Bone Infection Flashcards
localized infection of bone marrow
osteomyelitis
occurs when bone integrity is interrupted
osteomyelitis occurs due to (3)
hematogenous spread contagious spread (adjacent structures/joints) direct inoculation (sx, trauma)
hematogenous osteomyelitis
after bacteremia
typically mono microbial
hematogenous osteomyelitis mc affects?
vertebrae in adults (IVDA)
long bones in children and infants
mc organisms of hematogenous osteomyelitis
staph aureus
pseudomonas and enterobacter
hematogenous osteomyelitis patho
beings inside bone and grows towards cortex (perosteal elevation)
inflammation of overlying soft tissue and sinus track development to drain thru skin
contagious or direct inoculation osteomyelitis
MC from trauma and vascular dz
polymicrobial
post trama osteomyelitis
MC adults, in tibia, due to S. aureus
begins OUTSIDE cortex and works its way towards medullary canal
abscess increases pressure and compromises O2 delivery = expand and growth of more bacteria
osteomyelitis due to vascular disease
MC due to inadequate inflammatory respond to minor trauma and invasion of multiple organisms to feet
osteomyelitis due to vascular disease pathogens
strep species entroecoccus coagulase postive and negative staphylococci gram neg bacilli anerobic organisms
acute osteomyelitis
less than 2 weeks, MC in kids
several days of dull pain, LOCALIZED tenderness, warmth and swelling, systemic symptoms
children with acute osteomyelitis
decreased ROM of extremity and pain
malaise
fevers
irritability
chronic osteomyelitis
2-3 months, MC in adults
pain, redness, swelling, DRAINING sinus tract
DM
DM osteomyelitis
exposed bone or large ulcer (>2x2 cm) OR if bone is palpable on exam = LIKELY osteomyelitis
ESR > 60 also indicated
overall, ____ is mc etiologic agent in direct inoculation and hematogenous spread osteomyelitis
staphylococcus
bones affected by osteomyelitis DM
tarsal
metatarsal
phalanges
bones affected by osteomyelitis neonates, children
long bones (hematogenous spread_
bones affected by osteomyelitis CABG
sternum
bones affected by osteomyelitis endocarditis
vertebral bodies (diskitis)
osteomyelitis predisposing factors
DM IVDA ulcers trauma surgery hx of prosthesis
osteomyelitis PE
evaluate ulcers to “probe to bone” - assume osteomyelitis
pathognomonic osteomyelitis
sinus tract drainage
osteomyelitis WU
CBC
blod culture
wound culture
BONE BX and CuLTURE = golds standard
osteomyelitis imaging
plain films first
MRI test of choice (After plain films) to determine if soft tissue or bone infxn
osteomyelitis tx
abx (parenteral) and possible sx AFTER culture
surgery is indicated for osteomyelitis :
- failure of abx
- infected surgical hardware
- chronic osteomyelitis w/necrotic bone and soft tissue
- clear necrotic tissue at an ulcer site
osteomyelitis ABX
quinalones have a high degree of bone penetration
typically do Vanco + fluroquinaolone
osteomyelitis adjunctive tx
HBO
NPWT (wound vac)
+/- re-vascualrization (vascular insufficiency)
long term chronic osteomyelitis
squamous cell carcinoma or fibrosarcoma
septic arthritis
infection fo joint space
acute mono-articular arthritis (single, swollen joint)
RF of septic arthritis
DM immunosuppresive tx prosthetic hardware recent joint sx IVDA, alcoholism sexually active young
sources of infection septic arthritis
trauma
hematogenous spread
surgical infection
pathogenesis septic arthritis
bacteria enter joint via various mechanisms and produce inflammatory response = swelling, erythema, and warmth of joint space
MC pathogens in septic arthritis
Staph aureus overall
N. gonorrhea in young, sexually active adults
septic arthritis where
MC in knee
next hip
polyarticular septic arthritis
20% of case present with this
MC see overwhelming sepsis
pediatrics and septic arthritis
lower extremity joints
acute septic arthritis differential
monoarticular = septic arthritis or gout
poly articular = reactive arthritis or viral arthritis
chronic septic arthritis (>12 weeks)
mono= osteoarthritis
poly - osteoarthritis or RA
septic arthritis exam
fever, chills, rigors, systemic symtoms
joint pain, swelling, warmth, restricted ROM
hot, red painful joint
septic arthritis diagnosis
acute, hot painful joint
CBC, blood culture, ESR, CRP
XR normal
diagnostic study of choice for septic arthritis
arhtrocentesis to evaluate fluid
visualization, stain and culture, leukocyte could and glucose level
septic arthritis arthrocentesis results
opaque >3.5 volume leukocytes 15-100k often POSITIVE <25
septic arthritis tx
vanc + ceftriazone IV x 4-6 weeks
ortho consult and consideration for debridement
stage I septic arthritis
remove prothesis and place a spacer
six weeks of ABX (often all IV)
stage II septic arthritis
placement of new prosthesis with antibiotic impregnated cement (95% success)
septic arthritis prognosis
not much change
difficult to predict final outcome
polyarthrtiic joint higher mortality rate
predictors for poor outcome septic arthritis
old age
preexisting dz
synthetic material
