Classification. Chronic Osteomyelitis

Chronic Osteomyelitis

Treatment

Treatment is very similar to the typical treatment of the osteomyelitis in older children and adults.

Successful cure of osteomyelitis during the newborn period is dependent on a fast and true diagnosis and sufficient treatment. Empirical selection of antibiotic therapy depends on the age and the clinical situation of the infant. Antimicrobial therapy should be started as soon as the diagnosis is made and directed against the most common bacterial isolates responsible for hematogenous osteomyelitis according to age group.

For neonates an empiric regimen should include excellent coverage against S. aureus, group B streptococcus and enteric gram-negative bacteria, thus consisting of a third-generation cephalosporin (cefotaxime) plus an antistaphylococcal agent (amoxicillin). Infants at risk for hospital-acquired infection (methicillin-resistant or coagulase negative Staphylococcus aureus) should receive vancomycin instead of amoxicillin.

Duration of treatment depends on the extent of infection, the clinical response and the presence of underlying risk factors. Surgery is indicated to drain acute abscesses or when no improvement is achieved with antibiotic treatment.

Established osteomyelitis consists of new bone formation – the involucrum. Dead bone- known as sequestrum acts as a nidus of infection. Antibiotics will be ineffective until this is removed.

Involucrum - a layer of new bone growth outside existing bone seen in osteomyelitis.

Sequestrum - necrotic bone which has become walled off from its blood supply and can present as a nidus for chronic osteomyelitis.

Chronic suppurative osteomyelitis

· Primary (no preceding phase)

· Secondary (follows an acute phase)

The classic form of chronic osteomyelitis had its onset with acute osteomyelitis, as the abscess was forming and the involved bone was ischemic. If the amount of ischemic bone was substantial, it would remain as a sequestrum. Especially if the sequestrum was contaminated, it would remain as a focus of recurring infection; even if not contaminated, its presence activated a host response similar to that of a foreign body -an attempt to wall off the sequestrum. The new bone reacting to the sequestrum is called the involucrum. Chronic osteomyelitis is clinically evident by low grade drainage and inflammation about the infected site.

Patients may have all or only a few of the following:

§ Previous acute infection (either unresponsive to treatment or relapsing following treatment)

§ Localised bone pain

§ Erythema and swelling over affected area

§ Non-healing ulcer

§ Draining sinus tracts

§ Decreased range of motion of adjacent joints

§ Chronic fatigue

§ Generalised malaise

Occasionally, the infection becomes localised to form a chronic abscess (Brodie's abscess - chronic abscesses may become surrounded by sclerotic bone and fibrous tissue) within the bone. These patients may be asymptomatic for months or years or may have a history of intermittent, localised pain.

· Pathologic fracture may accompany chronic osteomyelitis.

Дата добавления: 2014-10-15