Could Soft Tissue Infection Influence the Outcomes of Diabetic Foot Osteomyelitis? Data from a Retrospective Study

The study aimed to assess the outcomes of patients with diabetic foot osteomyelitis (DFO) and concomitant soft tissue infection (STI). It is a retrospective observational study including consecutive patients affected by DFO located in the forefoot (toes and/or rays) who referred to a specialized diabetic foot service from 2019 to 2022. Patients were categorized in two groups: those with DFO and STI and those with DFO without STI. All patients were managed by a conservative surgical approach aiming to remove only the infected bone in association with antibiotic therapy. After 1-year of follow-up, the following outcomes were evaluated and compared between groups: healing, healing time, minor amputation, major amputation, and hospitalization. Overall, 166 patients were included. The mean age was 68.5 ± 13.2 years, 94.9% of them were affected by type 2 diabetes with a mean duration of 19.3 ± 7.1 years. One hundred fourteen patients (68.7%) had DFO complicated by STI, while 52 (31.3%) had DFO without STI. The outcomes for DFO with and without STI were: healing (52.3 vs 94.2%, p = 0.005), healing time (7.8 ± 5.8 vs 4.6 ± 2.7 weeks, p = 0.0002), minor amputation (13.1 vs 3.8%, p = 0.04), major amputation (0 vs 0%, ns), and hospitalization (66.7 vs 48.1%, p < 0.002) respectively. In addition, STI resulted an independent predictor of non-healing [OR 3.1, CI 95% (1.7-9.3), p = 0.002]. Patients with DFO complicated by STI showed higher rate of non-healing, delayed healing time, and more case of minor amputation and hospitalization in comparison to those without STI. STI was independently associated to the risk of non-healing, while any association was found for amputation and hospitalization.