musculoskeletal infections & TB

Question 1

infection of skin, subcutaneous, fat, or connective tissue (soft tissue infection)

Answer 1

cellulitis

Question 2

infection of bone (marrow spaces)

Answer 2

osteomyelitis

Question 3

infection of joint (synovial tissue, articular surfaces)

Answer 3

septic arthritis

Question 4

group of people prone to infections by unusual organisms at unusual sites

Answer 4

drug addicts

Question 5

most common organism for musculoskeletal infections

Answer 5

staph. aureus

Question 6

most common route of dissemination for musculoskeletal infections

Answer 6

hematogenous

Question 7

growth plates inhibit what route of dissemination

Answer 7

hematogenous.

Question 8

most common locations for musculoskeletal infections

Answer 8

knee, hip, ankle (distal tibia), shoulder, spine

Question 9

two major categories of musculoskeletal infection

Answer 9

suppurative (pus, staph.), non-suppurative (TB)

Question 10

bone marrow infectino by pyogenic non-TB organism

Answer 10

suppurative osteomyelitis

Question 11

clinical features of acute infection

Answer 11

edema, lymphadenopathy, warm skin, cellulitis, joint pain

Question 12

4 radiographic stages of infection

Answer 12

latent stage (1-10 days), early stage (days 10-21), middle stage (weeks), late stage (months)

Question 13

symptoms of early stage infection

Answer 13

soft tissue swelling, displaced lucent fat planes that become mass like, osteopenia

Question 14

characteristics of middle stage infection

Answer 14

permeative or lytic moth-eaten destruction and periosteal response; solid, laminated, codman’s trianlge

Question 15

characteristics of late stage infection

Answer 15

cortical destruction, draining sinus, involucrum, cloaca, sequestrum, sclerosis, debris, loss of joint space, ankylosis, chrinoic imcomplete resolution, immune deficient

Question 16

chalky, white area representing isolated dead bone; cortical and medullar infarcts

Answer 16

sequestrum

Question 17

chronic periosteal response. pus lifts the periosteum and causes new one formation that tries to wall off the infection.

Answer 17

involocrum

Question 18

bony collar

Answer 18

involocrum

Question 19

draining sinus, more common with chronic disease

Answer 19

cloaca

Question 20

a rare complication of cloaca is to develop a squamous cell carcinoma with malignant transformation has been called

Answer 20

marjolin’s ulcer

Question 21

localized, aborted form of suppurative osteomyelitis that has localized pain worse at night and relived by aspirin

Answer 21

brodie’s abscess formation

Question 22

mimics osteoid osteoma. located in the distal tibia.

Answer 22

brodie’s abcess

Question 23

chronic osteomyelitis and reactive sclerosis

Answer 23

brodie’s abcess

Question 24

respects growth plates/fascial plane

Answer 24

tumor

Question 25

does not respect growth plate or joint spaces

Answer 25

infection

Question 26

prognosis of infection

Answer 26

much better detection and treatment today, absolutely require antibiotic management

Question 27

infection of vertebral body

Answer 27

spondylitis

Question 28

risk factors for osteoporosis

Answer 28

female, older than 70, caucasian or asian, early onset of menopause, longer postmenopausal interval, inactivity, especially lack of weight bearing exercise

Question 29

modifiable risk factors for osteoporosis

Answer 29

smoking, alcohol abuse, excessive caffeine consumption, excessive dietary protein consumption, lack of dietary calcium, lack of sunlight exposure (to generate endogenous vit D)

Question 30

what is the tear drop distance normally

Answer 30

9 - 11 mm

Question 31

what are the hip fat planes

Answer 31

gluteus medius, obturator internus, iliopsoas

Question 32

early radiographic features of spine infection

Answer 32

rapid loss in disc space, endplate destruction

Question 33

upper limit size of the retro-tracheal interspace (RTI)

Answer 33

22mm

Question 34

upper limit size of the retro-pharyngeal interspace (RPI)

Answer 34

7mm

Question 35

water is white on which film

Answer 35

T2 weighted MRI

Question 36

fat is white on which flim

Answer 36

T1 weighted MRI

Question 37

most common cause of suppurative osteomyelitis

Answer 37

staph. aureus

Question 38

TRUE or FALSE: both infections and tumors respect epiphyseal growth plates

Answer 38

FALSE: tumors respect the boundary but infections do not

Question 39

disc space loss with endplate destruction is a classic example of

Answer 39

spine infection

Question 40

what are examples of risk groups for bone infection

Answer 40

immunosupressed, diabetic, post surgical, vascular insufficiency, sickle celll anemia, IV drug users

Question 41

some organisms that cause bone infection and the most common

Answer 41

STAPH. AUREUS (90%), mycobacterium TB, neisseria gonorrhea, pseudomonas, fungus, strep. Pyogenes

Question 42

what are some modes of infection

Answer 42

trauma/post surgical, UTI, pneumonia, skin infections, open wound or cellulitis, heel sticks in infants

Question 43

routes of dissemination for bone infection including the most common

Answer 43

HEMATOGENOUS (MC), direct extension, direct implantation, postoperative

Question 44

growth plates inhibit which type of dissemination/spread

Answer 44

hematogenous; children are affected less than adults or infants

Question 45

a study done that is sensitive to metabolic activity and increased vascular supply

Answer 45

bone scan

Question 46

what is the most important diagnosis to consider when a patient presents with unilateral sacroilitis

Answer 46

infection

Question 47

what exam is needed if there is loss in disc space and endplate destruction

Answer 47

think infection so; MRI

Question 48

what are some osteomyelitis findings on an MRI

Answer 48

decreased signal intensity on T1, increased signal intensity on T2

Question 49

most common cause of infection-related death world wide

Answer 49

TB

Question 50

most common type of TB

Answer 50

secondary

Question 51

most common location of TB in the spine

Answer 51

TL junction

Question 52

first radiographic finding of TB in an adult

Answer 52

earliest - anterior disc space narrowing.

Question 53

phemster's triad is indicative of

Answer 53

TB septic arthritis

Question 54

phemster's triad

Answer 54

juxtarticular osteoporosis, marginal erosions, slow joint space loss

Question 55

type of TB found in the spine, involving multiple levels with paraspinal cold abcesses, has slower progression of joint destruction, and has a poorer response to therapy

Answer 55

non-suppurative; as opposed to suppurative

Question 56

kyphotic angulation associated with TB

Answer 56

gibbus formation

Question 57

TB associated with the spine

Answer 57

pott's disease