1. Osteomyelitis in Children
Dr. Robert Deane
Janeway

2. Outline Age Incidence Etiology Pathophysiology Presentation
Laboratory investigations
Imaging
Treatment
Surgery
Complications
Summary
Special Groups

3. Age / Incidence / Etiology
1/1000 – 1/
Male > Female
Pre antibiotic era ……20-50% mortality

4. Age / Incidence / Etiology
Advances in treatment
Earlier dx
Antibiotic tx
Surgery less delay
Children better nourished

5. Age / Incidence / Etiology
Glasgow incidence decreased
New Zealand……. Madri > Whites
South Africa…….. Black > Whites
Changing disease / Changing organism
Seasonal Variation
Nutritional status, climate, lifestyle

6. Age / Incidence / Etiology
H Flu
Big cause 1970’s
1-4 yrs
Now decreased due to vaccinations
Kingella Kingae
OM in older kids
Septic Arthritis 1-3 yrs
Neonates separate group

7. Pathophysiology Poorly defined Direct inoculation Hematogenous spread
Local invasion

8. Pathophysiology Infection Starts in Metaphysis
Arteriole Loop / Venous Lakes
Spread via Volkman’s canal / Haversian system
Endothelium Leaks

9. Pathophysiology Few phagocytes in Zone of Hypertrophy
Highest incidence in fastest growing bone
Tubular > Flat bones

10. Pathophysiology Gaps in endothelium metaphyseal vessel  Bacteria pass
Adhere to Type 1 collagen
Increase pressure in bone/ decrease blood flow
Bone infarction / Dead Bone (sequestrum)

11. Pathophysiology Spread via Volkman Canal  Subperiosteal Pus
Cortex breaks down
May spread to joint
Hip / Shoulder / Fibula / Proximal Humerus

12. Pathophysiology Role of Trauma Rabbit experiment
IV injection of bacteria
With # start in hematoma

13. Pathophysiology Role of growth plate Over 18/12 Impermeable to spread
Under 18/12 infection crosses growth plate

14. Pathophysiology

15. Pathophysiology 1st osteoblasts die
Lymphocytes release osteoclast activating factor
Hole in bone

16. Diagnosis Pain Fever Lethargy Anorexia
Neonate peudoparalysis
NWB
Failure to use limb
Fever
Lethargy
Anorexia
Swelling (neonates / older kids)

17. Pathophysiology
Bloodwork
CBC Diff
ESR
CRP
Blood Culture

18. Pathophysiology WBC increased 30-40% Left Shift 65%
ESR increased 91%……….24-36hrs
CRP increased 97%…………4-6hrs

19. Pathophysiology CRP More rapid than ESR 2-4 hrs …..peak 72hrs
10-30x normal
Systemic ds (trauma, tumor)

20. Pathophysiology Blood Culture + 30-60% Decreased with antibiotic
Multiple cultures no significant increase in yield
48 hours to get most organisms

21. Diagnosis Pus aspiration 70% bone + cultures Septic arthritis
Gram stain
Lymphocyte count
% polymorphs
> = Septic arthritis
> in some series
also in JRA

22. Diagnosis Do blood and joint cultures
One or other not always +ve in same pt
Gram stain +ve 1/3 bone and joint aspirations
Future looking for bacteria DNA / RNA

23. Lab Diagnosis WBC not reliable Acute phase reactants
False sense of security
25% increased Mayo clinic
65% diff abnormal
Acute phase reactants
Change in plasma proteins d/t cytokines

24. Diagnosis ESR CRP Nonspecific acute phase reactant
Depends on fibrinogen concentration
Increased hrs
Increased in 90% of cases
Not affected by antibiotic tx
CRP
Increased in 98% of cases

25. Radiology Plain xray Soft tissue swelling 48hrs
Sensitivity 43-75%
Specificity 75-83%
Soft tissue swelling 48hrs
Periosteal reaction 5-7d
Osteolysis 10d to 2 wks
(need 50% bone loss)

26. Radiology Tc99 24-48hrs +ve Bone aspiration DOES NOT give false +ve
Decreased uptake in early phase d/t increased pressure
“cold” scan up to 100% PPV

27. Radiology Gallium Indium Monoclonal antibodies 48 hrs to do
Non specific
Indium
I131 leucocytes
24hrs to prepare
Monoclonal antibodies
Not proven to be better

28. Radiology MRI Marrow and soft tissue swelling Good in spine and pelvis
Sensitivity %
Specificity %
PPV = Tc99
Marrow and soft tissue swelling
Good in spine and pelvis

29. Radiology T1 Best for acute infection Gadolinium helps
Changes similar to #
Infarct
Bruise
Tumor
Post surgical
Sympathetic edema

30. Radiology CT
Gas
sequestrum

31. Treatment Mostly medical Timing !! Sx to improve local environment
Remove infected devitalized bone
Decompress abscess cavity
Timing !!
Early antibiotic before necrosis / pus then sx less likely to be needed

32. Treatment Antibiotic treatment Follow WBC / ESR/ CRP
Parenteral / oral combinations
Often empirical
Serum level more important than route
Follow WBC / ESR/ CRP
Organism / sensitivity

33. Treatment Treatment Failure High doses
Poor oral absorption / compliance
Inadequate monitoring of serum levels
Delay in Sx

34. Treatment Previously start IV Follow ESR to guide switch to oral
Newer studies
Follow CRP
Shorter period of tx needed
IV 5d / total 23 d tx
Cephalosporin 150mg/kd/day

35. Treatment Neonates No studies, little evidence CRP / ESR not reliable
Oral absorption not reliable
Therefore IV neonates
Cloxacillin

36. Treatment Longer treatment required Pelvis Vertebrae Diskitis
Calcaneus

37. Treatment Surgical intervention Sx less frequent with newer antibiotic
Controversial indications
Hole in bone not always Sx
If purulent aspirate Sx necessary
Sx less frequent with newer antibiotic
22-83% earlier studies
8-43% recent studies

38. Treatment Surgery Indicated Subperiosteal Abscess Soft Tissue abscess
Bone Abscess
Failure of clinical response to antibiotic
Associated septic arthritis

39. Complications Infection Complications Antibiotic Complications
Recurrence
Chronic osteo
Pathologic fracture
Growth plate injury
Antibiotic Complications
Diarrhea
N+V
Rash
Thrombocytopenia
Neutropenia