Musc 6 - Reactive Arthritis and Osteoarthritis

Question 1

Which branch of bone disorders does reactive arthritis fall under?

Answer 1

Seronegative spondyloarthropathies

Question 2

What is reactive arthritis

Answer 2

Sterile inflammation in joints following infection, especially urogenital and GI

Question 3

What are some extra-articular manifestations of reactive arthritis.

How can reactive arthritis be differentiated from rheumatoid arthritis

Answer 3

1. Enthesopathy
2. Skin inflammation
3. Eye inflammation

Rheumatoid arthritis doesn’t typically present with enthesopathy or eye inflammation.

Also, rheumatoid arthritis tends to be symmetrical whereas reactive arthritis is asymmetrical

Question 4

Reactive arthritis may be the first manifestation of which 2 diseases

Answer 4

HIV and Hep C infection

Question 5

Reactive arthritis is AFTER infection. What is infection in joints arthritis form called

Answer 5

Septic arthritis

Question 6

Describe the differences between arthritis, enthesitis and spondylitis

Answer 6

Arthritis = painful joints

Enthesitis = where ligaments/tendons insert into bones

Spondylitis = back pain

Question 7

What are the musculoskeletal symptoms of reactive arthritis

Answer 7

Asymmetrical, oligoarthritis (<5 joints)

Lower limbs typically affected

Question 8

What are some musculoskeletal symptoms of enthesitis (included as part of reactive arthritis)

Answer 8

Heel pain (achilles tendonitis)

Swollen fingers
Painful feet

Question 9

What are musculoskeletal symptoms of spondylitis (included as part of reactive arthritis)

Answer 9

Sacroiliitis (sacroiliac joint inflammation)

Spondylitis (inflammation of spine)

Question 10

What are the extra-articular features of Reactive Arthritis

Answer 10

Eye - sterile conjunctivitis

Genito-urinary - sterile urethritis

Skin - psoriasis like rash on hands and feet

Question 11

How is reactive arthritis diagnosed

Answer 11

1. Clinical diagnosis

2. Investigations (e.g. microbiology, immunology, synovial fluid examination) to exclude other arthritis causes

Question 12

In septic arthritis, synovial fluid culture comes back positive. What about reactive arthritis?

Answer 12

Sterile

Question 13

How is reactive arthritis treated

Answer 13

There is usually complete resolution within 2-6 months - so symptom management usually

Articular treatment: NSAIDs given, maybe intraarticular corticosteroid

Extra-articular: symptomatic therapy

Oral glucocorticoids given for refractory disease (or steroid sparing agent e.g. sulphasalazine)

Question 14

What is osteoarthritis

Answer 14

Chronic, slowly progressive disorder - caused by failure of articular cartilage - typically affect joints of the hand, spine, and weight bearing joints (hips and knees)

Question 15

Which joints of the hand does osteoarthritis typically affect

Answer 15

1. DIP
2. PIP
3. First CMC (thumb)

whereas in Rheumatoid arthritis, DIP is usually spared

Question 16

Which weight bearing joints of the lower limbs does osteoarthritis typically affect

Answer 16

First MTP joint

Question 17

What are common signs in the hands of osteoarthritis

Answer 17

Heberdens nodes - DIP (osteophytes present)

Bouchards nodes - PIP (osteophytes present)

Question 18

Rheumatoid arthritis typically gets better after the patient gets moving. What are the symptoms of osteoarthritis

Answer 18

1. Joint pain - worse with activity
2. Joint crepitus
3. Joint instability
4. Joint enlargement
   5 Joint stiffness after immobility
5. Limitation of motion

Question 19

What are the radiographic features of osteoarthritis

Answer 19

1. Joint space narrowing
2. Subchondral bony sclerosis
3. Osteophytes
4. Subchondral cysts

Question 20

What are some radiographic differences between Rheumatoid arthritis and osteoarthritis

Answer 20

Rheumatoid arthritis - has osteopenia and bone erosions

Osteoarthritis - has subchondral sclerosis and osteophytes

Question 21

Why does osteoarthritis occur?

What causes it to develop

Answer 21

Occurs due to defective and irreversible articular cartilage and damage to underlying bone

Develops due to:

1. Excessive loading on joints
2. Abnormal joint components

Question 22

Articular cartilage has 2 main components, and what type of cell resides in articular cartilage

Answer 22

1. Collagen, type 2
2. Aggrecan (type of proteoglycan)

Chondrocytes reside

Question 23

What is the only non-sulphated GAG?

Answer 23

Hyaluronic acid - major component of synovial fluid - has an important role in maintaining synovial fluid viscosity

Question 24

Describe the composition of aggrecan

Answer 24

100 chondroitin sulphate chains

60 keratin sulphate chains

Question 25

What are the cartilage changes in osteoarthritis

Answer 25

1. Reduced proteoglycan (aggrecan)
2. Reduced collagen
3. Chondrocyte changes (apoptosis)

Question 26

What are the bone changes in osteoarthritis

Answer 26

1. New bone formation at the joint margins (called osteophytes)
2. Changes in the denuded sub-articular bone:
   - proliferation of superficial osteoblasts - sclerotic bone production
   - focal stress on sclerotic bone = focal superficial necrosis

Question 27

How is osteoarthritis managed

Answer 27

1. Education
2. Physio/hydrotherapy
3. Occupational therpay
4. Weight loss if appropriate
5. Exercise
6. Analgesia - NSAID / paracetamol / intra-articular corticosteroid injection
7. Joint replacement

Question 28

What are the ECM proteoglycans

Answer 28

Glycoproteins w one or more sulphated GAG chains

GAGs = repeating disaccharide polymers

Question 29

What are the disaccharides in hyaluronic acid?

Answer 29

Glucuronic acid and N-acetyl glucosamine

Question 30

There are no disease modifying osteoarthritis drugs

Answer 30

no there are not