Basic Science & Non-Tumor pathology Flashcards Preview

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Flashcards in Basic Science & Non-Tumor pathology Deck (186)
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1

Which bone graft substitue disappears the most quickly in vivo?

Calcium sulfate

2

What is the rate of decay in bone mass after skeletal maturity?

After menopause in women?

0.3-0.5% per year after skeletal maturity

a further 2-3% for untreated women during the decade after menopause

3

Standard vs. MIPO plating has what effect on blood flow?

Decreased periosteal AND medullary blood flow

4

What kind of collagen is fibrocartilage?

Type 1

same as bone

So scar = type 1 collagen

5

What cell type accounts for 90% of the adult skeleton?

osteoCYTE

6

rhBMP-2 is approved for what uses?

Single level ALIF from L2-S1 in DDD with a fusion device

open tibial shaft fratures stabilized with an IM N and treated with 14 days of initial injury

7

What is the bending rigidity of a plate proportional to?

Thickness ^3

8

What is false about osteocalcin?

1. It is the most abundant noncollagenous protein of bone

2. It is secreted by osteoclasts

3. It is involved in mediating calcium homeostasis

4. It has been used as a biochemical marker of bone formation

5. It is part of the organic matrix of bone

2

It is secreted by osteoBLASTS

9

What is the increase in mortality risk after a fragility fracture of:

vertebra

hip

Vertebral fragility fracture: 15% increase

Hip fragility fracture: 20% increase

10

How much devascularization does reaming cause?

It devascularizes 50-80% of the cortex

11

Muscle duration and speed of contraction are most dependent on what?

Fiber type

Type II (fast twitch) contract faster, stronger and fatigue quicker

12

What happens with removal of the AER?

Limb truncation

AER controls longitudinal growth

13

Name the rare, but deadly, complication of Paget's

What is the prognosis?

Paget's Sarcoma

secondary transformation into osteosarcoma > chondrosarcoma > spindle cell sarcoma

<1%

5 year survival <5%

 

14

Distraction osteogenesis - bone forms by what type of ossifciation?

intramembranous (primary) ossifciation

15

Name 4 results of joint immobilization on articular cartilage

cartilage thinning

tissue softening

reduced proteoglycan content

cartilage erosion

16

What's the role of collagen in artiular cartilage?

Prevent swelling of articular cartilage that would otherwise occur due to the effect of aggrecan in drawing in water

17

What is the mechanism of botox?

Inhibition of ACh release from presynaptic vesicles

18

How do local anesthetics works?

Interfere with conduction (depolarization)

19

Rate of decrease of vertebral fragility fractures after bisphosphonate treatment at 1 & 3 years?

1 year: 60% decrease

3 years: 40% decrease

Also decreased non-vertebral fraglity fractures 40%

20

Area of growth plate pathology in rickets

zone of provisional calcification

This is why there is a widening of physis on xray, bc the physis doesn't ossify!

21

3 radiographic findings in osteopetrosis

Rugger jersey spine

Erlenmeyer flask distal femur

Thickened cortex/lack of a IM canal

22

Phases of ligament healing

inflammatory

  • neutrophils & macrophage mediated with growth factors involved

Proliferative

remodeling

maturation

23

What happens to water content of cartilage with normal aging?  in OA?

Decreases with normal aging

Increases with OA

24

What supplies the inner and outer parts of bone? (blood vessels)

Nutrient artery system supplies inner 2/3

is a high pressure system

Periosteal system supplies outer 1/3

is a low pressure system

25

50 year old DM patient comes in with sudden onset of unilateral leg weakness, absent reflexes on that side and weight loss of about 15 - 20 lbs.  No history of radiculopathy or back issues.  Diagnosis?  1 differential

Diabetic lumbosacral plexopathy (basically diabetic neuropathy)

Acute, stepwise onset of unilateral weakness

Associated with poor diabetic control, absent reflexes and weight loss (up to 40 lbs)

dDx: tumour

26

When does enchondral ossification occur in fracture healing (what stage)?

repair

27

Why don't you want your anesthesiologist to use nitrous oxide as an inducin agent for spine or pelvic surgery?

Causes abdominal distension and makes fluoroscopy difficult to interpret

28

Descirbe direct insertion of ligament or tendon onto bone:

= fibrocartilagenous insertion

via 4 transition zones:

Zone 1: tendon or ligament

Zone 2: fibrocartilage

Zone 3: mieralized fibrocartilage

Zone 4: bone

29

Effect of tapping prior to screw insertion on pullout strength

decreases it

30

The femur radiograph of a healthy 25-year-old female is compared to the femur radiograph of a healthy 85-year-old female:

What best describes the 25-year-old's femur in terms of cortical thickness and medullary canal volume?

Increased cortical thickness

Decreased medullary canal volume

As you age, you get thinner cortices and therefore larger canal volumes