Osteoarthritis

Question 1

Summarise what OA is.

Answer 1

· A degenerative joint disorder.

· Result of mechanical and biological events that:

• Destabilise the normal process of degradation.
• Destabilise the synthesis of articular cartilage chondrocytes.

· Involves the entire joint.
· Condition leads to loss of cartilage.

Question 2

Who is most affected?

Answer 2

· More common in women.

· Prevalence increases with age.

Question 3

What is the pathophysiology of OA?

Answer 3

· Failure in maintaining the homeostatic balance of the cartilage matrix synthesis and degradation.
· This results in reduced bone formation and increased catabolism.

Question 4

What is the aetiology of OA?

Answer 4

· No single cause.

· Host of biological and mechanical factors that culminate in the development of OA.

Question 5

What are the risk factors for OA?

Answer 5

· Age >50. 
· Hereditary predisposition.
· Female.
· Obesity - Knee OA. 
· Physical/manual occupation. 
· Joint trauma. 
· High bone mineral density. 
· Low oestrogen status, such as in post-menopausal women. 
· Conditions such as haemochromotosis and EDS.

Question 6

List the most common signs and symptoms.

Answer 6

· Most commonly affected joints are the knee, hip, hands, lumbar and cervical spine.
· Joint pain and stiffness that’s worse with activity.
· Pain.
· Swelling.
· Crepitus.
· Heberden’s nodes at DIP joints - ‘outer Hebrides’.
· Bouchard’s nodes at PIP joints.
· Functional difficulties - knee giving way/locking.
· Bony deformities.
· Limited range of motion.
Malalignment - particularly in the knee where OA causes both gene valgum (knock-knees) and genu varum (bow-legs).

Question 7

What investigations would you request if you suspected a patient had OA?

Answer 7

· X-ray.
· CRP.
· ESR.
· Rheumatoid factor and anti-CCP antibody - negative.

Question 8

What would the investigation results show?

Answer 8

· X-ray - LOSS:

• L - Loss of joint space.
• O - Osteophytes.
• S - Subchondral cysts.
• S - Sclerosis.

· CRP - normal.
· ESR - normal.
· Rheumatoid factor and anti-CCP antibody - negative.

Question 9

Suggest some differential diagnoses.

Answer 9

· Bursitis. 
· Gout.
· Pseudogout. 
· RA/Psoriatic arthritis. 
· Avascular necrosis.
· Internal derangements such as meniscal tears.

Question 10

What are the non-pharmacological treatment options?

Answer 10

· Physiotherapy.
· OT.
· Strengthening exercises.

Question 11

What are the pharmacological treatment options?

Answer 11

· Paracetamol, topical diclofenac, NSAIDS, opioids.
· Intra-articular corticosteroid injections.
· Gastro-protection.

Question 12

What other treatment options are available?

Answer 12

Surgery (TJR or TKR) - if patient’s don’t respond to medical or non-medical therapies.

Question 13

What complications may arise?

Answer 13

· Functional decline and inability to perform activities of daily living.
· Spinal stenosis in cervical or lumbar OA.
· NSAID-related GI bleeding.
· Gout.