Arthritis Flashcards
1
Q
Components of Synovial Joints
A
- Each bone is covered in cartilage
- Ligament attaches the 2 bones to strengthen the joint
- Fibrous capsule along inside of ligament; followed by synovial membrane (which forms articular capsule to protect synovial fluid); filled w/ synovial fluid
2
Q
4 General Types of Arthritis
A
- Mechanical/Degenerative
- Worse w/ activity
- <15 min morning stiffness
- No night pain
- Minimal swelling
- Hx trauma
- Esp weight-bearing joints
- Inflammatory (non-crystal)
- > 1 hr morning stiffness
- Better w/ activity; worse at night and w/ rest
- Warm, tender, swollen joints
- Inflammatory Crystal- Induced
- Gout
- More localized
- Severe constant pain, erythema, joint effusion
- Infectious
- Severe constant pain, erythema, joint effusion
3
Q
Synovial Fluid in Types of Arthritis
A
Mechanical
- Clear, high viscosity which is normal
- Maybe some WBCs
Inflammatory (non-crystal)
- Cloudy, opaque w/ less viscosity
- Many WBCs (5-25,000) and polys
Crystal
Cloudy, opaque w/ less viscosity
-Many WBCs (5-25,000) and polys
-ID monosodium urate crystals
Infectious
- Very opaque; low viscosity
- Most WBCs (50.000) and polys
- Low glucose as microbes consume glucose; and pos gram stain or cx
4
Q
How does osteoarthritis present?
A
- Knees (blacks), hips, spines, hands (whites)
- Joint pain and stiffness –> limited function and loss of motion
- Pain on passive movement of joints
- Cartilage has no nerve supply
- Pain from bone, joint capsule distention and secondary synovitis (can have inflammation in some cases)
- Crepitus (grinding or cracking) from cartilage loss and incongruity of joint
- Enlarged joint - do to bony protuberance, synovial inflammation or fluid (effusion)
- Deformity or subluxation (partial or total dislocation) in later stages
- HARD AND NODULAR
- Heberden’s Nodes - DIP joints
- Bouchard’s Nodes - PIP joints
5
Q
OA Pathogenesis
A
- Thinned/lost articular cartilage –> changes in subchondral bone –> osteophytes (bony protuberance)
- Can also lead to changes in synovium / deformed capsule
6
Q
OA Risks
A
- Hx joint damage
- Obesity
- Injurious physical activities
- Vulnerability - age, female, genetics, race, nutrition
- Knee mal-alignment (as OA evolves there is abnormal stress on cartilage –> bony remodeling)
- When meniscus removed or damaged there is less distribution of force; all concentrated in one place
7
Q
OA v. RA Imaging
A
OA - See less and less black space b/n 2 bones as cartilage lost
RA - BONE EROSIONS (as pannus invades bone)
8
Q
OA Tx
A
- PT, exercise (strengthen muscles around joints BUT do not run on bad knee joints), wt loss
- Pharm - acetaminophen, NSAIDs, topical NSAIDs (for pain relief)
- Joint replacement
- If surgery cannot be done may need to use opioids for pain reduction
9
Q
RA Presentation
A
- Symmetric inflammatory poly-arthritis (most commonly affects small joints of hands and feet)
- Female > male (approx 1% pop)
- Prolonged morning stiffness
- Low grade fever, wt loss, fatigue
- Local signs of inflammation - erythema, warmth at joint
- Symmetrical
- Wrists, MCP, PIP (not DIPs), sometimes feet
- Boggy, palpable swelling
- Weak grip and difficulty making fist due to pain
- Can progress - bone erosion and deformities
- Systemic feature - can involve vasculitis, lung (interstitial lung disease), anemia, eye inflammation, pericarditis, etc
10
Q
What is the major risk factor for RA?
A
Smoking
11
Q
RA Labs
A
- High RF titer (also prognostic - higher RF = worse disease); not specific
- Anti -CCPs more specific (directed against citrullinated antigens and inflammatory tissues are citrullinated)
12
Q
RA Tx
A
- Methotrexate -
- Similarly sulfasalazine, hydroxychloroquinolone, leflunomide)
- Anti-TNF Drugs - adalimumab, etanercept, infliximab
- Other Bio Drugs - anti-cytokines, anti- T cell, anti-B cell, oral small molecules targeting JAK pathway
13
Q
Gout and Pseudogout
A
- Gout = monosodium urate crystals (MSU)
- Hyperuricemia –> crystals in synovium phagocytosed –> activate inflammasomes w/in myeloid cells –> cytokines and other inflammatory mediators including IL-1
- Pseudogout = calcium pyrophosphate dihydrate crystals (CPPD)
- Similar, CPPD deposited in cartilage –> synovium
14
Q
Definition and Causes of Hyperuricemia
A
- Hyperuricemia if > 6.8 mg/DL
- Causes of hyperuricemia include… genetics, drugs, alcohol, diet
- Usually under-excretion ((kidneys) NOT over-production
15
Q
Gout Dx (+ how do images and crystals differ from pseudogout?)
A
- Presentation - podagra (swelling, warmth, red, pain of 1st MTP joint) and tophi under skin
- SO must r/o septic arthritis (emergency) esp if first time
- Aspirate joint - remove synovial fluid (arthrocenesis); often not performed b/c so much pain
- MSU - needle-shaped and neg bifringent (yellow) - yellow when parallel
- CPPD - rhomboid-shaped and pos bifringent (blue) - blue when parallel
- Must also do synovial fluid gram stain/cx and cell count
- Imaging
- Gout - circular destructive lesions of MTP joints in foot
- Pseudogout - see calcium deposits b/n bones (chondrocalcinosis)
