The traditional treatment approach to osteomyelitis is surgery followed by 4 to 6 weeks of parenteral antibiotics. No evidence shows that parenteral antibiotics penetrate necrotic bone. Therefore, surgical debridement is necessary to ensure that vascularized bone is treated. It takes 4 to 6 weeks for debrided bone to be protected by the revascularized tissue.12
Antibiotic selection should be based on targeting the causative organisms. In most cases, a broad-spectrum antibiotic is necessary because many of these chronic infections are polymicrobial. One antibiotic that is often used to treat osteomyelitis is vancomycin (Lyphocin, Vancocin). It is often a good choice because of its effectiveness in treating methicillin-resistant staphylococcal infections. Because vancomycin-resistant staphylococcal infections have also been reported, a combination antibiotic regimen is often recommended (Table 4).
Due to a lack of controlled trials and the heterogeneous nature of osteomyelitis, some treatment issues remain undecided. The optimal duration of antibiotic therapy and the most effective combination of medications are unknown. Medical treatment can involve the use of parenteral antibiotics, a combination of parenteral and oral antibiotics or long-term, high-dose oral therapy.9
General recommendations for treatment can also be based on the extent or staging of the osteomyelitis using the Cierny-Mader classification. For example, adults with type 1 Cierny-Mader should be treated with parenteral antibiotics for at least 4 to 6 weeks. To reduce costs, parenteral antibiotics are widely used in outpatient settings.
Adults with type 2 Cierny-Mader or Waldvogel hematogenous osteomyelitis should be treated with parenteral antibiotics for at least 2 weeks after surgical debridement of the infected bone.
Debridement of all nonviable bone is critical to prevent reccurrence. The remaining healthy bone should show punctuate bleeding known as the "paprika sign," which distinguishes it from the dead bone.13 Surgery is also important to eliminate dead space left after the bone is removed, to restore skin integrity through the use of skin grafts and flaps, and to enhance vascular supply to the area.
Patients whose infection is classified Cierny-Mader type 3 or 4 require extensive surgical debridement. Antibiotic therapy for these patients should be continued at least 4 to 6 weeks after the last surgical debridement. Therapy should not be stopped until the wound has completely healed.
Systemic disorders, which are common in patients with infections classified as Cierny-Mader Bs, affect prognosis. Even with optimal care, 20% to 30% of patients will develop recurrence within 2 years.2 Recurrent osteomyelitis is often resistant to treatment with surgery and antibiotics, leading to the conclusion that the infection may not have been totally eliminated.
Recently, hyperbaric oxygen therapy (HBO) has been used as an adjunct to surgery and antibiotics to treat chronic osteomyelitis. This approach is based on the premise that HBO improves available oxygen at the bone site, enhancing the ability of white blood cells to phagocytize the bacteria and promote osteogenesis.14 Research about this therapy is limited, however, and more studies are needed to define the adjunctive role of HBO in chronic osteomyelitis.
Because osteomyelitis is such a complex and costly condition, its prevention should be a top health priority. Measures to decrease risk include the following:
- Smoking cessation: NPs should encourage cessation in every patient who smokes, but for patients at risk for osteomyelitis, this act has additional importance. Offer every resource necessary, including pharmacologic aids and behavioral interventions and programs.
- Improved nutrition: Patients who are malnourished may have difficulty fighting off an infection such as osteomyelitis. The importance of a well-balanced diet to deliver adequate fluid and nutrients to the infection site cannot be overemphasized.
- Glycemic control: Nationally recognized guidelines recommend that patients with diabetes achieve an A1c level of 7% or less. Review self-glucose monitoring records and A1c levels at regular intervals to keep apprised of each patient's risk for all diabetes complications, including osteomyelitis. Prescribe or recommend all necessary interventions, including medication, weight loss and medical nutrition therapy.
- Offloading of pressure to bony areas: Patients with diabetes often develop neuropathy, which can result in structural deformities of the feet and inability to sense pain. Shoes protect the feet from injury, but in patients with diabetes, structural deformities may make it impossible to find shoes that fit without causing discomfort or injury. In a diabetes patient who is unable to sense pain, shoes may cause blisters or sores but go unnoticed because of the lack of feeling in the feet. When a standard shoe does not fit a patient's foot, referral to a certified pedorthist is warranted. A pedorthist can recommend appropriate types and styles of shoes, modify existing shoes or even order special shoes or orthoses to offload pressure areas. Shoes should be comfortable at the time of purchase, and patients should not expect them to "stretch out." Advise all patients with diabetes to check shoes for rocks and other objects before putting shoes on. Also advise them never to wear shoes without stockings or socks.
- Appropriate wound care: Osteomyelitis often presents as a draining wound or sinus tract. Absorbent wound care products or dressings, such as calcium alginates, can be helpful in managing the drainage. Negative pressure therapies can also be beneficial if the osteomyelitis is already being treated.
- Patient education: Provide detailed education about the clinical signs and symptoms of osteomyelitis to all patients at risk. Early diagnosis and treatment can improve outcomes.
Putting It Into Practice
Osteomyelitis is a challenging disease, particularly when complicated by the presence of diabetes. Prevention of osteomyelitis is key, since recurrence rates are high. Once osteomyelitis is diagnosed, adequate surgical debridement of the infected bone is the first step. The second is the initiation of appropriate antibiotic therapy. Hyperbaric oxygen therapy may provide some benefit as adjunctive therapy, but more research is needed.
Catherine Ratliff is a nurse practitioner and associate professor at the University of Virginia Health System in Charlottesville, Va. She is also certified in wound, ostomy and continence care.