Osteomyelitis

Inflammation of bone and bone marrow

Causes

1. Infective
   • Bacteria - staph aureus, ecoli, streptococci, bowel organisms
   • Viruses
   • Fungi
   • Parasites
2. Non-infective
   • Radiotherapy

Pathological Sequlae

1. Suppuration with pus in marrow cavity
2. Sequestrum: dead bone within periosteum that forms inner part of infected bone marrow
3. Involucrum: reaction of periosteum to form new bone that 'envelops' the infected site and contains it
4. Cloacae "sewer": holes in the involucrum through which pus formed in the medulla discharges
5. Sinus: drainage tract from the cloaca to skin
6. Septicaemia and pyaemia

Late complications

1. Amyloidosis
2. Malignant change in the sinus - Marjolin's ulcer
3. Septicaemia and pyaemia
4. Suppurative arthritis