Musculoskeletal Pain Flashcards
(46 cards)
What is the next diagnostic step for joint paint (monoarticular) that is not preceded by a history of joint pain, sudden onset, and non traumatic, but is edematous, erythematous, and warm?
- Joint aspiration for examination of joint fluid to identify crystals and exclude infection
What is the treatment of acute gout?
- NSAID
- Colchicine
- Glucocorticoids
Why must an infected joint be ruled out quickly (i.e. 24hrs?)
Exclusion of infectious etiology is paramount because cartilage can be destroyed within the first 24hrs of infection
What age groups are most affected by gout?
- Men => 30-50
- Women => 50-70
List some exacerbating factors of gout.
- Alcohol consumption
- Trauma
- Surgery
- Large meals (often protein) or thiazides that induce hyperuricemia
What type of crystals are seen in crystal induced arthritis?
- Upon microscopy, monosodium urate (MSU) crystals (look like needles) are seen; these have a strong negative birefringence.
Describe the appearance of calcium pyrophosphate dehydrate crystals under microscopy.
Calcium pyrophosphate dehydrate => rod shaped, rhomboid, weakly positive birefringence
Describe the appearance of calcium hydroxyapatite crystals under microscopy.
Calcium hydroxyapatite => cytoplasmic inclusions that are NOT birefringent
Describe the appearance of calcium oxalate crystals under microscopy.
Calcium oxalate => bipyramidal appearance, strongly positive birefringence; seen mostly in end stage renal disease patients
How does the CBC of a crystal induced arthritis differ from a septic joint?
- Crystal induced arthritis => white cells 2,000-60,000
- Septic joint => ~100,000 white cells and >90% PMNs
What is the difference between gout and pseudo gout?
- Gout => due to uric acid deposition in the joints
- Pseudogout => due to calcium pyrophosphate dehydrate crystals (rhomboid, weakly positive birefringent)
What is the DDX for non traumatic swollen joint/joint pain?
- Gout/Pseudogout
- Infectious arthritis
- Osteoarthritis
- Rheumatoid arthritis
What is the pattern of articular involvement in bacterial arthritis?
Monoarticular => often knee, hip, shoulder
What organisms may be responsible for chronic monoarticular pain?
- Mycobacterium
- Fungi
Acute, polyarticular arthritis may be due to what kinds of infections?
- Endocarditis
- Disseminated gonococcal infection
Patients with rheumatoid arthritis are susceptible to joint infections from which organisms?
- Staph. aureus
Patients with HIV are susceptible to joint infections from which organisms?
- Pneumococcal, salmonella, H. influenzae
Patients who are IV drug users are susceptible to joint infections from which organisms?
- Streptococcal, staphylococcal, gram negative, or psuedomonas
How does a septic joint differ from cellulitis, bursitis, or osteomyelitis?
- Septic joints have very limited ROM in comparison to cellulitis, bursitis, or osteomyelitis
What are the main features of osteoarthritis?
- > 65yo
- Associated with trauma, history of repetitive joint use, and obesity (especially knee)
- Primarily affects cartilage, but can damage bone surface, synovium, meniscus, and ligaments
- Dull, deep, and achey pain
- Worse with activity
- Crepitus with passive ROM
- X rays may reveal => bone sclerosis, subchondral cysts and osteophytes
What are the main features of rheumatoid arthritis?
- Onset at 30-55yo
- Women more than men
- Morning stiffness
- Involvement of 3+ joints
- Symmetric arthritis
- Positive rheumatoid factor, ESR, CRP, anemia, thrombocytosis, or low albumin
- Rheumatoid nodules
- Xray => decalicifications or erosions
What is the maintenance therapy for gout?
- Probenecid => increases urinary excretion of uric acid
- Allopurinol => reduces the production of uric acid
What is the therapy for a septic joint?
- A septic joint requires surgical debridement/ drainage and antibiotics
What is the therapy for DJD?
- Mobility exercises
- Weight loss
- Intra-articular corticosteroid injections every 4-6mo
- Joint replacement in severe disease
