Osteoarthritis and crystal arthropathies

Question 1

What is osteoarthritis?

Answer 1

Progressive degenerative condition affecting the joints. Gradual thinning of cartilage, loss of joint space and formation of bony spurs (osteophytes)

Question 2

Cartilage consists predominantly of what collagen?

Answer 2

Type II - linked by covalent bonds

Question 3

What happens to the joint during disease?

Answer 3

Loss of matrix, release of cytokines (IL1, TNF) and prostaglandins

Question 4

What is the term used to describe grinding or creaking on movement?

Answer 4

Crepitus

Question 5

What are the symptoms of osteoarthitis?

Answer 5

Stiffness, bony swellings, joint deformity, effusions, soft tissue swelling

Question 6

What are the bony enlargements seen at DIPs called?

Answer 6

Heberdens nodes

Question 7

What are the bony enlargements seen at PIPs called?

Answer 7

Bouchards nodes

Question 8

Genu varus is?

Answer 8

Bowing of the legs

Question 9

Genu valgus is?

Answer 9

Knock knee

Question 10

What are the risk factors for OA?

Answer 10

Age, Gender (more women), Genetic, occupation, previous injury, obesity

Question 11

What are the typical OA changes seen on XR?

Answer 11

Joint space narrowing
Subchondral sclerosis
Bony cysts
Osteophytes

Question 12

What joints does rheumatoid arthritis affect?

Answer 12

Metacarpophalangeal and proximal interphalangeal

Question 13

What joints does osteoarthritis affect?

Answer 13

Distal interphalangeal

Carpometacarpal

Question 14

What pharmacological managements are there for arthritis?

Answer 14

Analgesia - paracetamol, compound analgesics, topical analgesia
NSAIDs
Pain modulators - tricyclics (amitriptyline)
Anti convulsants (gabapentin)
Steroid joint injection

Question 15

What are the two main crystal arthropathies?

Answer 15

Gout (monosodium urate)

Pseudogout (calcium pyrophosphate dihydrate)

Question 16

What is gout

Answer 16

Inflammatory arthritis associated with monosodium rate crystal deposition

Question 17

What is gout caused by?

Answer 17

Overproduction (genetic - leech nyhan, Von Gierke - high cell turnover, overconsumption of foods rich in purines) or under excretion of uric acid (renal insufficiency, starvation, dehydration, hypothyroidism, hyperparathyroidism, drugs (diuretics, levodopa, cyclosporin A) alcohol abuse)

Question 18

When is the best time to measure serum urate?

Answer 18

2 weeks following an acute attack

Question 19

Describe acute monoarticular gout

Answer 19

Rapid onset, red hot joint, severe pain

Question 20

What are the differentials for gout?

Answer 20

Septic arthritis
Trauma
Seronegative arthritis (eg psoriatic arthritis)

Question 21

What are the investigations for gout?

Answer 21

CRP, PV/ESR, WCC, XR - normal in acute attacks

Question 22

What would be found on joint aspirate?

Answer 22

Needle shaped crystals, negative birefringence on polarised light

Question 23

What are forms of urate lowering therapy?

Answer 23

Allopurinol/ Febuxostat

Aim for target serum rate <0.3 mmol/l

Question 24

What does pseudo gout affect?

Answer 24

Fibrocartilage

Question 25

What shape are the crystals in pseudo gout

Answer 25

Rhomboid/ envelope shaped

Weakly positive birefringence

Question 26

What is the treatment of pseudo gout

Answer 26

NSAIDs
Colchicine
Steroids
Rehydration

Question 27

What is another crystal arthropathy?

Answer 27

Hydroxyapatite