Part 18

Question 1

what is brodie’s abscess?

Answer 1

localized, aborted form of suppurative osteomyelitis
mimics osteoid osteoma
metaphyseal location

Question 2

signs/symptoms of brodie’s abscess

Answer 2

localized pain worse at night, relieved by aspirin

Question 3

radiographic features of brodie’s abscess

Answer 3

oval, elliptical or serpiginous radiolucency with novisible matrix surrounded by heavy reactive sclerosis

Question 4

what organism is seen with brodie’s abcess?

Answer 4

there is none

Question 5

how do you differentiate between a tumor and infection?

Answer 5

tumor respects growth plates/fascial planes

infection- no respect for growth plates or joint spaces

Question 6

what do those with an osseous infection need?

Answer 6

antibiotics

Question 7

how does a spinl infection start for children?

Answer 7

<20 yo, disc is still vascular and if infection starts in disc then spreads to adjacent bodies

Question 8

how does a spinal infection start in adults?

Answer 8

start in anterior vertebral endplaes then goes to disc with vertebral collapse and soft tissue paraspinal mass

Question 9

describe radiographic features. Where do spinal infections occur MC?

Answer 9

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

Question 10

describe septic arthritis

Answer 10

joint effusion
juxtaarticular osteoporosis
erosions
joint space loss
lytic descruction that crosses the joint space

Question 11

describe teardrop distance

Answer 11

9-11 is normal
>11 is bad
>2mm difference from the opposite joint

Question 12

size of retrolaryngeal space?

Answer 12

7mm

Question 13

size of retropharyngeal space?

Answer 13

22mm

Question 14

limitations of plain film

Answer 14

not a sensitive exam
must have significatnt bone density loss before it is detected
takes about 3-4 weeks to notice

Question 15

bone scintigraphy

Answer 15

maybe positive within hours
technetium
gallium tagged (RBC)
indium tagged (WBCs)
very sensitive
often followed by MRI to evaluate the soft tissue

Question 16

CT

Answer 16

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

Question 17

MRI

Answer 17

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

Question 18

osteomyelitis findings on MRI

Answer 18

decreased signal intensity on T1

increased signal intensity on T2

Question 19

key points of osteomyelitis

Answer 19

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

Question 20

tuberculosis

Answer 20

nonsuppurative osteomyelitis

Question 21

bacteria that causes tuberculosis

Answer 21

mycobacterium tuberculosis

Question 22

name for tuberculosis in the spine

Answer 22

pott’s

Question 23

what isthe most common cause of infection related death worldwide?

Answer 23

tuberculosis

Question 24

pott’s disease?

Answer 24

MC seondary form of TB
MC spine TL junction
usually involved weight bearing joints
multiple levels MC

Question 25

classic radiographic features of TB

Answer 25

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

Question 26

clinical features of tuberculosis

Answer 26

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

Question 27

phemister’s triad

Answer 27

juxtaarticular osteoporosis
marginal erosions
slow joint space