Bone Healing and Bone Grafting Flashcards Preview

Mechanisms of Disease > Bone Healing and Bone Grafting > Flashcards

Flashcards in Bone Healing and Bone Grafting Deck (109):
0

What are 3 sources of long bone blood supply in mature animals?

- Principle nutrient artery
- Metaphyseal arteries
- Periosteal arteries

1

What are 2 sources of long bone blood supply seen in immature animals?

- Epiphyseal arteries
- Metaphyseal arteries

2

What is a source of long bone blood supply seen with fractured bones?

Development of extraosseous blood supply.

3

What are 2 types of bone healing?

- Indirect healing
- Direct healing

4

What are 3 steps seen in indirect healing (healing by intermediate callus formation)?

- Inflammation
- Repair
- Remodeling

5

Healing by intermediate callus formation is known as what?

Indirect healing

6

Primary osteonal reconstruction is known as what?

Direct healing

7

What are 2 kinds of direct healing?

- Contact healing
- Gap healing

8

What type of bone healing occurs with unstable mechanical environment and motion between fracture fragments?

Indirect bone healing

9

Indirect bone healing can be seen when the gap between the fracture fragments are what distance apart?

> 1mm

10

You will see what type of bone healing with impaired blood supply or impaired revascularization?

Indirect bone healing

11

Transient extraosseous blood supply develops with what type of bone healing?

Indirect bone healing

12

When does the inflammatory stage of indirect bone healing begin?

Immediately after the fracture.

13

How long does the inflammatory stage of indirect bone healing last?

3-4 days

14

What develops at the site of fracture?

Clot

15

Release of osteoinductive growth factors at the fracture site can cause what 2 things to happen?

- Stimulates angiogenesis
- Bone formation

16

Abundant mast cells at the site of fracture can cause what?

Vasoactive substances leading to new vessel formation.

17

Extraosseous blood supply to the site of fracture occurs when?

Within hours.

18

During which stage of indirect bone healing does the clot change into granulation tissue by action of mononuclear cells and fibroblasts?

Repair stage

19

During the indirect bone healing repair stage, slight gain in mechanical strength is achieved with the formation of what?

Formation of a soft callus.

20

During the indirect bone healing repair stage, mesenchymal cells become what which form what?

- Osteoblasts
- A medullary and external callus (fibrocartilage).

21

Resorption and mineralization of the fibrocartilage in the repair stage of indirect bone healing forms what?

A hard callus.

22

Bony union is achieved during what stage of indirect bone healing?

Repair stage

23

How long does the repair stage of indirect bone healing last?

Approximately 2 months

24

How long can the remodeling stage of indirect bone healing last in humans?

6-9 years

25

70% of total healing time seen with indirect bone healing takes place during what stage?

Remodeling stage

26

Which stage of indirect bone healing functions to provide optimal function and strength?

Remodeling stage

27

The balance of osteoclast resorption and osteoblast deposition takes place during what stage of indirect bone healing?

Remodeling stage

28

The remodeling stage of indirect bone healing is governed by what?
What are 2 aspects of this?

- Wolfe's Law
- Compression (osteoblasts) and Tension (osteoclasts)

29

Which type of bone healing refers to direct filling of fracture site with bone without callus formation?

Direct Bone Healing

30

Direct bone healing occurs by what?

Direct osteonal proliferation

31

Which type of bone healing requires precise reduction and rigid fixation that minimizes osteoprogenitor cells?

Direct bone healing

32

How long can direct bone healing take?

6-12 months for appropriate mechanical strength.

33

Contact healing of direct bone healing will be seen when the defect between the fracture site is what distance?

< 0.01mm

34

What type of healing will be seen with an interfragmentary strain < 2%?

Contact healing

35

Contact healing results in lamellar bone oriented in what direction?

Normal axial direction.

36

Bony union and remodeling occur simultaneously with what type of healing?

Contact healing

37

What type of bone healing is initiated by cutting cones of osteoclast directly followed by osteoblasts?

Direct bone contact healing

38

How far do cones of osteoclasts travel in a day?

50-100 micrometers/day

39

How big is a fracture gap?

< 1mm

40

How big is an interfragmentary strain?

<2

41

With direct bone gap healing, are bony union and remodeling separate steps or the same step?

Separate steps

42

Osteoblasts deposit what in the fracture gap in what orientation?

Laminar bones in fracture gap perpendicular to long axis.

43

With gap direct bone gap healing, the bone is mechanically weak where?

At the fracture ends.

44

In what time frame do osteoclasts form cutting comes allowing osteoblast to lay longitudinally oriented lamellar bone with direct bone gap healing?

3-8 weeks

45

T/F: Cancellous bone is more stable than cortical bone (fractures).

True

46

What is woven bone deposited on during the healing of cancellous bone?

Trabeculae

47

What occurs before the union of cortical shell in the healing of cancellous bone?

Bridging of fracture site.

48

Why does a physeal fracture occur?

Because the area is weaker than the surrounding bone.

49

How will a fracture of zone of hypertrophy will heal?

By continued growth of physeal cartilage.

50

How will a fracture of the zone of proliferation heal?

By endochondrial ossification.

51

What do physeal fractures prevent?

Normal physeal function.

52

Physeal fractures can lead to what?

Premature physeal closure.

53

An absolutely stable fracture is seen with what hype of bone healing?

Direct bone healing

54

An unstable fracture is seen with what type of bone healing?

Indirect bone healing

55

What are 6 factors affecting fracture healing?

- Location of fracture
- Stability
- Method of fixation
- Biological environment
- Blood supply
- Biomechanical vs biological osteosynthesis

56

What are 3 aspects of the biomechanical approach of fracture healing?

- Anatomical reduction
- Rigid fixation
- Will compromise soft tissue to achieve

57

T/F: Biological osteosynthesis emphasizes the role of soft tissue integrity.

True

58

What 2 things are restored with biological synthesis in fracture healing?

- Overall length
- Overall alignment

59

What 2 things should be limited with biological osteosynthesis with fracture healing?

- Surgical approach
- Soft tissue disruption

60

T/F: Biological osteosynthesis of fracture healing does not emphasize the use of bone grafts.

False - It does emphasize the use of bone grafts.

61

How do plates and ESF affect bone healing?

May result in direct (contact or gap) healing.

62

How do pins with wires, ESF and interlocking nails affect the type of bone healing?

Direct and/or indirect healing

63

How do casts and splints affect the type of bone healing?

Indirect healing

64

What type of bone healing is seen with no fixation?

Indirect healing

65

What 2 types of implants can disrupt endosteal blood supply and block medullary flow when in contact with endosteal surface?

Intramedullary pins and nails

66

Do cerclage wires and external fixator pins significantly impair vascularity?

No

67

Where do bone plates impair blood supply to?

The outer layer of cortical bone.

68

What results in increased stability of the fracture and allows early reformation of medullary blood supply?

Bone plate stabilization

69

Loose implants may significantly damage what?

Blood supply

70

Open reduction and fixation may result in what?

Damage to blood supply.

71

Bone grafts will enhance what but will not compensate for what?

Enhance healing but will not compensate for unstable mechanical environment.

72

What are 3 indications of bone grafts?

- At initial fracture repair
- Delayed or non-union fractures
- Arthrodeses

73

A bone graft from the patient's own bone is known as what?

Autograft

74

Bone grafts using bone from another individual of the same species as the patient is known as what?

Allograft

75

Bone grafts using bone from an individual of another species are known as what?

Xenograft

76

What are 3 types of bone grafts?

- Cancellous
- Cortical
- Cortical-cancellous

77

Laying down new bone by osteoblasts is known as what?

Osteogenesis

78

Recruitment of host mesenchymal cells to form new bone or osteogenesis is known as what?

Osteoinduction

79

Providing a scaffold for the growth of new bone is known as what?

Osteoconduction

80

What is the gold standard of cancellous bone grafts?

Autogenous

81

What type of cancellous bone graft is readily available?

Autogenous

82

What type of cancellous bone graft helps to avoid immune reactions?

Autogenous

83

What are 5 disadvantages of autogenous cancellous bone grafts?

- Mechanically weak
- Increased surgical time
- Limited storage time
- Pain at donor site
- Intraoperative blood loss

84

Which type of cancellous bone graft wis available as frozen chips or powder?

Allograph

85

What are 3 pros of allograph cancellous bone grafts?

- Decreased surgical time
- Readily available
- No donor site problems

86

What are 2 problems with allograph cancellous bone grafts?

- Expensive
- Lack osteogenic properties

87

Allograph cancellous bone grafts can be mixed with what other type of bone graft to increase volume?

Autograft

88

What are the 4 phases of cancellous bone graft effect?

- Phase I: inflammation (within hours)
- Phase II: revascularization and Osteoinduction (2 weeks)
- Phase III: Osteoconduction (3-4 weeks)
- Phase IV: mechanical support (up to 12 weeks)

89

What do cortical bone grafts provide?

Structural support

90

Do cortical bone grafts have osteoconductive properties?

Yes

91

What type of bone grafts are used with highly comminuted fractures/bone tumors?

Cortical bone grafts

92

What are 4 bones where cortical autographs can be used?

- Ribs
- Ulna
- Fibula
- Ilial wing

93

What are 3 forms you can find allographs in?

- Harvested
- Processed
- Frozen

94

What type of bone graft can be incorporated in the fracture site with surgical with surgical implants?

Cortical bone grafts

95

Osteoclasts move into the graft and do what?

Resorb bone

96

Osteoblasts follow osteoclasts and do what?

Lay down new bone.

97

The phases of cortical bone graft effect are termed as what?

"Creeping substitution"

98

What does a cortical-cancellous bone graft contain?

Both cortical and cancellous bone

99

What type of bone graft provides immediate mechanical support?

Cortical-cancellous bone grafts

100

Do cortical-cancellous bone grafts promote osteogenesis?

Yes

101

Are cortical-cancellous bone grafts both osteoinductive and osteoconductive?

Yes

102

What is the most commonly used type of bone graft?

Cancellous autograft

103

Are cancellous autografts readily available?

Yes

104

What type of bone grafts are highly cellular and mechanically weak?

Cancellous autografts

105

Which form of bone graft has less osteoconductive properties?

Cancellous autografts

106

Which type of bone graft has excellent mechanical support?

Cortical bone grafts

107

Which type of bone graft is more osteoconductive?

Cortical bone grafts

108

Which type of bone graft is acellular with no osteogenic properties?

Cortical bone grafts