Week 137 - Monoarthritis/ Gout Flashcards Preview

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Flashcards in Week 137 - Monoarthritis/ Gout Deck (67):
1

What causes gout?

The over-production and/or under-excretion of urate

1

What are the 2 main types of drugs used in urate lowering therapies?

  1. Xanthine oxidase inhibitors
  2. Uricosuric agents

2

What are the main organs involved in calcium homeostasis?

  • Gut
  • Bone
  • Kidneys

 

3

What hormone controls the activity of renal 1α-hydroxylase?

PTH; its stimulates its activity

 

3

What is the outcome if infective arthritis is treated?

  • 50% morbidity
  • Up to 50% mortality (average is 10%)

4

What factors determine the type of drug treatment used in gout?

  • Number of previous attacks
  • Degree og hyperuricaemia
  • Presence of reversible factors
  • Presence of tophi

 

4

What is pseudogout?

  • It is similar to gout with red, warm, swollen painful joint.
  • Calcium pyrophospahte crystals instead of urate.
  • Affects mainly elderly women
  • Longer attacks

 

5

What type of gout are tophi usually seen?

Chronic gout

6

What is the prognosis if infective arthritis is left untreated?

  • Rapid joint destruction
  • Sinus/ abscess formation
  • Sepicaemia
  • Multi-organ failure
  • Death

 

6

What uricosuric agents are available to prescribe in the UK?

  • Sulphinpyrazone
  • Benzbromarone

 

7

What are the non-modifiable risk factors for gout?

  • Age - over 40 for males
  • Male gender
  • Genetics
  • Impaired renal function

 

9

What molecule is the precursor for Vitamin D synthesis?

Sterol-7-dehydrocholesterol

9

Describe a chondral lesion

  • Lie entirely within cartilage
  • Do not penetrate subchondral bone
  • Do no heal spontaneously 

10

What medications does allopurinol interact with?

  • Warfarin
  • Azathioprine

 

11

How do xanthine oxidase inhibitors help lower urate in gout?

The reduce the amount of uric acid produced, therefore preventing crystal formation

12

What is gout?

A clincal syndrome caused by an inflammatory response to monosodium urate monohydrate crystals 

13

What enzyme acts on Vitamin D3 and where is it found?

25-hydroxylase

Found in the liver

14

What are the functions of Vitamin D3 on each of the calcium homeostasis organs?

Gut:

  • Stimulate transport of Ca2+ and PO43- in the small intestine
  • Increases serum Ca2+

Bone:

  • Stimulate terminal differentiation of OC directly and via OB
  • Increases serum Ca2+

Parathyroid:

  • Inhibit transcription of the PTH
  • Decreases production (negative feedback regulation)

14

What is the main treatment option of advanced OA or a very large cartilage defect?

Total joint replacement

14

What xanthine oxidase inhibitors are availiable to prescribe?

  • Allopurinol
  • Febuxostat

15

What enzyme is essential for the breakdown of purines into urate?

Xanthine oxidase

17

What are the sources of calcium influx into the bloodstream?

Intestinal absorption and bone resorption

18

What are the treatment options for small/intermediate cartilage lesion?

  • Debridement
  • Microfracture
  • Osteochondral graft
  • Cell based therapies
  • Osteotomy

19

What are the main causes of monoarthritis?

  • Infection
  • Gout/ crystal arthritis
  • Trauma/ haemathrosis
  • Osteoarthritis
  • Sero-negative (Psoriatic/ IBD)
  • Reactive arthritis
  • Sacroidoisis

 

20

What are the pros and cons of mircofracture repair of a cartilage lesion?

Pros:

  • Defect filling

Cons:

  • Fibrocartilage repair
  • Lasts about 5 years
  • Requires futher surgery

22

What are the major functions of calcium within the body?

  • Formationof calcified tissues
  • Normal activity of nerve and muscle
  • Neurotrasmitter release, hormonal and glandular secretion
  • Excitation-coupling
  • Integrity and permeability of cell membranes
  • Cell adhesion
  • Blood clotting 

22

What the hormones that control blood calcium levels?

  • PTH
  • Vitamin D3
  • Calcitonin

 

24

What type of receptor is the calcium sensing receptor in the parathyroids?

It is a 7-transmembrane spanning receptor which is coupled with a G-protein

 

 

25

Which patients should be started on urate lowering therapy?

  • After a single attack, decision based on individual characteristics
  • After a second attack within a year and/or renal impairment or urate stones and/or tophi and tissue damage

27

What cells in the parathyroid produce PTH

Chief cells

 

27

What are the symptoms of a focal cartilage lesion?

  • Pain
  • Swelling
  • Mechanical symptoms
  • Loss of function
  • Joint degeneration

27

What are the pros and cons of osteochondral grafting?

Pros:

  • Defect site filled with mature cartilage

Cons:

  • Donor site morbidity
  • Donor cartilage maybe different thickness

 

29

What are the main functions of PTH?

  • Stimulates bone resorption
  • Stimulates renal tubular reabsorption of calcium
  • Stimulates renal 1α-hydroxylase

31

Descrieb osteochondral lesions

  • Penetrate through vascularised subchondral bone
  • Some spontaneous repair as chondroprogenitor cells invade lesion

32

What are the causes of the synovial fluid changes in the picture below, far left is normal

  • 2nd left - Non inflammaotry disease (OA)
  • Middle - Inflammatory disease (RA)
  • 2nd right - Septic arthritis
  • Far right - Haemarthrosis

32

How long after an acute attack should urate lowering therapy be started?

1-2 weeks after the inflammation has resolved

 

34

What are the symptoms of infective monoarthritis?

Sudden onset of:

  • Pain
  • Difficulty weight bearing/ moving at all
  • Swelling
  • Erythema

35

What affect does an increase in serum calcium have on calcitonin secretion?

Increases caclitonin secretion

36

What investigations should be carried out if infective arthritis is suspected?

  • Blood; FBC, U&E's, CRP, cultures, urate etc
  • X-ray
  • Joint fluid aspiration

38

What are the pros and cons of an osteotomy?

Pros:

  • Re-establish normal loading and gait

Cons:

  • Highly invasive
  • Long recovery
  • No repair

 

39

What are the symptoms of acute gout?

  • Exquisite pain
  • Swelling
  • Erythema
  • Usually first MTP

40

What are the principle goals in the treatment of gout?

  • Treating acute attacks early and effectively
  • Correcting hyperuricaemia

 

41

How do uricosuric agents help lower urate in gout?

They increase the excretion of uric acid from the kidneys

42

What investigations are carried out to confirm gout?

Joint fluid examination:

  • Urate crystals seen - needle shaped and show negative birefringence under polaried light

  • Baseline urate, U&Es, blood sugar and fasting lipds
  • Urinalysis for blood and protein
  • CRP,  for acute attack

44

What stimulates the release of PTH?

Falling serum calcium levels

 

45

What is the best technique for focal cartilage repair?

Matrix-induced Autologous Chondrocyte Implantation (MACI)

45

What are some of the sources of infection for infective arthritis?

  • Haematogenously - main cause
  • Direct infection
  • Adjacent bone

 

48

Which is the greater cause of gout, over-production of urate or under-excretion?

Under-excretion - accounts for 90% of cases

49

What are the risk factors for infective arthritis?

  • Prosthetic joint
  • Immunosuppression - elderly/diabetic
  • RA
  • Existing joint disease
  • IV drug abuse

50

What enzyme in the kidneys converts 25-hydroxyvitamin Dto 1,25 (OH)2 Vitamin D3

Renal 1α-hydroxylase

50

What is the main effect of calcitonin?

Inhibits osteoclast bone resorption

51

What are the pros and cons of autologous chondrocyte implantation?

Pros:

  • Defect filling
  • Good outcomes

Cons:

  • Focal lesions
  • Variable tissue repair
  • Failure due to resumption of "high impact" activities

 

52

What properties of articular cartilage makes repair difficult?

  • Avascular - no fibrin clot or chemotactic factors
  • Slow diffusion of nutrients and waste from synovial capsule into synovial fluid into cartilage

54

What are the pros and cons of debridement of a cartilage lesion?

 

Pros:

  • Pain relief

Cons:

  • Altered joint congruency
  • No repair
  • Results last about 5 years

55

What are the 3 main causes of bacterial infective arthritis?

  1. Staphylococcus aureus - most common
  2. Gonococcus - yound adults
  3. E. coli/ Salomonella/ Proteus

 

56

What type of receptor is the PTH receptor?

G-protein coupled receptor

57

What are the modifiable risk factors for gout?

  • Hyperuricaemia
  • High-purine diet
  • Alcohol consumption
  • Obesity
  • Certain medication such as diuretics

58

What is the timecourse of an acute gout attack?

Mild attack:

  • 1-2 days

Severe attack:

  • 7-10 days

59

What are the drug options in the treatment of an acute gout attack?

  • NSAIDs - Naproxen, Ibuprofen
  • Colchine
  • Steroid; oral or intra-articular

DO NOT start urate lowering treatment during an acute attack, or stop urate lowering therapy if already on it

60

What are the 4 classifications of cartilage defects

  1. Grade 1 - fissure into superficial cartilage
  2. Grade 2 - increased fibrillation and multiple fissure
  3. Grade 3 - fissures extending down to subchondral bone, no denuded bone
  4. Grade 4 - complete cartilage loss and exposure of subchondral bone

61

Where does urate come from?

The breakdown of purines in the body

62

What is a side-effect of starting urate lowering therapy that might lower compliance?

Acute gout attacks are common after starting as the urate crystals are mobilised

63

What are the sites of calcium removal from the blood?

Renal excretion and bone formation

64

Where is sterol-7-dehydrocholesterol converted into Vitamin D3?

In the skin, when UV light is shone on it

65

What are the 2 types of focal cartilage lesion?

  1. Chondral lesion
  2. Osteochondral lesion

66

What are the diagnostic criteria used in psuedogout?

  • Aspirate - brick-shaped crystals
  • Chondrocalcinosis sometimes seen in X-Ray
  • Usually associated with hyperparathyroidism, OA, haemochromatosis, diabetes or acromegaly

67

What is the treatment for pseudogout?

There is no specific treatment, but give:

  • Analgesia
  • Steroid injection
  • Joint replacement if very severe