Osteomyelitis And Heel Ulcers: What You Should Know
Mindful of the limb-threatening consequences that can arise if one does not properly diagnose and treat calcaneal osteomyelitis, this author examines the most effective modalities for diagnosing the bone infection, as well as non-invasive and surgical treatments.
Calcaneal osteomyelitis is a complicated clinical scenario that is often very difficult to treat. It can occur in individuals of any age who are injured or immunocompromised, and requires aggressive management.
Treatment ranges from antibiotics alone to radical debridement or amputation. If there is a delay in both diagnosis and treatment, calcaneal osteomyelitis can be limb-threatening or even life-threatening. The calcaneus is a completely cancellous bone that never forms an involucrum and seldom forms an isolated sequestrum. With calcaneal osteomyelitis, pus perforates the periosteum without destroying much of its cortex.1
Osteomyelitis is an infection involving the bone caused by various microorganisms such as bacteria and fungi. These organisms can infect the bones in several ways:2
• injury (bacteria enter the bone through a traumatic wound)
• direct extension (spread to the bone from an adjacent wound or infection)
• hematogenous (enters the bone via the bloodstream)
Although the most common bacterial pathogens are species of Staphylococcus and Pseudomonas, it is important to identify the organism(s) responsible for each individual osteomyelitis infection. After irrigation with 20 cc normal saline to eradicate contaminant bacteria from the site, obtain culture and tissue specimens for quantitative analysis from the deepest point of the wound.
In regard to appropriate antibiotics, patients may take oral or intravenous antibiotics. Other options may involve direct application into the wound via antibiotic beads, gels, ointments, patches or suppositories.
In some instances, osteomyelitis can persist and become chronic due to the presence of injured tissue and foreign material within the wound. Osteomyelitis is classified according to what parts of the bone are involved in the disease and the health of the patient. Based on their medical history, patients are classified as either compromised (B-hosts) or uncompromised (A-hosts). Compromised patients have decreased healing potential in comparison to uncompromised patients. Conditions that may classify a patient as an immunocompromised healer include:
• use of steroids
• poor nutrition
• extensive scarring
• use of tobacco products
• previous radiation therapy
• organ failure
• chronic lymphedema
• old age
• peripheral arterial disease
Tobacco use (smoking in particular) is the most common compromising factor in patients treated for osteomyelitis. With failures ranging from 30 to 100 percent in many protocols, the use of tobacco products during treatment may make the difference between limb salvage and amputation.3
For review, the Cierny-Mader classification of osteomyelitis is based on a combination of anatomic and physiologic staging to determine appropriate therapy (see the table “A Review Of Osteomyelitis Classification” at left).4
Differentiating osteomyelitis from other bone diseases is fairly simple. Infectious osteitis occurs with suppuration of cortex without marrow involvement. Infectious periostitis does not show bone marrow edema but has periosteal contamination and inflammation.