Osteomyelitis of the foot in diabetic patients.

Osteomyelitis of the foot, a common and serious problem in diabetic patients, results from diabetes complications, especially peripheral neuropathy. Infection generally develops by spread of contiguous soft-tissue infection to underlying bone. The major diagnostic difficulty in diabetic patients is distinguishing bone infection from noninfectious neuropathic bony lesions. Certain clinical signs suggest osteomyelitis, but imaging tests are usually needed. The 111In-labeled leukocyte scan and magnetic resonance imaging are the most diagnostically useful. Staphylococcus aureus is the most common etiologic agent, followed by other aerobic gram-positive cocci. Aerobic gram-negative bacilli and anaerobes are occasionally isolated, often in mixed infections. Antimicrobial therapy is best directed by cultures of the infected bone, obtained percutaneously or at surgery. Antibiotic therapy should usually be given parenterally, at least initially, and continued for at least 6 weeks. Surgical debridement or resection of the infected bone, when feasible, improves the outcome. With appropriate therapy most cases of osteomyelitis can be successfully managed.