dificultati si diagn.diferential osteomielita acuta

7/30/2019 Dificultati Si Diagn.diferential Osteomielita Acuta

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Osteomyelitis: Always aDiagnostic Puzzle page 1 of 8

Ken L Schreibman, PhD/MD 1/30/10 www.schreibman.info

Ken L Schreibman, PhD/MD 2009 schreibman.info

Osteomyelitis

Always a Diagnostic

Puzzle

schreibman.info Ken L Schreibman, PhD/MD 2009 schreibman.info

Osteomyelitis: Put the Pieces Together

+GdAbscess

RADIOGRAPHSRecent

HISTORY

ClinicalSurgical

MRIMarrow


Osteomyelitis: TopicsDefinitionsActiveChronic

MechanismsHematogenousDirect spread

Imaging

RadiographsMRI

Bone Model

Cortex

Marrow


Osteomyelitis: Definitionscomes from Greek:

osteon= bonemyelos= marrow itis = inflammation

Inflammation of bone marrowInfection of bone marrow

MRIMarrow

High SensitivityLow Specificity

Marrow inflammationfrom infection lookslike inflammationfrom any other cause

Osteomyelitis


Osteomyelitis: DefinitionsActiveOsteomyelitis

vs

ChronicOsteomyelitis


Osteomyelitis: DefinitionsActiveOsteomyelitisAggressive

Resembles TumorCortex DestructionPeriosteal Reaction
http://www.schreibman.info/http://www.schreibman.info/http://d/SchreibmanHandouts/HI.ppthttp://www.schreibman.info/


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ActiveOsteomyelitis 16yoM distal fibula pain3w after inversion injury

HISTORY

Clinical Followup

AggressiveCortex DestructionPeriosteal Reaction


Osteomyelitis: DefinitionsChronicOsteomyelitisNon-AggressiveResembles Callus

3 Characteristics:Involucrum: wrap

Thick periosteum around infected bone

Sequestrum: set apartPiece of dead, infected, boneCloaca: sewer

Opening in cortex throughwhich pus can escape

RADIOGRAPHS

Active Chronic


Activevs ChronicOsteomyelitis

RADIOGRAPHS

Active Chronic

ActiveOsteomyelitis



ActiveOsteomyelitisAggressiveCortex DestructionPeriosteal Reaction

16yoM distal fibula pain3w after inversion injury

ActiveOsteomyelitis


ChronicOsteomyelitis 19yoM fibula pain2.5years later

2.5 years

Chronic

Osteomyelitis

RADIOGRAPHS

Active Chronic


ChronicOsteomyelitis 19yoM fibula pain2.5years later

Chronic

OsteomyelitisInvolucrum

Sequestrum

Cloaca

CT

Fibula

Tibia


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6 weeks later

Involucrum Developing

42yoM Diabetic

10 more weeksKen L Schreibman, PhD/MD 2009 schreibman.info

27yoM s/p removalRt Femoral RodChronicOsteomyelitis

Involucrum

27yoM s/p removalRt Femoral Rod

CT Scout



InvolucrumSequestrum


CT Scout

Axial Slice

Coronal ReformatKen L Schreibman, PhD/MD 2009 schreibman.info


InvolucrumSequestrumCloaca


CT Scout

Axial Slice

Oblique Coronal


Osteomyelitis: MechanismsDirect Spread adjacent tissuesMost common cause

Decubitus ulcerSeptic arthritis


Decubitus Ulcer Ischium

Ischium Ischium

T1

52yoMquadriplegic

T1


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Osteomyelitis: MechanismsDirect Spread adjacent tissuesMost common causeDecubitus ulcer

Septic arthritisPuncture into boneStepped on nailExternal fixatorRing sequestrum

Ring SequestrumChronicOsteomyelitis

InvolucrumSequestrumCloacaPoor Union

RADIOGRAPHS


Osteomyelitis: MechanismsDirect Spread adjacent tissuesMost common causeDecubitus ulcerSeptic arthritis

Puncture into boneStepped on nailExternal fixatorRing sequestrum

HematogenousSite related to patient age


Hematogenous OsteomyelitisSite related to patient age

MatureBone

ImmatureBone

PhysisEpiphysis

Metaphysis

Diaphysis

Arteriole

Venule

BloodSupply

Septic

Emboli

Infectionoccursat end

of

Infectionoccurs atmetaphysis

of


Hematogenous Osteomyelitis1yoM streppneumonia


Hematogenous Osteomyelitis1yoM streppneumonia

3 months later


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Osteomyelitis: ImagingMany Imaging Options:RadiographsCT

MRUSNuc Med

What to order when?


Osteomyelitis: What to Order WhenALWAYS!

May show evidence of active infectionBone destruction, periosteal reaction

May show evidence of chronic infection

InvolucrumScreen for metalOrthopedic hardware, foreign bodies

Unexpected findingsFractures,

Delineate current anatomySurgical resections,

RADIOGRAPHS NEED TO BE RECEN

vs

Radiographs

gas in soft tissues

neuropathic deformity


66yoM h/o DiabetesPresents in Sept swollen footMR is requested to r/o Osteo

Are there radiographs?Yes

3 months ago

Repeat radiographs obtained

now, prior to MR, reveal

Need for Recent Radiographs Example

June September

Neuropathic destructionof the Lisfranc joint

NormalLisfranc joint


Osteomyelitis: What to Order WhenRadiographsALWAYS!CT. Chronic CasesCT best for calcified structures InvolucrumSequestrumCloaca

CT of the extremities is insensitive for:Bone marrow pathologySoft tissue pathology


Osteomyelitis: What to Order WhenRadiographsALWAYS!CT. Chronic Cases

MRI...Active CasesShows extent of soft tissue edemaExcellent for demonstrating abscesses

and other drainable fluid collectionsSensitive for bone marrow pathologyCan be overlysensitive

at expense of specificity Infected bone marrow resembles

marrow edema due to other causes


Osteomyelitis: MR Imaging

T1 T2fsSurrounding

Tissues

(fat)

CortexMarrow

CortexMarrow

Surrounding

Tissues

(fat)

Bone Model

X-rays

CortexMarrow


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Osteomyelitis: MR ImagingPath=FluidT1=DarkT2=Bright

T1fs+GdEnhancement Inflamed UniformAbscessWallCyst NotT1

(STIR)T2fs


Osteomyelitis: MR Imaging

T1T1fs(STIR)

T2fs

+Gd

EnhancementInflamed UniformAbscessWallCyst Not


Osteomyelitis: MR ImagingDetection of the non-enhancingpus pocket (abscess) is crucialPresence of soft tissue abscess

proves the edema in underlyingbone marrow is osteomyelitis.

Site for aspiration for culture.

If IV Gd doesnt get into abscess,IV antibiotics wont get in either,abscess may require drainage.


Osteomyelitis: MR Imaging63yoM Diabeticwith heel ulcer

T1

IR

MinimalMarrowEdema

T1fsIVGd

Enhancing cellulitisNo non-enhancing

abscess pocket

Intact cortex


Osteomyelitis: MR Imaging63yoM Diabetic2 weeks later

Intact cortex

2 weeks earlier

Corticaldestruction

IRT1fs

IVGd

More marrow edemaMore tissue edema

Non-enhancingabscess pocket


Intact cortex

2 weeks earlier

Corticaldestruction

Osteomyelitis: MR Imaging63yoM Diabetic2 weeks later

T1T1fs

IVGdIR

Marrow edema

Abscess Pocket


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Decubitus Ulcer Ischium

T1

52yoMquadriplegic

T2fs

Abscess?

Abscess!

T1fs+Gd


Osteomyelitis: MR Imaging1yoF Swollenleft lower leg

R L Periosteal Reaction

Metaphyseallucency


Osteomyelitis: MR Imaging1yoF Swollenleft lower leg

T1T1fs

IVGdT2fs

Periosteal Reaction

MetaphysealNon-enhancingabscess

Intra-osseous

Brodie Abscess


Osteomyelitis: What to Order WhenRadiographsALWAYS!CT. Chronic CasesMRI...Active CasesUS.Fluid/AbscessUS guided aspiration for cultureCannot assess bone involvement

Nuc Med.. Problem CasesWhere MR specificity is decreasedNeuropathic feet Infected hardware


Infection around metal: MRI

T,K 21yoM

T2fs T1fsIVGd

We canseesoft tissues

around bone

Enhancing

granulation tissue(phlegmon?)

We cantsee the marrow within boneCannot evaluate for osteomyelitis


Infection around metal: Nuc MedRequires 2 Radiopharmaceuticals

1)Tc-Bone Scan(Active bone metabolism)

2)In-WBC Scan(Areas of WBC accumulation)

1)BS: Sen/Spec2)WBC:Spec/Sen


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Infection around metal: Nuc Med

Femur

Tibia

Femur

Tibia

S,B 31yoM

Tc-Bone Scan In-WBC Scan RemovedTibia Plate

PlacedAntibiotic

PMM-BeadsTibiaPlate

FemurPlate


Charcot (Neuropathic) Foot

P,K 65yoF

T1 T2fsT1fs+IV Gd

Tc99m MDP In111 WBC

Abscess

Infection


Osteomyelitis: Put the Pieces Together

+GdAbscess

RADIOGRAPHSRecent

HISTORY

ClinicalSurgical

MRIMarrow

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