OSTEOARTHRITIS

Question 1

Epidemiology

Answer 1

Commonest joint condition. Prevalence adult pop of 11% for hip and 24% knee. Women (3:1); O. 50

Question 2

What is the aetiology?

Answer 2

• General wear and tear leads to localised loss of cartilage, remodelling of adjacent bone and associated inflammation.
• Trauma
• Secondary to joint disease
• Obesity
• Haemochromatosis
• Occupational – gardening, sportsmen

Question 3

What are the risk factors?

Answer 3

• Genetics – hereditability = 40-60%
• Ageing
• Female
• Obesity
• High bone density – RF for development OA
• Low bone density – RF for progression of knee and hip OA
• Joint injury
• Occupational and recreational stresses on joints
• Joint laxity
• Red muscle strength
• Joint malignancy

Question 4

What are the symptoms?

Answer 4

• Pain on movement
• Crepitus
• Worse at beginning of day
• Background pain at rest
• Stiffness after rest up to 30 mins and am
• Joint instability
• Reduced function and participation restriction

Question 5

What are the commonly affected joints?

Answer 5

DIP joints, thumbs, MCP, knees, hip

Question 6

What are the signs?

Answer 6

• Reduced range movement
• Joint tenderness
• Derangement of joint
• Bony swellings – Heberden’s nodes (DIP) and Bouchard’s nodes (PIP)
• Pain on movement of joint
• Joint swelling – mild synovitis

Question 7

How would you investigate?

Answer 7

Plain radiogram shows loss joint space, subchondral sclerosis and cysts, and marginal osteophytes
CRP – may be slightly raised
Joint aspiration – to exclude other causes such as septic arthritis and gout
Diagnosis can be made clinically: If patient is >45, has activity-related joint pain and has either no morning joint-related stiffness, or morning stiffness lasting no longer than 30mins.

Question 8

What things can the patient do?

Answer 8

• Regular exercises to improve muscle strength and joint stability and keep active (eg quad exercises for knee; hydrotherapy for hip)
• Weight loss if BMI>28
• Walking aids, supportive footwear

Question 9

What can the dr offer?

Answer 9

• Regular paracetamol +/- codeine for pain. (consider NSAIDS only if para ineffective)
• Regular physio
• Topical NSAIDS and capsaicin
o Beware of NSAIDs – can lead to severe S/E incl GI bleeding and renal impairment. Contraindicated in pt with HF.
• Highly selective COX-2 inhibitors
• Intra-articular steroid injections may temporarily help
• Joint replacement

Question 10

What are the differentials?

Answer 10

• Knee OA: prepatellar bursitis, referred pain hip or spine
• Hip OA: Bursitis, referred pain knee or spine
• Pseudogout
• Psoriatic arthritis
• Septic arthritis
• Viral arthritis
• Reactive arthritis (Reiter’s syndrome)
• RA
• Gout
• CT disease
• Seroneg arthritis eg ankylosing spondylitis
• Referred pain
• Medical conditions presenting with arthrpathy eg sarcoidosis, infective endocarditis