Part 18 Flashcards
what is brodie’s abscess?
localized, aborted form of suppurative osteomyelitis
mimics osteoid osteoma
metaphyseal location
signs/symptoms of brodie’s abscess
localized pain worse at night, relieved by aspirin
radiographic features of brodie’s abscess
oval, elliptical or serpiginous radiolucency with novisible matrix surrounded by heavy reactive sclerosis
what organism is seen with brodie’s abcess?
there is none
how do you differentiate between a tumor and infection?
tumor respects growth plates/fascial planes
infection- no respect for growth plates or joint spaces
what do those with an osseous infection need?
antibiotics
how does a spinl infection start for children?
<20 yo, disc is still vascular and if infection starts in disc then spreads to adjacent bodies
how does a spinal infection start in adults?
start in anterior vertebral endplaes then goes to disc with vertebral collapse and soft tissue paraspinal mass
describe radiographic features. Where do spinal infections occur MC?
may have widening of RTI, RPI, paraspinal line deflection, psoas abscess
lumbar MC spinal site
SI joints higher incidence in IV drug users
endplate destruction
disc destruction
pre-vertebral ST swelling
SOL
describe septic arthritis
joint effusion juxtaarticular osteoporosis erosions joint space loss lytic descruction that crosses the joint space
describe teardrop distance
9-11 is normal
>11 is bad
>2mm difference from the opposite joint
size of retrolaryngeal space?
7mm
size of retropharyngeal space?
22mm
limitations of plain film
not a sensitive exam
must have significatnt bone density loss before it is detected
takes about 3-4 weeks to notice
bone scintigraphy
maybe positive within hours technetium gallium tagged (RBC) indium tagged (WBCs) very sensitive often followed by MRI to evaluate the soft tissue
CT
see findings earlier than plain films
good for hard to image areas
findings are more specific and suggestive of osteomyelitis (increased marrow density, sclerosis, demineralization, periosteal reaction
MRI
better than plain films and CT more sensitive for bone marrow paths direct view of intramedullary disorders may precede bone scan findings multiple slices visualized better soft tissue contrast better anatomic definition
osteomyelitis findings on MRI
decreased signal intensity on T1
increased signal intensity on T2
key points of osteomyelitis
supurrative- staph aureus
radiographic latency period of 10 days
lytic destruction of bone that crosses anatomical barriers
joint/extremity involvement classic
disc space loss with endplate destruction classic in the spine
effective treatment requires early diagnosis
antibiotics, surgerydebridement
surgical drainage
prognosis in improved with early diagnosis
tuberculosis
nonsuppurative osteomyelitis
bacteria that causes tuberculosis
mycobacterium tuberculosis
name for tuberculosis in the spine
pott’s
what isthe most common cause of infection related death worldwide?
tuberculosis
pott’s disease?
MC seondary form of TB
MC spine TL junction
usually involved weight bearing joints
multiple levels MC
classic radiographic features of TB
similar to osteomyelitis, but add multiple levels, paraspinal, sold abscess with Ca+
adults: typically starts in anterior endplate region
disc space narrowing earliest radiographic finding
vertebral collapse
decreased T1 and icnreased T2
similar to suppurative but much slower and indolent
clinical features of tuberculosis
TB skin test is positive in 90-100%
chest film positive for granulomas in 50%
weight loss, fever, childds, night sweats, tenderness in the involved bones and joints
phemister’s triad
juxtaarticular osteoporosis
marginal erosions
slow joint space
