Section 5: Inflamed Joints Flashcards
What is the synovial fluid cell count in
Normal
Inflammatory
Infections
< 2,000
2,000 - 50,000
> 50,000
Factors that precipitate gouty attacks
- Binge drinking of alcohol
- Thiazides
- Nicotinic acid
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4713-4726). . Kindle Edition.
Gout:
Best initial test
Most accurate test
- Arthrocentesis (aspiration of joint fluid)
- Polarized light examination of the fluid will show negatively birefringent needles
Gout = Negative birefringence
Pseudogout = Positive birefringence
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4713-4726). . Kindle Edition.
In the CCS, list tests to order for gout or inflammed joint
- Joint fluid examination for cell count, culture, and protein level
- Serum uric acid level: However, do not rely on uric acid level to make an accurate diagnosis
- X-ray of the toe: May show “punched-out” lesions
- Extremity examination for tophi
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4713-4726). . Kindle Edition.
Gout
Best initial Rx for acute gout
Alternative Rx if BIRx fails
NSAIDs
If there is insufficient response or a contraindication to NSAIDs, use steroids to treat acute gouty attacks
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4727-4761). . Kindle Edition.
When to use colchicine in Rx of gout?
Colchicine is useful under the following conditions:
- In the first 24 hours of an attack
- When there is a contraindication to the use of NSAIDs, such as renal insufficiency
- As part of preventive therapy to decrease the risk of a gouty attack
- Treat gout with colchicine only if NSAIDs and steroids cannot be used
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4727-4761). . Kindle Edition.
Adverse effects of colchicine
- Nausea and diarrhea
- Bone marrow suppression
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4727-4761). . Kindle Edition.
List the ways to prevent gout
- Febuxostat is an alternative to allopurinol. Prevention: –
- Allopurinol, probenecid, and sulfinpyrazone lower the level of uric acid. Allopurinol has the following adverse effects: rash, allergic interstitial nephritis, and hemolysis
- Weight loss
- Avoiding alcohol
Febuxostat is a xanthine oxidase inhibitor that markedly lowers uric acid levels. Febuxostat is the answer when the patient is intolerant of allopurinol
Uricase (rasburicase and pegloticase) are benign drugs to break down uric acid. Use if allopurinol or febuxostat is not enough
Do not start allopurinol during an acute attack of gout
Rasburicase and pegloticase break down uric acid to allantoin. Use if allopurinol and febuxostat are not enough
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4727-4761). . Kindle Edition.
- Synovial fluid finding in pseudogout
- Rx of Pseudogout
- Acute management of pseudogout
- Positively birefringent rhomboid-shaped crystals
- NSAIDS are the best initial therapy. Colchicine is used but is not as effective.
- Acute management is the same as gout: NSAIDs or steroids
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4769-4798). . Kindle Edition.
Septic Arthritis
The more abnormal the joint, the more likely a patient is to have septic arthritis: prosthetic joint > rheumatoid arthritis > osteoarthritis > normal joint.
Any arthritic joint or prosthetic joint is a risk factor for septic arthritis
List the CF of septic arthritis
Swollen, red, immobile, tender joint
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4769-4798). . Kindle Edition.
Causative organisms of septic arthritis
- Disseminated gonorrhea is diagnosed by culture of: • Joint fluid (50 percent positive) • Pharynx (10– 20 percent positive) • Rectum (10– 20 percent positive) • Urethra (10– 20 percent positive) • Cervix (20– 30 percent positive)
- Staphylococcus aureus (40 percent)
- Streptococcus (30 percent)
- Gram-negative bacilli (20 percent)
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4769-4798). . Kindle Edition.
True or False?
CCS Tip: Call an orthopedic surgery consult when you suspect a septic joint. The consultation won’t offer much on the CCS, but it needs to be done
True
Diagnostic testing in septic arthritis
Best initial test: Tap the joint (arthrocentesis).A finding of > 50,000 white cells is consistent with infection
Gram stain has a 50– 60 percent sensitivity
Most accurate test: Culture is > 90 percent sensitive but is never available when you must make an acute treatment decision
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4769-4798). . Kindle Edition.
Empiric Rx of septic arthritis
IV Ceftriaxone + IV vancomycin
Choice of antibiotics against Staph and strep in septic arthritis
Oxacillin
Nafcillin
Cefazolin
Penicillin allergy: Anaphylaxis
- Vancomycin
- Linezolid
- Daptomycin
- Clindamycin
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4799-4846). . Kindle Edition.
Choice of antibiotics against Gram-negative bacilli in septic arthritis
Ceftriaxone
Ceftazidime
Gentamicin
Penicillin allergy: Anaphylaxis
- Aztreonam
- Fluoroquinolone
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4799-4846). . Kindle Edition.
Paget’s Disease of Bone is often asymptomatic.
What are some CF?
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4799-4846). . Kindle Edition.
- pain
- stiffness
- aching
- fractures
Soft bones lead to bowing of the tibias. Sarcoma arises in 1 percent of patients. In cases of Paget’s, osteolytic lesions will be found initially. These may be replaced with osteoblastic lesions
if osteolytic, then think Paget’s or osteoporosis; but • if osteoblastic, think about metastatic prostate cancer in the differential diagnosis.
Paget’s disease:
Best initial test
Most accurate test
Alkaline phosphatase level. It will be elevated
Most accurate test: x-ray
For CCS, also order the following
- Urinary hydroxyproline
- Serum calcium level— It will be normal
- Serum phosphate level— It will be normal
- Bone scan
Treat with bisphosphonates and calcitonin.
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4799-4846). . Kindle Edition.
Rx of Paget’s disease
Bisphosphonates and calcitonin
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4799-4846). . Kindle Edition.
A Baker’s cyst is a posterior herniation of the synovium of the knee. Look for a patient with osteoarthritis or rheumatoid arthritis with a swollen calf. A ruptured Baker’s cyst is a “pseudo-phlebitis.” Unruptured cysts can be palpated.
Test to do
Rx
Diagnostic Testing:Exclude a deep vein thrombosis with ultrasound
Treat with NSAIDs and, occasionally, with steroid injection.
CF of plantar fascitis
Pain on bottom of foot
Very severe in the morning, better with walking a few steps
Stretch the foot and calf
Resolves spontaneously over time
CF of tarsal tunnel syndrome
Pain on bottom of foot
More painful with more use; like carpal tunnel of the foot; may have numbness of the sole, too
Avoid boots and high heels; may need steroid injection
May need surgical release
CF of Morton neuroma
Painful burning sensation in the interdigital web space between the 3rd and 4th toes
Tenderness when pressure is applied between the heads of the 3rd and 4th metatarsals
Sharp, intermittent pain radiating into the toes that feels better when shoes are taken off
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 4842-4872). . Kindle Edition.
Indications for Rx in Paget’s disease
- Bone pain
- Hypercalcemia of immobilization
- Neurological deficit
- High output cardiac failure
- Preparation for orthopedic surgery
- Involvement of weight-bearing bones (to prevent deformities)
Paget’s disease of the bone (osteitis deformans) is associated with normal serum calcium and phosphate levels and increased alkaline phosphatase and urinary hydroxyproline levels
