Orthopaedics (Unit 5:Common fractures) Flashcards Preview

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Flashcards in Orthopaedics (Unit 5:Common fractures) Deck (105)
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1
Q

Which part of bone has a nerve supply?

A

Periosteum (the membrane which covers the outside of bones)

2
Q

What are the 8 signs of a fracture?

A
Pain 
Deformity 
Tenderness
Swelling 
Tenderness
Discolouration/bruising
Crepitus 
Loss of function
3
Q

How is swelling in a suspected fracture managed?

A

Raise above level of the heart

4
Q

Why in a fracture does the disolouration change from dark to green then to yellow?

A

Dark = deoxygenated blood loss into soft tissues

As Hb in RBC is broken down and carried to liver by scavenger cells (colour changes to green then yellow)

5
Q

What methods are used for investigating fractures?

A
X-ray 
Tomograms 
CAT 
US 
Radioisotope scanning
6
Q

When is tomography useful when investigating fractures?

A

When area is difficult to distinguish due to overlapping structures (e.g. axis bone)

7
Q

How does radioisotope scanning work?

A

Radioactive substance attaches to phosphate molecules that are taken up actively taken up by bone.
The more metabolically active bone is the faster it takes up radioactive substance.
On x-ray unusual metabolic activity can be seen (i.e. fracture)

8
Q

When is radioisotope scanning useful?

A

When there is clinical doubt

In not acute situations (2 weeks after injury)

9
Q

Which bone in particular is radioisotope scanning useful for?

A

Scaphoid

10
Q

What should be commented on when describing a fracture?

A
Which bone & which side?
Open or closed?
Where on the bone is the break?
What shape is the fracture?
How many fragments 
What is the position of the distal fragment?
Could it be pathological?
11
Q

What are the 3 fracture shapes?

A

Spiral
Oblique
Transverse

12
Q

In what kind of injury do spiral fractures occur and how severe are they?

A

Twisting (low energy)

Associated with little soft tissue damage to blood supply is preserved and healing likely

13
Q

What might cause oblique or transverse fractures?

A

Buckling or direct injury to bone (high energy)

14
Q

What are the 3 ways to describe how many fragments are present in a fracture?

A

Simple
Butterfly
Comminuted

15
Q

How is the distal fragment of a fracture described?

A

In terms of displacement, angulation and rotation

16
Q

How is he angulation of the distal fragment of a fracture described?

A

As either anterior, posterior, varus or valgus

17
Q

What is a pathological fracture?

A

When a fracture seems out of proportion to the violence of the injury

18
Q

What does the immediate management of a fracture involve?

A

Pain relief splintage

19
Q

What can be used as an alternative to splintage to relieve muscle spasm in the early management of a fracture?

A

Traction (particularly useful in femoral neck fractures)

20
Q

Which fractures are most likely to be at risk of large blood loss?

A

Major long bones (femur, tibia)

21
Q

How many units will a patient with a femoral fracture lose?

A

2-3 units

22
Q

How many units will the average person with a tibia fracture lose?

A

1 unit

23
Q

How many units can an unstable pelvic fracture lose from the pelvic venous plexuses?

A

6 units or so

24
Q

What is the treatment strategy for open fractures?

A

Clean them out and remove all dead tissue as soon as possible

25
Q

Why are open fracture wounds sometimes left open?

A

If there is any doubt that closure can be achieved without any tension on the skin

26
Q

If a patients wound is left open what extra treatment will they require?

A

Broad spectrum antibiotics

Tetanus protection

27
Q

Why might a surgeon opt for a less than perfect result when managing a fracture?

A

The individual may be elderly or have poor bone quality and a less than perfect result might still allow them to do their daily activities (extensive treatment may have complications)

28
Q

What process is used to return a bone to its normal position?

A

Reduction

29
Q

How is closed reduction performed?

A

Traction on the distal fragment and relocation of the distal part back onto the proximal fragment by manipulation

30
Q

Name 4 methods of holding a fracture

A

Casting
External fixation
Internal fixation
Traction

31
Q

What factors should be considered when casting a fracture?

A

Maintained at proper length

Immobilise joint above & below

32
Q

How does a cast work?

A

Controls joint movement and position so pressure is exerted at 3 points

33
Q

What are the disadvantages of casting?

A
Heavy 
Immobilise joints 
Unable to examine 
Unable to use x-ray 
Muscle wasting (due to immobility)
34
Q

Why do functional braces tend to be used after a few weeks?

A

They are highly dependent on a very accurate fit (gives time for pain and swelling to settle)

35
Q

Which materials make ideal cast braces and why?

A

Glass fibre & polyurethane resin combinations (not so versatile but stronger and lighter)

36
Q

What are the 2 stages of treating a fracture?

A

Reduction & Holding

37
Q

Why are plaster splints highly unsuitable in high-energy fractures?

A

Assoc. with extensive soft-tissue damage so blood supply is severely damaged it is important to have an initial phase of soft tissue healing

38
Q

Why is internal fixation hazardous to use in the management of fractures with extensive soft-tissue damage?

A

Ischaemia

Increases infection risk

39
Q

How does an external fixator work?

A

Fixed to the bones by pins and stabilises limb by external scaffold (provides stability and allows access to soft tissues)

40
Q

Name a downside to external fixation?

A

Pin sites are an easy route for infection

41
Q

When is internal fixation used?

A

When a high degree of accuracy is required or other methods fail

42
Q

What are the 4 types of internal fixation?

A

Apposition
Interfragmentary compression
Interfragmentary compression plus onlay device
Inlay device

43
Q

What is apposition?

A

Once a fracture is realigned in only needs held in apposition for healing to procees

44
Q

In what group is apposition particulary useful in and how is it achieved?

A

Children (using K wires)

45
Q

What is interfragmentary compression and how is it achieved?

A

Holding 2 bone fragments firmly together (usually achieved by screws or sometimes tension band wires)

46
Q

When is solely interfragmentary compression particularly useful?

A

In cancellous bone around joints

47
Q

What are onlay devices used for in fracture management?

A

To buttress weak structures around joints

To fix long bones in the upper limb

48
Q

What is the downside of olay devices?

A

Very rigid and inhibit natural bone union

Allow early movement but ultimately delay healing and full load bearing

49
Q

Why are inlay devices good?

A

Achieve correct allignment
Don’t disturb natural healing
Very strong (particularly useful in lower limb)

50
Q

How can badly comminuted fractures be treated?

A

Cross screws inserted into bone using x-ray image intensifier

51
Q

How does traction work?

A

Pull stimulates muscles to contract which surround the bone and hold the fracture in place

52
Q

What are the 3 methods of traction?

A

Static
Dynamic
Balanced

53
Q

Name an example of static traction

A

Thomas splint

54
Q

When is balanced traction used?

A

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

55
Q

How does dynamic traction work?

A

Joints are still permitted to move by means of pulleys

56
Q

How long are weights applied for in traction?

A

Short periods of time (a few days)

57
Q

How does traction diminish the need for pain-killing drugs in femoral fractures?

A

Changes muscle tone to relieve spasm

58
Q

Which specific fractures is traction particularly useful in?

A

Femur fractures where splintage to include the hip joint is impractical

59
Q

What is the main downside of traction?

A

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

60
Q

Over what time frame does callus form in bone healing?

A

2-6 weeks

61
Q

Over what time frame does new bone start forming after a fracture?

A

6-12 weeks

62
Q

What sort of movement help to stimulate bone healing?

A

Micromovement directed along the long axis of bone at right angles to the break

63
Q

How should low energy fractures generally be treated?

A

Manipulation and casting (provided holding is possible)

64
Q

How should low energy fractures be treated if holding is difficult?

A

Traction

65
Q

If a fracture is displaced and involves a joint how should it be treated?

A

Internal fixation

66
Q

Why is internal fixation needed for fractures involving joints?

A

Needs to be very accurate and around joint cancellous bone tends to be fragmented and often with little soft tissue support

67
Q

Why method of holding is particularly valuable in high velocity injuries?

A

External fixation

68
Q

Name 6 early complications that are primary (as a consequence of the injury)?

A
Blood loss 
Infection (open) 
Fat embolism 
Renal failure 
Soft tissue injury 
Compartment syndrome
69
Q

Name 5 early complications that are secondary as a consequence of treatment?

A
Plaster disease 
Renal stones 
Immobility 
Infection 
Compartment syndrome
70
Q

Name 5 late complications of a fracture

A
Non-union 
Delayed union 
Mal-union 
Growth arrest 
Arthritis
71
Q

What is the commonest cause of bone infection in the western world?

A

Surgery

72
Q

What dictates whether an infected fracture will heal?

A

Infection + stable = union

Infection + movement = non-union

73
Q

How is an open infected fracture treated?

A

External fixation followed by surgical wound cleansing and later bone grafting

74
Q

What precipiates pneumonitis after a fracture?

A

Breakdown of fats to fatty acids

75
Q

Describe a typical patient who might get a fat embolism

A

Male
Under 20 y/o
Fracture of long bone

76
Q

When do symptoms of fat embolism present?

A

2-5 days from injury

77
Q

What are the symptoms of fat embolism?

A

Tachypnoea
Mild confusion
May have chest + neck rash

78
Q

How is fat embolism managed?

A

Early diagnosis important
High % oxygen
Chest physio
Steroids given early (controversial)

79
Q

What makes a patient prone to renal failure after a fracture?

A

Massive soft tissue injury
Trapped for prolonged periods
Ischaemia

80
Q

What is found in abundance in the kidneys of patient who die from renal failure after a fracture?

A

Myoglobin

81
Q

Where does compartment syndrome classically occur?

A

Forearm also calf

82
Q

What structure surrounds groups of muscles?

A

Fascial sheath

83
Q

What is the purpose of the fascial sheath?

A

Supports muscles
Gives muscles shape
Anchors muscles to bone and surrounding soft tissue
Acts as muscle boundary creating compartments

84
Q

Why does pressure increase in a compartment if a bone is broken?

A

Bleeding into adjacent compartments

Inflammatory reaction

85
Q

What is compartment syndrome?

A

Increased pressure leads to reduced blood flow locally to muscles resulting in ischaemia

86
Q

What are the symptoms of compartment syndrome?

A

Pain out of proportion to injury
Assoc. loss of function
Altered sensation over compartment

87
Q

How does compartment syndrome affect the distal pulse?

A

Distal pulse normal

88
Q

What is a useful diagnostic test for compartment syndrome?

A

Stretching muscles in compartment precipitates extreme pain

89
Q

What is the first step of management of compartment syndrome?

A

Remove all dressing and split the plaster

90
Q

If conservative measures fail how is compartment syndrome treated?

A

Surgical opening of fascia to decompress the compartment

91
Q

How can compartment syndrome be prevented?

A

Early elevation of injured limb and ensure dressing are not too tight

92
Q

What is fracture (plaster) disease?

A

Muscle wasting, stiffness and skin sores

93
Q

What does early mobilisation discourage the development of? (5 things)

A
Osteoporosis 
Renal stone formation 
Stiffness
Muscle wasting 
Skin sores
94
Q

What causes renal stone formation if patient are immobile?

A

Calcium from the thinning bone

95
Q

How long do upper limb fractures take to heal if left naturally?

A

6 weeks or so

96
Q

How long do lower limb fracture take to heal fi left naturally?

A

12 weeks or sp

97
Q

At which site in non-union most common?

A

Tbia

98
Q

Name 7 factors that might lead to non-union

A

Excess movement
Too little movement
Soft tissue interposition
Poor blood supply
Infection
Excessive traction or splinting bone too far apart
Intact adjacent bone (e.g. tib & fib)

99
Q

How long is roughly defined as non-union in the upper limb?

A

10 weeks

100
Q

How long roughly is defined as non-union in the lower limb?

A

20 weeks

101
Q

What is delayed union?

A

Period between expected union and accepted non-union

102
Q

How is non-union treated?

A

Remove cause

Bone graft

103
Q

What does an autologous bone graft mean?

A

Taken from the bone of that individual (usually pelvis)

104
Q

What is mal-union?

A

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

105
Q

What causes growth arrest after a fracture?

A

If it breaches the epiphyseal growth plate