Osteoarthritis

Question 1

What is osteoarthritis (OA)?

Answer 1

• OA = a disorder of synovial joints characterised by articular surface damage, formation of new bone, and secondary inflammation (‘natural wear and tear’)
• OA is known as a degenerative disease

Question 2

What is the pathology of osteoarthritis?

Answer 2

• Repeated microtrauma which causes damage to the weight-bearing cartilage surface, which eventually wears away, exposing the subchondral bone
• Chondrocytes attempt repair by releasing degradative enzymes
• Disorganised new bone formation occurs at the joint margins (osteophytes) and the synovial fluid becomes thickened and inflamed, producing excess synovial fluid (effusions)

Question 3

What are some risk factors for osteoarthritis (OA)?

Answer 3

• elderly
• occupation / sporting activities
• muscle weakness
• obesity

Question 4

What are the 4 typical features found on X-ray examination of osteoarthritis joints?

Answer 4

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

Question 5

Osteoarthritis anatomy diagram…

Answer 5

Question 6

What are the clinical features of osteoarthritis (OA)?

Answer 6

• pain (aching/burning), stiffness
• gradual onset and worse on activity
• muscle wasting, swelling, and deformity can occur

Question 7

Heberden node (DIPs) and Bouchard node (PIPs)…

Answer 7

• bony growth/swelling/cyst

Question 8

What are common findings on clinical examination in a patient with osteoarthritis (OA)?

Answer 8

• antalgic gait
• deformities (redness, scarring, swelling, muscle wasting)
• DIPs (Heberden nodes) and PIPs (Bouchard nodes) are most common within the hands
• reduced range of movement and joint line tenderness, crepitus

Question 9

What investigations should be done for suspected OA?

Answer 9

• diagnosis should be clear from history
• X-rays: to confirm diagnosis and see progression of disease

Question 10

OA x-ray (normal hip vs OA hip)…

Answer 10

Question 11

What is the management for osteoarthritis (OA)?
(there is no cure for OA, treatment is aimed at relieving pain and maintaining function)

Answer 11

• Conservative: weight loss, exercise. physio, OT
• Pharmacological: analgesia (paracetamol, NSAIDs), intra-articular steroid injections
• Surgical: joint arthroplasty (relieves pain, but function not as good), joint arthrodesis (relieves pain, but function lost), osteotomy (used to correct deformity)

Question 12

Osteotomy of knee (for varus deformity, aka. Bow legs)…

Answer 12

• wedge of bone is removed to fix the deformity and correct alignment
• (varus deformity caused by OA wearing down the bone on the medial aspect of the knee)