infection Flashcards
osteomyelitis
infection of bone caused by bacteria
Infantile vascular pattern
age: 0-1; penetration of metaphyseal vessels correlates with the frequency of infection
blood vessels pass thr the epiphyseal plate in tubular bones. Because of this, it is more common to see infections in the epiphysis because vascular channels here are more prominent than at at later age.
childhood vascular pattern
age: 1-16; the metaphyseal vessels do no penetrate thus injection is caused by the turbulence of the vascular supply
Metaphyseal vessels end at the epiphyseal plate, creating loops and blind-ended sacs in the metaphyseal vasculature. The toruosity of these vessels means that metaphyseal infection is much more common in children.
Adult vascular pattern
> 16; metaphyseal vessels penetrate the closing physis
-there is a re-connection btw the vascular supply of the metaphysis & bone
As the physis closes, the metaphyseal vessels can begin to cross back into the epiphysis again and so infection may be located anyway in the bone
sequestrum
dead, infected bone
involucrum
periosteal new bone formation to wall off infection
sequestrum and involucrum most often associated with?
hematogenous osteomyelitis
cloaca
A defect the involucrum that allows the evacuation of sequestrum fragments to pass fr/inside to outside thr cloaca
marjolin’s ulcer
malignant degeneration of soft tissue within the cloaca to a squamous cell carcinoma.
-The infection must be very chonic(up to 20-30 yrs) f/a marjoilin’s ulcer to form
Brodie’s abscess
A localized abortive form of suppurative osteomyelitis, which may present as a chronic infection
-this type of abscess is sterile
Roentgen features of osteomyelitis
Roentgen(radiographic) findings lag clinical findings by 7-10 days in the LE and up to 21 days in the spine
