Week 218 - Fractured Hip Flashcards Preview

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Flashcards in Week 218 - Fractured Hip Deck (53)
1

Loss of which line on an x-ray might indicated a fractured neck of femur?

Shenton's line

2

What contours does Shenton's line trace?

The inferior border of the superior pelvic ramus and the medial border of the proximal femur

3

What is the term used for the surgical procedure used to replace an individual's femoral head without replacing the acetabulum?

A hemiarthroplasty

4

What two surgical procedures are preferred in extracapsular NOF fractures

Dynamic Hip Screw
Cannulated Screw - provides more rotational stability

5

What two surgical procedures are generally preferred in intracapsular NOF fractures and why?

Hemiarthroplasty
Total Hip Replacement
As intracapsular NOF fractures carry greater risk of disruption to the blood supply to the femoral head and neck carrying a risk of AVN - may risk in young

6

How do you classify a NOF fracture as intra or extracapsular?

By the intertrochanteric line which runs between the greater and lesser trochanter - including or distal to this line is considered extracaspular

7

From which arteries does main blood supply to the hip joint come?

The lateral and medial femoral circumflex arteries

8

List 3 lifestyle factors that help improve bone health

Exercise (weight-bearing); healthy diet particularly with high calcium and Vit D; exposure to sun - Vit D

9

List 2 major lifestyle factors which reduce bone health and remodelling capabilities

Smoking
Alcohol

10

What two hormones have a protective effect on bone

Oestrogen (largely) and testosterone

11

Explain briefly the role of PTH on calcium in the body

PTH (parathyroid hormone) encourages calcium resorption and so increased blood plasma calcium levels and can, in large quantities, reduce bone strength

12

Describe the key steps in the Vitamin D production pathway.

UV light contacts skin converting cholesterol into Vit D3 > Liver hydroxylates Vit D3 to 25-hydroxyvitamin D(Calcidiol) > Kidneys further hydroxylate Calcidiol to 1, 25 dihydroxyvitamin D (Calcitriol - most potent form of Vit D!)

13

What affect does PTH have on serum calcium levels in the body and how?

PTH (parathyroid hormone) increases serum calcium in the body by 2 direct actions and 2 indirect actions. Direct - 1) increases osteoclastic activity in the bones 2) increases renal resorption of calcium
Indirect - 1) GI resorption of calcium 2) increases 1, 25 dihydroxy Vit D

14

What are the 4 main predisposing factors to osteoporosis?

Age; Female gender; Genetics (FHx); Oestrogen deficiency

15

name 5 further risk factors for osteoporosis (there are MANY)

Alcohol; smoking; poor diet (eating disorders); inactivity and low BMI

16

What effect does Vit have on calcium in the body?

Vit D helps calcium to be absorbed from the small intestine

17

Which hormone acts in opposition to PTH and what does it do?

Calcitonin - it increases bone calcium levels "tones the bone" by increasing osteoblastic activity and reducing osteoclastic activity

18

What is Trousseu's sign?

Flexion of wrist and thumb with extension of fingers. it is an indication of hypocalaemia along with tremor/spasm due to increased nerve and muscle cell excitability but with reduced neurotransmitter release at synapses

19

Name some drugs/treatments which are risk factors for osteoporosis

Glucocorticoids (corticosteroids); Lithium; Chemotherapy; SSRIs; anticonvulsants; GnRH agonists; Methotrexate; Prolonged heparin use; Aromatase inhibitors

20

What does an Aromatase inhibitor do and what is it used in the treatment of predominantly?

Breast and ovarian cancer - reduces the production of oestrogen

21

What is a DEXA scan used for and what does it stand for?

Measures bone mineral density (g/cm2)

22

On a DEXA scan a 'T' score of between -1 SD (standard deviation) and -2.5 from the healthy 'normal' suggests a diagnosis of what in an individual?

Osteopenia

23

For a patient to be considered osteoporotic by their DEXA result what should the result show?

A 'T' score of -2.5 SD (or below) below the normal

24

What tool can be used to estimate an individual's likelihood of suffering with a fragility fracture / osteoporosis?

A FRAX tool - you type in answers regarding known risk factors and it generates a 10-year probability score for that individual suffering a 'low energy trauma' fracture to their hip, wrist, vertebrae or shoulder

25

How do bisphosphonates work in the treatement of osteoporosis?

They decrease / inhibit osteoclastic activity thereby slowing the rate of bone breakdown

26

How does Strontium Ranelate act to help maintain bone strength?

It affects both osteoclastic and osteoblastic activity to reduce bone resporption (osteoclasts) and increase bone formation (osteoblasts) - only indicated if bisphosphonates are unsuitable

27

In osteoporotic treatment what does SERMs stand for and how does the drug work?

Selective Oestrogen Receptor Modulators - acts similarly to oestrogen which has a protective effect on bone through increasing bone density

28

What monoclonal antibody is used in the treatment of osteoporosis?

Denosumab

29

How does Denosumab act to treat osteoporosis?

By acting on the RANK ligand preventing osteocytes turning into osteoclasts thereby promoting osteoblasts

30

If hyperparathyroidism can cause osteoporosis how does human recombinant parathyroid hormone treatment help prevent / manage osteoporosis?

Fluctuant levels of parathyroid hormone (as is issued with parathyroid hormone treatment) has an anabolic effect on bone where continuous high levels of parathyroid hormone has a catabolic effect

31

When osteoporosis exists in men with hypogonadism what treatment might be appropriate?

Testosterone therapy

32

What is the difference between osteomalacia and rickets?

osteomalacia is simply the term used for 'Rickets' in adults - both are the result of a lack of Vitamin D and therefore weaker bones

33

What is the definition of osteoporosis?

Reduced bone mass (normal mineralisation! - despite the fact a DEXA scan measures bone mineral density!)

34

Name two drugs with increase bone formation

Teriparatide (recombinant parathyroid hormone)
Strontium ranelate

35

Name two drugs with decrease bone resorption

Denosumab (RANK ligand inhibitor)
Bisphosphonates

36

How should Bisphosphonates be taken and why?

At least half an hour before any food and with a full glass of tap water - bisphosphonates will bind to any calcium it comes into contact with

37

name 3 bisphosphonates

any 3 of the following:
- Alendronic Acid (alendronate)
- Risedronate
- Zolendronic Acid
- Ibandronate

38

Why should patients on bisphosphonates pay special attention to their gums?

A rare side effect is bone necrosis of the jaw

39

How is Denosumab administered?

Subcut injection 6 monthly

40

What 5 things does Vit D do in the body?

1) maintains calcium homeostasis
2) maintains bone health
3) increases Ca++ absorption in the gut
4) increases phosphate absorption in the gut
5) osteoclast maturation / function

41

What is Paget's disease?

Disordered bone metabolism - overactive osteoclasts followed by overactive osteoblasts resulting in a woven mosaic effect in the bone - weaker than normal

42

What are the direct and indirect symptoms of Paget's disease?

Direct - constant boring bone pain particularly on weight-bearing - pathological fracture - sacromatous change (rare)
Indirect - high cardiac output - compression effects

43

List the more common sites affected by Paget's

Spine; Pelvis; Skill; Femur

44

What compression injuries should you look out for?

Cranial nerve (palsies); Deafness; basilar invagination (potentially leading to brainstem compression and death); Cauda Equina (paraplegia); sciatica

45

How can you diagnose Paget's disease?

X-ray; Blood Tests; Isotope Bone Scan (increased uptake); Urinary Hydroxyproline (increased)

46

What would the following results be (high, low, normal) in a blood test for a Pt with Paget's - Alkaline Phosphatase;
Calcium; PTH; Vit D; phosphate ?

Alkaline Phosphatase - High
Calcium, PTH, Vit D, phosphate ALL normal

47

How should you treat someone with Paget's Disease?

ONLY if SYMPTOMATIC treat with bisphosphonates (Risedronate or Zolendronate)

48

In a blood test if serum calcium is normal, phosphate is low and Alkaline Phosphatase is high what is the likely diagnosis with regard to bone disease?

Osteomalacia

49

In a blood test if serum calcium is normal, phosphate is normal and Alkaline Phosphatase is very high what is the likely diagnosis with regard to bone disease?

Paget's Diease

50

In a blood test if serum calcium is high, phosphate is low and Alkaline Phosphatase is normal what is the likely diagnosis with regard to bone disease?

Primary hyperparathyroidism

51

In a blood test if serum calcium is high, phosphate is high and Alkaline Phosphatase is high what is the likely diagnosis with regard to bone disease?

Bone metastases

52

What affect do corticosteroids have on bone cells?

inhibit osteoblast activity and enhance osteoclastic activity therefore increasing bone resorption

53

What does calcitonin do?

Inhibits osteoclastic activity