34579554 Osteomyelitis Radiology[1]

7/28/2019 34579554 Osteomyelitis Radiology[1]

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THE RADIOLOGY OF

OSTEOMYELITIS

GRAND ROUND PRESENTATION

NBU

PRESENTED BY:

Dr. ALFRED ODHIAMBORADIOLOGIST PLAZA IMAGING SOLUTIONS

LECTURER THE UNIVERSITY OF NAIROBI


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The backgroundUnderstanding the blood supply to bone is key

to the comprehension of the varied age related

faces of osteomyelitis.

The blood supply to a long bone is via1. Nutrient artery :This is the major source of

blood throughout life supplying the marrow

and inner cortex.

2. Periosteal vessels : They supply the outer

cortex.

3. Metaphyseal and epiphyseal vessels.


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Entry of micro-organismsMicro-organisms may infect any of the

tissues of the musculoskeletal system

where they cause similar symptom

complexes of pain loss of functionvariably accompanied by fever systemic

illness.


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Blood supply variations

In the infant ,vessels penetrate the epiphysealplate in both directions.

Metaphyseal infections can thus pass to theepiphysis and subsequently result in joint

infection. The periosteum is loose and easilystripped.

In childhood between 2 and 16 years few vesselscross the epiphyseal plate although the

periosteum is still loose. Epiphyseal and jointinfections are less frequent.

In adults epiphyseal closure reconnectsepiphyseal and metaphyseal circulations.

However periosteum is firmly bound down and


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In summary


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Pathological changes inosteomyelitis The formation of pus in bone deprives local

cortex and medulla of its blood supply. Dead bone is resorbed by granulation tissue.

Pieces of dead bone especially if cortical orsurrounded by pus are not resorbed and

remain as sequestra. The devitalized sequestra remain dense while

the surrounding vital bones becomedemineralized due to hyperaemia.

Involucrum ( new bone) forms under intactperioteum elevated by pus

In areas of dead periosteum defects in theinvolucrum occur called cloacae which allow

pus and sequestra to escape. May cause sinustrack to the skin.


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Early changes at imaging

Most findings are subtle and often missed. Good quality films will show deep soft tissue

swelling with displacement of adjacent muscleplanes by day 2.

On day 3 to 4 while osseous structures stilllook normal muscle mass may appearincreased.

Plane between muscle and subcutaneoustissues becomes blurred.

At this time US, MRI and nuclear imaging aremost informative.

Destructive bone changes of acuteosteomyelitis with periosteal elevation are not

seen until 10 to 14 days after infection.


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What is special in the

neonate

The destructive processes are florrid

in the neonate owing to the fast

spread of infection through the

spongiosa and cortex. Localized metaphyseal rarefaction

rapidly progresses to irregular

destruction with the formation of

spicules of remaining bone


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Unique forms of OM Neonatal OM: Due to presence of transphyseal vessels

allowing spread of organisms into the growth plate and

later joint space . In the infant systemic response to bone infection is

compromised . One may only see STS, tenderness andfunctional loss.

Antibiotic modified OM may result in delay in diagnosis.

Chronic multifocal OM: Less aggressive with little or noperiosteal elevation and associated with plantopalmarpustulosis.

Sclerosing osteomyelitis of Garre: Sclerosis is gross withabsence of apparent bone destruction. dD OO

Brodies abscess: Is a localized OM usually seen incancellous bone . A circumscribed destructive lesion issurrounded by sclerosis. Simulates OO especially whenthere is sequestrum formation


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OM of CT


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OM in the forearm


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Imaging tools at work


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COM


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Sclerosing OM of Garres


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Bites are lethal


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And now our patient

The images follow


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OSTEOMYELITIS IMAGE -1


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THE END

THANKS

34579554 Osteomyelitis Radiology[1]

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