Metabolic bone disease

Question 1

1. Identify the modes of presentation of osteoporosis.

Answer 1

Fragility fractures (low trauma)

• Spine
• Hip
• Wrist

Question 2

2. Contrast the prevalence and causes of osteoporosis in men and women of different ages.

Answer 2

1.5 million total fragility fractures

Question 3

3. Recognize the impact of osteoporotic fractures on health and the economy.

Answer 3

1.5 million total fragility fractures

hip fracture equals death for many elderly

Question 4

4. Diagram normal and abnormal bone formation and resorption.

Answer 4

A. NORMAL
old bone signals to RANK-L which binds to rank receptors on osteoclasts, so they start resorbing, and osteoblasts follow them in rebuilding.
-OPG holds RANK-L inactive

WNT pathway through Beta catenin helps in regrowth, inhibitted by sclerostin

B. ABNORMAL
resoption is greater than formation

Question 5

5. Define osteoporosis and identify its risk factors.

Answer 5

osteopenia T score of -1
osteoporosis T score of -2.5
-compromised bone strength predisposing to increased risk of fragility fractures
- age, falls, low bone mass, previous fractures

risk factors

• age
• race
• gender
• family hx
• early menopause

modifiable risk factors

• cigareetes, alcohol, caffeine, certian meds
• sedentary, estrogen deficiency, low Vit D intake, low calcium intake

Question 6

6. Define osteomalacia and list its causes.

Answer 6

impaired bone mineralization resulting in soft weak bones in adults. called rickets in children

causes- inadequate calciumxphosphate product (

Question 7

7. Recognize the clinical presentation and course of Paget’s disease.

Answer 7

idiopathic bone condition characterized by excessive unregulated bone resorption and formation
-paramyxovirus (dogs), genetic (sequestosome, 18 q, osteoprotegrin)

features

• skeletal issues commonly in pelvis, skull, vertebrae, femur, tibia
• neurological issues- deafness, CN compression, spinal cord compression
• cardiovascular- atherosclerosis, aortic stenosis, CHF

Clinical course- all osteoclast activity at first, then equal blast and clast, then mostly blasts
- can follow NTX/CTX to see clast activity

Question 8

8. Contrast the pathological features of bones affected by osteoporosis, osteomalacia and Paget’s disease.

Answer 8

Pagets

• osteolytic lesions,
• osteosclerotic lesions,
• thickened disorganized trabeculae
• thickened, expanded cortex
• expansion of bony size
• “blade of grass sign”

Osteomalacia
-psuedo fractures, milmans fractures, loosers lines
Rickets- bowing of long bones, flaring of ends of bones

Osteoporosis

• fragility fractures
• loss of bone mass