Dr Shashidhar M R Osteomyelitis Pyogenic Tubercular Mycetoma OSTEOMYELITIS Osteomyelitis Nelaton 1834 coined osteomyelitis The root words osteon bone and myelo ID: 780454
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Slide1
OSTEOMYELITIS & MYCETOMA
Dr
Shashidhar
M R
Slide2Slide3Osteomyelitis
-
Pyogenic
, Tubercular
Mycetoma
OSTEOMYELITIS
Slide5Osteomyelitis
Nelaton
(1834) : coined
osteomyelitis
The root words
osteon
(bone)
and myelo (marrow) are combined with itis (inflammation) to define the clinical state in which bone is infected with microorganisms.
Slide6TYPES
Pyogenic
Tubercular
Chronic Non Specific
Slide7PYOGENIC OSTEOMYELITIS
Causative agents-
Staphylococcus
aureus
- MC
Neonates :H
influenzae
Streptococci in childrenSickle cell anemia: salmonellaE.Coli :GU infections
Slide8Why
staphylococcus
most common?
S.aureus
-----
normal skin flora
S.aureus
-----increased affinity for host proteins (traumatised bone)Enzymes (coagulase, surface factor A) ----- hosts immune response .
“
Biofilm
”
(polysaccharide “slime” layer) ---- increases bacterial adherence to any substrate .
Large variety of adhesive proteins and
glycoproteins
----- mediate binding with bone components.
Slide9Pathogenesis:
Direct inoculation
of microorganisms into
bone
penetrating injuries and surgical contamination are most common
causes
Hematogenous
spread
usually involves
the
metaphysis
of long bones in children or the vertebral bodies in
adults
Osteomyelitis
Microorganisms in bone
Contiguous
focus of
infection seen
in patients with severe vascular disease
.
Slide10Morphology
Three stages-
Acute
Subacute
Chronic
Acute- acute inflammation and necrosis of the bone. Dead bone -
Sequestrum
Metaphysis
– infection spreads to
subperiosteum
- segmental bone necrosis-
subperiosteal
abscesses- sinus tracts- discharge dead bone.
If crosses the epiphysis, may involve the joint.
Chronic-
Healing – osteoclasts resorb the bone, chronic inflammatory infiltrate, fibroblasts proliferate in the periphery. New bone formation from the periphery Central dead bone with surrounding new bone- involucrum
Slide12Sites of infection
Metaphysis
and epiphysis in infants and adults
Metaphysis
in children
Slide13Pathogenesis
Whatever may be the inciting cause the bacteria reaches the
metaphysis
of rapidly growing bone & provokes an
inflammatory
response
.
why metaphysis is involved
Infected embolus is trapped in U-shaped small end arteries located predominantly in
metaphyseal
region
Relative lack of
phagocytosis
activity in
metaphyseal
region
Highly vascularised region ---minor trauma—hemorrhage ----locus minoris
resistantae---excellent culture medium
Slide14–
sharp hairpin turns
– flow becomes considerably slower and more turbulent
PATHOLOGENESIS
These are end-artery branches of the nutrient artery
Obstruction
Avascular
necrosis of bone
tissue necrosis, breakdown of bone
acute inflammatory response due to infection
Squestra formation
Chronic
osteomyelitis
Slide16Pathology:
Pathologic features of chronic
osteomyelitis
are :
The presence of
sclerotic, necrotic
piece of bone usually cortical
surrounded by radiolucent inflammatory
exudate and granulation tissue known as sequestrum.
Features:
Dead piece of bone
Pale
Inner smooth ,outer rough
Surrounded by infected granulation tissue trying
to eat it
Slide17sequestrum
Involucrum
Pathology:
The
involucrum
is the sheath of
reactive, new, immature
,
subperiosteal
bone that forms around the
sequestrum, effectively sealing it off the blood stream just like a wall of abscess. The involucrum is irregular and is often perforated by openings.
The
involucrum
may gradually increase in density and
thickness.
There is exudation of
polymorphonuclear
leukocytes joined by large numbers of lymphocytes,
histiocytes
, and occasionally plasma cells.
Slide19local signs
calor
,
rubor
, dolor, tumor
Heat, red, pain or tenderness, swelling
Initially, the lesion is within the
medually cavity, there is no swelling, soft tissue is also normal.
The merely sign is
deep tenderness
.
Slide20Clinic picture
It is important to remember that the
metaphysis
lies within the joint capsule of the hip, shoulder, ankle. Therefore these joints can develop
septic arthritis
by extension of
osteomyelitis
.
If the infection and septicemia proceeded unabated, the patient may have toxic shock syndrome. Sinuses
Slide21Approach to diagnosis
The white blood cell count will show a marked
leucocytosis
as high as 20,000 or more
The blood culture demonstrates the presence of
bacteremia
, the blood must be taken when the patient has a chill, especially when there is a spiking temperature.
Radiology:
Lytic
focus of bone destruction surrounded by zone of sclerotic bone.
Slide22Varients
Brodie’s abcess
Bone abscess
containing
pus or jelly like granulation tissue surrounded by a zone of sclerosis
Age 11-20
yrs,
metaphyseal
area,
usually upper tibia or lower femurDeep boring pain, worse at night, relieved by restCircular or oval luscency surrounded by zone of sclerosis
Treatment:
Conservative
if no
doubt - rest + antibiotic
for 6 wks
.
if
no response
– surgical evacuation & curettage, if large cavity - packed with cancellous bone graft
Slide24Garre
’ s
osteomyelitis
Sclerosing
,
nonsuppurative
Jaw (mandible)
No
abcess, cortical thickeningAcute local pain, pyrexia subside-fusiform swellingAcute stage-rest, antibioticsSx: Gutter holing, excision+curettage
Slide25Complications of chronic
osteomyelitis
Pathologic fracture
Secondary
amyloidosis
Endocarditis
Sepsis
Squampous
cell carcinoma of the tractSarcoma
Slide26TUBERCULOUS OSTEOMYELITIS
Blood borne
Extension from adjacent sites-ribs
Adolescents
Common sites-
Spine- thoracic and lumbar
Knees
Hips
Pott spine- erosion of the intervertrebral discs and involvement of multiple vertebrae, cold abscess-psoas abscess
Slide27Microscopy :
tuberculous
granuloma
Clinical features :
Complications :
Spine :
scoliosis, kyphosis, cold & psoas abcsess Tuberculous arthritis Sinus tract formation Amyloidosis
Slide28Slide29MYCETOMA
Chronic
suppurative
infection
Actinomycosis
– bacterial form
Eumycetoma – fungal form
Slide30Actinomycosis
Actinomycetes
israelii
Filamentous & anaerobic
Forms
Cervicofacial
- lumpy jaw, sinuses Thoracic Abdominal Pelvic
Slide31Slide32Microscopy
Slide33Eumycetoma – Madura foot
Madurella
mycetomatis
or
Madurella
griesa
Gross- swelling, black granules from discharging sinuses
Slide34Slide35Thank you