Osteoporosis

Question 1

What is the role of osteoprogenitor cells?

Answer 1

Stem cell population, gives rise to osteoblasts

Question 2

What is the function of osteoblasts?

Answer 2

Responsible for bone formation, covers surface of bones

Question 3

what is the function of octeocytes?

Answer 3

maintain bones matrix via cell to cell communication

Question 4

What is the function of osteoclasts

Answer 4

They reabsorb bone matrix via demineralization in response to mechanical stress and physiological demand

Question 5

Describe bone mass at different ages

Answer 5

0-25 years = bone gain.
25-35 years = bone mass stable.
35+ = bone loss

Question 6

What are some key features of osteoporosis?

Answer 6

Decreased size of osteons, thinning of trabeculae, enlargement of haversain and marrow spaces.

Question 7

What are some risk factors for osteroporosis and the incidence in the population

Answer 7

Risk factors - Biological sex, life style, nutrition, medical conditions, drugs, previous fragility fracture. Affects 1 in 3 women and 1 in 12 men.

Question 8

describe some of the lifestyle and nutritional risk factors.

Answer 8

Smoking, excess alcohol, sedentary and prolonged immobilisation.

Question 9

Name some medical conditions that are risk factors for osteoporosis

Answer 9

Anorexia nervosa, rheumatoid arthritis, early menopause, hyperthyroidism and primary hypogonadism

Question 10

Name some drugs that are risk factors for osteoporosis

Answer 10

Chronic corticosteroid use, excessive thyroid therapy, gonadotrophin releasing hormone agonists or antagonists, anticoagulants, anticonvulsants and chemotherapy

Question 11

What are the factors that contribute to an osteoporotic fracture?

Answer 11

falls, bone strength, postural reflexes, soft tissue padding

Question 12

Describe the features of type 1 osteoporosis

Answer 12

Post menopausal. Mainly affects cancellous bone. Vertebral and distal radius fractures common. Related to loss of oestrogen. F:M = 6:1

Question 13

Describe features related to type two osteoporosis

Answer 13

Age related in 75+/ Affects cancellous and cortical bone, related to poor calcium absorption, hip and pelvic fractures common, F:M = 2:1

Question 14

What is disuse osteoporosis?

Answer 14

Conditions resulting in prolonged immobilisation typically neurological or muscle disease.

Question 15

What is a fragility fracture?

Answer 15

A fall from standing height or less, not something that would occur in a healthy skeleton

Question 16

What are the common sites for an osteoporotic fracture?

Answer 16

Proximal humerus, distal radius, spine, femoral neck and vertebral body

Question 17

What are some of the investigations for osteoporosis?

Answer 17

Blood tests, FBC, serum biochemistry, bone profile.
Thyroid function tests, testosterone and gonadotrophin levels in med.
X-ray of lumbar and thoracic spine.
Bone mineral density measurement

Question 18

What is Dexa?

Answer 18

Two low dose x-rays with two distinct energy peaks. Subtracting one from the other gives patient’s bone mineral density (BDM).

Question 19

What are the two dexa scores?

Answer 19

T score - comparison with young adult of same gender.

Z score - Comparison with patients BMD with data from same age/sex/size.

Question 20

What are the treatments for osteoprosis?

Answer 20

Bisphosphonates (disrupt activity of osteoclasts but side effects of oesophagitis and mandibular necrosis.) Anabolic agents, calcium supplements, hormone replacement therapy (risk of breast cancer) and increase exercise