Pathology 1- Bone healing

Question 1

What are the 2 types of wound healing

Answer 1

regeneration: healing by same type of tissues
fibrosis: healing by granulation tissue

Question 2

which type of bone has haphazardly oriented collagen

Answer 2

woven bone

Question 3

which type of bone has parallel layers of collagen

Answer 3

lamellar bone

Question 4

under which conditions can we see woven bone

Answer 4

1- sites of fracture healing
2- tendon or ligament attachment
3- pathological conditions

Question 5

how do osteons communicate with medullary cavity

Answer 5

volkmans canals

Question 6

what is lamellar bone comprised of

Answer 6

osteons (Haversian system)

Question 7

what percentage of bone does the organic matrix comprise, and list its contents

Answer 7

35% of bone

• collagen type 1
• osteocalcin
• osteonectin
• proteoglycans
• glycosaminoglycans
• lipids

Question 8

what percentage of bone does the inorganic matrix comprise, and list its content

Answer 8

65%

• Hydroxyapatite

Question 9

list all the TYPES of fractures

Answer 9

1- TRANSVERSE
2- OBLIQUE
3- SPIRAL
4- COMMUNIATED 
5- AVULSION
6- IMPACTED
7- FISSUE/STRESS/HAIRLINE
8- GREENSTICK
9- COMPOUND
10- COMPLICATED 
11- PATHOLOGICAL FRACTURES

Question 10

list all the fractures by CAUSE

Answer 10

1- TRAUMATIC
2-PATHOLOGICAL
3- STRESS

Question 11

what are the 3 healing phases

Answer 11

recycle, reuse, reduce

JK.. its REACTIVE, REPARATIVE, REMODELING

Question 12

how long does the reactive phase last

Answer 12

from the START to 2/3 weeks

Question 13

how long does the reparative phase last

Answer 13

soft callus:
2/3 weeks TO 4/8 weeks

hard callus:
4/8 weeks TO 8/12 weeks

Question 14

how long does the remodeling phase last

Answer 14

from 8/12 weeks TO years

Question 15

can the soft callus be seen on X-ray

Answer 15

NOOOOOOOOO

only the hard callus can be seen on X-ray!!!

Question 16

what is the soft callus made of

Answer 16

woven bone

Question 17

what is the hard callus made of

Answer 17

lamellar bone

Question 18

what promotes local regulation of bone healing

Answer 18

• growth factors
• cytokines
• prostaglandins/leukotrienes
• hormones
• growth factors antagonists

Question 19

which factors are more BONE RESORPTION

Answer 19

IL1
TNF a
TNF b

Question 20

which factors are more MIX

Answer 20

TGF b

PDGF

Question 21

which factors are more BONE FORMATION

Answer 21

IGF 1
IGF 2
FGF

Question 22

what is the role of prostaglandins and leukotrienes

Answer 22

stimulate osteoblasts

for prostaglandins only: inhibit osteoclast too

Question 23

what is the role of estrogens

Answer 23

stimulate fracture healing by modulating release of an INHIBITOR of IL1

Question 24

what is the role of thyroid hormones and glucocorticosteroids

Answer 24

stimulate osteoclasts (BONE RESORPTION)

Question 25

local factors affecting healing (5)

Answer 25

1- soft tissue injury
2- interruption of blood supply
3- interruption of soft tissue
4- bone necrosis
5- involvement of joint sturcture

Question 26

systemic factors affecting healing (5)

Answer 26

1- malnutrition
2- smoking
3- diabetes
4- cardiovascular disease 
5- anti-inflammatory meds

Question 27

name 3 complications of fracture healing

Answer 27

1- delayed union
2- malunion
3- non-union or pseudoarthrosis