Osteoarthritis

Question 1

Definition

Answer 1

Age-related degenerative joint disease when cartilage destruction exceeds repair, causing pain and disability

Question 2

Aetiology (primary)

Answer 2

Can be classified according to the distribution of affected joints

Primary Osteoarthritis
o UNKNOWN aetiology
o Multifactorial causes

Question 3

Aetiology (secondary)

Answer 3

Can be classified according to the distribution of affected joints

• Secondary Osteoarthritis
o Other diseases lead to altered joint architecture and stability
o Commonly associated diseases include:
• Developmental abnormalities (e.g. hip dysplasia)
• Trauma (e.g. previous fractures)
• Inflammatory (e.g. rheumatoid arthritis, gout, septic arthritis)
• Metabolic (e.g. haemochromatosis, acromegaly)

Question 4

Pathogenesis

Answer 4

Pathogenesis

o Synovial joint cartilage destruction
o Eventually, there is loss of joint volume due to altered chondrocyte activity
o Patchy chronic synovial inflammation
o Fibrotic thickening of joint capsules

Question 5

Epidemiology

Answer 5

• COMMON
• 25% of those > 60 yrs
• More common in FEMALES, CAUCASIANS and ASIANS

Question 6

Presenting symptoms

Answer 6

• Joint pain and discomfort
o Use-related

• Stiffness or gelling after inactivity
• Difficulty with certain movements
• Feelings of instability
• Restriction walking, climbing stairs and doing manual tasks
• Systemic features are usually absent

Question 7

Signs on physical examination

Answer 7

• Local joint tenderness

• Bony swellings along joint margins
o Heberden’s Nodes - DISTAL interphalangeal joint
o Bouchard’s Nodes - PROXIMAL interphalangeal joint

• Crepitus and pain during joint movement
• Joint effusion
• Restriction of range of joint movement

Question 8

Investigations

Answer 8

Joint X-Ray of the affected joint will show FOUR classic features:

o Loss of joint space (narrowing)
o Osteophytes
o Subchondral cysts
o Subchondral sclerosis