compact bone and trabecular bone
* Often no trace of fracture line on X-rays.
State what is represented by blue, the dot and the hashtage in this bone remodelling
= remodelling
Blue = calcified cartilage
dot = woven bone
hashtag = remodelling
