Bone Pathology I: Metabolic Bone Disease

Question 1

What cells develop into osteoblasts?

Answer 1

Osteoprogenitor Cells

Question 2

Which cells build bone?

Answer 2

Osteoblasts

Question 3

What are osteoblasts surrounded by matrix called?

Answer 3

Osteocytes

Question 4

What cells are responsible for bone resorption and differentiate from monocytes?

Answer 4

Osteoclasts

Question 5

Fracture

Answer 5

Discontinuity of the bone

Question 6

Callus

Answer 6

Osteogenic or chondrogenic reparative granulation tissue

Question 7

What is the most common bone disease?

Answer 7

Osteoporosis

Question 8

Osteoporosis

Answer 8

Trabecular bone loses mass and interconnections that lead to compromized bone strength

Question 9

What remains normal in osteoporosis?

Answer 9

Mineralization

Question 10

Type I Osteoporosis

Answer 10

Mainly trabecular bones and is related to menopause

Question 11

Type II Osteoporosis

Answer 11

Seen in older patients and is in trabecular AND cortical bones and is related to aging

Question 12

What drugs may cause secondary osteoporosis?

Answer 12

• Corticosteroids

- Alcohol

Question 13

What DEXA score shows osteoporosis?

Answer 13

-2.5 or less

Question 14

What is the treatment for osteoporosis?

Answer 14

• Vitamin D
• Exercise
• Estrogen Replacement

Question 15

Rickets/Osteomalacia

Answer 15

Vitamin D deficiency leads to mineralization defect which can cause structural abnormalities

Question 16

Osteopenia

Answer 16

Loss of skeletal mass

Question 17

Rickets

Answer 17

Seen in children where the growth plate is not adequately mineralized leading to irregular and thickened growth plate

Question 18

What is a clinical sign of rickets?

Answer 18

Bowed legs

Question 19

What is the treatment for rickets/osteomalacia?

Answer 19

Vitamin D

Question 20

Hyperparathyroidism

Answer 20

Increased PTH level leads to increased osteoclast action and bone resorption

Question 21

Osteitis Fibrosa Cystica

Answer 21

Bone is replaced with fibrous tissue with cystic change

Question 22

Paget Disease of Bone

Answer 22

Caused by osteoclast dysfuncton from increased RANK expression and induction of IL-6

Question 23

What are some clinical features of Paget Disease of Bone?

Answer 23

• Thickening of skull

- Bowing of legs

Question 24

What serum marker is elevated in Paget Disease of Bone?

Answer 24

Elevated alkaline phosphatase

Question 25

What is used to treat Paget Disease?

Answer 25

• Bisphosphonates - apoptosis of osteoclasts

- Calcitonin - inhibits osteoclast function

Question 26

What are the 3 phases of Paget’s Disease of Bone?

Answer 26

1. osteoclast overactivity
2. osteoblast activity
3. bone sclerosis

Question 27

Osteogenesis Imperfecta

Answer 27

Defect in type I collagen leads to brittle bone disease

Question 28

Achondroplasia

Answer 28

Defect in signal transduction from FGFR3 mutation causes dwarfism due to growth plate abnormality

Question 29

Osteonecrosis

Answer 29

Bone death with many causes from ischemia to corticosterois