What Is Osteomyelitis?
Osteomyelitis is a serious bone infection, usually caused by bacteria, with Staphylococcus aureus being the most common causative organism. The infection may affect either cancellous or cortical bone.
In its chronic form, osteomyelitis is one of the most challenging infections to treat in orthopaedic practice because of its tendency to recur despite prolonged antibiotic therapy.
It can occur at any age. In children, it commonly affects long bones, such as the femur and tibia. In adults, it is often associated with trauma, surgery, orthopaedic implants or underlying conditions such as diabetes mellitus.
Symptoms of chronic osteomyelitis may include localized pain and tenderness, swelling, redness, occasional discharge of pus through a sinus tract and episodes of fever during acute exacerbations.
Characteristics of Chronic Osteomyelitis
Chronic osteomyelitis is characterized by the presence of necrotic bone fragments, known as sequestra. Pathogenic microorganisms may form a biofilm around these fragments—a protective layer that makes them highly resistant to antibiotics and the body’s immune defences.
One of the most significant features of the condition is the hypoxic environment that develops in the affected area. Inflammation and necrotic tissue markedly reduce the blood supply, while many pathogenic bacteria, particularly anaerobic organisms, thrive in conditions of low oxygen availability.
This creates a vicious cycle: the infection worsens the ischaemia, while the ischaemia promotes the persistence of the infection.
Treatment usually requires a combination of surgical debridement, prolonged targeted antibiotic therapy and measures aimed at supporting the local immune response and the tissue repair process.
Scientific Basis
Hyperbaric oxygen therapy for chronic osteomyelitis is one of the most extensively documented applications in the field of hyperbaric medicine.
The Undersea and Hyperbaric Medical Society (UHMS) includes it among the recognised indications for treatment, based on a substantial body of clinical evidence.
Research has shown that the high oxygen concentrations achieved inside the hyperbaric chamber can exert direct bacteriostatic and bactericidal effects, particularly against anaerobic bacteria.
In addition, improved oxygenation enhances the phagocytic activity of neutrophils, which require adequate local oxygen levels to destroy bacteria, and may optimise the effectiveness of certain antibiotics, particularly aminoglycosides.
The Role of Hyperbaric Oxygen Therapy
In chronic osteomyelitis, hyperbaric oxygen therapy does not replace surgical debridement or antibiotic treatment. Instead, it serves as a powerful adjunctive therapy that supports and enhances both interventions.
Increasing the partial pressure of oxygen within the tissues helps break the vicious cycle of ischaemia and infection. It restores local immune defence, creates an unfavourable environment for anaerobic pathogens and improves the penetration of antibiotics into the tissues.
At the same time, the neovascularisation promoted by hyperbaric oxygen therapy allows blood flow to be gradually restored in ischaemic areas, contributing to long-term healing.
Following surgical debridement, hyperbaric oxygen therapy also supports wound healing and may help prevent recurrence. Patients with diabetic osteomyelitis or infections caused by multidrug-resistant bacterial strains may benefit particularly from this adjunctive approach.
A typical treatment protocol for chronic osteomyelitis consists of 30 to 40 sessions, administered daily during the intensive phase.
Hyperbaric oxygen therapy is always incorporated into the overall treatment plan in collaboration with the orthopaedic surgeon and infectious disease specialist.