OA PP

Question 1

Osteoarthritis

Answer 1

1. Articular cartilage
2. Bone
3. Synovial membrane
4. Capsule and ligaments
5. Muscles

Question 2

1. Articular cartilage

Answer 2

• Chondrocytes (the secretory cells that produce a matrix of collagen, proteoglycans and other proteins) are damaged
• Process of normal chondrocyte destruction and re-growth is disrupted allowing water content increases and proteoglycans decrease
• Fibrillation: softening, cracks, fissures, splitting and fragmentation occur
• Water further attracted into cartilage - further flaking of cartilage
• Flakes trapped inside joint space leading to locking and inflammation

Question 3

2. Bone

Answer 3

• Decreased protection, gets buffered by pressure, hardened and flattened
• Synovial fluid forced in by pressure of weight-bearing = subchondral cysts
• Micro-fractures occur and loose bodies can enter the join space
• Osteophyte formation (extra bone growth) due to bones rubbing together (destruction overtakes repairing)

Question 4

3. Synovial membrane

Answer 4

• Becomes oedematous
• Decreased secretions
• Reduced nutrition
• Reduced lubrication of articular cartilage
• Synovial membrane becomes less effective leading to more stiffness

Question 5

4. Capsule and ligaments

Answer 5

Low grade chronic inflammation leads to fibrous degeneration

Question 6

5. Muscles

Answer 6

Functional limitation and pain inhibition leads to atrophy