Current techniques to detect foot infection in the diabetic patient

Diabetic foot infections can be a challenge to diagnose, especially when osteomyelitis is in question. Evaluation of infection should involve a thorough examination of the extremity for clinical signs of infection along with appropriate laboratory and imaging studies. Laboratory markers of inflammation such as peripheral leukocyte count, erythrocyte sedimentation rate, C-reactive protein, and procalcitonin may provide useful information when diagnosing soft tissue and bone infection. However, laboratory markers alone should not be used to diagnose a diabetic foot infection as they are non-specific in nature. Imaging studies may also provide valuable clues regarding the presence of infection. Plain radiographs are a good initial screening tool as they are both inexpensive and easily accessible. However, their sensitivity in diagnosing osteomyelitis is poor. Thus, more advanced imaging such as radionuclide imaging and magnetic resonance imaging are warranted when osteomyelitis is suspected. Magnetic resonance imaging is presently considered the gold standard in diagnosing osteomyelitis, despite its wide variation in reported sensitivity and specificity. However, the significant cost of magnetic resonance imaging prevents its use as a screening tool. Collection of reliable microbiologic data is critical in making a diagnosis as well as for treatment of infection, especially when osteomyelitis is concerned. Deep swabs and transcutaneous bone biopsy are considered the ideal methods of obtaining the necessary information. Finally, monitoring treatment should also be performed with an eye towards both laboratory data and the clinical exam.