Monoarthropathy

Question 1

Risk factors for septic arthritis

Answer 1

Immunosuppression

Diabetes

Age >80

Chronic renal failure

Joint surgery/prosthetic joints

Pre-existing joint disease

Question 2

Investigation/management of septic arthritis

Answer 2

Joint aspiration + culture

Blood cultures

CXR (may have co-existing pneumonia)

Consider joint X-ray if ?osteomyelitis

Empirical abx

Irrigation IN THEATRE!

Question 3

NSAID side effects

Answer 3

GI bleeding

MI/stroke

Renal injury

Question 4

Management of NSAID GI side effects

Answer 4

PPI if >45/Hx of peptic ulcer

Avoid co-prescription of anticoagulants, antiplatelets, spironolactone, SSRI, steroids for bleeding risk

Question 5

Patient education for NSAID side-effects

Answer 5

Minimum: dose possible

Mixing: Avoid mixing w/ OTC formulation

Alcohol/smoking: Increase NSAID risk profile

Abdo: Urgent medical review if any abdo pain/bleeding symptoms

Question 6

Common causative organisms for septic arthritis

Answer 6

Staph aureus (most common)

Group B strep (esp neonates)

Neisseria gonococcus

G-ve bacilli

Question 7

Pathophysiology of gout

Answer 7

Sodium urate crystal deposition in joints

Primarily afects 1st MTP

May be polyarticular

Long-term: Tophi (urate deposits) and renal disease

Question 8

Precipitants for gout

Answer 8

Trauma

Starvation

Surgery

Diuretics

Infection

Question 9

Risk factors for gout: reduced excretion

Answer 9

Elderly

Men/post-menopausal women

Hypertension, diabetes

Diuretics (esp thiazide) antihypertensives, aspirin

Alcohol

Question 10

Risk factors for gout: excess production

Answer 10

Dietary: alcohol, red meat, seafood esp shellfish

Medical: tumour-lysis, psoriasis, myelo/lymphoproliferative disorders

Question 11

Associated conditions to screen for in gout

Answer 11

CKD

Dyslipidaemia, diabetes

Hypertension

Question 12

Investigations in gout

Answer 12

Joint aspiration –> urate crystals

Serum urate may be raised or normal

X-ray normal, long-term punched-out erosions on articular surface

Question 13

Management of acute gout

Answer 13

High-dose NSAIDs

Colchicine if NSAIDs contraindicated

Ice-pack and rest

Question 14

Crystals in gout

Answer 14

Needle-shaped

negatively birifringent

Monosodium urate

Question 15

Prevention of gout

Answer 15

Lose weight

Dietary modification (Alcohol, red meats)

Avoid prolonged fasts

Consider allopurinol, start slowly and titrate up

Question 16

Indications for allopurinol

Answer 16

>1 attack in 12mo

Renal stones, tophi

Question 17

Side effects of allopurinol

Answer 17

Rash, fever, low WCC

May trigger attacks so wait >3w after acute episoe

Question 18

Pathophysiology of pseudogout

Answer 18

Calcium pyrophosphate crystal deposition > acute monoarthropathy (usually larger joints, e.g. knees/shoulders)

Question 19

Risk factors for pseudogout

Answer 19

Old age

HyperPTH

Hypophosphataemia

Haemochromatosis

OA

Question 20

Management of psuedogout

Answer 20

Joint aspiration

Cool packs

Rest

NSAIDs

Colchicine

Question 21

Light microscopy of pseudogout aspirate

Answer 21

Positively birifringent

Rhomboid

Calcium Pyrophosphate

Pseudogout

Question 22

X-ray features of pseudogout

Answer 22

Joint space narrowing

Subchondral sclerosis

Chondrocalcinosis (esp. MCPs and TFCC of wrist)

Question 23

Causes of post-infectious arthritis

Answer 23

Reactive - GI/GU

HIV seroconversion

CMV

EBV

Parvovirus (slapped cheek)

Generally self-limiting <6w