common fractures Flashcards
which 2 X-ray views are usually taken to ix a fracture
coronal and saggital
what is a tomogram
a view of a slice through a part of the body
what will an U/S show following a fracture
accumulation of fluid (especially blood)
describe radioisotope scanning in ix of a fracture
- radioactive substance injected into bloodstream
- the substance ends up in bones because it attaches to phosphate molecules which are actively taken up by bone
- the more metabolically active the bone is the faster it will take it up
- therefore the areas of unusual metabolic activity (the fracture sites) can be seen
when would radioisotope scanning be used?
what bone in particular is it commonly used to ix?
if there is clinical doubt about whether or not there is a fracture
scaphoid
spiral fractures - a lot or little soft tissue damage?
usually little
fractures are described in terms of the ? fragment in relation to the ? fragment
distal
proximal
describing fractures
which bone open or closed where on the bone shape (spiral, oblique, transverse) how many fragments (simple, comminuted) position of distal fragment (displacement, angulation, rotation)
describing fracture angulation
anterior, posterior, varus, valgus
traction may be used early in tx to relieve what?
muscle spasm (which is a major component of post fracture pain)
a femoral fracture will cause how much blood loss?
between 2 and 3 units
one unit is about 450ml
major pelvic fractures are associated with what type of bleeding? how much blood could be lost?
major venous bleeding from pelvic plexuses
up to 6 units may be lost
vast majority of wounds should be left open or closed?
left open (if any doubt about closure causing tension on the skin)
describe a functional brace
accurate fit so needs to be fitted after swelling and pain have settled
hinges allow joint movement in one direction
modern casting materials
glass fibre and polyurethane resin combinations
when is external fixation advantageous
high energy fractures associated with soft tissue damage where access is needed for secondary surgery/skin grafting means internal fixation is not ideal (also because of risk of ischaemia)
when is internal fixation used
where a high degree of accuracy is required or other methods fail
types of internal fixation
apposition
inter fragmentary compression
inter fragmentary compression plus onlay device
inlay device
what is used in apposition
k wires
what is usually used in inter fragmentary compression
screws
in which type of bone is inter fragmentary compression particularly valuable
cancellous bone around joints
what do onlay devices usually consist of
a plate of metal
what is worse for disruption of natural bone healing - inlay or onlay devices?
onlay
are inlay devices useful around joints?
no because they are relatively inaccurate at restoring anatomical position
how does traction work in holding a fracture in reduction
the pull of a weight stimulates muscles to contract which holds the bones in position
in static traction what is the pull applied against? example?
another part of the body
e.g. Thomas splint - pull applied against a ring which presses against the pelvis
when is balanced traction used?
when static traction is in danger of causing damage to a part of the body through pressure
when is dynamic traction used
when joints are still permitted to move, but by means of pulleys, the pull is still maintained along the line of the broken bone
for long term dynamic traction, what is preferred - strapping stuck onto the skin or a pin inserted through the bone?
pin
stages of bone healing
first 2 weeks - swelling
2-6 weeks - callus forming
6-12 weeks - bone forming
1-2 years - remodelling has taken place and the bone returns to normal
bone heals in the presence of what type of movement?
micro movement directed along the long axis of the bone at right angles to the break
will bones heal as normal if there is no movement?
no, it will be slow and by a different process which does not involve natural external callus formation
bones fixed rigidly will heal slowly. this is most marked in
a) long bones
b) cancellous bone
a) long bones
what type of fixation is particularly valuable in high velocity injuries
external fixation
is fixation indicated in pathological fractures?
yes
Internal fixation leads to early/delayed mobility but fast/slow healing ? ?
internal fixation leads to EARLY mobility but SLOW healing
commonest cause of bone infection in the western world
surgery!
if a fracture is held stable but there is infection, will it unite?
yes
if an unstable fracture becomes infected what will be required?
stabilisation by external fixation followed by surgical wound cleansing and later bone grafting
when is fat embolism typically seen
following a long bone fracture in a man under 20
symptoms of fat embolism
rapid and shallow breathing
mild confusion
may have rash on chest and neck
other name for compartment syndrome
Volkmann’s ischaemia
can compartment syndrome occur without fracture
yes
in compartment syndrome is the distal pulse usually normal?
yes
what is found in abundance in the kidneys of people who die from renal failure following massive soft tissue injury
myoglobin
why does early mobilisation following fracture prevent renal stone formation
thinning bone releases calcium which can cause renal stones
if left to heal naturally how long will upper and lower limb fractures take to heal?
upper - 6 weeks
lower - 12 weeks
once growth ceases is the rate of union age dependent?
no
non union is most common in which bone
tibia
timescale when we would generally class a fracture as non union in a) per limb b) lower limb
a) upper limb - 10 weeks
b) lower limb - 20 weeks
what may be added to stimulate union
bone graft (autologous)
children have a great capacity to remodel mal united fractures, but what type of deformity will they not be able to remodel
rotary
what may arrest bone growth
fracture breaching the germinal layer of the epiphyseal growth plate
when is dynamic traction particularly useful
treatment of fractures of the femur where splintage to involve the hip joint is impractical
what is the main problem with traction
the injured person must remain in bed which prolongs hospital stay and makes nursing difficult
describe fat embolism in detail - onset, symptoms, management …
onset within 2-5 days from injury
mild confusion, rapid shallow breathing, rash on chest/neck
early dx important followed by high % oxygen, chest physio, maybe steroids
name 6 early complications caused by fracture
blood loss compartment syndrome renal failure infection soft tissue injury fat embolism
name 5 complications that may result from fracture treatment
plaster disease (skin sores, stiffness, muscle wasting) immobility infection compartment syndrome renal stones
Why may arthritis develop following fracture
if the fracture goes through the joint then the surfaces will no longer be congruent
a very angulated fracture will put uneven forces on the joint
causes of delayed/non union
excess movement too little movement infection poor bloody supply soft tissue interposition excessive traction intact adjacent bone
