Chronic osteomyelitis

Once osteomyelitis is established it is almost impossible to eradicate. The intraosseus blood vessels thrombose and the bone infarcts. Pus lifts the periosteum. If the process contin­ues the pus ruptures through the periosteum, tracks into the soft tissues and may even discharge through the skin remote from the initial site of infection. The bone may die and form a sequestrum. The new bone formed by the periosteum which has been lifted is known as an involucrum. Once there is dead bone the infecting organisms have a permanent site where they can survive beyond the reach of the body’s immune system or of antibiotics. Any time that the patient’s resistance to infection is reduced, the infection can break out again and produce a septicaemia. Brodie’s abscess is a chronic abscess walled off in sclerotic bone. This can remain dormant for many years.

Treatment of chronic osteomyelitis

All dead tissue needs to be removed. If there is a fracture, this will need to be stabilised. If there was previous fixation which has become infected then this will need replacing. The dead bone is very sclerotic and extremely difficult to remove without causing a new fracture. It is also very difficult to be certain that all dead bone has been removed. If it is not, then the infection will recur. The introduction of the Ilizarov fixator and modern distraction techniques allow much more radical excision with a real prospect of reconstructing a functioning limb.

Chronic osteomyelitis

Excise all dead tissue

Take deep cultures

Give appropriate antibiotics

Reconstruct limb