Osteoarthritis

Question 1

Define osteoarthritis

Answer 1

A progressive disorder of synovial joints due to loss of cartilage

Damage may occur through repeated excessive stress, or injury

Characterised by:

• Joint pain and stiffness
• Functional limitation
• Reduced QoL.

Question 2

Describe the pathophysiology of osteoarthritis

Answer 2

Imbalance between cartilage degradation and production

• Causes cartilage oedema and subsequent focal erosion
• Microfractures and cysts as the underlying bone is stressed
• Subchondral sclerosis & osteophytes during attempted repair

Question 3

Name three causes of secondary osteoarthritis

Answer 3

• Pre-existing joint damage:
  
  • ^eg. RA; gout; septic arthritis; avascular necrosis
• Hereditary haemochromatosis; acromegaly
• Haemophilia - recurrent haemarthrosis
• Sickle cell disease and other haemoglobinopathies
• Neuropathies

Question 4

List three complications of osteoarthritis

Answer 4

• Heberden’s and Bouchard’s nodes
• Functional impairment and disability
• Psychosocial impact ^eg. confidence; sleep; self-care
• Occupational impact
• Falls
• Chronic pain syndrome

Question 5

Name five risk factors for osteoarthritis

Answer 5

• Obesity
• Genetics; FHx
• Female
• Hypermobility; joint laxity
• PMH of joint damage ^eg. trauma; inflammatory arthropathy
• Joint malalignment: ^eg. DDH; FAI; varus and valgus deformity
• Occupational and exercise stresses

Question 6

Give three symptoms of osteoarthritis

Answer 6

• Activity-related joint pain
  
  • Only one or a few joint affected at a time
  • Onset by movement and/or weight-bearing
  • Worse at end of day
• Morning stiffness <30min
• Functional limitation - joint instability

Question 7

List four signs of OA

Answer 7

• Bony swelling; joint warmth and/or tenderness
• Restricted painful movement; crepitus
• Joint instability
• Muscle wasting and weakness
• Joint effusion: knee OA

Nodal OA (hands): Painless bony swellings ^eg. Heberden’s nodes (DIPJ); Bouchard’s nodes (PIPJ); squaring of thumb joint

Question 8

Describe the clinical subsets of OA

Answer 8

• Local:
  
  • Nodal OA: Single joints of the hand; menopause
  • Hip OA (7-25%)
  • Knee OA (40%): Women and over 75s; obesity
• Primary generalised OA (rare): Most commonly affects hands; sudden and severe onset; female; strong familial tendancy.

Question 9

Give three indications for an x-ray in suspected osteoarthritis

Answer 9

Routine X-ray is not usually needed to confirm diagnosis

Consider:

• If diagnosis uncertain
• Exclude DDx
• Sudden clinical deterioration in symptoms

Question 10

What radiological findings are seen in OA?

Answer 10

• Loss of joint space
• Osteophytes
• Subchondral cysts
• Subchondral sclerosis

Structural changes on X-ray may not correlate with reported symptoms and function impairment

Question 11

When can a diagnosis of osteoarthritis be made without radiological or laboratory investigations?

Answer 11

All of:

• Aged 45+yrs
• Suggest symptoms and signs
• Other conditions have been excluded.

Question 12

Outline the management of osteoarthritis

Answer 12

• Self-care:
  
  • Weight loss if overweight
  • Local muscle strengthening; aerobic exercise
  • Hot and cold packs
• Aids and devices ^eg. appropriate footwear; walking sticks
• Simple analgesia:
  
  • Oral paracetamol ± ibuprofen
  • Topical NSAIDs especially for hand and knee OA
• Consider intra-articular injections
• Psychosocial support

Question 13

Compare and contrast RA and OA

Answer 13

• RA:
  
  • Onset 20-40yr
  • Symmetrical
  • Morning stiffness >1hr
  • Pain worse on rest and in morning
  • Rapid deterioration; systemic involvement
• OA:
  
  • Onset >50yr
  • Asymmetrical
  • Morning stiffness <30min
  • Pain worse on movement and at end of day
  • Slower deterioration; no systemic involvement.