Osteoarthritis (OA): Cartilage Loss, Heberden's Nodes & Rehab

Osteoarthritis (OA)

Osteoarthritis is the most common joint disorder, characterized by degeneration of articular cartilage and new bone formation (osteophytes). It typically affects weight-bearing joints (Knee, Hip, Spine).

1. Pathophysiology

• Cartilage Loss: Fibrillation and erosion of hyaline cartilage.
• Bone Response: Sclerosis (hardening) and Osteophyte formation (spurs) to increase surface area.
• Sites: Knee (Medial compartment), Hip, Spine, Hands (DIP/PIP).

2. Clinical Features

• Pain: Worse with activity, relieved by rest. "Start-up pain" (stiffness after sitting).
• Stiffness: Morning stiffness < 30 minutes.
• Crepitus: Grinding sensation.
• Nodes: Heberden's (DIP) and Bouchard's (PIP).

3. X-ray Signs (LOSS)

L - Loss of joint space (Asymmetrical).
O - Osteophytes.
S - Subchondral Sclerosis (Whitening).
S - Subchondral Cysts.

4. Management

• Conservative: Weight loss (most effective), Exercise (Quadriceps strengthening), NSAIDs.
• Surgical: Osteotomy (for alignment), Arthroplasty (Replacement).

25 Practice MCQs

Q1. Osteoarthritis is primarily a disease of:

Answer: A). "Wear and tear".

Q2. Heberden's Nodes are found at the:

Answer: A). Characteristic of hand OA.

Q3. Bouchard's Nodes are found at the:

Answer: A). B for Basal (Proximal).

Q4. Morning stiffness in OA typically lasts:

Answer: A). Differentiates from RA (> 1 hr).

Q5. Joint space loss in OA is typically:

Answer: A). RA causes symmetrical uniform loss.

Q6. The single most modifiable risk factor for Knee OA is:

Answer: A). Losing weight significantly reduces load.

Q7. "Start-up Pain" refers to:

Answer: A). "Gelling" of the joint.

Q8. Osteophytes are:

Answer: A). Attempt to increase surface area and stabilize joint.

Q9. Subchondral Sclerosis appears on X-ray as:

Answer: A). Reaction to increased stress.

Q10. Viscosupplementation involves injection of:

Answer: A). To improve lubrication.

Q11. High Tibial Osteotomy is indicated for:

Answer: A). Corrects varus to offload the medial side.

Q12. Quadriceps exercises are important because:

Answer: A). Reduces load on the joint.

Q13. Primary OA has:

Answer: A). Secondary OA follows injury/disease.

Q14. Kellgren and Lawrence system is used for:

Answer: A). Grade 4 is bone-on-bone.

Q15. Patellofemoral OA pain is worsened by:

Answer: A). Activities loading the flexed knee.

Q16. Joint Mice are:

Answer: A). Common complication.

Q17. Arthrodesis (Fusion) is preferred over Replacement in:

Answer: A). Durable but stiff.

Q18. 1st CMC (Thumb base) OA presents with:

Answer: A). Common in women.

Q19. Hallux Rigidus is OA of the:

Answer: A). Limits dorsiflexion.

Q20. Glucosamine and Chondroitin supplements are:

Answer: A). May help symptoms in some.

Q21. Unloader braces for Medial Knee OA apply:

Answer: A). Shifts weight laterally.

Q22. OA is an inflammatory disease. True/False?

Answer: B). ESR/CRP are usually normal.

Q23. Hip OA pain is typically felt in the:

Answer: A). Groin pain = Hip joint. Buttock pain = Spine/SI.

Q24. Capsaicin cream works by:

Answer: A). Topical analgesic.

Q25. Girdlestone Procedure is a salvage for:

Answer: A). Leaves a flail joint.