osteoarthritis

Question 1

Epidemiology of osteoarthritis

Answer 1

Around 1 out of 5 people > 45 have osteo
Around 1 out of 3 people > 75 have osteo
2x more likely in women

Question 2

What’s osteoarthritis

Answer 2

A joint disorder characterised by micro and macro injuries that activates a maladaptive response including pro-inflammatory pathways of innate immunity. This causes the breakdown of cartilage that overlies the ends of bones of joints. As such, this leaves the bones rubbing together causing pain, swelling and loss of motion.

Question 3

Risk factors for osteoarthritis?

Answer 3

Altered loading:
- obesity
- joint injury or trauma
- lifestyle and occupational (manual labour)

Altered matrix (unprotected joint)
- advancing age
- family history (hand/ hip)
- female

Question 4

Signs and symptoms of osteoarthritis

Answer 4

• bone swelling; PIP and DIP joints
• morning stiffness
• pain of joints
• decreased range of motion
• instability
• many patients experience minimal progress but sudden and severe deterioration

Question 5

Diagnosis osteo

Answer 5

Usually made by sussing the patient out; family history, risk factors, symptom history, physical examination, functional and psychosocial assessment.
Hard to say bc radiological findings poorly correlated to symptoms and biochemistry markers are usually normal or minimally raised.

Question 6

Pathophysiology of osteoarthritis

Answer 6

Chronic joint stress (e.g. overuse, obesity, ageing) can lead to overproduction of enzymes.
ADAMTS4 and ADAMTS5 cleaves part of the cartilage which loses its water-retaining properties, becoming less resilient and more prone to damage.

MMP13 breaks down collagen II (which provides the cartilage which tensile strength), thus compromising its structural integrity.

The combined actions of these enzymes leads to degradation of cartilage matrix = cartilage thinning = loses its ability to protect the bones, leading to pain, reduced joint function and the development of osteoarthritis.

Question 7

non-pharm treatment for osteoarthritis

Answer 7

• weight control
  1% weight loss = 2% improvement in pain,
  function, and stiffness.
• therapeutic exercise
  Some discomfort from exercise is
  common; topical or oral analgesia may be
  required to facilitate exercise
• patient education
  patients should understand the cause of osteoarthritis and likelihood of slow or minimal disease progression, fluctuating nature of osteoarthritis symptoms, poor correlation between symptoms and radiological findings and modifiable risk factors for disease progression.
• psychological therapies (CBT)

Question 8

1st line pharmacological treatment of osteoarthritis

Answer 8

• topical NSAID (4 d) and capsaicin (3-4 d)
  Capsaicin releases substance P which helps to numb the area

Question 9

2nd line pharmacological treatment of osteoarthritis

Answer 9

• paracetamol
• oral NSAID (if low risk harm)

Question 10

3rd line pharmacological treatment of osteoarthritis

Answer 10

Intra-articular corticosteroids injections - ↓ pain and inflammation
Rapid relief for short term only
Use every 3 months prn

Betamethasone * usually smaller joints
Methylprednisolone acetate is crystalline * usually larger joints
Triamcinolone acetonide - least soluble * longest duration of action, up to 21 weeks

Question 11

Which SNRI can be used for osteoarthritis?

Answer 11

Duloxetine (SNRI)
Similar efficacy to oral NSAIDS.
Lack of head to head studies and unknown place in therapy.
SE: Nausea, dry mouth, constipation, weakness, sexual dysfunction.