Musculoskeletal 1 Flashcards

Question

septic arthritis pathogenesis and organisms

Answer 1

surgery or penetrating injuries staphylococcus aureus other gran positive / negative prostheric joints or artrosocpy -coagulase negative staphylocci human bites , decubitis ulcers or intra abdominal abcess -anaerobic organisms tramatic injuries polymicrobial infections foot penetrations pseudomonas aeruginosa sub acute chronic monoarthritis , oligoarthritis mycobacterial or fungal infection

Answer 2

acute onset: pain swelling , and heat chills and fever common absent up to 20% imagining: plain radiographys joint effusion and soft tissue swelling joint space narrowing and bony erosions indicates advanced infection ultrasound detect hip effusions CT or MRI demonstrate infection of the sacroiliac joint, sternoclavicular joint, and spine use for IVDA patients will seed in these joints laboratory work up CBC blood cultures ESR and CRP

Answer 3

synovial fluid analysis critical for diagnosis synovial leukocyte count 50,000 -100,000 gram stain and culture positive in 75% of staphylococcus infections positive in 50% of gram negative infections synovial fluid color turbid , serosanguinous or purulent synovial total protien , LDH , glucose total protien and LDH increased glucose decreases check for crystals rule out gout blood cultures postive 50%

Answer 4

recommend hospitilazation: - iv antibiotic and pain control -imaging -consultation broad spectrum abx cover for staphylococci, streptococci and gram negative vancomycin 1 g IV q12 and ceftriaxone 1-2 gram IV QD Joint drainage: consult orthopedics or IR arthrocentesis severe effusion: -arthroscopic lavage and dibridement with drain placement open surgical drainage -conservative treatments failed prosthetic joint infections dependant on timing of infection remvoval of prostetic

Answer 5

Infection of the bone: -various microorganisms with different routes -spontaneous hematogenous osteomyelitis -healthy individuals -local microbial spread -chronic conditions, compromised skin or tissue barrier -require orthopedic repair Cierry-mader staging system -hematogenous spread -vertebral column - Spread from contiguous site following surgery -long bones secondary infection dt vascular insufficiency -long bones etiology - uti skin or soft tissue compromise intra vascular catheterization sites endocardium Most common underlying condition diabeties

Answer 6

higher occurrence in males and age-dependent other names: disk space infection, septic discitis, spondylodiscitis, spinal osteomyelitis Bacterial invasion: microorganisms invade via the segmental arterial circulation and adjacent end plates - infection spread into the disc Alternative routes: -retrograde seeding -direct inoculation -epidural infiltration -trauma micoorganism spectrum: -the majority are monomicrobial - staphylococcus aureus 40-50% -streptococci 12 % -gram-negative bacilli 20%

Answer 7

leading pathogenic source: -exogenous infection -post surgical or post traumatic Microoganism spectrum hematogenous -S aureus implant associated - S aureus - coagulase-negative staphylococci Open fracture -gram negative bacilli -polymicrobial infected implanted devices classification -acute < 3 weeks delayed 3-10 weeks late , beyone 10 weeks

Answer 8

presents in 2 week after bone infection: inflammatory bone changes chronic osteomyelitis: presents -6 or more weeks after bone infection bone destruction and sequestrum verterbral colum infection S and S fever and back pain back pain leading symptoms 85% -location of pain corresponds with infection Neurologic deficits consider abscess -radiculopathy -weakness -sensory loss -bowel and bladder dysfunction - paralysis long bone infection - pain and low-grade fever manifest as clinical sepsis local signs of inflammation

Answer 9

Imaging : plane radiography MRI w/wo contrast CT W contrast Laboratory work up CBC, ESR, CRP, Blood cultures -leukocytosis, and neutrophilia, low sensitivity - elevated ESR and CRP high sensitivity positive BC x dependent on ABX pre-treatment High suspicion with negative blood cultures -CT-guided open biopsy -Culture bone - aerobic, anaerobic, and fungal agents histopathology high suspicion with negative blood and tissue culture Broad-range PCR analysis

Answer 10

acute osteomyelitis : antibiotic alone Chronic osteomyelitis: -Antibiotics and debridement surgery internal fixation infection therapeutic aim -consolidation of the fracture -prevention of chronic osteomyelitis -stable implants can be maintained vertebral infection therapeutic aim -elimination of the pathogens -protection from further bone loss -relief of back pain -prevention of complications -stabilization if needed

Answer 11

Consultation: ID neuro/spine surgery orthopedics IV vs PO antibiotic regimine: Optimal spectrum bioavailability Efficacy normal intestinal function no vomiting Duration of antibiotic therapy: 4-6 weeks regimen dependent on culture results empirical coverage vancomycin and cefepime