bone and joint infection Flashcards
what is osteomyelitis ?
infection of the bone tissue or bone marrow
what are thee types of osteomyelitis ?
acute hematogenous
subacute hematogenous
chronic osteomyelitis
post-traumaticc osteomyelitis
what is the etiology of acute hematogenous osteomyelitis ?
mainly a disease of the children
infection usually happens at the metaphysis
through diaphyseal networks in adults
through diaphysis and epiphyseal networks in children
what is the most common causative organism in acute hematogenous osteomyelitis ?
staph aureus
what are the two fates associated with acute hematogenous osteomyelitis ?
resolution and healing
or
chronicity and sinus formation
what are the clinical features of acute hematogenous osteomyelitis ?
malaise
fever
tenderness over the affected region
pain at rest , worsening with weight bearing
what is the best imaging modality for acute hematogenous osteomyelitis ?
PET CT
what lab investigations are the most certain for acute hematogenous osteomyelitis ?
bone aspirate
when should a blood sample and culture and sensitivity be done in cases of acute hematogenous osteomyelitis ?
if the fever is above 38 degrees
what is the management for acute hematogenous osteomyelitis ?
appropriate antimicrobial therapy
surgical drainage if required
reset and splintage
supportive treatment
what is the problem with using xrays to diagnose acute hematogenous osteomyelitis ?
changes are only seen after 2 weeks
what is subacute hematogenous osteomyelitis ?
a relatively mild pathology
milder form of acute hematogenous osteomyelitis
associated with lower organism virulence or higher resistance iin patient
what is the most common cause of osteomyelitis in adults ?
post traumatic osteomyelitis
what is the mainstay of management of post traumatic osteomyelitis ?
prevention
what is the presentation of chronic osteomyelitis ?
1- Persistently draining sinus tract or wound
2- Soft tissue damage
3- The presence of risk factors such as diabetes and peripheral vascular disease further supports the likelihood of chronic osteomyelitis
what arre the diffeerential diagnosis of chronic osteomyelitis ?
ewing sarcoma
osteosarcoma
what is the aetiology of septic arthritis ?
hematogenous spread
direct spread from adjacent bone
direct inoculation
what are the risk factors for septic arthritis ?
pediatrics
poor nutritional status
diabetes
underlying osteoarthritis
immunocompromised
IV drug abuser
what is the most common causative organism of septic arthritis in each of the age groups ?
neonates : s. aureus , group b strep, E coli
children : s.aureus , s.pyogenes
adults : s.aureus, streptococci
immunocompromised : s.aureus , mixed infection
what is the kocher criteria for determining the risk for pediatric septic joint ?
NEWT
non weight bearing
ESR > 40
WBC > 12000
temperature
all 4 ? 99%
3 ? 93%
2 ? 40%
1? 3%
what is the treatment for septic arthritis ?
open drainage and debridement
arthroscopic lavage
IV antibiotics
what is the sequelae for septic arthritis ?
resolution
spread
joint destruction
what are the criteria for thee diagnosis of periprosthetic joint infections ?
sinus tract infection connecting with the prosthesis
or
pathogen isolated by culture from at least 2 separate tissue or fluid samples
or
four of the following criteria :
elevated CRP and ESR
elevated synovial leukocyte count
elevated PMN
presence of purulence in the affected joint
isolation of an organism in the periprosthetic tissue
what is the presentation of periprosthetic joint infection ?
limitation of movement of a previously sound implant
presence of discharge
what is the treatment of periprosthetic joint infection divided into ?
early phase (<3 weeks )
one stage revision
two stage revision
salvage
what is the treatment for PPJI in the early phase ?
DAIR
debridement
antibiotics
implant retention
what is the two stage revision in the treatment of PPJI ?
1st stage - remove implant , extensive debridement, odd number of samples, insert antibiotics and spacer
2nd stage - remove spacer, new implant, no antibiotic
when do we use salvage treatment in PPJI ?
persistent infection
sepsis and septicemia
what are the steps involved in salvage treatment of PPJI ?
implant removal
arthrodesis
resection arthroplasty
amputation
