IC 16: Approach to the Management of Osteoarthritis and Rheumatoid Arthritis Flashcards
What are the differentials when patients present with joint pain?
- OA
- RA
- Gout
- Pseudogout
- Infection
- Trauma
- Tumours
What are the investigations required to differentiate gout, RA, septic arthritis, pseudogout
- Haematologic tests
- Erythrocyte sedimentation rate
- C-reactive protein
- Rheumatoid factor
- Anti-CCP
- Joint aspiration
- X-ray/MRI
What is OA?
Degenerative disease (with inflammation) of bone and joint cartilage
What are the risk factors for OA?
- Genetic predisposition
- Anatomic factors (varus alignment, valgus alignment)
- Joint injury
- Obesity (increase load on weight-bearing joints)
- Aging (change in ECM)
- Gender
- Occupation
What is the pathophysiology of OA?
- Articular cartilage damage
- Chondrocyte activity to remove/repair damage
- Aberrant chondrocyte function and more breakdown
- Subchondral bone release of vasoactive peptides and matrix metalloproteinases (increase break down of collagen)
- Cartilage loss and apoptosis of chondrocytes
- Formation of fibrillations in cartilage and cartilage “shards” (cartilage “shards” cause inflammatory and pathologic changes)
- Subchondral bones rub against each other
- Formation of osteophytes (a compensatory structure to stabilise osteoarthritis joints)
- Effusion and synovial thickening
What leads to pain in OA?
- Activation of nociceptive nerve endings within the joint by mechanical and chemical irritants
- Distension of synovial capsule from increase joint fluid, microfracture, periosteal irritation or damage to ligament, synovium or meniscus
What contributes to inflammation in OA?
- Formation of cartilage “shards”
- Meiscal damage (release of inflammatory cytokines)
- Ligament tears (release of inflammatory cytokines)
- Synovitis (release of inflammatory cytokines)
What leads to cartilage degradation in OA?
- Articular cartilage daamge
- Chondrocytes proliferate and undergo phenotypic switch
- Produce improperly mineralised collagen
- Weakening and degradation of collagen matrix in synovium
How does bone remodeling and osteophyte formation occur in OA?
- Weakened collagen matrix causes thickening of subchondral bone
- Sclerosis and formation of bone spurs (osteophytes)
- Widening of joints
How does synovial inflammation occur in OA?
- Weakening and degradation of collagen matrix
- Cartilage flakes off forming cartilage shards
- Lymphocytes and macrophages get recruited by synovial membrane
- Proinflammatory cytokines produced
- Synovitis
What are the key features of OA?
- Pain
- Swelling
- Erythematous and warm
- Morning stiffness < 30 mins (resolves with motion, recurs with rest)
- Limited joint movement
- Functional limitation/instability (falls)
- Asymmetrical polyarthritis (hand, knee, hip)
- Symptoms related to weather
How is the pain like for OA?
- Slow progression over years
- Worse with joint use and relieved by rest
- Worse in late afternoon/early evening
- For knees it is worse going down the stairs/slope
- Most severe over joint line
- May also have anxiety, depression, sleep disturbance
What are the various stages of OA?
- Stage 1: predictable sharp pain with mechanical insult, only modest effect on function
- Stage 2: pain becomes more constant, with unpredictable episodes of stiffness, daily activities to be affected
- Stage 3: constant dull/aching pain and often unpredictable intense, exhausting pain, severe limitations in function
What may be found on physical exam of an OA patient?
- Asymmetric monoarticular or oligoarticular
- Crepitus on motion (popping of joint)
- Reduced range of motion
- Transient joint effusion
- Palpable warmth
- Bone tenderness
- Bone enlargement
What may be found when doing an X-ray on a OA patient (done in advanced disease)?
- Joint space narrowing
- Marginal osteophytes
- Subchondral bone sclerosis
- Abnormal alignment of joint
Can diagnosis for OA be done without radiography? If yes when?
Yes.
* It can be done for patients >= 45 years old
* With activity-related joint pain
* Morning stiffness <= 30 mins
What are the non-pharm treatment for OA?
- Exercise (reduce pain and improve function) (strengthening, low-impact aerobic, mind-body exercise, neuromuscular training) (PT) (about 30 mins, 3 times a week)
- Weight management
- Information and support
What are the drugs that can be considered for OA?
- Topical NSAIDs (first) (for knee, less feasible for hand, unlikely to benefit for hip)
- Oral NSAIDs / coxib ( + PPI)
- Oral paracetamol / tramadol (if contraindicated to NSAIDs)
- Intraarticular glucocorticoid injections for short-term symptom relief
What are the common GI side effects of oral NSAIDs?
- Nausea
- Dyspepsia
- Anorexia
- Abdominal pain
What are the risk factors for NSAID-induced GI ulcer/bleed?
- > 65 y/o
- History of ulcer
- Use of high dose/chronic NSAID
- Concurrent glucocorticoids/antiplatelets/anticoagulants
- High risk is more those with >= 3 of 4 risk factors
What are signs of NSAID-induced GI complications?
- Fatigue
- Severe dyspepsia
- Signs of GI bleeding
- Unexplained blood loss anemia
- Iron deficiency
What NSAIDs should be given for patients with high risk of GI bleed or ulcers?
- Ibuprofen can be used instead of naproxen
- Give coxibs like celecoxib or etoricoxib
What is the CVS safety concerns of oral NSAIDs?
- There is a risk of cardiovascular events like MI, stroke, vascular death
- Use celecoxib at doses < 400 mg/day
- Use of high-dose systemic diclofenac is contraindicated in patients with established CV disease, can be used if <= 100mg/day if treatment for > 4 weeks
What are the renal safety concerns for use of NSAIDs?
- AKI
What are the risk factors for NSAID-induced AKI?
- CKD (can use if < 5-7 days in eGFR < 60, not in eGFR < 15)
- Volume depletion (emesis, diarrhea, sepsis, hemorrhage)
- Effective arterial volume depletion (HF, nephrotic syndrome, cirrhosis)
- Severe hypercalcemia/renal artery stenosis
- Aminoglycosides, amphotericin B, radiocontrast material
- Diuretics and ACEi/ARB
- more than 65 y/o
What are concerns for NSAIDs in terms of allergic reactions?
- Ig-E mediated allergic reactions
- Pseudoallergic reactions (related to COX-1 inhibition) (can use coxib with caution)
What side effects are associated with oral NSAIDs use?
- GI bleeds/ulcers
- AKI
- Allergic reactions
- Effects on BP and hypertension
- Hematologic effects (inhibit platelet function)
- CNS: drowsiness, dizziness, headaches, tinnitus