Orthopaedics Unit 5 Flashcards Preview

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Flashcards in Orthopaedics Unit 5 Deck (112):
1

what is the anatomical features of bone

has a very rich blood supply

periosteum is the membrane which covers the outside of the bone
- has a nerve supply

2

Mx of fracture priorities

early Mx
- minimise effects of blood loss
- reduce pain

Mx
- re-establish blood supply to the bone to allow it to heal

3

what questions need considered in the history of a fracture

what happened?

how did it happen?

where and when?

what was the injured person like before it happened?

who is the person?

4

what injuries are a person hit by a car likely to have

leg injuries from the bumper

pelvic and abdominal injuries from the bonnet

head injuries from the door pillar

5

what are the signs of a fracture

pain
deformity
tenderness
swelling
discolouration or bruising
loss of function
crepitus
injury to other tissues

6

what influences the deformity of the bone after a fracture

position of the distal fragment of a fractured bone is determined by gravity

position of the proximal fragment is determined by the muscles

7

how can swelling be reduced in a fracture

elevate the part of the body injured

injured arm
- raised about level of the heart

injured leg
- lie patient down, with leg raised above chest level

8

what causes the colours of bruising

bruise at first is dark
- due to deoxygenated blood loss into soft tissue

bruise then becomes green/yellow
- as haemoglobin in the red blood cells is broken down and carried away to the liver

9

what 2 x-ray views are taken on a suspected fracture

one in sagittal plane
one in coronal plane

10

what is radioisotope scanning

when a very small quantity of a radioactive substance is injected into the blood of the injured person

11

how does radioisotope scanning work

- radioactive substance attaches to phosphate molecules which are actively taken up by bone

- then an x-ray is taken

- more metabolically active the bone is, the faster it takes up the radioactive substance

- sites of unusual metabolic activity (i.e. at the site of the fracture) can be clearly seen

12

when is radioisotope scanning used

useful in determining whether a bone is fractured or not

often used when a scaphoid [bone of the wrist] fracture is suspected

13

what questions should be answered when describing a fractured bone

which bone is broken and on which side?

is the fracture open or closed?

where on the bone is the fracture?
- intra-articular [in the joint]
- mid shaft
- proximal, middle or lower third?

what is the shape of the fracture?
- spiral
- oblique
- transverse

how many fragments?
- simple
- butterfly
- comminuted

what is the position of the distal fragment?
- describe distal fragment in relation to proximal one

could it be a pathological fracture?

14

how do spiral fractures occur

through twisting, low energy injuries

associated with little soft tissue damage = blood supply is preserved and healing should be no problem

15

when do you see oblique or transverse fractures

caused by buckling or direct injury to the bone

lots of energy involved

associated with soft tissue stripping and damage to the blood supply

require a lot more consideration for choice of Tx and usually take longer to heal

16

what are the 3 considerations when describing the position of the distal part of a fracture

displacement
- anterior
- posterior
- medial
- lateral

angulation
- anterior
- posterior
- varus
- valgus

rotation
- internal
- external

17

what are signs of a pathological fracture

fracture seems out of proportion to the violence of the injury

suggests bone is weak = result of osteoporosis or other diseases such as cancer

18

what are the headings of the immediate management of fractures

pain relief

managing blood loss

managing open fractures

19

what are the 2 methods of immediate pain relief

pain-killers
- i.e. morphine or pethidine injections

splintage
- hold fracture steady
- should encompass the joint above and below an injury

20

what is an alternative to splint age

traction
- also used in early Tx to relieve muscle spasm

21

when is traction particularly useful

fractures of the femoral neck
as splint age is impossible to apply

22

what type of fractures can lead to significant blood loss

major long bone fracture
i.e. femur

tibial # = 1 unit blood loss
femoral # = 2-3 units
major pelvic # = 6 units [major venous bleeding]

23

what is the Mx of all patients with major long bone injuries

cross matched for blood

wide bore cannula
- 2 lines if pelvic fracture

24

what is the Mx of open fractures and why is it important it happens quickly

clean them out and remove all dead tissue
- remove bits of clothing, dirt, wood, metal

prevent infection from bacteria
prevents potenital sepsis

25

what is the wound management of an open fracture

wounds are better left open if there is any doubt that closure cannot be achieved without any tension on the skin

wounds closed as a secondary procedure after a few days or left to heal spontaneously

26

Tx of open fractures

broad spectrum antibiotics
tetanus protection

27

what factors will determine what the long term, definitive management is of a fracture

the injured person
the injury
the surgery

28

what needs to be considered in the injured person in terms of management of the fracture

age of the patient, physical health and occupation

- older people tend to have a poor bone quality (osteoporosis) and co-existing medical problems [heart disease, diabetes]

29

how might the treatment of a wrist fracture be different in an elderly person and a young person

elderly
- fracture may be treated under local anaesthesia in the A&E
- not perfect result, but can go home and may have a satisfactory level of function
- surgery would require bed rest which might lead to complications like bedsores, UTI

young
- might be prepared to spend months undergoing Tx to ensure perfect result
- need it for work etc

30

what is essential to ensure when considering surgery

benefits outweigh the risks

31

what is the name of the process of returning the bone to its normal position

reduction

[and then holding the bone in place to allow healing]

32

what is close reduction

achieved by traction on the distal fragment

then relocation of that distal part back onto the proximal fragment by manipulation

need adequate analgesia

33

what does the manipulation of the fracture usually involve

reversing the direction of the deforming force

34

what is open reduction

# site is open surgically and the fragments are relocated directly under vision

done if closed reduction doesn't work

35

why does a bone need to be held in the desired position

bone needs to become strong enough to support itself (united) and then protected until it is strong enough to bear some load (consolidated)

36

how can a fracture be held in place

Casting
- surrounding the broken limb with a hard ‘coat’ which holds the fracture steady.
􏰀
External fixation - an external ‘bar’ outside the body attached to pins sited in the broken bones.
􏰀
Internal fixation - holding broken bones together using screws and plates inside the body.
􏰀
Traction - pulling on a broken limb to align the bones.

37

what is casting

place limb in plaster of Paris cast until union

limb must be held in correct position and maintained at proper length [too long/short will delay union]

38

what must be covered in a plaster of paris cast

must immobilise the joints above and below the fracture site, as joint movement may result in distortion in one or more dimensions.

39

how does a cast work

acts as a splint

controls joint movement and position to control posture

plaster cast is folded so that pressure is exerted at 3 points

3 holding forces - mimics the direction of the reducing force sufficient to hold the reduction

40

disadvantages of casts

heavy
immobilise the joint
cannot examine the site
cannot x-ray

after cast is removed:
- muscle wasting
- limited mobility due to joint stiffness

41

what technique can be used to over come plaster cast

functional brace
- frees the joint

42

how does a functional brace work

accurate moulding and the provision of hinges, which permit motion in one direction, usually flexion and extension
- maintains 3D control of #

43

why is a functional brace normally fitted a few weeks after the injury

brace is reliant on a very accurate fit so need to wait for pain and swelling to reduce

44

what are disadvantages of the plaster of paris in regards to the material and what are alternatives

brittle
messy
difficult to apply well
heavy
can take 3 days to dry


glass fibre and polyurethane resin [however, not as versatile]

45

when are the alternative materials to plaster of paris used

used as secondary casts a week or two after the injury, once swelling has settled.

make ideal cast braces

46

why is external fixation (EF) used over internal fixation (IF) in some cases

High-energy # are associated with extensive soft-tissue damage
> blood supply is severely damaged
> need an initial phase of soft tissue healing

plaster splints are highly unsuitable because the wounds become inaccessible.

IF is hazardous because of ischaemia and wound contamination increases risk of an infection

47

how does EF work

device which is fixed to the bones by pins and which stabilises the limb by means of an external scaffold,

48

advantages of EF

provides stability of the bones

allows access to the soft tissues for dressings and secondary surgery i.e. skin grafting.

49

disadvantages of EF

pin sites are easy route for infection

50

what is internal fixation

holding of the fractured bone with devices such as screws, nails or plates.

51

what are the methods of IF

Apposition.
􏰀
Interfragmentary compression.
􏰀
Interfragmentary compression plus onlay device. 􏰀

Inlay device.

52

what is apposition

once # is realigned - they are held in apposition [i.e. together in alignment]

hold position without producing immobility and so healing occurs by natural callus formation

53

what are methods of apposition

K or Kirschner wires
- semi-flexible wires
- useful in children

54

how are K wires removed

can be left standing proud of the bone
- can easily be pulled out once union is established and before consolidation.

55

what is Interfragmentary compression and when are they particularly valuable

holding two bone fragments firmly together
- achieved by screws [mainly] or tension band wires

achieve great accuracy

valuable in cancellous bone around joints

useful in long bones, particularly in upper limb [but may require extra support from an onlay device]

56

what is an onlay device

usually consists of a plate of metal

they are used to support weak structures around joints and to fix long bones in the upper limb

57

can an onlay device be used in the lower limb?

yes

however, generally not strong and certainly should not be used in the lower limb without interfragmentary compression

58

what are the disadvantages of an onlay system

rigid which inhibits natural bone union

delay healing and full load bearing due to eliminating micro-movement at the fracture site

59

what is an example of an inlay device

intra-medullary nails

60

advantages of an inlay device

- achieve correct alignment of the broken bones without unduly disturbing natural bone healing

- great strength make them ideal devices for Tx long bone #, particularly in the lower limb

61

disadvantages of an inlay device

- relatively inaccurate method of restoring anatomical position and so are not useful around joints

62

what is a potential Tx plan for a badly comminuted or rotated fracture

cross screws can be inserted in the bone using an X-ray image intensifier to show the bone and nail during surgery

63

why is the bone next to a fixation device weaker than normal bone

as it shares the load with the fixation device

bone at # gets thinner

adjacent unsupported bone is normal

thus a boundary is created between normal bone and weak, fixed bone leading to stresses at the abnormal/normal bone interface

[Wolff's Law]

64

what is the current protocol for removal of implants [nails, screws]

possibility of link to bone tumours around implants but not proven

probably safer to remove implants in young people
- is risk of infection, damage to nerves and blood vessels during surgical removal

65

how does using traction as a holding device work

application of a relatively small weight to a limb, which exerts a pull along the axis of the broken limb

pull of at most 5 kilograms stimulates muscles to contract

this slight contraction [increase in muscle tone really] is sufficient to hold a broken bone in the position achieved at reduction

66

what are the 3 ways traction can be applied

static
dynamic
balanced

67

what is static traction and an example of it

where the pull is applied against another part of the body

In the Thomas splint, the pull is applied against the ring which presses against the pelvis
- used for femur #

only used for relatively short periods

68

when is balanced traction used

when static traction is in danger of causing damage to a part of the body through pressure

69

how does balanced traction work

the pull against the ring (and thus the pelvis) is balanced by a WEIGHT attached to the whole splint

takes pressure off the skin round the ring while maintain traction on the leg

70

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

71

how does dynamic traction work

weights provide the pull and the counter force is achieved by tilting the bed

weights are not large and are only applied for a few days

useful when traction is being used to relieve pain, like following a femoral neck #

72

advantage of short term dynamic traction

results in a change in muscle tone, relieving muscle spasm and reduces need for pain-killers

73

what is required for long term traction

larger weights
- a pin inserted through the bone is preferable and in the long run easier to manage.

Pins can loosen, and/or become infected.

Regular nursing care of pin tracts is essential to keep them clean and dry.

74

when is dynamic traction useful

useful where other external Tx fail

1 - femur #'s where splint age to include the hip is impractical

2 - extensive soft tissue damage as an alternative to EF

75

what is the main disadv of dynamic traction

injured person must remain in bed, making hospital stay prolonged and nursing care difficult.

76

what is the time line for bone healing

first 2 weeks = swelling

2-6 weeks = callus forming

6-12 weeks = bone forming

6-12 months = hard callus

1-2 years = remodelling has taken place and the bone returns to normal

77

what is need to stimulate bone healing

micro-movement directed along the long axis of the bone at right angles to the break

[heal least efficiently if subjected to shearing forces or large movements.]

[bones will heal if there is no movement, they do so very slowly and by a different process]

78

what is bone healing highly dependant on

a good blood supply

79

why is rigid fixation not great for bone healing

does not allow micro movements - bone will heal but at a slower rate

most marked in long bones and less problematical in cancellous bone, which tends to heal fairly quickly

80

general overview of management of low energy injuries #

manipulation and casting provided that holding is possible

if holding is difficult, may use traction, functional brace or IF

IF justified if it leads to early mobilisation of the injured person

81

general overview of management of # involving joints

generally, IF if # is displaced

Open reduction is mostly needed to get the degree of accuracy required

holding requires accurate reconstruction of the fragments, usually with screws to aid stability or k-wires

[cancellous bone tends to be fragmented which can make holding difficult]

82

general overview of management of high velocity injuries

require special attention because of the damage to the blood supply

EF useful if soft tissue damage

83

what type of cancers is bone cancer commonly secondary too

lung, breast, thyroid and kidney

84

why are internal fixation techniques used for fractures of the elderly

permit early mobilisation and thus a return to normal function as soon as possible.

85

what are the early complications of a fracture

Blood loss.
􏰀 Infection.
􏰀 Fat embolism.
􏰀 Renal failure.
􏰀 Soft-tissue injury.
􏰀 Compartment syndrome

86

what are the late complications of a fracture

non-union
delayed union
mal-union
growth arrest
arthritis

87

what are early complications of the Tx of a fracture

Plaster disease. 􏰀
Renal stones. 􏰀
Immobility.
􏰀Infection.
􏰀Compartment syndrome.

88

what are late complications of the Tx of a fracture

mal-union
infection

89

what is the commonest cause of bone infection in the western world

surgery

90

why would a bone infection sometimes not be treated? what could be done?

Provided a fracture is held stable then it will unite despite infection.

[If there is infection AND movement then non- union is most likely]

Tx
- drain any pus collection
- give antibiotics until union has occurred

91

what is the management when an open # that is unstable OR for an unstable but FIXED # becomes infected

stabilisation by EF followed by surgical wound cleansing

later bone grafting will be required.

92

who is a fat embolism normally seen in and how does it present

after the fracture of a long bone in men < 20 years old

Sx commence within 2-5 days after injury

Sx
- tachypnoea [shallow rapid breathing]
- mild confusion
- may have rash on chest and neck

93

Tx of fat embolism

high percentage oxygen and chest physiotherapy

[late diagnosis will lead to ventilation being required, high mortality rate]

94

how is renal failure caused after a #

people trapped for prolonged periods, become ischaemic

skeletal muscle begins to break down, high levels of myoglobin released

toxic to the kidneys >>> causes renal failure

95

what is compartment syndrome

All muscles are surrounded by tough fibrous tissue called fascia.

Groups of muscles are surrounded by a thicker layer of fibrous tissue (the fascial sheath).

Fascial sheath creates compartments containing muscle, blood vessels and nerves

Bone # >>> bleeding into compartment and swelling from inflammatory reaction

Leads to increase in pressure within the compartment

Leads to reduced blood flow locally to the muscles >> ischaemia

96

where does compartment syndrome classically happen

in the forearm
[also in the calf]

97

what is an example of a non fracture related compartment syndrome

shin splints

98

Sx of compartment syndrome

Pain - out of proportion to injury

Pressure

Paralysis - loss of function

Pulse distal to compartment is normal

Pallor/pale

Paresthesia (numbness)

99

what is the test for compartment syndrome

passive stretching from the examiner causes severe pain

100

Tx of compartment syndrome

fasciotomy

101

what are the features of fracture disease

Muscle wasting, stiffness and skin sores

102

what are side effects of immobility

osteoporosis

renal stones - caused by calcium from thinning bones

stiffness

muscle wasting

skin sores

103

what is the normal healing period for upper and lower limb fractures

upper - 6 weeks

lower - 12 weeks

[although growing children do heal faster than adults]

104

what bone is non-union most common in

tibia
- due to its rather exposed site under the skin with little surrounding muscles and soft tissue

105

what are the factors thought to cause non-union

excess movement
little movement [rigid IF]
poor blood supply
soft tissue between bone ends
infection
excessive traction

106

when is non-union said to occur

when injured person and/or the surgeon feels that healing has taken too long

rule of thumb:
lower limb - 20 weeks
upper limb - 10 weeks

107

what is delayed union

period between expected union and accepted non-union when the decision to do something is contemplated.

108

Tx for non union

relies on underlying cause and then stimulating union

1 - stabilise fracture
2 - add an autologous bone graft [taken from another bone, usually the pelvis, of the same individual]
3 - graft placed next to the # site

109

what is mal union

fracture has been allowed to heal in a position that inhibits normal function

due to failure of Tx method

110

how is mal union Tx

ORIF

111

what is growth arrest

when there has been a # within the epiphyseal growth plate

may cause arrest at point of breach

resulting in deformity

112

when is secondary OA at a fracture site likely

1 - if fracture goes across a joint and disturbs the surfaces so joint is no longer congruent [i.e. 2 surfaces are no longer parallel]

2 - an angulated fracture as it puts uneven forces on a joint

[good Mx should minimise risk of OA but will not totally exclude]