Osteoporosis Flashcards
1
Q
What is osteoporosis?
A
disorder affecting the skeletal system characterised by loss of bone mass - defined by WHO as presence of bone mineral density (BMD) of less than 2.5 standard deviations (SD) below the youn adult mean density
2
Q
Why is detecting osteoporosis important?
A
increases risk of fragility i.e. non traumatic fractures
certain fragility fractures e.g. fractured neck of femur are associated with significant morbidty and mortality
3
Q
What is an example of a certain type of fragility fracture that is assoicated with significant morbidity and mortality?
A
fractured neck of femur
4
Q
What proportion of post-menopausal women will suffer an osteoporotic fracture?
A
50%
5
Q
What are 8 risk factors for osteoporosis?
A
- Female gender
- Age
- Corticosteroid use
- Smoking
- Alcohol
- Low BMI
- Family history e.g. of parental hip fracture
- Rheumatoid arthritis
6
Q
What is recommended by guidelines for screening for osteoporosis?
A
screening tool such as FRAX or QFracture
7
Q
What information do FRAX or QFracture provide when screening for osteoporosis?
A
10 year risk of a patient developing a fragility fracture
8
Q
If a patient has sustained a fragility fracture e.g. Colles’ wrist fracture, what should be done?
A
assess for osteoporosis
9
Q
What type of investigation can be used to assess actual bone mineral density?
A
dual-energy X-ray absorptiometry (DEXA) scan is used
10
Q
What does a DEXA scan look at?
A
bone mineral density, looks at hip and lumbar spine
11
Q
How does the result of the DEXA scan guide treatment?
A
If either hip or lumbar spine have T score of < -2.5, treatment is recommended
12
Q
What is the first line treatment for osteoporosis?
A
oral bisphosphonate such as alendronate
13
Q
What are the 2 most significant risk factors for osteoporosis?
A
advancing age and female sex
14
Q
How does the prevalence of osteoporosis change with age?
A
increases from 2% at 50 years to more than 25% at 80 years in women
15
Q
What are 6 risk factors that are used by major risk assessment tools for fragility fractures, such as FRAX?
A
- History of glucocorticoid use
- Rheumatoid arthritis
- Alcohol excess
- History of parental hip fracture
- Low BMI
- Current smoking
16
Q
What are 8 weaker risk factors for fragility fractures?
A
- Sedentary lifestyle
- Premature menopause
- Caucasians and Asians
- Endocrine disorders: hyperthyroidism; hypogonadism e.g. Turner’s, testosterone deficiency; growth hormone deficiency; hyperparathyroidism; diabetes mellitus
- Multiple myeloma, lymphoma
- GI disorders: IBD, malabsorption e.g. Coeliac, gastrectomy, liver disease
- CKD
- Osteogenesis imperfecta, homocytinuria
17
Q
What are 5 endocrine risk factors for osteoporosis?
A
- Hyperthyroidism
- Hypogonadism e.g. Turner’s, testosterone deficiency
- Growth hormone deficiency
- Hyperparathyroidism
- Diabetes mellitus
18
Q
What are 6 medications (other than glucocorticoids) that may worsen osteoporosis?
A
- SSRIs
- Antiepileptics
- Proton pump inhibitors
- Glitazones
- Long term heparin therapy
- Aromatase inhibitors e.g. anastrozole
19
Q
What are 4 reasons to perform further investigations if a patient is diagnosed with osteoporosis or has a fragility fracture?
A
- Exclude diseases that mimic osteoporosis e.g. osteomalacia, myeloma
- Identify cause of osteoporosis and contributory factors
- Assess risk of subsequent fractures
- Select the most appropriate form of treatment
20
Q
If osteoporosis or fragility fracture are diagnosed, what are 9 further investigations that should be performed?
A
- History
- Physical examination
- FBC
- Sedimentation rate or CRP
- U+Es
- Bone profile - ALP, calcium, phosphate, albumin, creatinine
- LFTs
- TFTs
- DXA (bone denitometry)
21
Q
What are 11 possible additional investigations to perform when osteoporosis/ fragility fracture are diagnosed, if indicated?
A
- Lateral radiographs of lumbar and thoracic spine/ DXA-based vertebral imaging
- Protein immunoelectrophoressi and urinary Bence-Jones proteins (MM)
- 25OHD
- PTH
- Serum testosterone, SHBG, FSH, LH (in men)
- Serum prolactin
- 24 hour urinary cortisol/ dexamethasone suppression test
- Endomysial and/or tissue transflutaminase antibodies (coeliac disease)
- Isotope bone scan
- Markers of bone turnover, when available
- Urinary calcium excretion
22
Q
Who should be assessed for risk of fragility fracture?
A
all woman aged ≥65 and all men aged ≥75 should be assessed
younger patients should be assessed in the presence of any of these 8 risk factors:
- previous fragility fracture
- current use of frquent recent use of oral or systemic glucocorticoid
- history of falls
- family history of hip fracture
- other causes of secondary osteoporosis
- low body mass index (BMI) (less than 18.5kg/m²)
- smoking
- alcohol intake of more than 14 units per week
23
Q
What age group is the FRAX assessment tool valid for?
A
40-90 years
24
Q
What patient population group is the FRAX tool based on?
A
international data - not limited to UK patients
25
Of FRAX and QFracture, which considers more risk factors?
QFracture - e.g. cardiovascular disease, falls, chronic liver disease, diabetes, tricyclic antidepressants
26
When is DEXA recommended to be performed to improve the accuracy of FRAX?
if FRAX without BMD shows an intermediate result
27
What population group is the QFracture tool based upon?
UK primary care dataset
28
Which age group of patients can QFracture be used for?
30-99 years
29
What are 2 situations when NICE recommend arranging BMD assessment i.e. DEXA scan rather than using one of the clinical prediction tools?
1. *_Before starting treatment_* that may have a rapid adverse effect on bone density e.g. sex hormone deprivation for breast or prostate cancer
2. People *_\<40*_ years who have a _*major risk factor_*, such as:
1. history of **multiple** **fragility** **fracture**,
2. _major_ **osteoporotic** **fracture**,
3. or current or recent use of high-dose oral or high-dose systemic **glucocorticoids**
30
If the FRAX assessment is performed without a bone mineral density, what 3 categories can the result lie within for 10-year risk of fragility fracture? What action should be taken for each?
1. Low risk: reassure and give lifestyle advice
2. Intermediate risk: offer BMD test
3. High risk: offer bone protection treatment
31
Once the FRAX assessment has been performed with a bone mineral density measure, what 3 groups can the result be categorised into?
1. Reassure
2. **Consider** treatment
3. **Strongly recommend** treatment
32
What result of QFracture will be given when using this to assess fracture risk?
not a category but raw data relating to risk; this can then be interpreted alongside either local or national guidelines, taking into account certain factors such as patient's age
33
What are 2 situations when you should recalculate a patient's fracture risk i.e. repeat FRAX/QFracture?
1. If original calculated risk was in the region of the intervention threshold for a proposed treatment and only after a minimum of 2 years
2. When there has been a change in the person's risk factors
34
When is treatment for osteoporosis indicated? 2 situations
1. following osteoporotic fragility fractures in postmenopausal women confirmed to have osteoporosis (T-score or -2.5 SD or below)
2. if DEXA scan on screening has identified T score -2.5 or less
35
What is the management for a patient deemed at high risk of fragility fracture from FRAX/QFracture but will a T-score \> -2.5? 3 aspects
1. modify risk factors
2. treat any underlying conditions
3. repeat DXA at interval appropriate for person based on risk profile (usually within 2 years)
36
What is the management of people at low risk of fragility fracture?
Do not offer drug treatment - offer lifestyle advice and follow up within 5 years
37
What is the first-line treatment for osteoporosis (T \< -2.5 on DEXA)?
Bisphosphonates: alendronate first line
38
When might a DEXA scan not be required?
women aged 75 and older, if clinician considers it to be clinically inappropriate or unfeasible
39
What proportion of patients cannot tolerate alendronate and why?
25%, usually due to upper gastrointestinal problems
40
What should the patient be offered next if they don't tolerate alendronate?
risedronate or etidronate - other bisphosphonates
41
What are the 2 options that are recommended if patients can tolerate any bisphosphonates?
1. Strontium ranelate
2. Raloxifene
42
How do the criteria for taking etridonate or risedronate compare to that for alendronate? How about for strontium and raloxifene?
T-score criteria are less, implying these are second line drugs
strontium and raloxifene even lower scores e.g. 60 year old woman would need T score \<-3.5
43
For patients who do not tolerate alendronate, what are 4 things that are taken into account when determing what to use next?
1. T score
2. Parental history of hip fracture
3. Alcohol intake of 4 or more units per day
4. Rheumatoid arthritis
44
For which type of treatment for osteoporosis are the criteria the strictest?
Denosumab
45
Overall what are 9 aspects of treatment of osteoporosis?
1. Bisphosphonates
2. Vitamin D and calcium
3. Raloxifene - selective oestrogen receptor modulator (SERM)
4. Strontium ranelate
5. Denosumab
6. Teriparatide
7. Hormone replacement therapy
8. Hip protectors
9. Falls risk assessment
46
Which particular types of osteoprosis are bisphosphonates particularly good for treating/preventing? 2 things
1. Post-menopausal
2. Glucocorticoid-induced
47
When should vitamin D and calcium supplements be recommended?
should be offered to all women unless clinician confident they have adequte intake and are vitamin D replete
48
What evidence of benefit of vitamin D and calcium exists?
poor evidence base to suggest reduced fracture rates in general population at risk, but may reduce rates in frail, housebound patients
49
What are 4 beneficial effects of raloxifene?
1. Shown to prevent bone loss
2. Reduces risk of vertebral fracures (not non-vertebral though)
3. Increases bone density in spine and proximal femur
4. May decrease risk of breast cancer
50
What are 2 negative effects of raloxifene?
1. Increased risk of thromboembolic events
2. May worsen menopausal symptoms
51
What is the drug class of raloxifene?
SERM: selective oestrogen receptor modulator
52
What is the mechanism of action of strontium ranelate?
dual action bone agent: increases deposition of new bone by osteoblasts (promotes differentiation of pre-osteoblast to osteoblast) and reduces resorption of bone by inhibiting osteoclasts
53
Who can prescribe strontium?
specialists in secondary care only
54
What are 3 risks associated with strontium ranelate?
1. Increased risk of CV events - containdicated if history of CVD/significant risk
2. Increased risk of thromboembolic events - don't use if history of VTE
3. May cause serious skin reactions such as Stevens Johnson syndrome
55
What is the mechanism of action of denosumab?
human monoclonal antibody that inhibits RANK ligand, which in turn inhibits the maturation of osteoclasts
56
How is denosumab given?
single subcutaneous injection every 6 months
57
What does initial data on denosumab suggest for the treatment of osteoporosis?
Effective and well-tolerated
58
What is teriparatide and what is its role?
recombinant form of parathyroid hormone, very effective at increasing bone mineral density but role in management of osteoporosis yet to be clearly defined
59
What is the benefit of HRT for treating osteoporosis/ prevention?
has shown to reduce incidence of vertebral fracture and non-vertebral fractures
60
When is HRT recommended for treatment of osteoporosis?
not recommended for primary or secondary prevention of osteoporosis unless woman is suffering from **vasomotor symptoms**, due to concerns about increased rates of **CVD** and **breast** **cancer**
61
What is the benefit and drawback of hip protectors?
evidence to suggest significantly reduce hip fractures in nursing home patients, but compliance is a problem
62
What is the benefit of performing a falls risk assessment?
no evidence to suggest reduced fracture rates, however do reduce rate of falls and should be considered in management fo high risk patients
63
When does the risk of osteoporosis rise significantly with glucocorticoid therapy?
if patient taking equivalent of prednisolone 7.5mg a day for 3 or more months
64
When should you commence bone protection for glucocorticoid-induced osteoporosis?
start bone protection straight away if going to be at risk - anticipatory management
65
What are the 2 groups that patients are divided into when it comes to glucocortoid-induced osteoporosis and how are they managed?
1. \>65 years or previous fragility fracture: offer bone protection
2. \<65 years: offer bone density scan, with management dependent on score
1. \>0: reassure
2. 0- -1.5: repeat scan in 1-3 years
3. \<-1.5: offer bone protection
66
What are the 3 possibilities for management of patients under 65 who are being treated with glucocortcoids?
based on T score:
1. \>0: reassure
2. 0 to -1.5: repeat densiy scan in 1-3 years
3. \<-1.5: offer bone protection
67
What is the management for patients requiring bone protection for glucocorticoid induced osteoporosis (risk thereof)?
alendronate first line; should be calcium and vitamin D replete
68
What does the management of patients following a fragility fracture largely depend upon?
age: over or under 75 years of age
69
What is the management of patients who've had fragility fracture but who are 75 and older?
presumed to have underlying osteoporosis, should be **started on first-line therapy (oral bisphosphonate)** without need for DEXA scan
70
What is the management of patients who've had fragility fracture but who are \<75 years old?
DEXA scan should be arranged, then enter results in FRAX assessment (along with fact they've had fracture) to determine ongoing fracture risk
71
What is the T score from a DEXA scan based on?
bone mass of young reference population
e.g. T score of -1.0 means bone mass of one standard deviation belo that of young reference population
72
What is the Z score that is generated from a DEXA scan?
score adjusted for age, gender and ethnic factors
73
What are 3 broad categories indicated by the DEXA scan?
1. \> -1.0 normal
2. -1.0 to -2.5 osteopenia
3. \<-2.5 osteoporosis
74
What is one of the commonest sites of osteoporotic fractures and how do they present?
vertebra (in spine) - acute onset back pain but can also be asymptomatic
75
What is the male to female ratio of osteoporosis?
6:1
76
Why is it difficult to determine the prevalence of vertebral osteoporotic fractures?
not all patients present to a clinician and fractures may not always be clearly identifiable on x-ray
77
What are 5 ways that patients with osteoporotic vertebral fractures may present?
1. asymptomatic - can be incidental finding on x-ray
2. acute back pain
3. breating difficulties - changes in shape and length of vertebrae, compression of lungs, heart and intestine
4. gastrointestinal problems - compression of abdominal organs
5. only minority will have history of fall/ trauma
78
What are 3 clinical signs of vertebral fracture?
1. loss of height: compression of spinal vertebrae and reduction in overall spine length
2. kyphosis - curvature of spine
3. localised tenderness on palpation of spinous processes at fracture site
79
What are 3 investigations which may be performed in suspected vertebral fracture?
1. X-ray of spine: first line
2. CT spine: more detailed view of bone structure, can see extent/ features more clearly
3. MRI spine: useful for differentiating osteoporotic fractures from other pathology e.g. tumour
4. assessment for treatment based on age (\> or \<75) - DEXA, riskf factors, treat accordingly
80
What are 2 things that might be found on an x-ray of the spine in vertebral fracture?
1. wedging of vertebra due to compression of bone
2. old fractures - can have sclerotic appearance
81
What is the mechanism of action of bisphosphonates?
inhibit osteoclasts by reducing recruitment and promoting apoptosis.
82
What are 4 clinical uses of bisphosphonates?
1. Prevention and treatment of osteoporosis
2. Hypercalcaemia
3. Paget's disease
4. Pain from bone metastases
83
What are 5 adverse effects of bisphosphonates?
1. Oesophageal reactions: oesophagitis, oesophageal ulcers (especially alendronate)
2. Osteonecrosis of jaw
3. Increased risk of atypical stress fractures of proximal femoral shaft (alendronate)
4. Acute phase response: feer, mylagia and arthralgia may occur following administration
5. Hypocalcaemia: due to reduced calcium efflux from bone (usually clinically unimportant)
84
How does the BNF recommend patients take bisphosphonates?
swallow tablet whole with plenty of water while sitting or standing; to be given on empty stomach at least 30 minutes before breakfast (or other oral meds)
patient should stand or sit upright for at least 30 minutes after
85
What is recommended about the duration of bisphosphonate treatment?
varies according to risk but some recommend stopping bisphosphonates at 5 years if following apply
1. patient is \<75 years old
2. femoral neck T-score of \>-2.5
3. low risk according to FRAX/NOGG
