Transcript Osteomyelitis - Hastaneciyiz's Blog | Just another

Bone Infections
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Outline

Acute Osteomyelitis

Subacute Osteomyelitis

Post-Operative Infections
Defining Osteomyelitis
What’s in a Name?
Osteomyelitis (Osteo- bone, MyeloMarrow, and –itis -Inflammation)
Defining Osteomyelitis
What is it?
It is an infection of the of the bone or bone
marrow which leads to a subsequent
Inflammatory process.
Defining Osteomyelitis
Where does it come from?
Micro-Organisms may reach bones via the
Bloodstream or by Direct Invasion.
Defining Osteomyelitis
What affects it’s
development?

Organism involved

Host Factors (i.e. Age, Immunity, Diseases)

Site of Involvement (i.e. local factors)
Defining Osteomyelitis
What affects it’s
development?

Organism involved

Host Factors (i.e. Age, Immunity, Diseases)

Site of Involvement (i.e. local factors)
Acute Osteomyelitis
Types of Acute
Osteomyelitis
I.
Hematogenous Osteomyelitis
II.
Direct Inoculation Osteomyelitis
Acute Osteomyelitis
Hematogenous Osteomyelitis:

Bacterial seeding from the blood.

Seen primarily in Children.

The most common site is the Metaphysis at
the growing end of Long Bones in Children,
and The Vertebrae and pelvic in Adults.
Acute Osteomyelitis
Direct Inoculation
Osteomyelitis

Direct contact of the tissue and bacteria
as a result of an Open Fracture or
Trauma.

Tend to involve multiple organisms.
Acute Osteomyelitis
Causative Organisms:

Staphylococcus aureus (Mainly)

Streptoccous pyogens or pneumoniae.
(Less)

H.Influenzae (Young Children)

Salmonella (Sickle-Cell)
Acute Osteomyelitis
Pathology:

•
•
Inflammation.
Earliest Change
Increase interaosseous pressure leads to Pain.
Suppuration.
Pus @ Medulla =Volkmann canals=>Surface =>
Subperiosteal Abscess=> spread along the shaft=>
re-enter the bone or burst into the soft tissue
• May extend to Epiphysis and Metaphysis in
Neonates and Children. May extend to
Interverteberal Discs in Adults.

•
Acute Osteomyelitis
Pathology:

•

•
•

Necrosis.
Begin to see signs with in one week.
New-bone formation.
Bone thickens to form an involucrum enclosing the
infected tissue.
Perforation may occur converted acute into chronic
osteomyelitis.
Resolution.
Acute Osteomyelitis
Clinical Features:
Pain
 Fever and Malaise
 Tenderness
 Restricted Joint Movement
 Redness, Edema, Warmth (Signify Pus)
 History preceding Skin Lesion or Sore Throat.

Acute Osteomyelitis
Imaging:
First 10 days X-Rays Show No Abnormality.
 By the end of the 2nd Week signs of rarefaction
of Metaphysis and New Bone Formation.
 With Healing there is Sclerosis and thickening
of Cortex.
 MRI may help to distinguish between Bone and
Soft-Tissue Infection.

Acute Osteomyelitis
Investigations:

CBC

Leucocytosis
 C-reactive protein level usually is elevated
 ESR usually is elevated
Investigations
1.
Lab studies
2.
Radiological studies
Lab studies

CBC: leucocytosis
 The C-reactive protein level usually is elevated
(nonspecific but more useful than ESR).
 ESR usually is elevated (90%) nonspecific.

Aspiration of the pus from the subperiosteal
abscess and culture, and test sensitivity for
antibiotics

Blood culture results are positive in only 50% of
patients with hematogenous osteomyelitis.
Radiological studies
X-Ray:
 First sign is soft-tissue edema at 3-5 days after
infection.
 Bony changes are not evident for 14-21 days:
1. early radiographic signs of rarefraction (thining of bony
tissue sufficient to cause decreased density of bone) of the
metaphysis and periosteal new bone formation
2. increasing ragged if treatment is delayed
3. sclerosis and thickening of the bone at healing
 Approximately 40-50% focal bone loss is
necessary to cause detectable lucency on plain
films.

Plain-film radiograph showing
osteomyelitis of the second
metacarpal (arrow). Periosteal
elevation, cortical disruption
and medullary involvement are
present.

The above X-ray of the left
ankle of a 10-year-old boy
shows lucency in the tibial
metaphysis secondary to
acute hematogenous
osteomyelitis (AHO).

The above X-ray of the
right ankle of a 10-yearold boy shows lucency in
the tibial metaphysis
secondary to acute
hematogenous
osteomyelitis (AHO).
Here is an X-ray of an
AHO lesion extending
into the growth plate.
Radiological studies

MRI :
Early detection and surgical localization of
osteomyelitis.
Sensitivity ranges from 90-100%.

Radionuclide bone scanning :
A 3-phase bone scan with technetium 99m is
probably the initial imaging modality of choice
Show increase activity but it is a non specific sign of
inflamation.
This MRI sagittal section shows the same
AHO lesions with the right lesion
extending into the growth plate.
Bone scans, both anterior (A) and lateral (B), showing
the accumulation of radioactive tracer at the right
ankle (arrow). This focal accumulation is
characteristic of osteomyelitis.
Radiological studies
CT scan (spinal vertebral lesions, complex
anatomy: pelvis, sternum, and calcaneus)
Ultrasound
In children with acute osteomyelitis.
May demonstrate changes as early as 1-2 days after
onset of symptoms.
Abnormalities include soft tissue abscess or fluid
collection and periosteal elevation.
Ultrasonography allows for ultrasound-guided
aspiration.
It does not allow for evaluation of bone cortex
Diagnosis
Diagnosis requires 2 of the 4 following criteria:
◦
◦
◦
◦
Localized classic physical findings of bony
tenderness, with overlying soft-tissue erythema
or edema.
Purulent material on aspiration of affected bone.
Positive findings of bone tissue or blood culture.
Positive radiological imaging study.
Treatment
Principles of treatment:
1.
Analgesia an general supportive measures.
2.
Rest of the affected part
3.
Antibiotic treatment.
4.
Surgical eradication of pus and necrotic
tissue(debridement).
Treatment
Antibiotic treatment:
Start with IV antibiotics for 1-2 weeks then oral for 3-6 weeks.
Take cultures to detect the organism and its sensitivity pattern.
Start empirical treatment before the results came back, then
modify it according to the results.
Treatment
Antibiotic choices:
Older children and adults (staph infection): fluloxacillin and fusidic acid.
MRSA: Vancomycin
Children younger than 4 year-old or those with gram negative
organisms: 3rd generation cephalosporins.
Heroin addicts and immuno-compromised patients: more specific
antibiotics.
Cont…
 Sickle cell anemia and osteomyelitis: fluoroquinolone antibiotic
(not in children). A 3rd cephalosporin (eg, ceftriaxone) is an
alternative choice.
 Nail puncture occurs through an athletic shoe (S aureus and
Pseudomonas aeruginosa): ceftazidime or cefepime.
Ciprofloxacin is an alternative treatment.
 Trauma (S aureus, coliform bacilli, and Pseudomonas
aeruginosa): nafcillin and ciprofloxacin. Alternatives include
vancomycin and a 3rd cephalosporin with antipseudomonal
activity.
Treatment
# Drainage:
 Subperiosteal abscess
 Pyrexia and local tenderness more than 24 hour
after adequate antibiotic treatment.
# Removal of prosthetic implants:
If they become unstable after a trauma.
Or intractable infection following joint replacement.
# Severe cases may lead to the loss of a
limb.
Prevention

Improve immunity.

Post-traumatic infection (regular wound dressing for
established infection):
1.
2.
3.
4.

Debridement of open fractures.
Stabilization of fractures.
Antibiotics.
Closure of exposed bone surfaces.
Postoperative infection:
1.
2.
3.
4.
Cleanest possible surgical environment.
Careful haemostasis.
Suction drainage.
Prophylactic antibiotics in high risk surgeries.
Subacute Osteomyelitis
Results from a less virulent Microorganism,
or a patient with an elevated resistance.
 Occurs Mostly at the Distal Femur or
Proximal Tibia
 On X-Ray we See Brodie’s Abcess:
Small and Oval in shape
It is surrounded by sclerotic bone
May be mistaken for Ostieoid
Osteoma

Subacute Osteomyelitis

An image depicting subacute osteomyelitis
Post Operative Infections

Prophylaxis is KEY in prevention.

Treated According to Infection
Post Operative Infections

Not Uncommon, about a 5% incidence.

Predisposed by:
Debility
Chronic disease
Previous Infection
Tight Dressing
Corticosteroid Treatment
Long Surgery
Hematoma
Foreign Material Implants
1.
2.
3.
4.
5.
6.
7.
8.
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