Y2B2 Micro- Infections Of The Musculoskeletal System-1

Front 1

what is a sequestrum? what is it a hallmark of?

Back 1

a part of bone or cartulage which has be irreparably separated out. Hallmark of osteomyelitis

Front 2

How is the sequestrum formed?

Back 2

The local inflammatory response and pus cause impaired blood circulation leading to avascular necrosis of the affected part

Front 3

what is the most common route of infection for the musculoskeletal system?

Back 3

hematogenous

Front 4

what is the number one pathogen causing osteomyelitis?

Back 4

staphylococcus aureus

Front 5

what disease is most commonly associated with osteomyelitis caused by salmonella species?

Back 5

sickle cell anemia

Front 6

what is the pathophysiology of sickle cell anemia?

Back 6

the pt hb is defective (SHB) and becomes rigid. As it goes through the vasculature and undergoes hemolysis. The cells that clean it up are apart of the reticular sys like macrophages and since the macrophages are busy cleaning up hemolysis, they can't fight against salmonella.

Front 7

what is a rarely encountered cause of osteomyelitis?

Back 7

mycobacterium tuberculosis.

Front 8

what pathogen causes more than 90% of acute osteomyelitis in children?

Back 8

S. aureus

Front 9

Localized pain, fever, tenderness to palpation over the the affected site.

what are these classic characterizations of?

Back 9

osteomyelitis

Front 10

In hematogenous long bone osteomyelitis, the infection is usually ______ whereas in contiguous infection it is usually ______

Back 10

monobacterial; polymicrobial

Front 11

what are the four species most commonly encountered for osteomyelitis?

Back 11

S. aureus, coagulase-negative staphylococcus, aerobic gram-negative bacteria and peptostreptococcus species

Front 12

what is peptostreptococcus?

Back 12

is a genus of anaerobic, Gram-positive, non-spore forming bacteria. The cells are small, spherical, and can occur in short chains, in pairs or individually. They are slow-growing bacteria with increasing resistance to antimicrobial drugs.

Front 13

when do you usually start to find radiological signs of osteomyelitis?

Back 13

in the second week of infection

Front 14

what are the radiological signs found in the 2nd week of osteomyelitis infection?

Back 14

periosteal new bone formation, patchy rarefaction (thinning of the bone) of metaphysis, metaphyseal bone destruction

Front 15

In cases of diagnostic doubt, what can be helpful?

Back 15

bone scanning

Front 16

what is the cornerstone of management of acute osteomyelitis?

Back 16

early intervention with bactericidal antimicrobials and surgical drainage (if and when necessary)

Front 17

how does the tx for chronic osteomyelitis differ from acute osteomyelitis?

Back 17

chronic: requires long-term antibiotic tx and surgical intervention which includes removal of sequestrum and any other necrotic tissue and drainage of bone abscesses.

Front 18

what is the aim of surgical procedures for managing osteomyelitis?

Back 18

aims at controlling the infection while preserving the integrity of the affected bone

Front 19

what are the two most commonly used antimicrobials for txing chronic osteomyelitis? what other two can be used as well?

Back 19

B-lactams and vancomycin; cephalosporins and pencillinase-resistant penicillin.

Front 20

what percentage of contaminated open fractures lead to the development of osteomyelitis?

Back 20

3-25%

Front 21

what are the determinant factors for a development of osteomyelitis secondary to a contaminated open fracture?

Back 21

1) type of fracture
2) Level of contamination
3) degree of soft tissue injury
4) administration of systemic or local antimicrobials

Front 22

what are the five microorganisms involved in the development of osteomyelitis secondary to a contaminated open fracture? which ones are more common?

Back 22

staphylococcus and aerobic Gram- neg bacilli ---> common

enterococci, fungi and atypical mycobacteria ---> less common

Front 23

how do you properly manage contaminated open fractures to prevent osteomyelitis?

Back 23

1) early aggressive wound irrigation and debridement
2) administration of parenteral antimicrobials
3) fracture fixation
4) soft tissue coverage

Front 24

what is spondylodiskitis?

Back 24

infection of Intervertebral discs and the adjacent vertebrae.

Front 25

Pott's disease involves what type of abscess? what disease is it involved in?

Back 25

Psoas abscess; Tb

Front 26

what are the organisms most responsible for vertebral osteomyelitis, spondylodiskitis, and epidural abscesses?

Back 26

S. Aureus, Coagulase negative staphylococci ---> most common

Front 27

which organisms are most likely responsible for vertebral osteomyelitis, spondylodiskitis, and epidural abscesses in IV drug abusers, immunocompromised pts and post-operative patients?

Back 27

Gram-negative aerobic bacteria and candida

Front 28

what organism can be encountered in endemic areas causing vertebral osteomyelitis, spondylodiskitis, and epidural abscesses?

Back 28

M. tuberculosis and Brucella

Front 29

why does bacteria thrive better in a diabetic?

Back 29

due to the amount of glucose in the body

Front 30

Most of the infections associated with diabetics are _______. what are the key approaches to management?

Back 30

polymicrobial; broad spectrum antimicrobials in combo and surgical debridement

Front 31

what populations are most effected by acute hematogenous osteomyelitis?

Back 31

prepubertal children, elderly pts, IVDA, and pts w/ indwelling central catheters.

Front 32

what are the most common organisms involved in acute hematogenous osteomyelitis?

Back 32

S. aureus (#1), Streptococcus pneumoniae (#2)
H. Influenza type b--> #1 for neonates

Front 33

what are the organisms involved in neonatal infections for acute hematogenous osteomyelitis?

Back 33

Group B streptococcus, e. coli

Front 34

what are the organisms encountered in IVDA that cause acute hematogenous osteomyelitis?

Back 34

candida and pseudomonas aeruginosa

Front 35

pts that develop continguous osteomyelitis of the extremities are most likely suffering from what 2 diseases?

Back 35

diabetes mellitus and/or peripheral vascular disease.

Front 36

what organism is the most common cause of osteomyelitis in hemodialysis patients?

Back 36

S. aureus w/ a significantly higher rate of methicillin resistence.

Front 37

what is the most common microorganism that causes osteomyelitis in sickle cell pts?

Back 37

salmonella

Front 38

what microorganism is most common cause of needle licker osteomyelitis?

Back 38

Eikenella corrodens

Front 39

Osteitis pubis is encountered following what situations?

Back 39

surgical procedures (pelvic), prolonged catheterization and complicated vaginal delivery

Front 40

what are the three most commonly encountered organisms causing osteitis pubis?

Back 40

S. aureus
Enterococcus
E coli

Front 41

how prevalent is osteomyelitis of the clavicle? what organisms cause it?

Back 41

<3%
- S. aureus ---> most common
- M. Tuberculosis and gram-negative bacteria ----> less common

Front 42

chronic unilateral osteomyelitis of SI joint may be cause by what organism?

Back 42

brucella

Front 43

what is the most common osteoarticular manifestation of TB?

Back 43

Pott's disease

Front 44

Bone lesions are common in which 3 fungi?

Back 44

1) blastomycosis dermatidis
2) disseminated coccidomycosis (desert bump)
3) extracutaneous sporothrix

Front 45

which fungi can cause pneumonia in urban alcoholic homeless?

Back 45

extracutaneous sporothrix.

Front 46

what is the most common pathogen for bacterial septic arthritis?

Back 46

STAPH AUREUS

Front 47

what is the major pathogen category that causes bacterial septic arthritis?

Back 47

gram positive cocci

Front 48

what are the common causes of septic arthritis for neonates? 1mo- 4y? 4-16 y? 16-40 y? >40y?

Back 48

neo- S. aureus, group B strept, gram negative rods
1mo -4y: S. aureus, group A strept, Strept p, neisseria meningitidis, haemophilus influenzae
4-16y: S. aureus, strept pyogenes
16-40: Neisseria gonorrhoeae, S. aureus
>40y: S. aureus

Front 49

which age group does not have S. aureus as their number one cause of septic arthritis?

Back 49

16-40: sexually active group.

Front 50

what is another name for strepococcus pyogenes?

Back 50

group A streptococci

Front 51

what are the clinical features of septic arthritis?

Back 51

pain (in one or multiple joints), fever, inflammation (swelling, erythema, etc), and excessive irritability (in infants)

Front 52

what are the causes of gout?

Back 52

monosodium and disodium urate

Front 53

which diagnostic technique is definitive for diagnosis septic arthritis?

Back 53

examination of synovial fluid:
1) chemical
2) cellular
3) gram staining
4) culture

Front 54

the synovial fluid in a pt with RA looks like...
clarity and color?
viscosity?
WBC?
polymorphonuclear cells (%)?
Glucose level?

Back 54

1) translucent, yellow or opalescent
2) low
3) 2000-20,000
4) >or = to 50
5) 50-80%

Front 55

the synovial fluid in a pt with degenerative joint disease or trauma looks like...
clarity and color?
viscosity?
WBC?
polymorphonuclear cells (%)?
Glucose level?

Back 55

1) clear, yellow
2) high
3) 200-2000
4) 25-50
5) nearly equal

Front 56

the synovial fluid in a pt with septic arthritis looks like...
clarity and color?
viscosity?
WBC?
polymorphonuclear cells (%)?
Glucose level?

Back 56

1) opaque, yellow to green
2) variable
3) 25,000-100,000
4) >75
5) <25%

Front 57

the synovial fluid in a pt without any abnormalities look like...
clarity and color?
viscosity?
WBC?
polymorphonuclear cells (%)?
Glucose level?

Back 57

1) clear
2) high
3) <200
4) <25
5) nearly equal

Front 58

high leukocytosis w/ triple the PMNs and very low glucose.

what form of arthritis is this?

Back 58

septic arthritis

Front 59

leukocytosis w/ double PMNs and lower glucose than normal.

what form of arthritis is this?

Back 59

RA, gout

Front 60

slight leukocytosis, a few more PMNs, nearly equal glucose.

what type of arthritis is this?

Back 60

degenerative joint disease, trauma

Front 61

when is open drainage indicated in septic arthritis?

Back 61

hip joint to avoid avascular necrosis because there is limited collateral supply.

Front 62

what are the 2 most common places of septic bursitis?

Back 62

subcutaneous olecranon and prepatellar bursae.

Front 63

what is the causative agent (>80%) of septic bursitis?

Back 63

S. aureus

Front 64

how does septic bursitis present?

Back 64

painful swelling, redness, increased warmth, overlying skin injury and lesion, decreased ROM.

Front 65

in olecranon bursitis, when does pain increase? In septic arthritis of the elbow, when does pain increase?

Back 65

with flexion; with extension

Front 66

how are recurrent cases of septic bursitis txed?

Back 66

bursectomy

Front 67

what are the top 3 pathogens associated with prosthetic joint infections? (in order)

Back 67

gram negative aerobic bacilli, coagulase negative staphylococci, and staph aureus

Front 68

An infection of the prosthetic joint may be a consequence of hematogenous spread due to what three scenarios?

Back 68

1) S. aureus bacteremia
2) dentogingival infections and manipulations leading to S. viridans or anerobic infections
3) pyogen skin processes predisposing to staphylococcal and streptococcal infections

Front 69

for infections of the prosthetic joint, in order for a probability of infection to be 94.8%, how many positive cultures must you get from the pt?

Back 69

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