Injury + Healing

Question 1

What are the 3 mechanisms of bone fracture?

Answer 1

• Trauma
• Stress
• Pathological

Question 2

What are the 2 main types of trauma fractures?

Answer 2

• Low energy

* High energy

Question 3

How does a stress fracture occur?

Answer 3

overuse ➡ stress exerted on bone is greater than bones capacity to remodel ➡ bone weakening ➡ stress fracture ➡ risk of complete fracture

Question 4

What is a stress fracture?

Answer 4

fracture caused by abnormal stresses on normal bone

Question 5

What is a pathological or insufficiency fracture?

Answer 5

fracture caused by normal stresses on abnormal bone

Question 6

What are 6 causes of pathological fractures?

Answer 6

• osteoporosis
• paget’s disease
• osteogenesis imperfecta
• vitamin D deficiency
• osteomyelitis
• malignancy

Question 7

What is the difference between osteopenia + osteoporosis?

Answer 7

• penia = not so severe bone loss, T-score of -1 to -2.5

* porosis = more severe bone loss, T-score of -2.5 or less

Question 8

What is osteopenia + osteoporosis?

Answer 8

• OC activity > OB activity
• bone microarchitecture is disrupted
• more common in females (F : M , 4 : 1)

Question 9

What is primary osteoporosis? What is it caused by?

Answer 9

• caused by natural age-related changes to bone

* e.g. postmenopausal or senile

Question 10

What is secondary osteoporosis? What is it caused by?

Answer 10

• caused by other clinical disorders or conditions
• e.g. hypogonadism, glucocorticoid excess, alcoholism
• more common in males

Question 11

What is congenital osteogenesis imperfecta?

Answer 11

• hereditary autosomal dominant or recessive disorder
• causes a reduction in Type I Collagen due to:
• Decreased secretion
• Production of abnormal collagen
• results in insufficient osteoid production

Question 12

What is Paget’s disease?

Answer 12

• excessive bone break down + disorganised remodelling
• leading to deformity,
pain, fracture or arthritis

Question 13

What are 4 examples of primary bone cancers?

Answer 13

• Osteosarcoma
• Chondrosarcoma
• Ewing sarcoma
• Chordoma

Question 14

What is secondary bone cancer?

Answer 14

when tumours from other tissue metastasise to bone

Question 15

What 5 most common tissues to cause secondary bone cancer?

Answer 15

• prostate (blastic)
• breast (blastic + lytic)
• kidney (lytic)
• thyroid (lytic)
• lung (lytic)

Question 16

What 3 ways in which fractures are patterned or classified?

Answer 16

• soft tissue integrity
• bony fragments
• movement

Question 17

What are the 2 types of soft tissue integrity fractures?

Answer 17

• open

* closed

Question 18

What are the 3 types of bony fragment fractures?

Answer 18

• greenstick
• simple
• multifragmentary

Question 19

What are the 2 types of movement fractures?

Answer 19

• displaced

* undisplaced

Question 20

What are the general principles of tissue healing? What cells do they involve?

Answer 20

• bleeding (blood)
• inflammation (neutrophils + macrophages)
• new tissue formation (blasts)
• remodelling (macrophages, OCs + OBs)

Question 21

What does the inflammation phase of fracture healing involve?

Answer 21

• haematoma formation
• release of cytokines
• granulation tissue + blood vessel formation

Question 22

What does the repair phase of fracture healing involve?

Answer 22

• soft callus formation (Type II collagen - cartilage)

* converts to hard callus (Type I collagen - bone)

Question 23

What does the remodelling phase of fracture healing involve?

Answer 23

• callus responds to activity, external forces, functional demands + growth
• excess bone is removed

Question 24

What is Wolff’s Law?

Answer 24

bone grows and remodels in response to the forces that are placed on it

Question 25

What is primary bone healing?

Answer 25

• Intermembranous healing

* Absolute stability

Question 26

What is secondary bone healing?

Answer 26

• Endochondral healing
• Involves responses in the periosteum + external soft tissues
• Relative stability

Question 27

What is the range of fracture healing times?

Answer 27

3-12 weeks

Question 28

What are the general principles of fracture management?

Answer 28

• Reduce
• Hold
• Rehabilitate

Question 29

What are the 4 ways in which a fracture can be reduced?

Answer 29

• manipulation (closed)
• traction (closed)
• mini-incision (open)
• full exposure (open)

Question 30

What is reduction by closed manipulation?

Answer 30

n

Question 31

What is reduction by closed traction (skin or skeletal)?

Answer 31

m

Question 32

What are the different types of fracture fixation?

Answer 32

m

Question 33

What are 4 components of rehabilitation?

Answer 33

o

Question 34

What are 3 forms of tendinopathy?

Answer 34

Or

Question 35

How are ligament injuries classified?

Answer 35

See

Question 36

How are tenden / ligament tears treated?

Answer 36

@a

Question 37

What are the benefits of immobilization of injured ligamentous tissue?

Answer 37

m

Question 38

What are the disadvantages of immobilization of injured ligamentous tissue?

Answer 38

g

Question 39

What are the benefits of mobilization of injured ligamentous tissue?

Answer 39

Woo

Question 40

What factors of the mechanical environment that affect fracture healing?

Answer 40

Lec

Question 41

What factors of the biological environment that affect fracture healing?

Answer 41

E

Question 42

How does Vitamin D deficiency result in fractures?

Answer 42

• vitamin D facilitates calcium, magnesium + phosphate absorption​
• inadequate Ca or PO4 = defect in osteoid matrix mineralisation

Question 43

What does severe Vitamin D deficiency cause in children?

Answer 43

rickets

Question 44

What does severe Vitamin D deficiency cause in adult?

Answer 44

osteomalacia