AIM STEP 10 • STUDENT MEMORY SUPPORT
Student Memory Support
Osteoarthritis, Rheumatoid Arthritis and Rheumatoid Pharmacotherapy
3rd Year MBBS • High-yield revision and memory reinforcement
1. High-Yield Flashcards
Tap each question to reveal the answer.
“`
What is the central pathological defect in osteoarthritis?
Progressive failure and loss of articular cartilage with subchondral bone remodeling.
Which major factors contribute to primary osteoarthritis?
Age, inherited susceptibility, obesity and cumulative mechanical loading.
What is eburnation in osteoarthritis?
A smooth, polished ivory-like surface formed by exposed subchondral bone.
Which radiographic changes favor osteoarthritis?
Non-uniform joint-space narrowing, osteophytes, subchondral sclerosis and cysts.
What is the central lesion in rheumatoid arthritis?
Chronic proliferative autoimmune synovitis with pannus formation.
How does rheumatoid arthritis produce marginal bone erosions?
RANKL stimulates osteoclast differentiation at inflamed joint margins.
What is the microscopic pattern of a rheumatoid nodule?
Central fibrinoid necrosis surrounded by palisading macrophages.
Which joint pattern strongly suggests rheumatoid arthritis?
Symmetrical wrist, MCP and PIP synovitis with relative DIP sparing.
Which antibody is more specific for rheumatoid arthritis?
Anti-citrullinated protein antibody.
What is the role of NSAIDs in rheumatoid arthritis?
They reduce pain and stiffness but do not prevent structural joint damage.
Why are glucocorticoids used as bridging therapy?
They rapidly suppress synovitis while slower-acting DMARDs begin to work.
What defines a disease-modifying antirheumatic drug?
A drug that suppresses the disease process and reduces structural progression.
What is the key anti-inflammatory action of low-dose methotrexate?
It increases anti-inflammatory adenosine signaling and reduces immune-cell activity.
Which major toxicities require monitoring during methotrexate therapy?
Bone-marrow suppression, hepatotoxicity, mucosal injury and pulmonary toxicity.
What communication method helps prevent methotrexate dosing errors?
Teach-back: ask the patient to repeat the weekly schedule and warning symptoms.
“`
2. Mnemonics
“`
Mnemonic Title
Osteoarthritis Morphology
SCON
Meaning: Subchondral sclerosis, Cysts, Osteophytes, Narrowed joint space.
Mnemonic Title
Rheumatoid Hand Pattern
WMP, DIP Skip
Meaning: Wrists, MCP and PIP joints are commonly involved; DIP joints are relatively spared.
Mnemonic Title
Methotrexate Major Toxicities
BLMP
Meaning: Blood marrow, Liver, Mucosa and Pulmonary toxicity.
“`
3. Memory Tables
“`
Osteoarthritis versus Rheumatoid Arthritis
| Feature | Osteoarthritis | Rheumatoid Arthritis |
|---|---|---|
| Main process | Degenerative cartilage failure | Autoimmune synovitis |
| Pain pattern | Worse with activity | Prominent after rest |
| Morning stiffness | Brief | Prolonged |
| Typical joints | Knee, hip, DIP, PIP | Wrist, MCP, PIP |
| Imaging | Osteophytes, sclerosis, cysts | Osteopenia, uniform loss, erosions |
Rheumatoid Drug Groups
| Group | Main Role | Key Memory Point |
|---|---|---|
| NSAIDs | Pain and stiffness relief | No structural protection |
| Glucocorticoids | Rapid inflammation control | Limit cumulative exposure |
| Conventional DMARDs | Disease modification | Methotrexate is prototype |
| Biological DMARDs | Target immune pathways | Serious infection risk |
| Targeted synthetic DMARDs | Block cytokine signaling | JAK inhibition |
“`
4. Rapid Revision Points — Last-Minute Revision
Must Remember:
- Osteoarthritis is a whole-joint degenerative process, not passive wear alone.
- Cartilage fissuring, eburnation, sclerosis, cysts and osteophytes are core OA changes.
- Rheumatoid arthritis begins with immune-mediated chronic synovitis.
- Pannus destroys cartilage and bone; RANKL promotes osteoclast activation.
- Prolonged morning stiffness supports inflammatory arthritis.
- Rheumatoid factor supports but does not independently confirm the diagnosis.
- NSAIDs provide symptom relief without reliable disease modification.
- Glucocorticoids act rapidly but can cause osteoporosis and infection.
- Methotrexate is commonly used as the anchor conventional DMARD.
- Methotrexate is administered weekly and requires CBC, liver and renal monitoring.
“`
KMU Trap: Symptom improvement after an NSAID does not indicate that rheumatoid joint destruction has been controlled.
“`
5. Clinical Memory Hooks
“`
Knee pain worsened by stairs with crepitus → mechanical cartilage and subchondral bone disease of osteoarthritis.
Symmetrical MCP/PIP swelling with prolonged stiffness → chronic autoimmune synovitis of rheumatoid arthritis.
Pain improves but erosions progress during NSAID use → symptom relief without disease modification.
Mouth ulcers, bruising or breathlessness during methotrexate therapy → possible mucosal, marrow or pulmonary toxicity.
“`
6. Starred High-Yield Exam Points
- ⭐ Osteophytes with subchondral sclerosis strongly support osteoarthritis.
- ⭐ Pannus formation is the hallmark destructive lesion of rheumatoid arthritis.
- ⭐ Anti-citrullinated protein antibodies are more specific than rheumatoid factor.
- ⭐ Methotrexate is the prototype conventional DMARD and is given weekly.
- ⭐ Methotrexate can cause marrow suppression, hepatotoxicity and pneumonitis.
- ⭐ Biological and targeted DMARDs increase the risk of serious or reactivated infection.