Current Concepts In Treating Osteomyelitis
It has been estimated that a person with diabetes has a 25 percent lifetime risk of developing a foot ulceration.1 Diabetic foot ulcers commonly become infected, can involve bones and joints and may progress to amputation. Osteomyelitis frequently complicates ulcerations in people with diabetes and may be present in up to 20 percent of mild to moderate and 50 to 60 percent of severely infected wounds.2
Diagnosing osteomyelitis in people with diabetes who present with a foot ulcer is challenging and becomes a clinical conundrum. Misdiagnosis may lead to unnecessary treatment, specifically prolonged antibiotic therapy and surgery. Accordingly, let us take a closer look at osteomyelitis in the diabetic foot, the importance of early detection, the benefits and limitations of the available diagnostic tests, and the current evidence of both surgical and non-surgical treatment.
Osteomyelitis is an inflammatory process caused by an infecting microorganism.3,4 This infectious process is accompanied by bone destruction and, in most cases, clinical signs of inflammation.4,5 Waldvogel classified osteomyelitis based on etiology and developed three categories: hematogenous, contiguous and osteomyelitis associated with vascular insufficiency.6
Hematogenous osteomyelitis mostly occurs among children and elderly patients, and the infected bone is caused by bacteria seeded in the blood. Most often, this form of osteomyelitis involves the metaphysis of long bones. Local (chills, fever and malaise) and systemic (pain and local swelling) signs are typical.4 In contiguous osteomyelitis, the bone becomes infected from an external contaminated source (penetrating trauma, open fracture, bone surgery or joint replacement). This can occur at any age and can affect any bone.
In regard to osteomyelitis associated with vascular insufficiency, physicians will most often see this among patients with diabetic neuropathy.6 Foot ulcers serve as portals for infection and bacteria to gain access to the bone by contiguous spread. If a diabetic foot ulcer fails to heal after at least six weeks of appropriate care and offloading, one should suspect osteomyelitis.7 In almost all cases of osteomyelitis in the diabetic foot, the infection starts in the soft tissue and spreads to bone.