Bone and Joint infections Flashcards
Bone Infection
Osteomyelitis (almost always bacterial)
what are the possible routes for osteomyelitis?
Haematogenous
Non-Haematogenous
direct inoculation, local invasion
where does the bone receives its major blood supply?
loop capillaries around the metaphysis
what is the area where most haematogenous spread goes to?
metaphysis
epiphysis can be infected if the shaft of the born is infected?
no because of the mineralisation of the metaphysis
(can only happen during childhood)
in children a condition can develop from osteomyelitis that does not happen in adulthood
Septic Arthritis
what is the main bacteria that causes osteomyelitis? where does it tend to come from?
Staphylococcus aureus (99%) same bacteria can be isolated i the skin (82% of cases)
what is a possible causative agent of osteomyelitis after chicken pox infection?
Streptococcus pyogenes (GAS) ß haemolysis
what is a possible causative agent of osteomyelitis in new borns and infants?
Haemophilus influenza type B (encapsulated)
other Gram-
Group B streptococci (S. agalactiae)
ß haemolysis
osteomyelitis is more prevalent in children than adults T/F
more prevalent in boys than girls T/F
T
what are the symptoms of osteomyelitis?
fever, painful limping, history of trauma (1/3 of cases)
what are the most common bones involved in osteomyelitis?
humerus
femur and tibia
diagnosis of osteomyelitis requires?
Blood culture not always good as the bacteria might have disappeared from the blood
WCC
however inflammatory markers give a clue
CRP, Erythrocyte Sedimentation Rate (ESR)
Xray
which one between CRP, Erythrocyte Sedimentation Rate (ESR) peaks faster and stays elevated for longer?
CRP protein within 24hrs
ESR lasts for longer
what is the best study undergone for the diagnosis of osteomyelitis?
Bone Scan
MRI
aspiration of the bone
