2. INTRODUCTION
Infection of bone and bone marrow
Can progress to osteonecrosis, bone destruction and septic arthritis
Bimodal age distribution:
Children under 5 years old
Adults over 50 years of age
Risk factors:
Recent trauma or surgery
Immunocompromised patients
Illicit IV drug use
Poor vascular supply
Systemic conditions such as diabetes and sickle cells
Peripheral neuropathy
3. CLASSIFICATION
I. Acute
within 2 weeks
II. Subacute
2 – 6 weeks
III. Chronic
after 6 weeks
Incidence of infection increases with increase in grade of open fracture:
Type I – II : 2%
Type III : 10 – 50%
based on duration, mechanism, and host response
DURAT I ON
4. CLASSIFICATION
I. Hematogenous
Originated or transported by blood
Etiology of 20% of osteomyelitis
Vertebrae most common site; and metaphysis of long bone
S. aureus is most common organism
II. Contiguous factor
Associated with previous surgery, trauma, wounds or poor vascularity
Can be bacterial (most common), mycobacterial or fungal in nature
III. Direct inoculation
Penetrating injuries
Surgical contamination
based on duration, mechanism, and host response
MECHANI SM
5. CLASSIFICATION
based on duration, mechanism, and host response
HOST RESPONSE
SY S T E M I C LO C A L
Malnutrition Vascular compromise
Renal failure, hepatic failure Chronic lymphodema
Diabetes Extensive scarring
Autoimmune disease Radiation fibrosis
Malignancy Neuropathy
Extreme age
Immunosuppression drugs
Immunodeficiency
Smoking
6. CIERNY-MADER STAGING
Medullary OM
Infection confined to medullary cavity
Superficial OM
Contiguous type of infection. Confined to surface of bone
Localized OM
Full-thickness cortical sequestration which can easily be
removed surgically
Diffuse OM
Loss of bone stability, even after surgical debridement
A N AT O M I C P H Y S I O L O G I C
Stage I: Medullary A. Host, good systemic defense and local vascularity
Stage II: Superficial B. Host, good systemic and local compromise
Stage III: Localized C. Host, non-candidate for surgery with treatment
more problematic than disease process
Stage IV: Diffuse
7. ORGANISM
OST EOMYEL I T I S ORGANI SM TAB L E
A G E G R O U P M O S T C O M M O N O R G A N I S M S
Newborns
(younger than 4 mo)
S. Aureus
Enterobacter species
Group A & B streptococcus species
Children
(aged 4 mo to 4 y)
S. Aureus
Group A streptococcus species
Kingella kingae
Enterobacter species
Children, adolescents
(aged 4 y to adult)
S. Aureus (80%)
Group A streptococcus species
H. Influenzae
Enterobacter species
Adult S. Aureus
Occasionally Enterobacter or
Streptococcus species
Sickle Cell Anemia Patients S. Aureus is typically most common
But Salmonella species is pathognomonic
8. ACUTE
OSTEOMYELITIS
Mainly a disease of children
Occurs after an episode of bacteremia
Trauma may determine the site of infection
Possibly by causing small haematoma of fluid
collection in the bone
Most common organism in both children and adult
is Staphyloccocus aureus (70%)
9. PATHOPHYSIOLOGY
Affects metaphyseal region of
long bones; femur (27%), tibia
(22%), fibula (5%) more than
upper extremity
Bacteremia is the common
event in childhood,
consequence of other infections
such as otitis media, pharyngitis
and sinusitis
Its presumed that bacteria gain
access to metaphyseal location
via nutrient arteries.
10. PATHOPHYSIOLOGY
Staphylococcus aureus:
Surface antigen plays key role
in bacterial adherence to type
1 collagen and endotoxins
that suppress local immune
response
Glycocalyx: may form around
bacteria and enhance
adherence to other bacteria
and metallic implants
11. PATHOPHYSIOLOGY
CAUSES OF METAPHYSEAL OST EOMYL I T I S
Hair pin bend vessels
Increased vascularity causes pooling of
blood also called as “lake of blood”
Immature cells in metaphysis due to
high cell turnover
Relative lack of phagocytosis
Presence of degenerative cartilage cells
End arteries in metaphysis
Prone for trauma
Single endothelial lining in metaphyseal
arteries
12. PATHOPHYSIOLOGY
CASCADE OF EV ENTS
Infective embolus enters nutrient artery trapped in vessels of small caliber
Blocks vessels, area of bone become necrotic
Active hyperemia in vicinity with infiltration of PMN cells which is poured as
exudate
Increased intraosseous pressure due to exudate and debris (intense pain)
13. PATHOPHYSIOLOGY
CASCADE OF EV ENTS
Vessels compressed, further necrosis occurs
Exudate follow path of least resistance
Gets accumulated in sub-periosteal spaces to form abscess and damage the blood
supply
If perforates, can spread to soft tissue
14. PATHOPHYSIOLOGY
SECOND ROUT E OF SPREAD OF I NF EC T I ON
Exudate into medullary cavity destroying marrow elements, blood supply
In advanced stages cortex may be surrounded by pus, depriving blood
supply
Diaphyseal sequestration
T HI RD ROUT E OF SPREAD OF I NF EC T I ON
Through the physis into joints
16. CLINICAL FEATURE
infant, children and adult
I NFANT
Failure to thrive
Metaphyseal tenderness, restricted joint movement
CHI L DREN
Fever (high grade)
Child refuse to use limb (pseudoparalysis)
Local redness, swelling, warmth, odema
17. CLINICAL FEATURE
infant, children and adult
ADULT
Commonest site is thoracolumbar spine
History of urological procedure
Followed by mild fever and backache
Local tenderness
18. PHYSICAL EXAMINATION
Ill looking
Increase temperature and pulse
Limb is held still
Local redness, swelling and warmth
Tenderness at near one of the larger joint
Restricted joint movement – pseudoparalysis
Edema
Lymphadenopathy
19. INVESTIGATIONS
A physical examination may shows bone tenderness and possibly swelling and redness
Tests may include:
Blood cultures
Bone biopsy
Bone scan
Bone x-ray
Full blood count
C-reactive protein (CRP)
Erythrocyte sedimentation rate (ESR)
MRI of the bone
Needle aspiration of the area around affected bone
20. INVESTIGATION
B LOOD & F LUI D
Leukocytosis
Elevated CRP & ESR
Anti-staphylococcal antibody titre may be elevated
Positive fluid or tissue aspiration
Blood culture at the peak of fever may yield the causative organism
X-RAY
Earliest abnormality detected after first week of the onset of symptom
Extra cortical outline (periosteal new bone formation at metaphysis)
21. INVESTIGATION
ULT RASONOGRAPHY
May detect a sub-periosteal
collection of fluid in the early stages
But it cannot distinguish between
hematoma or pus
B ONE SCAN (RADI ONUCL I DE
SCANNI NG)
Technetium – 99
Increased activity in both perfusion and bone phase
Highly sensitive investigation even in the very early stages
22. INVESTIGATION
MAGNET I C RESONANCE I MAGI NG (MRI )
Helpful in cases of doubtful diagnosis
Best method of demonstrating bone marrow inflammation
24. TREATMENT
I. Supportive treatment for pain and dehydration
Analgesic
IV fluid
II. Splintage for comfort and prevent joint contracture
III. Antibiotic therapy
Bactericidal drugs are important to:
a. Stop the spread of infection to healthy bone
b. Control acute flares
Oral therapy followed by IV route for 10 – 14 days
Antibiotics used in treating OM :
a. Amoxicillin
b. Ciprofloxacin plus clindamycin
c. Levofloxacin plus clindamycin
Antibiotics is continued for another 6 weeks (min) but usually more than 6 months
25. TREATMENT
IV. Surgical drainage
If antibiotics are given early (within first 48 hours) it is often unnecessary
But if clinical features do not improve within 36 hours of starting treatment, or even
earlier and there is sign of deep pus, drainage is required
Debridement of infected tissues
WHEN ANTIBIOTICS CAN BE STOPPED?
CLINICALLY : Signs of healing, reduction of pain, no fever, can walk, no
discharging sinus
INFLAMMATORY PARAMETERS : normalizes
SERIAL X-RAY : bone healing, no new OM changes
27. DIFFERENTIAL DIAGNOSIS
I. Rheumatic fever
Gradual, poly-joint swelling
II. Ewing’s sarcoma
Radiological signs
III. Acute suppurative arthritis
Muscle spasm more marked, limited movements, effusions
IV. Cellulitis
No intense pain
V. Erysipelas
Raised red margin
28. COMPLICATIONS
I. Epiphyseal damage and altered bone growth
II. Suppurative arthritis
III. Metastatic infection
IV. Pathological fracture
V. Chronic osteomyelitis