The detection of pedal osteomyelitis in diabetic patients

Abstract

Pedal osteomyelitis in diabetic patients is a serious clinical problem. There is no single, reliable diagnostic tool; plain films are inaccurate, bone scans nonspecific and the role of human pooled immunoglobulin (Hig) scans remains unclear. Magnetic Resonance Imaging (MRI) may prove useful. We therefore aimed to compare these four diagnostic modalities. Thirteen diabetic patients with possible pedal osteomyelitis were recruited. Nine were found to have osteomyelitis based on clinical, microbiological, and surgical findings. All were scanned with all four modalities and the results compared. MRI scans correctly identified all positive cases, with two false positive cases, and excelled in localising infection, allowing for surgical planning. Plain film and Hig scans were less sensitive (6/9 and 7/9 cases, respectively), were difficult to interpret and were poor in localising infection. Bone scans identified eight of the nine cases, with no false positives. In conclusion, this small study suggests that plain films and Hig scans did not confer any additional benefit in the diagnosis of pedal osteomyelitis. Bone scans are a useful screening tool, but when positive an MRI scan should be sought to confirm the diagnosis.