44 Infectious Arthritis and Osteomyelitis

Question 1

Frequently affected joint in septic arth

Answer 1

Knee and hip

Question 2

Acute septic arth, duration

Answer 2

<2 weeks

Question 3

Subacute septic arth,septic arth,, duration

Answer 3

2w-3m

Question 4

Chronic osteomy, duration

Answer 4

> 3m

Question 5

Usual sites of infection in reactive arth

Answer 5

Upper airway
GI
GU

Question 6

Septic arth, MC pathogenic mechanism

Answer 6

Hematogenous

Question 7

Joints with intraarticular metaphyses, giving increased risk for extension of infection from bone to joint space

Answer 7

Hips and shoulders

Question 8

Conditions MC associated with hip septic arth

Answer 8

URTI with oral ulceration
Atopic derm with erosive skin infection
Varicella

Question 9

Joints affected with septic arth, in IV drug users

Answer 9

SI joint
SC joints

Question 10

Septic arth is MC caused by this organism

Answer 10

S. aureus

Question 10

Organism implicated in septic arth in sickle cells dse

Answer 10

Salmonella

Question 11

Organism that should be considered in young children with culture-neg skeletal infections

Answer 11

Kingella kingae

Question 12

MC sites of septic arth

Answer 12

Joints of lower ext: knees > hips

Question 13

Predisposes to multiple joint septic arth

Answer 13

Chronic granulomatous dse
AIDS

Question 14

Recomm labs for septic arth

Answer 14

CBC, CRP, ESR, PCT

Question 15

Very important test for synovial fluid since culture can be negative

Answer 15

GS

Question 16

Protein and gluc content in septic arth

Answer 16

Protein >2.5g/dL, glucose low relative to plasma

Question 17

Blood cultures are (+) in ___% of patients with septic arth

Answer 17

40

Question 18

T/F No causative agent is ever identified in significant number of children with septic arth

Answer 18

T

Question 19

Synovial fluid PCR remains diagnostic in up to ___ days after antibiotic initiation

Answer 19

6

Question 20

T/F S. aureus is common even in culture neg MSK infections

Answer 20

T

Question 21

Imaging modality of choice in children with septic arth

Answer 21

UTZ

Question 22

T/F UTZ should be performed in all patients suspected to have septic arth

Answer 22

T

Question 23

Common organisms in septic arth per age

Answer 23

Pg 588 box

Question 24

MC organism in hematogenous nonneonatal septc arth

Answer 24

S. aureus

Question 25

1st-line for S. aureus in previously healthy children in communities with low (<10%) rate of CA-MRSA

Answer 25

1st- or 2nd-gen cephalosporin (Cefaz, Cefu)

Question 26

Drug of choice for S. aureus in previously healthy children in communities with>10% rate of MRSA and resistance to Clinda is low (<10%)

Answer 26

Clinda

Question 27

REgionally common causative agent of septic arth in children <4y

Answer 27

Kingella kingae

Question 28

Drug of choice for Kingella kingae septic arth

Answer 28

Cephalosporins

Question 29

Drug of choice for Salmonella septic arth

Answer 29

Ceftriaxone

Question 30

Duration of septic arth treatment

Answer 30

IV: 2-4 days with clinical recovery and CRP decreasing Oral: 10d-2w in previously healthy nonneonatal children if with clinical recovery and CRP decreasing

Question 31

Target vanco trough level

Answer 31

15-20 ug/mL

Question 32

Duration of septic arth treatment for CA-MRSA

Answer 32

IV: 1-2 weeks Total IV + oral: 4-6 weeks

Question 33

T/F Salmonella requires longer duration treatment than salmonella septic arth

Answer 33

T

Question 34

Flowchart for workup and treatment of septic arth in children

Answer 34

Pg 591

Question 35

Recommended empiric abx for septic arth: Child <3m

Answer 35

Cefotax + nafcillin/oxacillin (if >1week in NICU, consider Vanco)

Question 36

Recommended empiric abx for septic arth: Child >3m

Answer 36

CA-MRSA <10%: Nafcillin/oxacillin or cefazolin CA-MRSA >10%: Clinda or vanco

Question 37

Surgery for septic arth is reserved for

Answer 37

Cases unresponsive to abx or have delayed presentation

Question 38

T/F Intraarticular administration of abx may be necessary in some cases of septic arth

Answer 38

F, abx penetrate joints fluid readily

Question 39

Excellent lab measure for recovery in septic arth

Answer 39

Serial CRP

Question 40

T/F Decreasing CRP indicates clinical recovery even if fever persists

Answer 40

T

Question 41

Duration of monitoring of septic arth patients

Answer 41

At least 1 year

Question 42

Cause neonatal septic arth through seeding from birth canal

Answer 42

S. aureus, GBS, G- (e. coli, neisseria)

Question 43

REcommended treatment for neonatal septic arth

Answer 43

Anti staph penicillin + aminoglycoside

Question 44

Predisposing factors for septic arth in neonates

Answer 44

Umbi cath Prematurity Septicemia

Question 45

Pathognomonic findings for neonatal septic arth

Answer 45

Motionless hip joint that is flexed, abducted, and externally rotated

Question 46

Hip septic arth MC affects what age group

Answer 46

Infants and young children

Question 47

Organism that may cause purulent arthritis in several joints

Answer 47

N. gonorrhea

Question 48

MC mechanism of spread of mycobacterial arthritis

Answer 48

Hematogenous