Detailed discussion on acute osteomyelitis

2. ACUTE OSTEOMYELITIS

3. Osteomyelitis is defined as an inflammation of the
bone and bone marrow caused by an infecting
organism.
The infection may be limited to a single portion of the
bone or may involve numerous regions, such as the
marrow, cortex, periosteum, and the surrounding soft
tissue.
The infection generally is due to a single organism,
but polymicrobial infections can occur, especially in
the diabetic foot.
INTRODUCTION

4. Classification:
 Duration Acute, Subacute or Chronic
 Route of infection Hematogenous or Exogenous
 Host response Pyogenic or Granulomatous

5. ACUTE OSTEOMYELITIS
Incidence:
 Age More in children
 Sex Boys > Girls
 Bone affected All bones
 Site of infection Metaphysis (children)
and
Thoracolumbar spine
(adult)

6. Factors predisposing to bone
infection
• Malnutrition and general debility
• Diabetes mellitus
• Corticosteroid administration
• Immune deficiency
• Immunosuppressive drugs
• Venous stasis in the limb
• Peripheral vascular disease
• Loss of sensibility
• Iatrogenic invasive measures
• Trauma

7. RELEVANT ANATOMY
The non anastomosing
terminal branches of the
nutrient artery twist back
in hairpin loops before
entering the large network
of sinusoidal veins;
The relative vascular
stasis and consequent
lowered oxygen tension
are believed to favour
bacterial colonization.

8. RELEVANT ANATOMY
It has also been suggested
that the structure of the
fine vessels in the
hypertrophic zone of the
physis allows bacteria
more easily to pass
through and adhere to
type 1 collagen in that
area (Song and Sloboda,
2001)
The metaphysis has
relatively fewer
phagocytic cells than the
physis or diaphysis.

9. RELEVANT ANATOMY
In children younger than 2 yrs
small metaphyseal vessels
penetrate the physeal cartilage
and this permits the infection to
spread into the cartilaginous
epiphysis.

10. ETIOLOGY
In Children
Hematogenous spread of bacteremia to bones , from
a minor skin abrasion, treading on a sharp object, an
injection point, a boil, a septic tooth
In adults
The source of infection may be a urethral catheter, an
indwelling arterial line or a dirty needle and syringe
In the newborn
Infected umbilical cord
Umbilical vein catheterisation

11. BACTERIOLOGY
Staphylococcus aureus is the most common (70%) in older
children and adults
Otherwise healthy infants 2 to 4 weeks - Group B
Streptococcus
infants - S. aureusis, group B Streptococcus , gram­
negative
coliforms
children 6 months to 4 years old - Haemophilus influenzae
intravenous drug abusers -Pseudomonas
SC hemoglobinopathies – Salmonella osteomyelitis
(This infection tends to be diaphyseal rather than metaphyseal)
Chronically ill patients receiving long­
term intravenous
therapy or parenteral nutrition -Fungal osteomyelitis

12. PATHOLOGY
Most common mode of infection is
hematogenous.
In children metaphysis of long bone (usually
lower end femur & upper end tibia) is earliest
and most commonly involved.
If a long bone is infected, the abscess is likely to
spread within the medullary cavity, eroding the
cortex
and extending into the surrounding soft tissues.
In adults commonest site of infection is
thoracolumbar spine.
A vertebral infection may spread through the
end-plate and the intervertebral disc into an
adjacent vertebral body.

13. Stages:
• Primary focus and stage of inflammation
• Suppuration with pus formation
• Formation of subperiosteal abscess
• Bone necrosis
• Reactive new bone formation
• Resolution and healing
ACUTE OSTEOMYELITIS

14. PATHOPHYSIOLOGY
Bacterial seeding an inflammatory reaction
local ischemic necrosis of bone
subsequent abscess formation
intramedullary pressure increases
Cortical ischemia
purulent material escape through the cortex into the subperiosteal
space
A subperiosteal abscess then develops
extensive formation of sequestra and chronic

15. Age variation
Neonates:
• Extensive bone necrosis
• Physeal damage may be
irreparably leading to deformity.
• Subperiosteal abscess
• Epiphysio-metaphyseal vascular
connection leading to secondary septic arthritis
ACUTE OSTEOMYELITIS

16. Age variation
Adults:
• Vertebrae usually affected
• No subperiosteal abscess due to adherent periosteum
• Soft tissue abscess
• Leading towards subacute and chronic osteomyelitis.
ACUTE OSTEOMYELITIS

17. Clinical Pictures
History:
Skin lesion
Sore throat
Ear discharge
Trauma
ACUTE OSTEOMYELITIS

18. CLINICAL FEATURES
In Infants
Symptoms :
• Irritable
• Drowsy
• Failure to Thrive
Signs :
• Metaphyseal tenderness and resistance to joint
movement can signify either osteomyelitis or
septic arthritis;
• indeed, both may be present, so the distinction
hardly matters

19. CLINICAL FEATURES
In Children
Symptoms :
• Fever
• Severe pain with refusal to use the affected limb or even
touched
• Malaise
• In neglected cases – toxaemia
Signs :
• Fever, Tachycardia, Dehydration
•Acute Tenderness on palpation , the limb is held still and
restrict even gentle manipilation “Pseudoparalysis”
•Local rise of temperature, redness of skin, swelling are later
findings and suggest escape of pus on soft tissues
•Lymphadenopathy is common but non specific

20. CARDINAL FEATURES OF ACUTE OSTEOMYELITIS IN
CHILDREN
 Pain
 Fever
 Refusal to bear weight
 Elevated white cell count
 Elevated ESR
 Elevated CRP

21. 1. Apley’s System of Orthopaedics and Fractures 9th Edition
2. Campbell’s operative orthopaedics 12th
edition
3. Miller’s review of Orthopaedics 6th
edition
References:

22. Thank you