The risk of infection in open distal tibial fracture: the DANGER score

Introduction: Open fractures of the distal tibia can be functionally devastating, and they remain one of the most challenging injuries treated by trauma surgeons usually burdened with a high rate of complications, including surgical site infections (SSI). Our aim is to analyze the most significant risk factors of SSI and propose a new scoring system-called the DANGER scale-potentially able to predict reliably and quantify the infection risk in distal tibia open fractures.

Methods: We identified six variables summarized in the acronym DANGER where D stands for Diabetes, A for Antibiotic, N for Nature of trauma (high- or low-energy trauma), G represents Grade of fracture following the AO/OTA classification, E indicates Exposure of the fracture according to the Gustilo-Anderson classification, and R represents Relative risk of patient, including use of tobacco, alcoholism, and psychiatric disorders. Therefore, total score ranged from 1 to 14, with a lower score indicating less risk to develop SSI.

Results: A total of 103 patients with open distal tibial fractures were enrolled, 12 patients (11.6%) developed SSI. Regarding DANGER score, a rating of 8.2 was calculated in SSI group and 4.8 in non-SSI group. Based on Fisher's test, diabetes (odds = 31.8 p < 0.05), grade of articular involvement (p < 0.05), severity of open fracture (p < 0.05), and dangerous behavior such as use of tobacco, alcoholism, and psychiatric disorders (p < 0.05) were significantly correlated with infection. Significant difference between total DANGER scores in SSI and non-SSI groups was found (p < 0.001). ROC curve was calculated founding a potential threshold of 7.5 (p < 0.001).

Conclusion: Based on the above well-accepted risk factors, DANGER scale represents an advantageous and practical tool in order to readily estimate the risk of surgical site infection of open distal tibial fractures.