orthopaedics: osteomyelitis and MSK infections Flashcards
what is osteomyelitis
infection of bone including compact bone, spongy bone and bone marrow
what infective organisms normally cause osteomyelitis
occasionally fungal, usually bacterial: staph A (90%), H influenza, salmonella
how does osteomyelitis spread
haematological
what are the symptoms of osteomyelitis
fever, localised pain and tenderness over bone, erythema
what is an involucrum
new bone forming around dead, necrotic bone
what investigations are done in osteomyelitis
MRI>xray, blood cultures, biopsy and culture
who normally gets acute osteomyelitis
children (boys) and immunocompromised
why are children more likely to get osteomyelitis
metaphysis has torturous vessels with slow flow that can accumulate bacteria
what can subacute osteomyelitis lead to
brodies abscess
how do you treat acute osteomyelitis
IV AB, surgical drain of abscess, if AB fails then cultures and washout of infected bone
how do you get chronic osteomyelitis
untreated acute,
where does chronic where does it commonly affect commonly affect
axial skeleton (spine/ pelvis)
how do you manage chronic axial skeleton (spine/ pelvis)
surgical debridement and biopsy, bone grafting, long hospital recovery and IV AB’s
what should be avoided in osteomyelitis
emperic AB’s
who can get Haematogenous vertebral osteomyelitis
children, post trauma, IV drugs, diabetics, central lines
what is gold standard diagnosis in osteomyelitis
bone biopsy
what is Haematogenous vertebral osteomyelitis
infection of bone from blood spread elsewhere in body
how do you manage Haematogenous vertebral osteomyelitis
drain and debride, avoid emperic AB’s unless sepsis, antimicrobials for 6 weeks
name 3 unusual osteomyelitis
sickle cell, Gaucher’s disease, SAPHO, CRMO
what causes TB osteomyelitis
blood spread from reactivated TB, usually affects spine
what disease is common in TB osteomyelitis and what are the symptoms
Pott’s disease, asymptomatic
who is at risk of prosthetic joint infections
RA, diabetes
what are symptoms of prosthetic joint infections
haemotoma, puss,, tender, pain, loss of function
what organisms cause prosthetic joint infections
normally staph epidermis, staph A, e.coli, pseudomonas, fungal
how do you manage prosthetic joint infections
remove joint, vancomycin and replace
how do you get septic arthritis
direct invasion from penetration which then spreads through blood
what organisms commonly cause septic arthritis
staph A, strep, N gonnorhea, H influ (kids), e.coli (elderly, IV drug users)
what are symptoms of septic arthritis
red, hot, swollen, sore, not working, fever, systemically V unwell
what viral causes can cause arthritic sepsis
hep B, parovirus
how do you treat septic arthritis
presumed staph A –> fluclox, under 5 ceftriaxone (h influ), surgical wash out (avoid empiric ABs)
what organisms cause pyomyositis
90% staph, pseudomonas, B haemolystic strep, enterocoous
what causes tetanus and what type of bacteria is it
clostridium tetani, gram +ive anaerobic rod
what do toxins of tetanus do
cause spastic paralysis eg lockjaw
how do you treat tetanus
penicillin and metro, vaccines
what antibiotic should be given to staph and strep
fluclox
what antibiotic should be given to staph and strep if penicillin allergy
vancomycin
what AB is given to staph epi
vanco
what AB is given to strep pyogens
doxy
what is given to gram -ive
clindamycin
what is given to anaerobes
metro
