Osteoarthritis

Question 1

What is osteoarthritis?

Answer 1

Non-inflammatory disorder of movable joints characterised by degeneration of synovial joint cartilage

Question 2

Is there any inflammatory component in osteoarthritis?

Answer 2

Sort of, inflammation does occur but it is a result of the joint damage caused by other things

Question 3

Who is affected by osteoarthritis?

Answer 3

Older people, prevalence increases with age
Most people over age 60 have some evidence of osteoarthritis

Men affected at a younger age than women are

Question 4

What are the risk factors of osteoarthritis?

Answer 4

Age
Male gender
Family history of OA
Obesity

Joint problems:

• previous fracture through a joint
• congenital joint dysplasia
• joint damage

Occupation: heavy labour, lifting etc.
Sport

Question 5

What’s the difference between primary and secondary arthritis?

Answer 5

Primary: idiopathic, genetic

Secondary: secondary to a joint disease of other condition

Question 6

Describe the pathogenesis of osteoarthritis?

Answer 6

Progressive destruction and loss of articular cartilage

Exposed subchondral bone becomes sclerotic, more vascular and cysts develop

Attempts at repair by the body result in cartilaginous growths at the margins of joints

These become calcified becoming osteophytes

Question 7

What does sclerotic mean?

Answer 7

Sclerosis: excessive hardening of bone

Question 8

What are osteophytes?

Answer 8

Bony projections/lumps

They form because of degeneration, aging, disease of bone

Question 9

What is the link between osteoarthritis and osteoporosis?

Answer 9

Many patients have both, but the link is not fully understood

Question 10

Which cells are most important in the pathogenesis of osteoarthritis?

Answer 10

Chrondrocytes

Question 11

What is the role of chondrocytes in osteoarthritis?

What is their normal role?

Answer 11

Their normal role is to produce and maintain cartilaginous matrix

In OA they are more active
Meaning:
- more proliferation of chondrocytes
- more degradation of bone

Question 12

Which mediators are involved in pathogenesis of osteoarthritis?

Answer 12

Anabolic cytokines: build up bone, growth factors

Catabolic cytokines: break down bone, IL-1, TNF-a

Question 13

Which enzymes are involved pathogenesis of osteoarthritis?

Answer 13

Proteases, specifically metalloproteases

These destroy cartilage

Question 14

What are the clinical features of osteoarthritis?

Answer 14

Joint pain

Crepitus on movement (grating sound or sensation

Swelling

Stiffness after rest, briefly in the morning

Instability, tenderness, restricted movement

Osteophytes may be palpable

Muscle wasting, deformity

Heberden’s + Bouchards nodes

No systemic involvement

Question 15

What types of swelling occur in osteoarthritis?

Answer 15

Intermittent: due to effusion caused by the joint damage

Continuous: due to capsular thickening/fibrosis

Question 16

Describe the classic joint pain you get with osteoarthritis?

Answer 16

Gradual onset
Usually in hip or knee
Pain on movement, relieved at rest

Question 17

In terms of morning stiffness, which suffers more with this:

• osteoarthritis
• rheumatoid arthritis?

Answer 17

Rheumatoid arthritis

It occurs with osteoarthritis but not for as long, only about 30 mins

Question 18

What does derangement mean?

Answer 18

Reduced range of movement

Question 19

Which joints are usually affected in osteoarthritis?

Answer 19

Distal interphalangeal joints

1st carpometacarpal joints of hands

1st metatarsophalangeal joints of feet

Weight bearing joints: hip, knee, vertebrae

Question 20

What are Heberden’s nodes?

Answer 20

Bony swellings at the distal interphalangeal joints

Question 21

What are Bouchard’s nodes?

Answer 21

Bony swellings at the proximal interphalangeal joints

Question 22

Heberden’s nodes VS Bouchard’s nodes?

Answer 22

Bony swellings

H = at the distal interphalangeal joint

B= at the proximal interphalangeal joint

Question 23

How can you differentiate between rheumatoid arthritis and osteoarthritis?

Answer 23

OA:

• older age at presentation
• slower onset
• can be uni or bilateral joints affected
• usually weight bearing joints
• less morning stiffness
• no systemic features

RA:

• can present at any age
• quicker onset
• bilateral joints affected
• any joints except rarely DIP
• morning stiffness
• systemic features

Question 24

Which joint is rarely affected by rheumatoid arthritis?

Answer 24

Distal interphalangeal joint

Question 25

Investigations of osteoarthritis?

Answer 25

X-ray: look for classic signs

CT/MRI

Isotope bone scan: look for hot areas as this indicates OA

Blood tests:

• ESR/CRP should be normal in OA
• Rh factor

Take a decent history re previous joint damage

Question 26

How does arthritis cause pain, since articular cartilage has no nerve supply?

Answer 26

The pain is caused by stretching of the joint capsule due to effusion/swelling etc.

Pain also due to vascular congestion of bone

Question 27

What should you look for on an X-ray

Answer 27

LOSS

Loss of joint space
Osteophytes
Subarticular sclerosis
Subchondral cysts

Question 28

What does sclerosis look like on an X-ray?

Answer 28

Looks more white

Question 29

What is an isotope bone scan?

Answer 29

A scan that uses radioisotopes to detect areas of increased bone activity

In these areas the bone is growing or being repaired

Question 30

Non-surgical management of osteoarthritis?

Answer 30

Decrease load on joint

• weight loss
• splints/orthotics
• walking sticks

Improve muscle strength

• exercise
• physio

Pain relief:

• NSAIDs
• Codeine
• heat or cold packs

Steroid injection

Question 31

Surgical management of osteoarthritis?

Answer 31

Joint replacement