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SSC > Osteoporosis > Flashcards

Osteoporosis Flashcards

1
Q

What is a fragility fracture?

A

A fracture caused by falling from standing height due to weakened bones

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2
Q

What is the definition of osteoporosis?

A

A skeletal disorder characterised by compromised bone mineral density, quality and strength which predisposes an individual to increased risk of fracture

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3
Q

What are the major risk factors for osteoporosis?

A

Age, sex, previous fracture

Long term steroid use, family history

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4
Q

What populations are most and least likely to fracture their bones and why?

A

Most likely - Europeans/Caucasians; longer head of femur

Less likely - Asians/Africans; shorter neck of femur, physically larger bones

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5
Q

Why do those at highest risk of osteoporosis need to be identified?

A

Bone loss is asymptomatic and therapy need to be targeted to those who will benefit most

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6
Q

What is the approximate turnover of cortical and trabecular bone?

A

Cortical 4%

Trabecular 20%

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7
Q

What is FRAX?

A

Fracture risk assessment tool which gives the 10 year probability of a fracture by combining several risk factors

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8
Q

At what percentage risk of fracture would an individual be treated?

A

20%

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9
Q

What are the limitations of FRAX?

A

Not all risk factors are covered
Lacks detail
Epidemiological data required

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10
Q

Why must treatment options be balanced carefully with the patient’s age?

A

All therapy options have limitations on length of their use and there is no evidence that they have beneficial effects when used thereafter

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11
Q

What are the mortality and morbidity statistics of a hip fracture in an elderly patient?

A

33% mortality
67% survival (70% independent, 30% dependent)
Large proportion of independent patients using walking aids

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12
Q

What is the only drug used for osteoporosis which encourages bone growth?

A

Teriparatide (PTH)

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13
Q

How can fracture risk be reduced?

A

Decrease bone turnover
Increase bone mineral density
Increase bone quality

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14
Q

What are the modifiable risk factors for osteoporosis?

A

Smoking, weight, alcohol, exercise, diet

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15
Q

What is the most common cause of iatrogenic osteoporosis?

A

Long term (>3 months) steroid use (>7.5mg prednisolone or equivalent)

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16
Q

What iatrogenic causes of osteoporosis are there?

A

Phenytoin, heparin, immunosuppressants, depo-provera

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17
Q

What are the common secondary causes of osteoporosis?

A

Rheumatoid arthritis, transplantation (immunosuppression), anorexia nervosa, chronic liver disease, coeliac disease, hyperparathyroidism, irritable bowel syndrome, steroids, male hypogonadism, renal disease, depo-provera, vitamin D deficiency, excess alcohol, smoking

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18
Q

What factors are involved in peak bone mass?

A

Genetics, nutrition, hormones, lifestyle

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19
Q

What are the problems with monitoring treatment of osteoporosis?

A

Slow response, low signal/noise ratio, increased bone mineral density may not be an adequate marker

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20
Q

Why are vertebral fractures important to identify?

A

Often silent and unrecognised but increase risk x2

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21
Q

What types of vertebral fractures are there?

A

Concave deformity, wedge fracture, compression fracture

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22
Q

Which cancers can most commonly give rise to bone metastases?

A

Breast, prostatic, colonic

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23
Q

What are the risk factors for falling?

A

Vision, balance, medication, dizziness, footwear, home, environmental

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24
Q

What are the causes of osteoporosis in men?

A

Primary (idiopathic) - 50%

Secondary (glucocorticoids, alcoholism) - 50%

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25
Q

What are the treatment options for men with osteoporosis?

A

Same as women despite lack of evidence

Androgens, limit glucocorticoids, thiazides

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26
Q

What do osteocytes secrete and what does it do?

A

Sclerostin to inhibit Wnt signalling

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27
Q

What is the role of magnesium in the kidneys?

A

Co-factor for parathyroid hormone

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28
Q

What body status affects calcium protein binding?

A

Acid-base balance

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29
Q

In what months is an appropriate wavelength of UVB available in the UK?

A

May - September

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30
Q

What are the biochemical changes in osteoporosis?

A

Everything normal, 25 OH vitamin D low

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31
Q

What are the biochemical changes in osteomalacia?

A

Calcium, phosphate, 25 OH vitamin D - low

Alkaline phosphatase, PTH - high

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32
Q

What are the biochemical changes in primary hyperparathyroidism?

A

Phosphate, 25 OH vitamin D - low

Calcium, alkaline phosphatase, PTH - high

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33
Q

What are the biochemical changes in secondary hyperparathyroidism?

A

Calcium - low
PTH - high
Phosphate - unchanged

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34
Q

What is the Scottish vitamin D deficiency reference amount?

A

<20 nmol/L

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35
Q

What must be considered alongside vitamin D for accurate measurement?

A

C-reactive protein

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36
Q

What are the risk factors for vitamin D deficiency?

A

Age (>65), decreased sun exposure, dark skin, pregnancy/breastfeeding

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37
Q

What is the normal vitamin D supplement concentration?

A

800-1000 IU/day

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38
Q

What are the main drugs used to treat osteoporosis?

A

Bisphosphonates, calcium and vitamin D, denusomab, HRT, raloxifene, teriparatide

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39
Q

What is the aim of osteoporosis treatment?

A

Reduce fracture risk by 50%

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40
Q

What is the mechanism of action of bisphosphonates?

A

Bind to calcium salts in the body/skeletal bone and is then taken up by osteoclasts which reduces their resorption

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41
Q

What is the difference between simple and nitrogenous bisphosphonates?

A

Simple - metabolised to cytotoxic ATP analogues to promote apoptosis
Nitrogenous - inhibit farnesyl diphosphate synthetase to prevent prenylation of small GTPases necessary for osteoclast function

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42
Q

What advice is given to patients before starting bisphosphonate therapy?

A

Complete dental work before starting and attend regular 6 monthly dental appointments while on therapy

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43
Q

Why are calcium and vitamin D supplements required alongside bisphosphonate therapy?

A

Decrease in bone resorption will decrease free calcium leading to paraesthesia/spasms

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44
Q

What is the mechanism of action of denusomab?

A

Binds and inhibits RANKL to prevent osteoclast resorption

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45
Q

What are the benefits and limitations of teriparatide?

A

Benefits - only anabolic treatment option, very effective for vertebral fractures
Limitations - not suitable for patients with history of malignancy, daily injections over 2 years, no hip fracture data

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46
Q

How long are the courses of alendronate and zolendronate?

A

Alendronate - 5 years (can be used for a further 5 years)

Zolendronate - 3 years

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47
Q

How is alendronate administered?

A 
Daily
Oral (tablets or solution)
10mg 
With water 
Upright position (maintained for 30 minutes)
Wait 4 hours before taking calcium
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48
Q

What are the contraindications of alendronate?

A 
Pregnancy and breastfeeding 
Kidney dysfunction (eGFR <35 ml/min)
Gastrointestinal problems (oesophageal abnormalities, ulcers)
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49
Q

What are the side effects of alendronate?

A

Oesophageal irritation, indigestion, abdominal pain
Atypical femoral stress fracture (persistent thigh pain)
Osteonecrosis of the jaw

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50
Q

Why are x-rays not used diagnostically in osteoporosis?

A

Only identifies depletion of bone >30%

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51
Q

What are x-rays used to investigate?

A

History of pain, height loss, acute bone pain, fracture investigation

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52
Q

How much bone loss does a T-score of -2.5 relate to?

A

15-20%

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53
Q

What x-ray features of osteoporosis can be seen on x-ray?

A

Decreased joint space, bony spurs (osteophytes)

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54
Q

What is the anterior/hunched curvature of the spine called?

A

Kyphosis

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55
Q

What wrist fracture is associated with osteoporosis/elderly patients?

A

Colles’ wrist fracture

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56
Q

What conditions are isotope bone scans useful for?

A

Paget’s, metastatic disease

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57
Q

What is multiple myeloma?

A

Malignancy of plasma B cells causing proliferation of a single clone which produces abnormal immunoglobulin (monoclonal paraproteins)
Plasma cells activate osteoclasts resulting in osteolytic bone lesions

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58
Q

At which stage of sample processing is there the highest percentage of error?

A

Pre-analytical phase - 68% human error

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59
Q

What is the difference between plasma and serum?

A

Plasma still has clotting factors present, serum does not

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60
Q

What substances can affect lab results and when might this happen?

A

Alkaline phosphatase - high in babies/children when growth is occurring
Cholesterol - increased in adolescence
Urate - increases with age and decreased renal function

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61
Q

What factors can affect lab tests?

A 
Sex steroids and gonadotrophins
Body composition 
Fasting 
Time
Stress
Medication
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62
Q

What analytical and post-analytical errors can occur in sample testing?

A

Analytical - operator error, miscalibration

Post - failure to communicate results, software error

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63
Q

What are the 2 main methods used to test samples?

A

Spectrophotometry - U&Es, LFTs; 2 minutes, small sample needed
Immunoassay - testosterone, cortisol; 20 minutes, large sample needed

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64
Q

What are the effects of oestrogen/androgen on bone and how do they act?

A

Slow bone remodelling and protect against bone loss
Increase osteoblast acitivty, decrease osteoclast activity
Sex steroid receptor and local biosynthesis on bone cells

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65
Q

What are the 3 forms of testosterone in the body?

A

Free (active)
Bound to steroid hormone binding globulin
Bound to albumin (active)

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66
Q

At what time of day does testosterone reach its peak?

A

Morning

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67
Q

What are the heavy and light chain options for immunoglobulins?

A

Heavy - IgM, IgA, IgD, IgG, IgE

Light - kappa, lambda

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68
Q

What is a poor prognostic marker in multiple myeloma?

A

Free light chain proteins in urine

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69
Q

How are paraproteins in multiple myeloma identified?

A

Serum protein electrophoresis

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70
Q

How are paraproteins in multiple myeloma typed?

A

Serum immunofixation

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71
Q

What is the gold standard method of measuring bone turnover?

A

Radiotracer kinetic studies

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72
Q

How long do formation and resorption take?

A

Formation - 3-6 months

Resorption - 10-20 days

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73
Q

What 2 types of bone markers can be measured?

A

Bone matrix components

Enzymatic activity

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74
Q

What is the main bone marker for resorption?

A

Serum collagen type I telopeptides (CTx)

Others - calcium, hydroxyproline, pyridinium

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75
Q

What is the main bone marker for formation?

A

Serum collagen type I propeptides (P1NP)

Others - bone alkaline phosphatase, osteocalcin

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76
Q

What is tartrate resistant acid phosphatase?

A

Bone marker
Dissolves matrix
Type 5b in bone (5a in prostate)
Not affected by food intake

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77
Q

How are bone markers validated?

A

Must change in parallel manner with turnover - high in high turnover, low in low turnover

78
Q

What factors affect bone markers?

A

Nutrients, lifestyle, medication, fasting, time, subject variability

79
Q

What percentage difference is needed for changes in a bone mineral scan to be significant?

A

3-4%

80
Q

What affect can suppression of CTx have on P1NP?

A

P1NP suppression

81
Q

What are the potential applications of bone markers?

A

Identification of osteopenia
Monitoring disease of rapid bone loss (e.g. stroke, SCI, immobilisation)
Supplement to FRAX and BMD
Response monitoring
Compliance testing
Tailoring choice of treatment to degree of turnover (high = anti-resorptive, low = anabolic)

82
Q

What are the limitations of using bone markers?

A

No quality control
Variability
Lack of reference ranges

83
Q

Why do bones need to bear weight?

A

Weight bearing pulls on the muscle and periosteum which encourages bone growth (thickness)

84
Q

What non-pharmacological treatments are there for osteoporosis?

A

Exercise

85
Q

What type of exercise is required for osteoporosis therapy?

A

Low impact weight bearing

On feet for 4 hours a day

86
Q

Why is calcium supplementation best avoided if possible?

A

Risk of arrhythmia and renal stones

87
Q

How frequently is a DEXA usually repeated?

A

Every 2 years

88
Q

What is the result of steroid induced osteoporosis?

A

Increased osteoclast and decreased osteoblast activity
Decreased calcium absorption in gut
Impaired tissue healing

89
Q

How can steroid induced osteoporosis be managed?

A

Decrease steroid dose
Alternative route of administration
Maintain good nutrition

90
Q

When would a DEXA scan not be required to diagnose osteoporosis?

A

2 or more vertebral fractures

91
Q

What is osteogenesis imperfecta?

A

Collagen I defect

Prone to fracture, ligamentous laxity, blue tint sclera

92
Q

What is pseudohypoparathyroidism?

A

Parathyroid hormone is present but not able to act

93
Q

What is Looser’s zone?

A

Pseudo fracture/non-mineralised cartilage in osteomalacia

94
Q

What does DEXA stand for?

A

Dual-energy x-ray absorptiometry

95
Q

How is single-energy x-ray absorptiometry carried out?

A

X-ray passed through wrist or heel while immersed in water to remove effects of soft tissue

96
Q

How is dual-energy x-ray absorptiometry carried out?

A

2 x-ray beams of different energy levels (one reduced more by bone and the other by soft tissue) passed through hip and spine

97
Q

What are the 3 images taken by the DEXA scan and what are they used for?

A

Hip - neck of femur density
Lumbar spine - T1-4 density
Lateral spine - vertebral fracture

98
Q

What is the T-score range for osteopenia?

A

-1 to -2.5

99
Q

What is the T-score range for osteoporosis?

A

Less than -2.5

100
Q

What is a T-score?

A

Statistical value
Compares patient bone density to a standard group of young (25-29) white females
Amount of standard deviations from average gives T-score

101
Q

What is the T-score a strong indicator of?

A

Fracture risk

102
Q

What is a Z-score?

A

Compares patient bone density to people of the same age, sex and ethnicity

103
Q

What factors are important to ensure repeatability of a DEXA scan?

A 
Positioning of the patient 
Using the same machine 
Using the same operator 
No repeat within 1 year 
Artefacts
104
Q

Why are DEXA scans not repeated within 1 year?

A

Errors in positioning and machine calibration exceed the maximum changes bones can achieve in this time

105
Q

What are the limitations of DEXA scanning?

A

Not suitable for patients who cannot lie down
Affected by contrast agents etc from other scans
Results can be affected by artefacts/degenerative changes
Height and weight required - patient needs to stand
2 dimensional
Combines cortical and trabecular measurements

106
Q

What are the benefits of DEXA scanning?

A 
Low radiation dose
Quick 
Precise
Scan speed/exposure can be adjusted 
Cheap 
Can monitor efficacy of treatment
107
Q

How is zolendronate administered?

A

5mg over 15 minutes yearly for 3 years

Patient should be well hydrated

108
Q

What is the most common side effect of zolendronate?

A

Flu-like symptoms - mild fever, headache, muscle/joint/bone pain

109
Q

What effect do bisphosphonates have on osteocytes?

A

Prevent osteocyte apoptosis; anti-fracture effect

110
Q

What drugs are licensed for treatment of osteoporosis in men?

A

Alendronate, risedronate, zoledronate, denosumab, teriparatide

111
Q

What factors affect compliance of osteoporosis drugs?

A 
Silent disease 
Failure to perceive benefits vs side-effects 
Relative importance 
Polypharmacy 
Lack of understanding
Inconvenient dosing regimens
112
Q

What new agent is under development to treat osteoporosis and how does it work?

A

Anti-sclerostin antibodies
E.g. romosozumab
Monoclonal antibody binds sclerostin to increase bone formation and decrease resorption - reduces vertebral fracture risk

113
Q

How much does fracture risk increase with each T-score unit reduction?

A

2.5x

114
Q

What are DEXA, QCT and QUS used for?

A

DEXA and QCT - diagnosis and monitoring

QUS - risk assessment

115
Q

What are the advantages of QCT?

A

Sensitive
Direct measurement of trabecular bone
3 dimensional volume measurement

116
Q

What are the disadvantages of QCT?

A

Higher radiation
Less precision
More expensive

117
Q

What are the advantages of QUS?

A

Inexpensive
Portable
No radiation

118
Q

What are the disadvantages of QUS?

A

Unknown effectiveness of fracture risk prediction and osteoporosis diagnosis

119
Q

What is scintigraphy?

A

Isotope bone scan

Radioactive fluid injected and taken up by bones which are scanned after 3 hours for osteoblastic activity

120
Q

What is the composition of bone?

A

70% inorganic hydroxyapatite

30% organic/water collagen I and non-collagenous proteins

121
Q

Outline the bone remodelling cycle

A

Quiescence, resorption, reversal, formation

122
Q

Which hormones increase osteoblast activity?

A 
Growth hormone 
Oestrogen 
Growth factors 
25 OH vitamin D 
Calcitonin
123
Q

Which hormones increase osteoclast activity?

A

Cytokines
Parathyroid hormone
1,25 OH vitamin D

124
Q

What percentage of calcium is in the bones?

A

99%

125
Q

How is calcium distributed in extracellular fluids?

A

41% bound to albumin
9% calcium salts
50% ionised/free

126
Q

What hormones increase blood calcium?

A

Parathyroid hormone

1, 25 OH vitamin D

127
Q

What hormones decrease blood calcium?

A

Calcitonin

25 OH vitamin D

128
Q

What are the actions of parathyroid hormone?

A

Mobilises calcium from bone
Increase renal retention of calcium
Increase renal phosphate excretion
Increases renal production of 1, 25 OH vitamin D

129
Q

Outline the vitamin D pathway

A

Sunlight → skin → 7-dehydrocholesterol → cholecalciferol → liver → 25 hydroxyvitamin D → kidney → 1, 25-dihydroxyvitamin D → calcium maintenance

130
Q

Name sources of vitamin D2 and D3

A

D2 - plants

D3 - fish, liver, milk, egg yolk

131
Q

What are the gut and bone effects of vitamin D?

A

Gut - increases calcium and phosphate absorption

Bone - increases resorption and formation

132
Q

What are the effects of vitamin D deficiency on bones?

A

Decreased calcium absorption
Decreased bone mineral density
Induction of secondary hyperparathyroidism
Increased bone turnover/remodelling/loss/fracture

133
Q

What are the effects of vitamin D deficiency on muscles?

A

Muscle weakness

Abnormalities in contraction and relaxation

134
Q

What are the classifications for vitamin D levels?

A

<20 nmol/L - deficient
20-49 - insufficient
50-70 - sufficient
>70 - optimal

135
Q

How can breastfeeding lead to vitamin D deficiency in infants?

A

Vitamin D passes poorly into human milk

136
Q

What are the common symptoms of vitamin D deficiency?

A

Bone pain, muscle pain, muscle weakness, irritability, rickets/osteomalacia, falls/fragility fractures, developmental delay

137
Q

What are the severe symptoms of vitamin D deficiency?

A

Neonatal hypocalcaemia

Infant cardiomyopathy

138
Q

What are the symptoms of rickets?

A

Bone pain, poor growth, beaded ribs, bowed legs, knock knees, curvature of the spine, widening of ankles/wrists/knees, softening of bones including the skull (craniotabes), delayed closure of fontanelles, waddling gait, delayed walking, short stature, dental caries

Extreme cases -
hypocalcaemia (convulsions, irritability, tetany, breathing difficulties, cardiac arrest and heart failure)

139
Q

What is the structure of CTx?

A

Two 8 amino acid stretches with various crosslinks (pyridinoline and deoxypyridinoline)

140
Q

What are the 2 forms of TRACP?

A

TRACP 5a - macrophages

TRACP 5b - osteoclasts

141
Q

What are the advantages of TRACP 5b over CTx?

A

Does not accumulate in circulation in renal/hepatic failure
Diurnal variation is low
Not affected by feeding

142
Q

What are the aims of pharmacological management of osteoporosis?

A

Target therapy to those with a high probability of fractures
Reduce incidence of fractures
Alleviate fracture related morbidity

143
Q

How much calcium should postmenopausal women aim to ingest per day?

A

1000mg

144
Q

What medications have been proven to reduce vertebral and non-vertebral fracture risk?

A

Alendronate, risendronate, HRT, zolendronate

145
Q

When is teriparatide prescribed for osteoporosis?

A

> 65 years old with T-score -3.5 and 2 previous vertebral fractures/>3 other, intolerant to bisphosphonates despite PPIs

Failure to respond to bisphosphonates, vertebral fracture/>2 other

146
Q

List non-pharmacologic therapies for osteoporosis

A 
Orthoses (spine brace, hip protector)
Exercise 
Calcium and vitamin D supplement 
Fall prevention 
Kyphoplasty 
Patient education and lifestyle measures
147
Q

What are the advantages of exercise in osteoporosis?

A

Muscle strength, flexibility, balance, self-confidence, decreased risk of falling, increased bone mineral density

148
Q

What types of exercise are useful in osteoporosis?

A 
Spinal extension/flexion 
Low impact weight bearing 
Strength training 
Tai chi 
Physiotherapy classes
149
Q

Why should calcium supplements be taken with food?

A

Calcium carbonate requires an acidic environment

150
Q

How can falls be prevented in the elderly?

A 
Gait analysis
Environment modification
Medication review
Exercise assessment
Provision of assistive devices
Identification of concomitant neuromuscular condition
151
Q

What is vertebral kyphoplasty?

A

Minimally invasive spine procedure involving infiltration of bone cement into vertebral body after fracture
For relatively acute, painful compression to diminish pain and reduce kyphosis

152
Q

How does bone grow?

A

In length by endochondral ossification
In width by subperiosteal opposition
Medullary cavity is expanded by endosteal bone resorption

153
Q

Name a bone disease where there is loss of mineralisation

A

Osteomalacia/rickets

154
Q

Name a bone disease where there is low bone mass

A

Osteoporosis

Osteogenesis imperfecta

155
Q

Name a bone disease where there is high bone mass

A

Osteopetrosis

156
Q

Name a bone disease where there is high bone turnover

A

Pagets
Hyperparathyroidism
Thyrotoxicosis

157
Q

Name a bone disease where there is low bone turnover

A

Adynamic disease

Hypophosphatasia

158
Q

What would be the biochemical findings in rickets?

A

Calcium - normal/low
Phosphate - normal/low
Alkaline phosphatase - high

159
Q

What types of rickets are there?

A 
Nutritional 
Congenital 
Premature 
Genetic 
Neoplatic 
Hypophosphataemic
Drug-induced
160
Q

What would be the biochemical findings in vitamin D deficiency?

A 
25 OH vitamin D - low
1, 25 OH vitamin D - normal/low
Calcium - low
Parathyroid hormone - high
Alkaline phosphatase - high
Phosphate - low
161
Q

What enzyme is needed for the first hydroxylation of vitamin D?

A

Alpha 1 hydroxylase

162
Q

In what disease is alpha 1 hydroxylase mutated?

A

Vitamin D dependent rickets type 1

163
Q

In what disease is the vitamin D receptor defective?

A

Vitamin D dependent rickets type 2

164
Q

What is hypophosphataemic rickets?

A

Impaired renal tubular absorption of phosphate
FGF-23 mutation
Low phosphate, high alkaline phosphatase

165
Q

What is osteodystrophy?

A

Renal rickets
Failure of kidney to excrete phosphate which binds to calcium and causes parathyroid hormone to be released which leaches calcium from bone

166
Q

What are the biochemical findings in renal rickets?

A

Calcium - low
Phosphate - high
Alkaline phosphatase - high
Parathyroid hormone - high

167
Q

How is renal rickets treated?

A

High dose vitamin D

168
Q

What are the consequences of renal rickets?

A

Stunted growth, pasty face, rachitic deformity, myopathy

169
Q

What is osteomalacia?

A

Reduced mineralisation of bone matrix due to calcium deficiency

170
Q

What are the causes of hypercalcaemia?

A

Primary hyperparathyroidism, malignancy, excess vitamin D, calcium supplementation, granulomatous disease, thiazides

171
Q

What are the clinical features of hypercalcaemia/primary hyperparathyroidism?

A

Bones (resorption, brown tumours), stones (kidney), groans (muscle pain), moans (depression)

172
Q

What are the biochemical findings in hypercalcaemia?

A

Calcium - high
Phosphate - low
Alkaline phosphatase - high
Parathyroid hormone - high

173
Q

What is measured in hypercalcaemia to determine the cause?

A

Parathyroid hormone
Undetectable - malignancy
Detectable - adenoma

174
Q

What are the causes of hypocalcaemia?

A

Hypoparathyroidism, vitamin D deficiency, renal disease, magnesium deficiency, anticonvulsant treatment, citrated blood transfusion

175
Q

What are the clinical features of hypocalcaemia?

A

Tingling, numbness, muscle cramps, tetany, convulsions, behavioural disturbance, cataracts, coagulation defects

176
Q

What is measured in hypocalcaemia to determine the cause?

A

Check for renal disease and then parathyroid hormone
Low - post-surgical, magnesium deficiency, idiopathic
High - vitamin D deficiency, pseudohypoparathyroidism

177
Q

What endocrine disorders can cause osteoporosis?

A

Cushings

Hyperthyroidism

178
Q

What happens to bones in menopausal/oestrogen deficiency osteoporosis?

A

Reduced bone mineral mass but normal mineral to matrix ratio
Higher resorption rates than formation

179
Q

What is Paget’s disease?

A

Increased rate of bone turnover with development of disorganised woven bone

180
Q

What are the symptoms/complications of Paget’s disease?

A

Leg bowing, fractures, enlarged teeth, pain
Hypervascularity causing high output heart failure
Deafness, arthritis, osteosarcoma, stroke, paralysis

181
Q

How is Paget’s disease treated?

A

Bisphosphonates

182
Q

How is osteogenesis imperfecta treated?

A

Bisphosphonates

Surgery for fractures/deformities

183
Q

What is osteopetrosis?

A

Failure of osteoclast and chondroclast resorption = remodelling failure
Genetic disorder

184
Q

What is fluorosis?

A

Abnormal matrix mineralisation

Fluoride replaced calcium in hydroxyapatite

185
Q

What are the side-effects of teriparatide therapy?

A

Common - anaemia, depression, dizziness, dyspnoea, fatigue, GI disorders, haemorrhoids, headache, muscle cramps, nausea, palpitation
Uncommon - hypercalcaemia, injection-site reactions, urinary disorders
Rare - hypersensitivity reactions

186
Q

What are the contraindications of teriparatide therapy?

A

Pregnancy/breastfeeding, renal impairment, metastatic disease

187
Q

What is OPG?

A

Osteoproteregin

Decoy receptor which binds RANKL to inhibit resorption

188
Q

What is RANK?

A

Receptor for RANKL which activates resorption

189
Q

When is peak bone mass reached in men and women?

A

Men - 15/16

Women - 13/14

190
Q

Outline bone acquisition and loss with age

A

From puberty until 30 - 2-3% annual increase
30-40 years - steady
After 40 - 0.3-0.3% loss (2-3% in menopause)

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