BackgroundThe primary goals of orthopedic treatment of open fractures are to prevent infection, stabilize bone injury and restore limb function. The objective of the current study was to identify risk factors associated with infection in patients suffering from open fractures, using the strength of association of these factors to propose a score that enables risk stratification in initial care.Materials and methodsA retrospective analysis was performed on 122 patients who underwent open fracture treatment. Clinical and demographic data were collected and the results were divided into two groups: those without infection and those with infection. Both groups were evaluated searching for associated factors that could lead to infection.ResultsThirty-one patients out of 122 were infected (25.4 %). Infection was significantly associated with exposure time up to 24 h (mean 30.3 h; p = 0.007). Fractures classified as Gustilo III had a greater chance of infection (74.2 %; p = 0.042), especially type IIIB (41.9 %). Fractures classified as Tscherne II and III had a greater chance of infection (48.4 and 25.8 %, respectively; p = 0.001).ConclusionsIt was possible to show that the exposure time and the types of fracture classified as Gustilo III and Tscherne II and III are associated with the outcome of infection. It was also possible to create a risk score (IRS) for predicting infection in these types of fractures, which can be used in the initial care of the patient, with a sensitivity of 0.840, specificity of 0.544, cut-off of 6.5 and area under the curve of 0.709 (p = 0.002).Level of evidenceLevel III.