Metabolic Bone Disease

Question 1

What are some causes of acute onset of severe back pain?

Answer 1

Acute disc disruption +/- nerve root compression
Acute vertebral fracture
Bony metastases

Question 2

What is the likely cause of height loss?

Answer 2

Loss of height of vertebrae/intervertebral disc spaces

Question 3

What are common sites of compression fractures, and why?

Answer 3

Lower thoracic
Upper lumbar
Spine more mobile

Question 4

What are the the three most common endocrine diseases, and are also associated with osteoporosis?

Answer 4

Diabetes
Thyroid disease (mainly hyper)
Primary parathyroid disease

Question 5

What is the investigation used to diagnose osteoporosis?

Answer 5

X-ray

Question 6

What is the investigation used to screen for osteoporosis?

Answer 6

Bone densitometry

Question 7

What is the WHO criteria for osteoporosis?

Answer 7

Normal = equal to or more than -1 T-score
Osteopaenia = between -2.5 and -1 T-score
Osteoporosis = equal to or less than -2.5 T-score
Severe osteoporosis = equal to or less than -2.5 T-score and 1+ fracture

Question 8

What is the Z-score in DXA testing?

Answer 8

Number of standard deviations above and below mean for patient’s age, sex, and ethnicity

Question 9

What is the T-score in DXA testing?

Answer 9

Number of standard deviations above and below mean for healthy 30 year old adult of same sex and ethnicity as patient

Question 10

How can the Z-score be useful in identifying underlying accelerated causes of bone loss?

Answer 10

Score of

Question 11

What is DXA?

Answer 11

Dual energy x-ray absorptiometry

Question 12

What is P1NP?

Answer 12

Bone formation marker

Question 13

What is CTX?

Answer 13

Bone resorption marker

Question 14

What are the common secondary causes of osteoporosis?

Answer 14

Cushing's syndrome
Exogenous corticosteroids
Excessive alcohol use
Smoking
Malabsorption
Primary/secondary hypogonadism

Question 15

What are the less common secondary causes of osteoporosis?

Answer 15

BMI <20 and associated eating disorders
Lack of/excessive exercise
Thyrotoxicosis/thyroxine over-replacement
Primary hyperparathyroidism
Chronic liver/kidney disease
Hypercalciuria
Rheumatoid arthritis/ankylosing spondylitis
T1 and T2D
Multiple myeloma
HIV/its treatment
Mastocytosis
Organ transplant/immunosuppressive drugs
Osteogenesis imperfecta

Question 16

How do you decide on appropriate treatment for osteoporosis?

Answer 16

Patient's/family's wishes
Benefit/risk ratio for each treatment
Severity of disease
Prior treatment
Co-morbidities that might influence choice of medication

Question 17

What are the goals of management in osteoporosis?

Answer 17

Fracture risk reduction
Avoid hip fractures > reduction in mortality
Improve quality of life
- Preserve mobility and independence

Question 18

How do hormone replacement therapy (HRT) and selective oestrogen receptor modulators (SERMs) work?

Answer 18

Stimulate osteoblast activity

Question 19

How do bisphosphonates work?

Answer 19

Inhibit osteoclast formation

Induce osteoclast apoptosis

Question 20

How does denosumab work?

Answer 20

Binds RANKL > osteoclasts not activated

Question 21

How does teriparatide work?

Answer 21

PTH analogue, given intermittently

Stimulates osteoblasts

Question 22

How does strontium work?

Answer 22

Stimulates osteoblasts

Inhibits osteoclast formation

Question 23

What are the contraindications and relative contraindications for strontium use in women?

Answer 23

Contraindications
- History of ischaemic heart disease/peripheral venous disease/cardiovascular disease
- HTN
Relative contraindications
- Significant risk factors for cardiovascular events

Question 24

How are bisphosponates excreted?

Answer 24

Renally

Question 25

How is osteoporosis treatment different in chronic kidney disease?

Answer 25

Stage 1-3a = same as patients without chronic kidney disease
Stage 3b = Caution with IV bisphosphonates; dose reduction with oral bisphosphonates
Stage 4 = bisphosphonates with hypocalcaemia precaution
Stage 5 = no data

Question 26

What are the presentations at different stages of osteonecrosis of the jaw?

Answer 26

Stage 1 = asymptomatic
Stage 2 = pain and inflammation/infection
Stage 3 = pain and inflammation/infection, and osteolysis

Question 27

What are the risk factors for osteonecrosis of the jaw?

Answer 27

IV bisphosphonates
Prolonged bisphosphonates
Steroids
Smoking
Poor oral hygiene