Chapter 132 - Musculoskeletal Infection in Children and Adolescents

Question 1

best test for kingella?

Answer 1

PCR

Question 2

radiographic changes in osteomyelitis?

Answer 2

• 0-5 days: no changes
  5-7 days: new periosteal bone formation
  10-14 days: osteolysis
  1-2 weeks: metaphyseal rarefaction, possible intraosseous abscess

Question 3

kocher criteria

Answer 3

• fever >38.5
• inability to bear weight
• esr >40
• wbc >12k

if four positive - 99% positive for septic joint

Question 4

modified kocher criteria

Answer 4

crp >2.0 is independent risk factor for septic arthritis

order of importance of factors:
- fever
- crp
- esr
- refusal to bear weight
- wbc

Question 5

chronic recurrent multifocal osteomyelitis

Answer 5

not actually bacterial osteomyelitis -> autoimmune bone inflammatory disorder

diagnosis of exclusion

girls>boys, peak age of onset 10yo

metaphyseal long bone most common, then medial clavicle, spine (vertebra plana)

normal inflammatory markers, negative bone cultures

XR with eccentric metaphyseal lesions with sclerosis, osteolysis, new bone formation that is often SYMMETRIC

tx = scheduled NSAIDs

Question 6

pathogens for septic arthritis acocrding to age

Answer 6

birth -1yo
- staph
- group a strep (strep pyogenes)

1-4
- staph
- kingella kingae
- strep pneumo

> 5
- staph

Question 7

panton valentine leukocidin

Answer 7

cytotoxin associated with MRSA severity
multifocal, complex infections, prolonged fever, subperiosteal abscess, DVT, septic PE

Question 8

what differentiated MSSA from MRSA

Answer 8

mecA gene transfer to s. aureus -> mutated penecillin binding protein, low affinity for beta lactams

Question 9

kingella

Answer 9

gram negative coccobacillus

difficult to grow - need blood agar, held for like 2 weeks, and at 38c

better to test via PCR!!!

Question 10

spinal manifestations of TB

Answer 10

anterior vertebral body
thoracolumbar junction
can form paravertebral abscess with associated neurologic issues

acid fast bacilli on gram stain

Question 11

lyme causative bacteria

Answer 11

borrelia burgdorferi

erythema migrans

deer tick

workup is ELISA + confirmatory WESTERN BLOT

tx: doxycycline, amoxicillin, cefuroxime

Question 12

how to culture n. gonorrhoeae?

Answer 12

chocolate blood agar

tx: ceftriaxone, or cefixime

Question 13

special considerations in neonatal osteomyelitis

Answer 13

• prior to the appearance of the secondary ossification center, the metaphyseal vessseals also supply the epiphysis often causing the spread of osteomyelitis in the metaphysis to the epiphysis and the joint

Question 14

discitis in childre

Answer 14

kids <5yo

begins in the vertebral endplates and moves to the disc via vascular channels

staph

blood cultures ARE necessary
local cultures are NOT necessary

tx = antibiotics then more antibiotics