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Describe co-occurrence or clustering of microbial taxa in fracture-related infections to inform further exploration of infection-related interactions among them.Retrospective review.Level 1 trauma center.Four hundred twenty-three patients requiring surgical intervention for deep surgical site infection between January 2006 and December 2015.None.Connection between microbial taxa.Methicillin-resistant Staphylococcus aureus, methicillin-sensitive Staphylococcus aureus, and coagulase-negative Staphylococcus represented the majority of monomicrobial observations (71%). Gram-negative rods, gram-positive rods, and anaerobes presented more frequently in polymicrobial infections. Enterobacter, vancomycin-sensitive Enterococcus, and Pseudomonas are present in polymicrobial infections with the highest frequencies and represent the top 3 most important nodes within the microorganism framework, with the highest network centrality scores.The present study indicates that there are common microbial taxa (Enterobacter, Enterococcus, and Pseudomonas) that tend to co-occur with other microbes greater than 75% of the time. These commonly co-occurring microbes have demonstrated interactive relationships in other disease pathologies, suggesting that there may be similar important interactions in fracture-related infections. It is possible that these microbial communities play a role in the persistently high failure rate associated with management of infection after trauma. Future studies are needed to study the intermicrobial interactions that explain the frequency at which taxa co-occur. Understanding and potentially disrupting these intermicrobial relationships could inform improvements in the treatment of established infections and in the prevention of infection in high-risk patients.Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

To compare infection rates after second-stage definitive surgery for high-energy tibial plateau fractures between groups of patients who had the external fixator prepped into the surgical field and those who did not.Retrospective cohort study.Two academic Level 1 trauma centers.Two hundred forty-four patients met inclusion and exclusion criteria between the 2 institutions.Prepping of the external fixator into the surgical field during second-stage definitive open reduction and internal fixation. 162 patients were in the prepped group, and 82 patients were in the nonprepped group.The primary outcome was the rate of deep infection after definitive fixation. Secondary outcome was operative time.There were no significant differences in infection rates between prepped (11.7%) and nonprepped (18.3%) groups ( P = 0.162). Patients in the prepped groups had significantly decreased operative time (168.2 minutes vs. 221.9 minutes, Plt; 0.001) even after controlling for confounders in regression analysis.There is no increased risk of infection associated with prepping and maintenance of the external fixator during definitive internal fixation for high-energy tibial plateau fractures. These data suggest that this practice may lead to shorter operative times as well.Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background: Currently, there is no consensus regarding the principles of empiric antibiotic treatment of suspected periprosthetic infection following total knee and hip arthroplasties. This study was undertaken to attempt to establish such principles. Methods: We performed a retrospective analysis of 146 patients who had had a total of 194 positive cultures of specimens obtained at the time of a reoperation following a total knee or total hip arthroplasty at one of two institutions. Patient demographic data, comorbid conditions, bacterial species, the antibiotic sensitivity profile, and the postoperative day on which the culture tested positive were recorded. Results: Specimens from 110 hips and eighty-four knees were positive on culture. Seventy percent of the infections were classified as chronic; 17%, as acute postoperative; and 13%, as acute hematogenous. The mean time between the operation and the positive culture results was three days. Gram-positive organisms caused the majority of the infections. In the series as a whole, 88% of the bacteria were sensitive to gentamicin; 96%, to vancomycin; and 61%, to cefazolin. The most antibiotic-resistant bacterial strains were from patients for whom prior antibiotic treatment had failed. Acute postoperative infections had a greater resistance profile than did chronic or hematogenous infections. Bacteria isolated from patients with a hematogenous infection had a high sensitivity to both cefazolin and gentamicin. Conclusions: Empiric antibiotic treatment for suspected periprosthetic infection should be guided by the class of the infection and the findings of Gram staining. We believe that, until the final culture results are available, acute hematogenous infections should initially be treated by a combination of cefazolin and gentamicin therapy. All chronic and acute postoperative infections with Gram-positive bacteria and all cases in which a Gram stain fails to identify bacteria should be managed with vancomycin. Infections with Gram-negative bacteria should be managed with a third or fourth-generation cephalosporin. Infections with mixed Gram-positive and Gram-negative bacteria should be managed with a combination of vancomycin and a third or fourth-generation cephalosporin. Furthermore, we believe that if culture results and other confirmatory tests are not positive by the fourth postoperative day, termination of empiric antibiotic therapy should be considered. Level of Evidence: Diagnostic Level IV. See Instructions to Authors for a complete description of levels of evidence.