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Flashcards in Musculoskeletal Deck (141):
1

What is the benefit of doing an x-ray early on in osteomyelitis?

Rules out fracture and malignancy

1

Which cells produce osteoid?

Osteoblasts

1

What stimulates PTH release?

Low Ca2+

1

Which bone cells does PTH act on directly to increase calcium?

Osteoblasts

1

What are the 3 organs that PTH acts on to increase calcium levels?

Bone, kidney and GIT

1

What type of collagen is in hyaline cartilage?

Type 2

1

Where are the 3 places that elastic cartilage is present?

Ear, epiglottis and thyroid cartilage

1

What are osteocalcin and alkaline phosphatase both markers of?

Osteoblast activity

1

What are the little tubes that provide nutrients to osteocytes?

Canaliculae

1

What is a displaced fracture?

Edges of fracture are not apposed

1

What causes a stress fracture?

Repeated low force injury to a normal bone

1

What are the 4 stages of fracture healing?

Inflammatory Reparative - Soft callus Reparative - Hard callus Remodelling

1

What are the 2 major processes during the remodelling phase of fracture healing?

Osteoblasts and osteoclasts repopulate the bone Woven bone is remodelled to give lamellar bone

1

Over what time frame does the hard callus phase of fracture healing occur?

Weeks to months

1

Over what time frame does the remodelling phase of fracture healing occur?

Months to years

1

What kind of fracture is most susceptible to infection?

Compound fracture

1

What is the definition of osteoporosis?

Bone mass >2.5 SDs below the mean for healthy young women

1

What is the definition of osteopaenia?

Bone mass 1-2.5 SDs below the mean for healthy young women

1

What is the main concern with long term bisphosphonate treatment?

Oesophageal cancer

1

What are the 2 main risks of long term oestrogen therapy for bone health?

Cardiovascular disease and breast cancer

1

Is sarcopenia inevitable?

Yes

2

What effect does VitD have in the gut?

Increases absorption of Ca and PO4 (phosphate)

4

What are the 2 major processes during the hard callus phase of fracture healing?

Osteoblasts synthesise osteoid Osteoid becomes mineralised

5

What class of hormone is VitD?

Steroid

5

At what age does muscle mass start to deteriorate?

50 years old

6

What is the most common form of calcium phosphate in bone?

Hydroxyapatite

8

What is the difference between the actions of PTH and VitD3 in the distal nephron?

PTH causes phosphate excretion, whereas VitD3 promotes phosphate reabsorption

9

What word means progressive loss of skeletal muscle mass with aging?

Sarcopenia

10

What is the motor uni?

An alpha motor neurone and all muscle fibres it supplies 

11

Which protein is abnormal in Becker muscular dystrophy?

Dystrophin

13

What are osteocalcin and osteonectin?

Calcium binding proteins in the ECM of bone

15

Which bone cells produce collagen for cartilage?

Chondrocytes

16

What is the second common pathogen in osteomyelitis?

Strep pyogenes / Group A strep

16

Which pathogen is more common for osteomyelitis after a sneaker penetration injury?

Pseudomonas aeruginosa

17

What protein is a marker of muscle damage?

Creatine kinase

19

What causes progressive stiffening of muscle fibres with age?

Loss of elastin

21

Which gene can be knocked out in mice to cause massive muscles?

Myostatin

22

Define sarcopenia

Progressive loss of skeletal muscle mass and strength or performance with aging

23

In which 2 structures is fibrocartilage found?

Menisci and intervertebral discs

23

What percentage of muscle mass must be lost before there is the risk of mortality?

40%

24

How does denosumab treat osteoporosis?

It is a human monoclonal antibody that binds RANKL and iblocks RANK activity => reduces osteoclast activity

25

What type of collagen is in fibrocartilage?

Type 1

25

What is a compound fracture?

Open fracture, ie bone exposed to external world

25

What are the 2 major processes during the inflammatory phase of fracture healing?

Haematoma and granulation tissue

26

What are the 2 layers of the periosteum?

Inner cellular layer with osteoprogenitor cells Outer fibrous layer

27

Which bone cells are multinucleate?

Osteoclasts

29

In what direction do osteoclasts dig their holes in bone?

Along the stress axis of the bone

30

What are osteons aka?

Haversian systems

31

What is at the end of a bone? (-physis)

Epiphysis

32

What are the main types of muscle atrophy?

Disuse atrophy

Denervation atrophy

Cachexia

33

What is a comminuted fracture?

Fracture with more than 2 bits of bone

34

What percentage of cases of osteomyelitis occur in children <5 years old?

50%

35

Over what time frame does the soft callus phase of fracture healing occur?

Days to weeks

37

What is osteomyelitis better known as?

Bone infection

39

What is the proper way to say 'bone infection'?

Osteomyelitis

41

Which bones are most commonly involved in osteomyelitis?

Long bones: femur, tibia, humerus

43

What is a pathological fracture?

Fracture where underlying bone pathology has made it more vulnerable to fracture

45

How do tendons and ligaments attach to bone?

Sharpey's fibres

46

What is raloxifene?

Selective oestrogen receptor modulator

47

What are bisphosphonates used to treat?

Osteoporosis

48

In which 3 locations is red bone marrow found in adults?

Skull, scapula and pelvis

50

Which protein is abnormal in Duchenne muscular dystrophy?

Dystrophin

51

What is the scaffolding for bone that is laid down by osteoblasts?

Osteoid

52

What do we call infection of a joint?

Septic arthritis

53

What percentage of the body's calcium is in bone?

99%

53

What effect does oestrogen have on bone?

Maintains bone density by promoting osteoclast apoptosis and increasing life span of osteoblasts and osteocytes

55

Which cells resorb bone?

Osteoclasts

56

How is most calcium lost from the body?

Urine

58

What is the main complication with a compound fracture?

Infection

60

Which cells are osteoblasts modified from?

Fibroblasts

61

What is a greenstick fracture?

Only one side of cortical bone is broken

62

How do bisphosphonates work?

They are an analogue of pyrophosphate thus taken up into bone matrix Taken up by osteoclasts, causing apoptosis

63

What do osteoclasts secrete?

HCl and proteases

65

What effect does PTH have on [Ca2+] in plasma?

Increases it

67

How long do most lower limb fractures take to heal?

12-16 weeks

68

What can be done to attenuate sarcopenia?

Strength training

68

Decreases in which 3 hormones are thought to be related to sarcopenia?

Growth hormone, IGF-1 and testosterone

69

What do osteoblasts turn into when they are less active?

Osteocytes

70

What is the name of the process by which long bones grow in length?

Endochondral ossification

72

What effect does PTH have on plasma [phosphate]?

Decreases

74

What is another name for cortical bone?

Compact bone

76

Which cells build bone?

Osteoblasts

78

Which two conditions are especially common in travellers to Asia?

Dengue fever and typhoid fever

79

Which cells are responsible for ongoing maintenance of cartilage?

Chondrocytes

80

What is calcitriol?

VitD3

81

How long do most upper limb fractures take to heal?

6-8 weeks

82

What is a complete fracture?

A bone is broken all the way through

84

What is the most common pathogen in osteomyelitis?

Staph aureus

85

How does PTH increase VitD levels?

PTH activates the kidney enzyme to hydroxylate/activate VitD3

87

What are 4 synonyms for the inner bit of a bone?

Medullary; cancellous; trabecular; spongy

89

Which NSAID should not be given for gout?

Aspirin

90

What does PTH cause osteoblasts to do?

Release OPG and RANK ligand to activate osteoclasts

91

What is Gower's sign?

Muscle weakness causes difficulty getting of floor, so Pt uses accessory muscles such as arms to help themselves get up

92

What is a sarcolemma?

Cell membrane of skeletal muscle

94

Where do osteoprogenitor cells usually reside?

Periosteum or endosteum

95

What type of muscle is more susceptible to sarcopenia?

Fast fatiguable

96

What is the goal of management of a fracture?

Unite the ends of the fractured bone

97

Over what time frame does the inflammatory phase of fracture healing occur?

Days

98

What is the antibiotic of choice for osteomyelitis?

Flucloxacillin

99

What are the 2 major processes during the soft callus phase of fracture healing?

Progenitor cells turn into chondrocytes Chondrocytes form cartilage

100

What is the role of dystrohpin?

It i links actin in the cytoskeleton to laminin via glycoproteins

101

What is at the middle of a bone? (-physis)

Diaphysis

102

What type of cell is in hyaline cartilage?

Chondrocyte

103

Name 4 things found inside a Haversian canal

Capillary, nerve, supportive connective tissue and lymphatic

104

For joint pathology, what will be the consequence of fibrillation and sloughing of articular cartilage?

Loss of joint space

105

For joint pathology, what will be the consequence of calcification of periarticular cartilage and synovium?

Osteophytes

106

For joint pathology, what will be the consequence of synovial fluid entering bone?

Subchondral cysts

107

For joint pathology, what will be the consequence of thickening of subchondral bone and trabeculae?

Subchondral sclerosis

108

What are the 4 main components of hyaline cartilage?

Type 2 collagen

Glycoaminoglycans

Chondrocytes

Water

109

What type of blood vessels are present in hyaline cartilage?

None

110

What type of nerves are present in hyaline cartilage?

None

111

How is hyaline cartilage nurished?

Perfusion by compression and decompression of the cartilage 

112

What is added to plasma filtrate in the formation of synovial fluid?

Hyaluronic acid

113

What are the two types of cell in synovium?

Type A cells (macrophage-like)

Type B cells (fibroblast-like)

114

Give a 4 word definition of the pathophysiology of osteoarthritis

Chronic degeneration of cartilage

115

Which disease is characterized by degeneration of cartilage that results in structural and functional failure of synovial joints?

Osteoarthritis

116

How would you explain osteoarthritis to a lay person in 5 words?

Wear and tear of joints

117

At what time of day is pain from osteoarthritis worse?

At the end of the day

118

Pain at the end of the day suggests what type of arthritis?

Osteoarthritis

119

Which joints tend to be most affected by osteoarthritis?

Weight-bearing joints

120

At what time of day does pain from rheumatoid arthritis tend to be worst?

In the morning

121

Morning stiffness of joints suggests what type of arthritis?

Rheumatoid arthritis

122

Which disease is characterised by autoimmune inflammatory joint disease with systemic involvement?

Rheumatoid arthritis

123

What is podagra?

Gout in the great toe

124

What do we call gout in the big toe?

Podagra

125

Define gout

Very painful

acute inflammation

due to accumulation of uric acid crystals

in a joint

126

In which part of bone would you find osteons?

Cortical bone

127

What are 3 signs of osteoarthritis?

Reduced ROM

Crepitus

Osteophytes

128

What are 3 microscopic pathological features of rheumatoid arthritis?

Mononuclear infiltrate

Synovial hyerplasia forming pannus

Germinal centres 

129

List 3 signs of rheumatoid arthritis

Inflamed joints

Rheumatoid nodules

Destruction and deformity of joints

130

Which joints of the hand are often spared in rheumatoid arthritis?

Distal interphalangeal joint

131

What diagnosis should you consider when someone presents with swollen joints, nodules and deformed joints?

Rheumatoid arthritis

132

What is the prevalence of rheumatoid arthritis?

1% of the population

133

List 3 x-ray features of rheumatoid arthritis

Juxta-articular osteopaenia

Subchondral erosions

Uniform joint space loss

134

What percentage of rheumatoid arthritis is genetic?

50%

135

List 3 risk factors for rheumatoid arthritis

Female gender

Age 25-55

Smoking

136

Accumulation of what causes gout?

Uric acid crystals

137

What are tophi?

Uric acid crystal depositions in soft tissues other than joints

138

What is the cardinal sign of gout?

Acutely inflamed, intensely painful joint

139

What type of inflammation is caused by tophi?

Granulomatous inflammation

140

What is the gold standard diagnostic test for gout?

Joint or tophus aspiration during an acute attack