Osteomyelitis

Osteomyelitis is an extensive inflammation of a bone. It involves the cancellous portion, bone marrow, cortex, and periosteum

Conditions that alter HOST IMMUNITY

Leukemia, Severe anemia, Malnutrition, AIDS, IV- drug abuse, Chronic alcoholism, Febrile illnesses, Malignancy, Autoimmune disease, Diabetes mellitus, Arthritis, Agranulocytosis

Conditions that alter vascularity of bone

Osteoporosis, Paget’s disease, Fibrous dysplasia, Bone malignancy, Radiation, Virulence of the organisms

Certain organisms precipitate thrombi formation by virtue of their destructive lysosomal enzymes.

Organisms proliferate in enriched host medium while protected from host immunity.

Etiology

- Odontogenic infections
- Trauma
- Infections of oro facial region
- Infections derived from hematogenous route
- Compound fractures of the jaws.

PATHOGENESIS

DEV . OF INFECTION --> BACTERIAL INVASION -->  PUS FORMATION -->  SPREAD OF INFECTION --> INCREASED INTRAMEDULLARY PRESSURE , BLOOD FLOW , OSTEOCLASTIC ACTIVITY --> INFLAMMATORY RESPONSES --> INCREASED PERIOSTEAL PRESSURE --> PROCESS BECOMES CHRONIC GRANULATION TISSUE FORMATION --> LYSIS OF BONE --> SEQUESTRUM FORMATION

Classification

Classification based on clinical picture, radiology, and etiology

Suppurative osteomyelitis

I. Acute suppurative osteomyelitis

II. Chronic suppurative osteomyelitis

– Primary chronic suppurative osteomyelitis

– Secondary chronic suppurative osteomyelitis

III. Infantile osteomyelitis

Nonsuppurative osteomyelitis

I. Chronic sclerosing osteomyelitis

  – Focal sclerosing osteomyelitis

  – Diffuse sclerosing osteomyelitis

II. Garre's sclerosing osteomyelitis

III. Actinomycotic osteomyelitis

IV. Radiation osteomyelitis and necrosis