Chapter 19 - Assessment and treatment of Osteoporosis and Vertebral Fractures

Question 1

Most common site for osteoporotic fragility fracture?

Answer 1

Spine

Question 2

Radiographic definition of osteoporosis

Answer 2

Normal: T score (compared to YOUNG healthy females) >-1.0
Osteopenia: -1 to -2.5
Osteoporosis: <-2.5 STDev different than a young healthy female

Question 3

Functions of vitamin D

Answer 3

1. promotes calcium absorption
2. osteoblastic differentiation
3. osteoblastic-mediated mineralization
4. calcium regulation
5. collagen cross-linking

Question 4

Vitamin D Metabolism

Answer 4

7-dehydrocholesterol gets converted to cholecalciferol (D3) in the skin

Cholecalciferol (D3) gets hydroxylated in the LIVER to 25(OH)vitamin D

KIDNEY then hydroxylates 25(OH)D to 1,25(OH) VItamin D (active form

Question 5

What form of vitamin D do serum assays measure?

Answer 5

2(OH) vitamin d (inactive)

Question 6

Treatment recommendations for Vitamin D supplementation based on serum levels

Answer 6

Normal: serum level >30 - tx with 1000-2000U
Insufficiency: serum level 20-30 - tx with 2000U daily
Deficiency: serum level <20: 5000Udaily, recheck in 12 weeks OR 50,000U weekly for 8-12 weeks, then recheck

Question 7

Daily recommendations for vitamin D supplementation

Answer 7

Young females and all males: 1000U
Older/postmenopausal females: 1200U

Question 8

Mechanism of action of bisphosphonates

Answer 8

Bind to hydroxyapatite, preven osteoclastic resorption and promote osteoclast apoptosis

• Nitrogen containing bisphosphonates mechanism: inhibits osteoclast farnesyl pyrophosphate synthase enzyme, required in mevalonate (cholesterol pathway) (inhibits GTPase formation)
• Non-nitrogen containing bisphosphonates (simple) mechanism: induce osteoclasts to undergo premature death and apoptosis (does so by forming a toxic adenosine triphosphate (ATP) analogue)

Question 9

Non-nitrogen containing bisphosphonates:

Answer 9

tiludronate
clodronate
etidronate

Question 10

Nitrogen containing bisphosphonates

Answer 10

alendronate
risedronate
pamidronate
zolendronate - relatively new and appealing to patients, due to IV adminstration every 12 months

Question 11

What type of drug are Teriparatide and abaloparatide?

Answer 11

Parathyroid analogs

Contraindicated in Paget disease dur to 2ndary risk of osteosarcoma

Question 12

What is the risk of mortality following vertebral fragility fracture?

Answer 12

2-3x compared to age matched controls

only 30% of patients survive 5 years compared to 70% of age matched controls

Question 13

results of vertebroplasty/kyphoplasty:

Answer 13

No difference in adjacent level fractures following surgery

Pain/function outcomes are a little more hinky - mixed results showing both no difference, and significant improvement following vertebroplasty/kyphoplasty

Lower mortality following vertebroplasty/kyphoplasty

Question 14

Contraindications for kyphoplasty:

Answer 14

1. burst fractures (bc then cement could enter canal)
2. any possibility of infection

Question 15

Risk of non-union following spinal fusion in osteoporotic patients compared to normal?

Answer 15

50% compared to 10% in low bone density/normal bone density group