Osteoarthritis Flashcards
What is osteoarthritis?
Non-inflammatory disorder of movable joints characterised by degeneration of synovial joint cartilage
Is there any inflammatory component in osteoarthritis?
Sort of, inflammation does occur but it is a result of the joint damage caused by other things
Who is affected by osteoarthritis?
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
What are the risk factors of osteoarthritis?
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
What’s the difference between primary and secondary arthritis?
Primary: idiopathic, genetic
Secondary: secondary to a joint disease of other condition
Describe the pathogenesis of osteoarthritis?
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
What does sclerotic mean?
Sclerosis: excessive hardening of bone
What are osteophytes?
Bony projections/lumps
They form because of degeneration, aging, disease of bone
What is the link between osteoarthritis and osteoporosis?
Many patients have both, but the link is not fully understood
Which cells are most important in the pathogenesis of osteoarthritis?
Chrondrocytes
What is the role of chondrocytes in osteoarthritis?
What is their normal role?
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
Which mediators are involved in pathogenesis of osteoarthritis?
Anabolic cytokines: build up bone, growth factors
Catabolic cytokines: break down bone, IL-1, TNF-a
Which enzymes are involved pathogenesis of osteoarthritis?
Proteases, specifically metalloproteases
These destroy cartilage
What are the clinical features of osteoarthritis?
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
What types of swelling occur in osteoarthritis?
Intermittent: due to effusion caused by the joint damage
Continuous: due to capsular thickening/fibrosis
Describe the classic joint pain you get with osteoarthritis?
Gradual onset
Usually in hip or knee
Pain on movement, relieved at rest
In terms of morning stiffness, which suffers more with this:
- osteoarthritis
- rheumatoid arthritis?
Rheumatoid arthritis
It occurs with osteoarthritis but not for as long, only about 30 mins
What does derangement mean?
Reduced range of movement
Which joints are usually affected in osteoarthritis?
Distal interphalangeal joints
1st carpometacarpal joints of hands
1st metatarsophalangeal joints of feet
Weight bearing joints: hip, knee, vertebrae
What are Heberden’s nodes?
Bony swellings at the distal interphalangeal joints
What are Bouchard’s nodes?
Bony swellings at the proximal interphalangeal joints
Heberden’s nodes VS Bouchard’s nodes?
Bony swellings
H = at the distal interphalangeal joint
B= at the proximal interphalangeal joint
How can you differentiate between rheumatoid arthritis and osteoarthritis?
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
Which joint is rarely affected by rheumatoid arthritis?
Distal interphalangeal joint
Investigations of osteoarthritis?
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
How does arthritis cause pain, since articular cartilage has no nerve supply?
The pain is caused by stretching of the joint capsule due to effusion/swelling etc.
Pain also due to vascular congestion of bone
What should you look for on an X-ray
LOSS
Loss of joint space
Osteophytes
Subarticular sclerosis
Subchondral cysts
What does sclerosis look like on an X-ray?
Looks more white
What is an isotope bone scan?
A scan that uses radioisotopes to detect areas of increased bone activity
In these areas the bone is growing or being repaired
Non-surgical management of osteoarthritis?
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
Surgical management of osteoarthritis?
Joint replacement
