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Flashcards in 6 - Fractures Deck (105)
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1
Q

List the 3 cell types involved in the maintenance and remodelling of bone.

A
  1. Osteoblasts
  2. Osteoclasts
  3. Osteocytes
2
Q

What is osteomalacia?

A

Softening of the bone; caused by INSUFFICIENT MINERALIZATION

3
Q

List 3 medical conditions associated with low trauma fractures.

A
  1. Osteoporosis
  2. Osteopenia
  3. Cancer
4
Q

What type of collagen would you find in reticular fibres?

A

Type III

Remember: THREE is in reTHREEcular fibres

5
Q

List 4 pharmacological treatments for osteoporosis.

A
  1. Bisphosphonates
  2. Calcium supplements
  3. Vitamin D supplements
  4. Hormone replacement therapy (in younger women)
6
Q

What is the impact of steroids on bone cells?

A

INHIBIT OSTEOBLASTS

7
Q

What type of connective tissue forms bone?

A

Dense connective tissue

8
Q

Where does vitamin D come from?

A
  1. Sun exposure (70%)

2. Diet (30%)

9
Q

List 2 activities signalled by calcium ions.

A
  1. Muscle contraction

2. Cellular secretion

10
Q

What type of collagen would you find in bone?

A

Type I

Remember: ONE is in bONE

11
Q

What is the major protein of bone?

A

Type I collagen

12
Q

What does the T-score indicate?

A

Number of standard deviations above or below mean bone density for a healthy 30-year-old

13
Q

What type of bone cells break down matrix and release minerals?

A

Osteoclasts

14
Q

Which cells produce collagen?

A

Fibroblasts

15
Q

Compact bone tissue organizes in concentric layers called ___ to form osteons.

A

Lamellae

16
Q

What percentage of bone is replaced each year?

A

10%

17
Q

Why is old age a risk factor for osteoporosis?

A

Bone mass declines with age

18
Q

What is kyphosis?

A

Outward curvature of the upper back

Remember: Hunchback of Notre Dame

19
Q

Compare the cartilage and bone changes in osteoarthritis.

A

Cartilage: thins and cracks
Bone: rubs against bone; may form osteophytes

20
Q

Why is collagen abundant in connective tissue, bone, cartilage, tendons, etc.?

A

Provides strength

21
Q

Which hormone stimulates osteoclast activity?

A

PTH

22
Q

How does PTH raise blood calcium?

A

Stimulates osteoclast activity

23
Q

Where would you find type IV collagen?

A

Basal lamina

Remember: FOUR is in the FLOOR

24
Q

Compare a primary and secondary tumor.

A

Primary: at site of origin
Secondary: travelled from site of origin

25
Q

How does a dramatic dip in estrogen hormones affect bone homeostasis in postmenopausal women?

A

Causes the amount of bone broken down by osteoclasts to exceed the amount of bone formed by osteoblasts

26
Q

What is osteopenia?

A

Early stage bone density loss; precursor to osteoporosis

27
Q

What causes calcium stones?

A

High calcium levels in the urine

28
Q

What is the most common site of osteoporosis-related fracture?

A

Spine

29
Q

What type of connective tissue forms bone?

A

Dense connective tissue

30
Q

List 2 methods of identifying those at risk of osteoporosis.

A
  1. Presence of risk factors

2. DEXA scan (bone density screening)

31
Q

At what age is peak bone mass reached?

A

25-30

32
Q

You are performing a thyroidectomy. Why is it important to leave the parathyroid gland behind when the thyroid gland is removed?

A

Thyroid hormones are replaceable, but it is difficult to manage lost PTH

33
Q

Bone is made up of calcium salts (mainly calcium hydroxyapatite) embedded in a(n) ___.

A

ECM

34
Q

Compare a normal fracture and a pathological fracture.

A

Normal: huge force applied to normal bone
Pathological: small force applied to weakened bone

35
Q

Describe how menopause increases risk of osteoporosis.

A

Low estrogen ->
Decrease in osteoblast activity +
Increase in osteoclast activity ->
Net bone loss

36
Q

A patient has poor calcium and vitamin D intake early in life. How will this increase their risk of developing osteoporosis down the line?

A

Reduced peak bone density makes it easier for bone to wear down with age

37
Q

What are the 4 stages of bone remodelling?

A
  1. Hematoma (blood clot)
  2. Fibrocartilaginous callus formation (fibres and cartilage)
  3. Bony callus formation (spongy bone)
  4. Remodelling (compact bone)
38
Q

Why is spongy (a.k.a. trabecular) bone more susceptible to fractures from osteoporosis?

A

Osteoporosis weakens trabeculae

39
Q

You suspect septic arthritis and decide to aspirate the joint in question. What features of the aspirate would support your diagnosis?

A

Pus

40
Q

When is osteoporosis usually detected? (Hint: unfortunate timing.)

A

After first fracture

41
Q

When does bone remodelling occur?

A

All times; process is constant

42
Q

Where is collagen found in the bone?

A

ECM

43
Q

How does the molecular structure of collagen relate to its mechanical strength?

A

Secondary structure of collagen is a triple helix

44
Q

Compare the efficacy of hormone replacement as a treatment for osteoporosis in younger females vs. older females.

A

Younger: favourable
Older: unfavourable as it increases risk of HEART DISEASE

45
Q

What are the 3 R’s of fracture treatment?

A
  1. Reduction (place bone in normal position)
  2. Retention (retain reduced position until bone has healed)
  3. Rehabilitation (restore previous function)
46
Q

How does osteoporosis increase risk of bone fracture?

A

Deteriorates trabeculae, weakening the bone

47
Q

Which component gives the ECM of bone its strength?

A

Type I collagen

48
Q

How does the body compensate for insufficient levels of calcium ingestion or absorption?

A

Breaks down bone to increase blood calcium

49
Q

What part of cancellous bone is broken down in osteoporosis?

A

Trabeculae

50
Q

What type of collagen would you find in bone?

A

Type I

Remember: ONE is in bONE

51
Q

Which component of bone ECM mediates the deposition of minerals?

A

Glycoproteins

52
Q

Why is osteoarthritis more likely to develop in the hand than in the shoulder?

A

Joints in hand have more repetitive movements

53
Q

Where is most calcium stored?

A

Bone

54
Q

In broad terms, what characterizes osteoporosis?

A

Reduced bone mass

55
Q

What is osteomalacia called in childhood?

A

Rickets

56
Q

What is the hallmark sign of tetany?

A

Muscle spasms

57
Q

What type of bone is most commonly broken down in osteoporosis?

A

Spongy bone

58
Q

Which vitamin aids in the absorption of calcium?

A

Vitamin D

59
Q

Which hormone controls blood calcium?

A

Parathyroid hormone (PTH)

60
Q

How does osteoporosis lead to kyphosis?

A

Vertebral collapse causes spinal curvature

61
Q

Why does women’s bone mass dip sharply at menopause while men’s declines gradually?

A

Gonadal hormones build bone mass; estrogen levels plummet at menopause while testosterone levels decline gradually

62
Q

List 2 reasons why arthritis would develop after an injury or fracture.

A
  1. DAMAGE to the articular surface

2. Disturbed BALANCE of bone turnover

63
Q

Which population do T-scores apply to?

A

Post-menopausal women and older men

64
Q

What is the effect of low levels of gonadal hormones on peak bone density?

A

Lower peak bone density

65
Q

What type of collagen would you find in hyaline and elastic cartilage?

A

Type II

Remember: TWO is in carTWOlage

66
Q

List 8 risk factors for osteoporosis.

A
  1. Old age
  2. Female
  3. Estrogen deficiency (e.g., menopause)
  4. Hypogonadism
  5. Long term steroid treatment
  6. Diet (poor calcium or Vitamin D)
  7. Immobility
  8. Family history
67
Q

List 12 parameters used by the FRAX tool.

A
  1. Age
  2. Sex
  3. Weight
  4. Height
  5. Previous fracture?
  6. Hip fracture in the subject’s mother or father?
  7. Smoking?
  8. Glucocorticoid treatment?
  9. Rheumatoid arthritis?
  10. Presence of disease strongly associated with osteoporosis?
  11. Alcohol > 3 units/day?
  12. Femoral neck BMD
68
Q

How is bone able to resist fracture?

A

Balance between its flexibility and rigidity; lamellae are usually able to “slip” relative to each other to disperse forces

69
Q

Steroid drugs are analogues of ___ from the adrenal cortex.

A

Glucocorticoids

70
Q

What are the 4 most common sites of injury for patients with osteoporosis?

A
  1. Wrist (Colles’ fracture)
  2. Spine (vertebral collapse)
  3. Hips
  4. Ribs
71
Q

What procedure would confirm gout, and what would you look for?

A

Joint aspiration to check for urate crystals

72
Q

Why is the 1st MTP joint the most common site of osteoarthritis in the foot?

A

Under most strain due to a) weight-bearing and b) repetitive movements during walking

73
Q

Which fracture has the most serious consequences?

A

Hip

74
Q

What is the major protein of bone?

A

Type I collagen

75
Q

The FRAX tool combines clinical risk factors and bone density at the femoral neck to calculate the ___ year probability of bone fracture.

A

10

76
Q

List 2 synonyms for spongy bone.

A
  1. Cancellous bone

2. Trabecular bone

77
Q

List 5 conditions that would cause low bone mineral density.

A
  1. Osteoporosis
  2. Hyperparathyroidism
  3. Vitamin D deficiency
  4. Rheumatoid arthritis
  5. Chronic kidney disease
78
Q

Which class of drugs inhibit osteoclast activity?

A

Bisphosphonates

79
Q

List 2 impacts of estrogen and testosterone (i.e., gonadal hormones) on bone activity.

A
  1. Stimulate osteoblast activity

2. Inhibit osteoclast activity

80
Q

What would differentiate a fragility fracture from a normal fracture?

A

Low impact

81
Q

Where would you find type VII collagen?

A

Anchoring the basement membrane to underlying connective tissue

82
Q

Compare a primary and secondary tumor.

A

Primary: at site of origin
Secondary: travelled from site of origin

83
Q

List 2 proteins found in the ECM of bone.

A
  1. Type I collagen

2. Glycoproteins

84
Q

Why might you refrain from operating on an osteoporosis patient with a bone injury?

A

Bone could be too weak to withstand stress of surgery

85
Q

Why do women reach a lower peak bone density?

A

Testosterone builds more bone mass than estrogen

86
Q

In broad terms, what determines bone mass?

A

Balance between osteoblast and osteoclast activity

87
Q

Compare a Colles’ fracture and a Smith’s fracture.

A

Colles’: fractured wrist with hand pointing OUTWARDS

Smith’s: fractured wrist with hand pointing INWARDS

88
Q

List 5 evidence-based recommendations for preventing falls in the elderly.

A
  1. Training for STRENGTH and BALANCE (e.g., Tai Chi)
  2. Medication review (i.e., eliminate side effects)
  3. Diet (i.e., increase calcium and vitamin D)
  4. Home hazard assessment
  5. Safety education
89
Q

What is the cause of tetany?

A

Low blood calcium

90
Q

Increased hydroxylation of proline and lysine strengthens collagen’s triple helix via H bonds. However, the stability of the final collagen fibre is reduced. Why?

A

Formation of covalent cross-links requires free lysine residues; increased hydroxylation prevents these bonds from being formed

91
Q

What is the basic unit of compact bone?

A

Osteons

92
Q

Compare intra-cellular and extra-cellular calcium concentration.

A

Intra-cellular: lower

Extra-cellular: higher

93
Q

List 2 components of calcium hydroxyapatite.

A
  1. Calcium

2. Phosphate

94
Q

You are a GP. A patient presents with septic arthritis. What is the next step in management?

A

Administer antibiotics and admit patient to the hospital

95
Q

What is the WHO definition of osteoporosis?

A

T-score of -2.5 or lower

96
Q

What would be the first investigation in a patient with a suspected low trauma fracture?

A

X-ray

97
Q

What is the most common bone disease?

A

Osteoporosis

98
Q

List 5 conditions that would cause low bone mineral density.

A
  1. Osteoporosis
  2. Hyperparathyroidism
  3. Vitamin D deficiency
  4. Rheumatoid arthritis
  5. Chronic kidney disease
99
Q

How does immobility increase risk of osteoporosis?

A

Bones need stress to remodel; no stress causes osteoblast activity < osteoclast activity
Remember: use them or lose them

100
Q

Corticosteroids increase risk of contracting which joint disease?

A

Osteoporosis

101
Q

What type of bone cells secrete matrix and facilitate mineralisation?

A

Osteoblasts

102
Q

What is the term used to describe a joint infection?

A

Septic arthritis

103
Q

What is the T-score range in osteopenia?

A

-1 to -2.5

104
Q

Which 2 areas are common sites for DEXA (bone density) scans?

A
  1. Lumbar spine

2. Femoral neck

105
Q

What are the two main estrogen hormones in humans?

A
  1. Estriol

2. Estradiol