Osteomyelitis, an infection of the bone and bone marrow, can lead to serious health complications. It is often overlooked in its early stages in individuals with diabetic foot problems. Diabetes, a chronic condition characterized by elevated blood sugar levels, significantly increases the likelihood of developing osteomyelitis, particularly in the feet. Understanding the link between diabetes and bone infections is important for managing this severe complication.
How Diabetes Increases Osteomyelitis Risk
Diabetes creates several physiological changes that elevate an individual’s susceptibility to osteomyelitis. A primary factor is diabetic neuropathy, which involves nerve damage. This nerve damage reduces sensation in the feet, leading to unnoticed injuries that can develop into open wounds. These wounds serve as direct entry points for bacteria, allowing them to reach the bone.
Another contributing factor is peripheral artery disease (PAD), where narrowed blood vessels restrict blood flow. Reduced blood flow impairs the delivery of oxygen, nutrients, and infection-fighting white blood cells to tissues, hindering the body’s ability to combat bacteria. This compromised circulation also impedes wound healing, allowing minor injuries to persist and become chronic.
Elevated blood sugar levels also impair the immune system’s function. High glucose concentrations can compromise the activity of neutrophils, making the body less effective at clearing bacterial infections. This allows infections to spread more easily to the bone. These factors often lead to chronic, non-healing foot ulcers, which act as open gateways for bacteria to spread from soft tissues into the underlying bone, causing osteomyelitis.
Identifying Osteomyelitis
Recognizing the signs and symptoms of osteomyelitis is important for individuals with diabetes and their caregivers. Common indicators of a bone infection include persistent pain in the affected area, swelling, redness, and warmth over the bone. Some individuals may also experience systemic symptoms such as fever, chills, and general fatigue.
In individuals with diabetes, specific foot symptoms are particularly noteworthy. A non-healing foot ulcer is the most common entry point for infection, and its presence should raise suspicion for underlying osteomyelitis. Other localized signs include pus drainage, a foul odor from an ulcer, or new or worsening swelling and redness around an existing wound. Visible bone or bone that can be probed through an ulcer suggests bone involvement. However, diabetic neuropathy can mask pain, making early detection challenging as typical pain signals may be diminished or absent.
Diagnosis and Treatment Approaches
Confirming a diagnosis of osteomyelitis in individuals with diabetes involves a combination of medical assessments. A physical examination of the affected area is an initial step to assess for signs of infection such as tenderness, swelling, or an ulcer. The “probe-to-bone” test, using a sterile blunt probe to check if it can reach the bone surface through an ulcer, is also often performed.
Laboratory tests, such as blood tests for elevated white blood cell counts, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), can indicate infection and inflammation. While these markers suggest infection, they are not specific for osteomyelitis alone. Imaging studies are also used; plain X-rays are often the first, but may not show changes until 10 to 20 days after infection onset. Magnetic resonance imaging (MRI) is highly sensitive for early detection, showing changes within days. CT scans and nuclear medicine scans, like bone scans or white blood cell scintigraphy, can also provide additional information, especially when MRI is contraindicated or inconclusive.
The definitive method for diagnosing osteomyelitis and identifying the specific bacteria is a bone biopsy, often performed percutaneously or during surgery. This procedure provides tissue for microbiological culture and histopathological examination, guiding appropriate antibiotic therapy.
Treatment for osteomyelitis involves a multi-pronged approach. Long-term, high-dose intravenous antibiotics are a primary treatment, administered for several weeks to months, guided by the specific bacteria identified. Surgical debridement, the removal of infected bone and tissue, is necessary to eliminate infection sources that antibiotics cannot penetrate. In severe, unresponsive cases, or when infection threatens to spread, amputation of the affected limb or digit may be a last resort. Adjunctive therapies, including specialized wound care, offloading strategies, and sometimes hyperbaric oxygen therapy, complement antibiotic and surgical interventions.
Preventing Osteomyelitis in Diabetics
Preventing osteomyelitis in individuals with diabetes focuses on managing underlying diabetic complications and meticulous foot care. Maintaining strict blood sugar control through diet, medication, and regular monitoring is important. Consistent glycemic management improves immune function and blood circulation, reducing infection risk and enhancing the body’s healing capabilities.
Comprehensive diabetic foot care is also important. This includes daily self-inspections of the feet for any cuts, blisters, redness, swelling, or other skin changes. Proper hygiene, such as washing feet daily with mild soap and water and thoroughly drying them, especially between the toes, helps prevent fungal or bacterial growth. Moisturizing the skin on the feet, avoiding the areas between toes, can prevent dryness and cracking, which might otherwise create entry points for bacteria.
Wearing appropriate, well-fitting footwear is also important to prevent injuries and pressure points that can lead to ulcers. Shoes should be comfortable, provide adequate support, and protect the feet from trauma. Regular professional foot examinations by a podiatrist are advisable to identify and manage any foot deformities, calluses, or early signs of neuropathy or vascular disease. Prompt medical attention for any foot injury, ulcer, or signs of infection, regardless of how minor it appears, can prevent a superficial infection from progressing to involve the bone. Smoking cessation is also important, as smoking impairs circulation and wound healing, increasing the risk of foot complications and osteomyelitis.