Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

- Y6 Orthopaedics & Rheumatology > Osteoporosis > Flashcards

Osteoporosis Flashcards

1
Q

Define osteoporosis.

A

Osteoporosis is a complex metabolic bone disease characterised by low bone density and micro-architectural defects in bone tissue, resulting in increased bone fragility and susceptibility to fracture

Normal ageing process with normal ratios and normal ALP.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What score defines osteoporosis?

A

T score of equal to or less than -2.5 = osteoporosis i.e. BMD result is equal to, or more then, 2.5 SDs below the young adult mean BMD

T score -1 to -2.5 = osteopenia i.e. The BMD result is between 1 and 2.5 SDs bellow the young adult mean BMD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does DEXA stand for?

A

Dual X ray absorptiometry

?hip and lumbar spine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define T score on DEXA.

A

SD from the mean of a young healthy population (useful to determine risk of #)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define Z score on DEXA.

A

SD from mean of AGE-MATCHED control (useful to identify accelerated bone loss in younger patients)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does DEXA stand for?

A

Dual X ray absorptiometry

?hip and lumbar spine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does T score correlate with fracture risk?

A

For each standard deviation fall in BMD, there is an 1.5-3 fold increase risk of fracture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does osteoporosis usually present?

A

Asymptomatic until fracture occurs - e.g. NOF, Colle’s.

Fall prevention is first-line therapy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When is the Z score used?

A

Children, adolescents, young adults and adults before 50s

T score cannot be used in this population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which bone is most important for DXA scanning in hyperparathyroidism?

A

Forearm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A 56 year old woman sustains a right wrist fracture after a fall. She has a T scores of -2.9 at the neck of femur. Which treatment is most appropriate?

A

Alendronic acid 70mgs once a week and vitamin D3 1000 units once a day - low threshold for post-menopausal women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A 68 year old woman has taken denosumab 60mgs every six months for five years. Her BMD has improved. You decide to stop treatment in order to reduce risks of longer term treatment. How should you advise your patient?

A

Start and continue alendronic acid or zoledronic acid afor 2 years after treatment

NB: Stopping denosumab can be associated with a ‘rebound’ increase in bone turnover, leading to rapid falls in bone density and vertebral fractures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What type of bone is most bone made up of?

A

Cortical 90%

Trabecular 10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the most common sites for osteoporotic fractures?

A
  • Spine
  • Neck of femur
  • Forearm (Colle’s)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the 4 stages of normal bone remodelling?

A
  1. Resorption
  2. Reversal
  3. Formation
  4. Resting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the risk factors for osteoporosis?

A

Constitutional

  • Female gender
  • Age
  • Asian or Caucasian
  • Sex hormone deficiency
  • Previous fragility fracture
  • Family h/o fragility fracture
  • Comorbidities
  • Neuromuscular disorders

Lifestyle

  • Low BMI
  • Smoking
  • Excessive alcohol
  • Prolong immobilisation
  • Low dietary calcium intake
  • Vit D deficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

List 5 modifiable risk factors for fracture.

A
  • Low BMD
  • Steroid use
  • Low BMI
  • Hypogonadism in men
  • Smoking
  • Excessive alcohol intake
  • Poor diet/low Ca intake
  • Vit D deficiency
  • Long term immobilisation
18
Q

What investigations would you do for osteoporosis?

A

DXA scan (dual-energy x-ray absorptiometry) - DIAGNOSTIC, much less radiation than CXR so safe.

  • T score <-2.5 = osteoporosis
  • T score <-2.5 with fragility fracture = severe osteoporosis
  • T score -1 to -2.5 = osteopenia

X-ray - may show osteopenia and or fractures but is NOT DIAGNOSTIC.

Bloods to rule out cause:

  • 25-hydroxyvitamin D levels of <20 nanograms/mL
  • Testosterone deficiency
  • TFTs - ?hyperthyroidism
  • PTH - ?hyperparathyroidism
  • Urinary free cortisol - high in Cushing’s
  • Serum/urine protein electrophoresis - abnormal in myeloma
  • Combination of low serum 25-hVitD, low serum/urine Ca, low serum phosphate and high PTH and AlkPhos = Vitamin D deficiency with or without osteomalacia.
19
Q

How is osteoporosis managed?

A

Conservative:

  • Weight bearing exercise
  • Stop smoking
  • Reduce EtOH
  • Exclude secondary causes e.g. mets, MM, osteomalacia, Paget’s, endocrine (menopause, hyperthyroid)

Medical -

ALL PATIENTS ON CALCUM + COLECALCIFEROL

1st line: Bisphosphonates e.g. alendronate/risedronate PO - bone resorption reduced (morning on empty stomach). NB: check renal function, CI if eGFR <30ml/min → refer. Continue for 5yrs if well tolerated.

Other:

  • Teriparatide SC (PTH derivative) - anabolic
  • Raloxifene PO - SERM, used in post-menopausal women if alendronate CI
  • Denosumab SC = for prevention and treatment; denosumab is a human monoclonal antibody to RANKL, a cytokine that is involved in mediating osteoclast activity.
  • Strontium PO- anabolic + anti-resorptive
20
Q

What is the recommended calcium and vitamin D3 dose daily?

A

calcium - 800-1000mgs daily

vitamin D3 - 1000 units daily

21
Q

Which treatment is used where spinal T scores are very low?

A

Teriparatide = a peptide including the 34 amino acids of the N terminal part of parathyroid hormone. It is self-injected daily and is expensive so not first line.

22
Q

What is the most effective intervention for osteporosis in anorexia nervosa?

A

Weight gain and resumption of periods is better than any other intervention (e.g. COCP, alendronic acid, calcium, vit D3)

23
Q

What drugs for osteoporosis are contraindicated in very low eGFR?

A
  • Alendronic acid
  • Ibandronic acid
  • Risedronate
  • Zolendronic acid

These are all cleared via the kidneys. Denosumab is a monoclonal antibody and so could be used in the situation

24
Q

What is important to check before calculating a FRAX score for a patient?

A

That the correct country has been selected - calculations vary by country

25
Q

What are the conservative measures for management of osteoporosis?

A
  1. Physical activity
  2. Prevention of falls
  3. Protein intake
  4. Fracture Liaison Service ( clinical pathways in liaison with Orthopaedic Units for diagnosis and treatment of osteoporosis in patient with fragility fractures
  5. Calcium and Vit D supplementation
26
Q

What are the categories of pharmacological treatment for osteoporosis?

A

Anti-resorptive

Anabolic

  • Parathyroid hormone
  • Romosozumab
27
Q

Which anti-resorptive treatments are used for osteoporosis?

A

Bisphosphonates, oral or IV - oral 5-10yrs, IV for 3yrs.

  • Oral: Alendronic acid, Etidronate, Risedronate, Ibandronate
  • IV: Zoledronic acid, Ibandronate

Denosumab, s/c

HRT

Selective oestrogen receptor modulators (SERMs) -Raloxifene

Strontium Ranelate

28
Q

What is the MOA of Denosumab?

A

Denosumab= fully human monoclonal antibody (IgG2) to RANKL

RANKL = receptor activator of nuclear factor Kbeta ligand

29
Q

Which anabolic treatments are used for osteoporosis?

A
  • Parathyroid hormone
  • Romosozumab
30
Q

What is the MOA of romosozumab?

A

mAb taregtting sclerostin which is a negative regulator of bone formation produced by osteocytes

31
Q

What is the MOA of bisphosphonates?

A

Synesthetic analogues of pyrophosphate that bind to hydroxyapatite at site of active bone remodelling

32
Q

Name 2 contraindications to bisphosphonate use.

A
  • Women of child bearing age
  • Breastfeeding

Oral bisphosphonates should not be used in:

  • Delayed gastric emptying (i.e. stricture or achalasia)
  • eGFR <30
33
Q

List 5 side effects of bisphosphonates.

A
  • IV: Flu like symptoms (acute phase reaction within 48-72 hrs of treatment
  • Upper GI discomfort ( oral); rarely Oesophageal CA
  • Muscle & bony pain
  • Osteonecrosis of the jaw
  • Atypical fragility fracture of the femur
  • Other : AF, renal toxicity
34
Q

What are the side effects of SERMs vs HRT for osteoporosis treatment?

A

HRT

  • increased risk of breast CA,
  • stroke
  • venous thromboembolism (VTE)

SERMs

  • aggravating menopausal symptoms
  • stroke
  • venous thromboembolism (VTE)
35
Q

Which bisphosphonate is first line after hip fracture?

A

Zolendronic acid

36
Q

What is the MOA of SERMs?

A

SERMs = non-steroidal , partial agonist that act preferentially as agonist in bone but as antagonist in reproductive tissues

37
Q

What is the pathophysiology of osteoporosis?

A

Bone is constantly remodelling.

Osteocytes transmit signals to osteoclasts and osteoblasts which initiates bone remodelling.

Osteoclasts resorb bone matrix by creating resorption pit and then they apoptose sending a signal to osteoblasts to synthesise bone matrix which undergoes minerlisation.

Many factors are involed in regulating bone remodelling e.g. PTH, interleukins, vit D, calcitonin, oestrogen, RANK and RANKL, OPG (osteoprotegerin)

RANKL is expressed by osteoblasts which interact with RANK receptors on osteoclasts. Stimulation of RANK causes osteoclastic formation, function and differentiation. OPG released by osteoblasts naturally inhibitrs RANKL-induced activation of RANK.

38
Q

Why are postmenopausal women at higher risk of osteoporosis?

A

In oestrogen deficiency, overexpression of RANKL activity overrides the natural inhibitory activity of OPG.

There is dysregulation in the bone remodelling process.

39
Q

What are the signs and symptoms of osteoporosis?

A

Asymptomatic until fracture occurs

Low impact fragility fracture. These may indicate or predispose to fracture:

  • Back pain
  • Kyphosis
  • Impaired vision
  • Impaired gait, imbalance, lower-extremity weakness
  • Vertebral tenderness
40
Q

Why might bisphosphonates be given for bony metastases?

A
  • They have good pain relieving properties in most patients
  • They reduce bone turnover
  • They decrease progression of bony metastases
41
Q

What are bisphosphonates analogues of?

A

Bisphosphonates are analogues of pyrophosphate - which usually inhibit mineralisation of bone so they reduce resorption of bone in dose dependant manner by inhibiting recruitement and promiting apoptosis of osteoclasts. They are also incorporated into the bony matrix, and thus may be released by osteoclasts when they resorb bone.

42
Q

What is shown here?

A

X ray of lateral thoracic spine

This shows a wedge fracture of T vertebral body - bones are osteopenic, there is kyphosis and a crush fractue in the lower thoracic spine

Osteoporosis is the most common cause of vertebral wedge fracture

- Y6 Orthopaedics & Rheumatology (57 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions