Diagnosis and management of acute osteoarticular infections in children Flashcards
Definition of osteomyelitis
inflammation of bone and bone marrow due to infection with microbial pathogen
Acute osteomyelitis definition
- symptoms <2 weeks traditionally
* Outcomes similar in patients with symptoms up to 4 weeks
Chronic osteomyelitis
symptoms > 1 mo where avascular bone (sequestrum) alone or surrounded by new bone (involucrum) is present (Brodies’ abscess)
Organisms for SA & osteomyelitis
Staph aureus, Kingella king, S pneumonias, S pyogenes
Kingella
* dominant pathogen in children < 4 years with SA +/- AO
H flu if <4 yrs and unimmunized or area with high prevalence
congenital syphilis presentation?
present with pseuoparalysis due to painful periostitis, osteitis, lytic lesions in metaphysis of long bones
What makes the AO/SA probability low?
Normal or low CRP
When do ESR/CRP peak in AO and osteo?
day 2 presentation
95% sensitivity
What is the most sensitive and specific noninvasive test for AO?
What is earliest finding?
MRI
Earliest finding of AO: bone marrow edema
What is the gold standard for assessment of osteomyelitis?
Bone specimen (biopsy)
When should bone scan be used for osteo?
sensitivity - 80%, but early on can be false negative
Lower specificity than MRI
* Location - metaphysis supportive, diaphysis suggestive of other etiology
* when multifocalsites of infection are suspected, nuclear imaging may be a useful initial test
What is the gold standard for assessment of septic arthritis?
- Joint aspiration
Empiric antibiotics for OA/SA?
- cefazolin 100 - 150 mg/kg/day divided q6-8h for MSSA and K kingae
- K kingae resistant to clinda, vanco, clox
H flu
cover if < 4 years and unimmunized or live in area of higher prevalence
cefuroxime 150 mg/kg/day divided q8h
- MRSA
- consider if high prevalence in community or known carrier
- add vanco empirically if cultures will be available because bone biopsied or joint aspirated
Antibiotics for H flu in OA/SA?
- cover if < 4 years and unimmunized or live in area of higher prevalence
- cefuroxime 150 mg/kg/day divided q8h
if OA/SA fail to improve clinically within first few days of treatment?
repeat imaging and reconsider debridement surgery
Contraindications to oral therapy of OA/SA?
- expected poor medication compliance or follow-up
- malabsorption
- slow clinical resolution of infection
Transition to oral therapy for OA/SA?
- uncomplicated AO - afebrile, clinical improvement after 3-7 days IV therapy
- lower extremity: should weight-bear
- upper extremity: only mild pain with use
- CRP level: exact level unclear
- 50% decrease over 4 day period
- or level between 20-30 mg/L
If bacteremic: recommendations are regardless of whether blood cultures were positive and always assume a positive clinical response
Duration of antibiotic therapy of AO/SA?
- Total duration for uncomplicated AO and SA: 21-28 days
* if SA of hip —> 4-6 weeks
Follow up of OA/SA?
When is ortho FU needed?
When do you do Xray?
- document normal CRP
- routine radiographs only indicated if growht plate involved or large lytic lesion initially
- sclerosis at end of therapy
- ortho follow up if infection involves growht plate or adjacent epiphyseal or metaphyseal region
