Imaging for detection of osteomyelitis in people with diabetic foot ulcers: A systematic review and meta-analysis

Background: Osteomyelitis is an infection of the bone which can occur in people with diabetic foot ulcers. It can be diagnosed using X-rays, ultrasound, scintigraphy, magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT) and positron emission tomography (PET). Objectives: To review the evidence on the diagnostic accuracy of imaging tests to diagnose osteomyelitis in people with diabetic foot ulcers. Methods: We conducted a systematic review and meta-analysis. MEDLINE, EMBASE and other databases were searched to July 2018. Risk of bias was evaluated. Diagnostic accuracy was estimated using bivariate meta-analyses. Results: Thirty-six studies were included in the meta-analysis. Eight studies were at high risk of bias MRI had high diagnostic accuracy (22 studies: 96.4 % sensitivity (95 % CI 90.7-98.7); 83.8 % specificity (76.0-89.5)). PET scans also had high accuracy (6 studies: 84.3 % sensitivity (52.8-96.3); 92.8 % specificity (75.7-98.2)), and possibly also SPECT, but with few studies (3 studies: 95.6 % sensitivity (76.0-99.3); 55.1 % specificity (19.3-86.3)). Scintigraphy (17 studies: 84.2 % sensitivity (76.8-89.6); 67.7 % specificity (56.2-77.4)), and X-rays (16 studies: 61.9 % sensitivity (50.5-72.1); 78.3 % specificity (62.9-88.5)) had generally inferior diagnostic accuracy. Conclusions: MRI and PET both reliably diagnose osteomyelitis in diabetic foot ulcer patients. SPECT may also have good diagnostic accuracy, although evidence is limited. This review confirms most current guidelines, showing that MRI may be the preferable test in most cases, given its wider availability and the lack of potentially harmful ionising radiation.