The infected diabetic foot: Risk factors for re-infection after treatment for diabetic foot osteomyelitis

Our objective was to evaluate risk factors for re-infection in patients after treatment for diabetic foot osteomyelitis (OM). We used pooled patient level data from two RTCs that evaluated patients with diabetic foot infections. We evaluated 171 patients with OM. OM was confirmed with bone culture or histopathology. Data from the 12-month follow-up were used to determine clinical outcomes. Re-infection occurred in 47 (27.5%) patients. Risk factors for re-infection were Toe Brachial Index <0.40 (25.7% vs. 9.8%, p = 0.02), skin perfusion pressure <40 mmHg (6.3% vs. 5.9%, p = 0.04), wound healing (55.3% vs. 75.0%, p = 0.01), time to heal (156.0, 69.5–365 vs. 91.5, 38.8–365, p = 0.001), and history of MI (14.9% vs. 3.2%, p = 0.005). During 12-month follow-up, patients with re-infections were 198.8 times more likely to require a foot related hospitalisation (81.8% vs. 0.0%, p = 0.001), 10.4 times more likely have an all-cause hospitalisation (70.2% vs. 18.5%, p = 0.001) and 9.4 times more likely to need an amputation (36.2% vs. 5.6%, p = 0.001). Patients with re-infection had a significantly longer median length of hospitalisation (20.0, 13.5–34.5 vs. 14.0, 10.0–22.0, p = 0.003) and median length of antibiotic duration (55.0, 35.0–87.0 vs. 46.0, 22.8–68.0, p = 0.03). Patients with re-infection are less likely to heal and have more foot-related hospitalizations and amputations.