2 - Acute osteomyelitis Flashcards
bone infection?
osteomyelitis
joint infection?
septic arthritis
what type of osteomyelitis is more common?
non-specific
give 4 RFs for acute osteomyelitis?
children, M, history of minor trauma, other disease (e.g. diabetes)
3 general sources of infection in acute osteomyelitis?
haematogenous spread (children and elderly), local spread from trauma, 2y to vascular insufficiency
main route of infection for acute osteomyelitis in infants?
infected umbilical cord
3 main routes of infection for acute osteomyelitis in children?
boils, tonsilitis, skin abrasions
2 main routes of infection for acute osteomyelitis in adults?
UTI, arterial line
3 organisms causing acute osteomyelitis in infants <1 yr?
staph aureus, group B streptococci, E. coli
3 organisms causing acute osteomyelitis in older children?
staph aureus, strep pyogenes, haemophilus influenzae
main causative organism of acute osteomyelitis in adults?
staph aureus
main causative organism of acute osteomyelitis in adults with diabetic foot/ pressure sores?
mixed infection including anaerobes
main causative organism of acute osteomyelitis in adults with sickle cell disease?
salmonella spp
main causative organism of acute osteomyelitis in fishermen?
mycobacterium marinum
main causative organism of acute osteomyelitis in adults with HIV AIDS/ debilitating illness?
candida
pathology of acute osteomyelitis - 3 locations of metaphysis in long bones?
distal femur, proximal tibia, proximal humerus
pathology of acute osteomyelitis - 2 locations of metaphysis in joints?
hip, elbow
first 3 stages of pathology of acute osteomyelitis?
metaphysis trauma, vascular stasis, acute inflammation
4 later stages of pathology of acute osteomyelitis which leads to recovery?
release of pressure, necrosis of bone, new bone formation, resolution
what happens if acute osteomyelitis is not resolved?
chronic osteomyelitis
4 clinical features in infant?
minimal signs - failure to thrive, drowsy/irritable, swelling (usually at knee), positional change
4 clinical features in child?
severe pain, reluctant to move, tender fever, tachycardia
4 clinical features of 1y acute OM in adult?
thoracolumbar spine, backache, UTI history, diabetic (immunocompromised)
when is 2y acute OM seen?
after open fracture, surgery (ORIF)
diagnosis of acute OM?
3 blood cultures - @ peak temperature 60% +ve
other tests to diagnose acute OM?
FBC & WBC (neutrophil leucocytosis), ESR, CRP, U&Es
4 common differentials for acute OM?
acute septic arthritis, acute inflammatory arthritis,
trauma, transient synovitis
4 rare differentials for acute OM?
sickle cell crisis, Gaucher’s disease, rheumatic fever, haemophilia
4 soft tissue infection differentials for acute OM?
cellulitis, erysipelas, necrotising fasciitis, gas gangrene
3 imaging tests for acute OM?
X-ray - normal in the first 10-14 days, US, isotope Bone scan
what is used in the isotope bone scan?
Tc-99, Gallium-67
when do periosteal changes occur on radiographs?
10-20 days
what changes occur at the lytic areas?
medullary changes
late osteonecrosis?
sequestrum
late periosteal new bone?
involucrum
3 microbiological diagnosis?
blood cultures, bone biopsy, tissue from up to 5 sites around implant
treatment for acute OM?
supportive treatment, rest & splintage, antibiotics, surgery
supportive treatment?
analgesia, IV fluids, etc.
route of antibiotics?
IV/ oral
duration of antibiotics?
4-6 weeks
type of antibiotics?
empirical - fluclox and benzylpen
3 reasons antibiotics fail to work?
drug resistance, poor tissue penetration, poor drug absorption
name 4 complications of acute OM?
septicemia, metastatic infection, septic arthritis, altered bone growth
