Osteoarthritis & Reactive arthritis

Question 1

Define reactive arthritis

Answer 1

sterile inflammation in joints following infection especially urogenital (e.g. Chlamydia trachomatis) and gastrointestinal (e.g. Salmonella, Shigella, Campylobacter infections) infections

Reactive arthritis is not due to ongoing infection. (septic arthritis

Question 2

What are the important extra-articular manifestations?

Answer 2

Enthesopathy
Skin inflammation
Eye inflammation

Question 3

What can RA be a first manifestation of?

Answer 3

HIV or Hepatitis C infection

Question 4

What are the musculoskeletal symptoms of RA?

Answer 4

Arthritis 
- Asymmetrical
- Oligoarthritis
(<5 joints)
- Lower limbs typically
affected

Enthesitis

• Heel pain (Achilles tendonitis)
• Swollen fingers (dactylitis)
• Painful feet (metatarsalgia due to plantar fasciitis)

Spondylitis

• Sacroiliitis (inflammation of the sacro-iliac joints)
• Spondylitis (inflammation of the spine)

Question 5

Describe the extra-articular features of RA?

Answer 5

Occular - Sterile conjunctivitis
Genito-urinary - Sterile urethritis
Skin - Circinate balanitis, Psoriasis- like rash on hands a feet

Question 6

Rheumatoid arthritis vs Reactive arthritis?

Answer 6

See slides

Question 7

How is reactive A diagnosed?

Answer 7

• Clinical diagnosis
• Investigations to exclude other causes of arthritis e.g. septic arthritis
• Examples of important investigations

See slides

Question 8

Septic arthritis vs Reactive arthritis?

Answer 8

See slides

Question 9

How is reactive A treated?

Answer 9

in majority of patients complete resolution occurs within 2-6 months
No role for antibiotics

Just give anti-inflammatorys
See slides

Question 10

Define osteoarthritis?

Answer 10

Chronic slowly progressive disorder due to failure of articular cartilage that typically affecting joints of the hand (especially those involved in pinch grip), spine and weight-bearing joints (hips and knees)

There is defective and irreversible articular cartilage and damage to underlying bone

Question 11

What joints are affected by osteoarthritis?

Answer 11

Joints of the hand
Distal interphalangeal joints (DIP)
Proximal interphalangeal joints (PIP)
First carpometacarpal joint (CMC)

Spine

Weight bearing joints of the lower limbs - Knees hips, First metatarsophalangeal joint

Question 12

What can osteoarthritis be associated with?

Answer 12

Joint pain
 - worse with activity, better with rest
Joint crepitus
 - creaking, cracking grinding sound on moving affected joint
Joint instability
Joint enlargement
 - e.g. Heberden’s nodes
Joint stiffness after immobility (‘gelling’)
Limitation of motion

Question 13

What are the clinical features of osteoarthritis?

Answer 13

Boney out growths at the DIP/PIP - called osteophytes

Heberden’s nodes - DIP
Bouchard’s nodes - PIP

Question 14

What are the radiographic features of osteoarthritis?

Answer 14

Joint space narrowing
Subchondral bony sclerosis - white
Osteophytes
Subchondral cysts

Question 15

What are the radiographic changes in Rheumatoid Arthritis vs. Osteoarthritis

Answer 15

Eroisions are seen in RA not osteoarthritis

See slides

Question 16

Why does osteoarthritis develop?

Answer 16

Excessive loading on joints

Abnormal joint components

Question 17

What is the viscosity of synovial fluid based on?

Answer 17

Viscosity of synovial fluid is depenedent on hyaluronic acid.

Question 18

What is articular cartilage composed of?

Answer 18

Type II collagen

Proteoglycan (aggrecan)

Question 19

Articualar cartilage

Answer 19

…

Question 20

ECM Proteoglycans

Answer 20

…

Question 21

How does the cartilage change in osteoarthritis?

Answer 21

• Reduced Proteoglycan
• Reduced collagen
• Chondocyte changes (apoptosis)

Question 22

What are the bone changes in osteoarthritis?

Answer 22

Changes in denuded sub-articular bone
Proliferation of superficial osteoblasts results in production of sclerotic bone e.g. subchondral sclerosis
Focal stress on sclerotic bone can result in focal superficial necrosis

new bone formation at the joint margins (termed osteophytes)
Sometimes you can detect osteophytes clinically (‘at the bedside’) and these have names
Osteophytes at the distal inter-phalangeal joints are called ‘Heberden’s nodes’
Osteophytes at the proximal inter-phalangeal joints are called ‘Bouchard’s nodes’

Question 23

What is the management of osteoarthritis?

Answer 23

Education
Physical therapy – physiotherapy, hydrotherapy
Occupational therapy
Weight loss where appropriate
Exercise
Analgesia
- Paracetamol
- Non-steroidal anti-inflammatory agents
- Intra-articular corticosteroid injection
Joint replacement