Osteoporosis

Question 1

What is osteoporosis?

Answer 1

reduced bone density resulting in bone fragility + increased fracture risk

Question 2

What are the primary causes of osteoporosis?

Answer 2

Idiopathic (if < 50 yrs)

Post-menopausal

Question 3

What are 4 endocrine causes of secondary osteoporosis ?

Answer 3

Cushing’s disease
Thyrotoxicosis
Primary hyperparathyroidism
Hypogonadism

Question 4

List 11 risk factors for osteoporosis

Answer 4

Age  
FH
Low BMI  
Low calcium intake  
Smoking  
Lack of physical exercise  
Low exposure to sunlight  
Alcohol abuse  
Late menarche  
Early menopause  
Hypogonadism

Question 5

What are the non endocrine causes of secondary osteoporosis ?

Answer 5

Malignancy: myeloma, metastatic carcinoma
Drugs: corticosteroids, heparin
Rheumatological: RA, ankylosing spondylitis
GI: Malabsorption (e.g. coeliac), Liver disease (e.g. PBC)
Anorexia

Question 6

Describe the epidemiology of osteoporosis

Answer 6

COMMON
F > M
Older
More common in CAUCASIANS than Afro-Caribbeans

Question 7

How does osteoporosis often present?

Answer 7

Often ASYMPTOMATIC until fractures occur

Question 8

Which types of fractures are common in osteoporosis ?

Answer 8

Neck of femur (after minimal trauma)
Vertebral fractures (leads to loss of height, stooped posture + acute back pain on lifting)
Colles’ fracture (of distal radius after falling on an outstretched hand)

Question 9

List 3 signs of osteoporosis

Answer 9

Tenderness (over vertebral fractures) 
Thoracic kyphosis (due to multiple vertebral fractures) 
Severe pain when hip flexed + externally rotated (suggests NOF fracture)

Question 10

What bloods should be taken in osteoporosis?

Answer 10

Calcium (exclude osteomalacia or hyperparathyroidism)
Phosphate + ALP (exclude osteomalacia)
U+Es (exclude other causes)

Question 11

What may be seen on X ray in osteoporosis?

Answer 11

Dx fractures
Often normal as it takes > 30% loss of bone density before showing any changes in radiolucency or cortical thinning
May show biconcave vertebrae + crush fractures

Question 12

What are isotope bone scans used for in assessment of osteoporosis?

Answer 12

Highlights areas of stress + microfractures

Not often used

Question 13

What DEXA score indicates osteoporosis?

Answer 13

> 2.5 SDs below peak bone mass achieved by healthy adults (T-score < - 2.5))

Question 14

How is osteomalacia managed?

Answer 14

Bisphosphonates
Calcium + vitamin D
HRT (if menopausal prophylactically)

Question 15

What tool is used to predict the 10 year probability of major osteoporotic fracture? What does high score indicate?

Answer 15

FRAX

Pharmacological tx may be necessary