Osteomyelitis, Septic Arthritis (Masumoto) & Crystal Arthropathies (Vogelgesang) Flashcards
An open pressure ulcer with wound drainage in a diabetic patient is an example of what pathogenic mechanism of osteomyelitis?
A. Contiguous spread of infection with both gram positive cocci and gram negative rods
B. Trauma related wound infection with streptococcus
C. Hematogenous spread of infection with staph aureus
D. Contiguous spread of infection with staph aureus or streptococcus
E. Trauma related wound infection with both gram positive cocci and gram negative rods
A
Continguous spread of infection is usually polymicrobial, with staph aureus being the most common of the infecting microbes.
Hematogenous spread of infection is associated with central lines and IV drug use.
Surgical/trauma wound infections can be serious, as in the case of an open fracture, because of the high morbidity associated with bone infection under these conditions; early antibiotic administration and washout are critical.
what is the most frequent pathogen in osteomyelitis?
staph aureus
the picture below shows chronic or acute osteomyelitis?
Chronic osteomyelitis, such as a non-healing ulcer. Acute osteomyelitis has a much more angry look with redness, fever, and pus.
devitalized bone acting as a foreign body that is not easily reached by antibiotics is known as what?
sequestrum
A 46 yo male with schizophrenia and dental carries has dental pain for several years. The x-rays show a lytic lesion, suggestive of osteomyelitis. Which is the likely mechanism of pathogenesis?
A. Contiguous spread
B. Hematogenous spread
C. Surgical/trauma wound infection
A. And it is likely due to a polymicrobial infection with oral microbes (Streptococcus, anaerobes).
signs and symptoms of this disease are red, hot, painful joints that are usually mono-arthralgiac, and systemic symptoms like fever and chills
septic arthritis (or crystal arthritis)
type of migratory polyarthritis resulting from a gram negative, sexually transmitted infection, and is diagnosed via joint fluid and urethra/cervix/throat cultures
gonococcal arthritis
what is the most frequent pathogen in septic arthritis?
staph aureus
what is the organism that can cause septic polyarthritis in a sexually active patient?
neisseria gonorrhoeae
All of the following favor diagnosis of septic arthritis EXCEPT:
A. WBC of 50,000
B. Neutrophils > 50% of WBC
C. Elevated protein
D. Gram + cocci in clusters on culture
E. No crystals
B. Should be a higher percentage of PMNs, like > 90%
Which of the following treatments are important for septic arthritis?
A. Washout
B. Antibiotics (3-4 week course for non-gonococcal, 2 weeks for gonococcal)
C. Joint ROM exercises
D. All of the above are important treatments
D
recurrent attacks of acute arthritis caused by monosodium urate crystals in the synovium and elevated serum uric acid > 7.0 mg/dl
gout
aggregated deposits of urate crystals are known as ______
tophi
Describe the asymptomatic hyperuricemia stage of gout with respect to duration, onset, and likelihood of advancement to acute gout.
- 10-20 years
- Onset: men - during puberty; women - during menopause
- only 1-10% with hyperuricemia develop acute gout (+ correlates with level of uric acid)
- abrupt onset of pain, usually at night
- no constitutional symptoms
- self-limited to one week with complete resolution of symptoms
acute gout
skin sloughing is a clinical feature seen in what stage of gout?
acute gout stage
Which of the following statements regarding acute gout is FALSE?
A. MTP is the most commonly affected joint
B. Prepatellar and olecranon bursae are commonly affected
C. Uric acid is almost always largely elevated during an acute attack
D. Potential triggering events include trauma, dietary/alcohol excess, and diuretic use or change
E. Almost all of the time, presentation is monoarticular
C. Uric acid is normal in 1/2 of patients having an acute attack
T/F: 50% of people who experience an acute attack of gout will have no recurrence.
False. Only 7% have no recurrence. 60% recur within the 1st year.
Which of the following is not descriptive of chronic gout?
A. Monoarticular with systemic features
B. Radiography shows punched out erosions with surrounding radiodensity
C. Affects the ulnar surface of forearms among other sites
D. When aspirated looks like toothpaste
E. Joint spaces are preserved and normal mineralization
A. This is one main way it differs from acute - it tends to be polyarticular.
T/F: Current understanding of gout is that it is the precipitation of uric acid crystals that causes chronic kidney disease.
False. Studies in lab animals have showed that raising the serum uric acid induces glomerular hypertension and tubular interstitial fibrosis, despite the absence of renal crystals.
T/F: Less than 10% of patients with gout also have kidney stone disease.
True.
Which of the following is NOT considered to be part of the pathophysiology of hyperuricemia?
A. Cold and decreased oxygen tension may trigger an attack of gout
B. WBCs that have attempted to phagocytose precipitated crystals are lysed and this triggers an inflammatory resopnse
C. Activation of the innate immune response leads to recruitment of cytokines and neutrophils
D. Diet is thought to make very little contribution to the pathophysiology of hyperuricemia, as there is a strong familial predisposition
D. Diet high in purines, alcohol, and sugar are all thought to contribute to the formation of hyperuricemia.
gout is yellow or blue when parallel to the plane of polarization on microscopy, and negatively or positively birefringent?
yellow; negatively birefringent
*in “pseudo gout” crystals are blue and weakly or positively birefringent, with more of a rhomboid rather than needle shape.
Which of the following would NOT be an acute therapy for the treatment of gout?
A. Colchicine
B. NSAID
C. Prednisone
D. Aspirin
E. Joint injection
D
