Comparison of bacteria isolated from open fractures following debridement and subsequent infection.

BACKGROUND: One of the major objectives for the management of open fractures is to prevent bone and soft tissue infection. Here, we identified species and drug sensitivities of bacterial isolates recovered during open fracture debridement and after infection and compared the results between the two time points. METHODS: A total of 61 hospitalized patients with open fractures who developed post-operative wound infection between October 2016 and December 2017 were included in this study. The cohort included 43 males and 18 females aged between 4 and 72 years. Patients were admitted to hospital 1-14 h after injury. Samples were collected after debridement and after infection and submitted for bacterial culture. Resulting isolates were identified using a VITEK 2 Bacterial Identification System and tested for drug sensitivity using the disc diffusion method. Results from the two time points were then compared. RESULTS: The positive bacterial culture rate following debridement was relatively low (14/61, 22.9%). In addition, bacteria cultured after debridement were generally inconsistent with those cultured after wound infection, with a concordance rate of only 3.3% (2/61). Gram-negative bacteria accounted for 91.3% (63/69) of isolates recovered from wound infections following surgery, among which Acinetobacter baumannii was baumannii was the predominant pathogen, accounting for 49.3% (42/69) of all isolates. Overall, 60.8% (42/69) of postoperative infections were caused by multi-drug resistant bacteria, with A. baumannii isolates accounting for 80.9% (34/42) of these cases. Rates of cefoperazone/sulbactam resistance were relatively low among the isolates (15/34, 44.1%), and most isolates showed a sensitive or intermediate resistance phenotype. CONCLUSIONS: Results of bacterial culture after debridement could not predict pathogenic bacteria causing postoperative infection. Therefore, we propose that open fracture infections are predominantly nosocomial and are mainly caused by multidrug-resistant Gram-negative bacteria. Further attention should be paid to the control of these pathogens in clinical settings.

Actualización en el manejo de fracturas abiertas: prevención de infección: utilidad de cultivos de herida: revisión bibliográfica / Update on the management of open fractures: infection prevention: utility of wound culture: bibliographic review / Atualização sobre o manejo de fraturas expostas: prevenção de infecções: utilidade das culturas de feridas: revisão bibliográfica

En las fracturas abierta una de las complicaciones más temidas por los cirujanos ortopédicos es la infección de partes blandas y ósea. A pesar de múltiples investigaciones, las pautas de manejo terapéutico para las fracturas abiertas continúan en constante cambio. El objetivo principal de nuestro trabajo fue realizar una actualización sobre la prevención de la infección en las fracturas abiertas a través de una búsqueda bibliográfica poniendo especial énfasis en la utilidad de los cultivos (recuento microbiano) de heridas en el perioperatorio de estas fracturas.

In open fractures, one of the most feared complications by orthopedic surgeons is soft tissue and bone infection. Despite multiple investigations, therapeutic management guidelines for open fractures, is constantly changing. The main objective of our work was to make an update on the prevention of infection in open fractures through a bibliographic search, with special emphasis on the usefulness of cultures (microbial count) of wounds in the perioperative period of these fractures.

Nas fraturas abertas, uma das complicações mais temidas pelos cirurgiões ortopédicos é a infecção de tecidos moles e ossos. Apesar de várias investigações, as diretrizes de tratamento terapêutico para fraturas expostas estão mudando constantemente. O principal objetivo do nosso trabalho foi atualizar a prevenção de infecção em fraturas expostas por meio de uma pesquisa bibliográfica, com ênfase especial na utilidade das culturas (contagem microbiana) de feridas no período perioperatório dessas fraturas.

Hurricane Harvey Aftermath.

Natural disasters, such as hurricanes and severe flooding, pose a threat of increased skin and soft-tissue infections, especially in the event of open fractures and wading through the waters. The purpose of this case study is to present a complex patient sustaining trauma resulting in an open bimalleolar fracture, multiple wounds, and exposure to a variety of water-borne pathogens during Hurricane Harvey in Houston, Texas, in 2017. He underwent multiple incision and drainage procedures, tissue cultures, and placement of antibiotic beads, with an application of external fixation to the left ankle. Several unique multidrug-resistant water-borne pathogens were identified, including Aeromonas hydrophila, Pseudomonas fluorescens/putida, and Serratia marcescens. Once the soft-tissue envelope was restored and infection cleared, a full-thickness rotational flap with tissue expansion was performed. Ultimate reconstruction was delayed several weeks and final left ankle open reduction and internal fixation was performed following antimicrobial treatment with split-thickness skin autograft and wound vacuum-assisted closure application. The patient was discharged after 28 days with no further complications. In instances such as these, all caretakers coming into contact with the patient should be aware of the potential risks of the possible infectious diseases and management to optimize the recovery following hydrologic disasters.

Open Fractures: Are We Still Treating the Same Types of Infections?

Background: To analyze the rate of methicillin-resistant Staphylococcus aureus (MRSA), gram-negative, and polymicrobial infections in open fractures, measure the efficacy of the current open fracture antibiotic regimen against these infections, identify the most effective agent(s) to cover these infections, and analyze risk factors for infection. Methods: We examined retrospectively 451 patients with open fractures from January 2008 to December 2012 who were treated at our facility. Positive cultures during surgical debridement after wound closure defined an infection. Infecting organisms and their antibiotic sensitivities were identified through microbiology culture reports. Rates of MRSA, gram-negative, and polymicrobial infections were determined. The efficacy of the current regimen (cefazolin and gentamicin) was calculated against gram-positive and gram-negative organisms. Efficacy profiles against infectious organisms were calculated for all commonly tested antibiotics. Patient factors, injury characteristics, and treatment options were analyzed to determine risk factors for infection. Results: Ninety patients (20%) were identified as infected at surgical debridement. Of those 90, 21 (23.3%) were diagnosed with MRSA, 56 (62.2%) were found to have a gram-negative infection, and 46 (51.1%) had polymicrobial infections. Cephalosporins and ß-lactam agents had a 59.2% efficacy rate against gram-positive bacteria and gentamicin showed a 94% sensitivity rate against gram-negative bacteria. Vancomycin (95.8% sensitivity) demonstrated the highest sensitivity for all gram-positive organisms. Amikacin (98.8% sensitivity), meropenem (96.3% sensitivity), and gentamicin (94.2% sensitivity) demonstrated excellent efficacy for all gram-negative organisms. Immuno-compromised status and Gustilo-Anderson type were the only independently predictive risk factors for infection in a multivariable model. Conclusions: Based on this analysis, the rate of MRSA, gram-negative, and polymicrobial infections in open fractures is high and increasing compared with historical cohorts. With the sensitivity of early generation cephalosporins being relatively poor against gram-positive organisms, the present antibiotic regimen for open, long-bone fractures may need to be reconsidered with these emerging trends.

Timing of antimicrobial initiation and reduced infection risk in open limb fractures: a cohort study.

To assess whether early administration of antimicrobials in open fractures of the limbs reduces infection risk. A historical cohort study included all adult patients admitted with an open fracture of the limbs, between January 1, 2012, and December 31, 2016. Epidemiological, clinical, and microbiological data was collected and analyzed. Microbiological infection was defined by positive wound cultures during the first 30 days, and clinical infection as defined by the treating physician. Of 167 patients, microbiological infection was identified in 12 (7%) patients, and clinical infection in 27 (16%) patients. All patients received the first dose of antimicrobials within 15 h of admission (median 1.29 h). Very early administration of the first dose did not reduce the risk of infection (median of 1.06 h and 1.31 h for patients that did vs. did not develop infection, respectively P = 0.58). In multivariate logistic regression, location of fracture in the lower limbs was associated with an increased risk of infection (OR 4.654, CI 1.407-15.398), and Gustilo-Anderson classification grade 1 or 2 was associated with a decreased risk of infection (OR 0.301, CI 0.104-0.872). Very early administration of antimicrobials did not reduce risk of infection in open limb fractures.

Piperacillin/Tazobactam versus Tobramycin-Based Antibiotic Prophylaxis for Type III Open Fractures.

Background: Type III open fractures are associated with an infection rate as high as 50%. The optimal antibiotic for open fracture prophylaxis remains unclear, and the literature comparing the safety and efficacy of different antibiotic regimens is limited. The aim of this study was to compare the composite adverse events (AEs) in patients before and after a change in prophylactic antibiotic management for these injuries from a tobramycin- to a piperacillin/tazobactam-based regimen. Methods: This was a retrospective single-center cohort study of patients with Type III open fractures admitted from January 2010 to December 2016. Patients were included if they received either tobramycin plus cefazolin or clindamycin or piperacillin/tazobactam for fracture prophylaxis. The primary outcome was the rate of composite AEs, which included nephrotoxicity, surgical site infection (SSI), and hospital re-admission with surgical intervention. Secondary outcomes included the rate of SSI within 30 and 60 days after injury. Data were analyzed using the Student t-, Mann-Whitney U, and Fisher exact tests. Results: Eighty-five patients were included. There were 29 events in the tobramycin group compared with three in the piperacillin/tazobactam group. At 30 days, SSI had occurred in 17 patients (27.5%) in the tobramycin group and 1 patient (4.3%) in the piperacillin/tazobactam group (p = 0.033). At 60 days, SSI had occurred in three additional patients in the tobramycin group (p = 0.009). Conclusion: There was no difference in the composite AEs in the piperacillin/tazobactam compared with the tobramycin group. However, SSI within 30 and 60 days was significantly more common with tobramycin.

Evaluation of infection rates with narrow versus broad-spectrum antibiotic regimens in civilian gunshot open-fracture injury.

INTRODUCTION: Civilian gunshot open-fracture injuries portray a significant health burden to patients. Use of antibiotics is endorsed by guideline recommendations for the prevention of post-traumatic infections, however, antimicrobial selection and their associated outcomes remains unclear. Therefore, we sought to compare infectious and other clinical outcomes between three antimicrobial cohorts in patients with gunshot-related fractures requiring operative intervention. MATERIALS AND METHODS: Patients were identified by retrospectively querying the University of Kentucky Trauma Registry for gunshot wound victims. A narrow regimen, an expanded gram-negative regimen, and a regimen containing a fluoroquinolone antimicrobial were identified for comparison. The primary outcome was a composite of infections at or before 14 days of hospitalization. Secondary endpoints included hospital length of stay, incidence of multidrug resistant bacteria and methicillin-resistant Staphylococcus aureus colonization, number of drug-related adverse events, number of Clostridium difficile infections, and 30-day mortality. RESULTS: 252 patients were selected for inclusion: 126 in the narrow regimen, 49 in the expanded gram-negative regimen, and 77 in the fluoroquinolone-based regimen. There were no statistical differences in the primary endpoint of early infectious outcomes between groups (p = 0.1797). The expanded gram-negative regimen was associated with increased hospital length of stay, and increased incidence of multi-drug resistant bacteria and methicillin-resistant Staphylococcus aureus colonization. There were no statistically significant differences in any of the remaining secondary endpoints. CONCLUSION: In this study evaluating civilian gunshot trauma, broad spectrum antibiotic coverage was not associated with improvements in post-traumatic infections. A randomized trial is needed to confirm these results.

Is the proximity of external fixator pins to eventual definitive fixation implants related to the risk of deep infection in the staged management of tibial pilon fractures?

INTRODUCTION: In the staged management of tibial pilon fractures, overlap between definitive internal fixation and external fixation pin sites has been investigated as a risk factor for infection with equivocal conclusions. Our aim was to determine if overlap or proximity of definitive internal fixation to external fixation pin sites influences the risk of deep infection. PATIENTS AND METHODS: We reviewed 280 AO/OTA 43B or 43C type distal tibia fractures in 277 patients at two level-one trauma centers. Patients underwent staged management using early temporizing external fixation followed by definitive open reduction and plate fixation. Primary outcome was the association between pin site overlap and the development of deep infection. Secondary outcome was the relationship between development of deep infection and the distance from pin site to definitive fixation. RESULTS: The average duration between external fixation and definitive internal fixation was 14 days. 24% of fractures developed deep infection requiring surgical intervention. There was no association between pin site overlap and the development of deep infection (p = 0.18). There was no relationship between infection and the distance between proximal plate extent and pin site (p = 0.13). DISCUSSION: We identified no association between pin site overlap and the development of deep infection. We suggest that temporizing external fixation pins should be placed so as to obtain optimal stability of the construct with lesser emphasis on aiming to be absolutely outside the zone of future fixation. LEVEL OF EVIDENCE: Level III Therapeutic Retrospective Comparative study.

Early outcome of culture-negative infection in open fractures of the lower limb: A prospective study.

Background: Culture-negative infections in open long bone fractures are frequently encountered in clinical practice. We aimed to identify the rate and outcome of culture-negative infections in open long bone fractures of lower limb. Methodology: A prospective cohort study was conducted from November 2015 to May 2017 on Gustilo and Anderson Grade III open long bone fractures of the lower limb. Demographic data, injury details, time from injury to receiving antibiotics and index surgical procedure were noted. Length of hospital stay, number of additional surgeries and occurrence of complications were also noted. Patients with infected open fractures were grouped as culture positive or culture negative depending on the isolation of infecting microorganisms in deep intraoperative specimen. The clinical outcome of these two groups was statistically analysed. Results: A total of 231 patients with 275 open fractures involving the femur, tibia or fibula were studied. There was clinical signs of infection in 84 patients (36.4%) with 99 fractures (36%). Forty-three patients (51.2%) had positive cultures and remaining 41 patients had negative cultures (48.8%). The rate of culture-negative infection in open type III long bone fractures in our study was 17.7%. There was no statistical difference in the clinical outcome between culture-negative and culture-positive infections. Conclusion: Failure to identify an infective microorganism in the presence of clinical signs of infection is routinely seen in open fractures and needs to be treated aggressively.

Clinical practice in prevention of fracture-related infection: An international survey among 1197 orthopaedic trauma surgeons.

INTRODUCTION: Open fractures are still a challenge in orthopaedic trauma surgery, and compared to closed fractures, the rate of complications including fracture-related infection (FRI) remains significantly higher. Although different guidelines on prevention of FRI have been published in past decades, the current recommendations vary significantly. The objectives of this international questionnaire were to evaluate clinical practice procedures for the prevention of FRI in open fractures and to evaluate adherence to available guidelines. METHODS: A 17-item questionnaire regarding prophylaxis against infection in fracture care was administered by SurveyMonkey® and was sent via blast e-mail to all users of AOTrauma (Davos, Switzerland). RESULTS: Overall, 1197 orthopaedic trauma surgeons answered the survey. Although cephalosporins were the most commonly prescribed agents for perioperative antibiotic prophylaxis (PAP) in open fractures, a total of 13 different antibiotics were mentioned in the survey. Furthermore, the duration of PAP was extremely variable with a tendency towards longer treatment periods with increasing open fracture severity. The majority of surgeons (71%) agreed that the optimal duration of PAP was not well defined in the literature. The use of local anti-infective agents varied significantly, although all options received additional votes with increasing injury severity. Some of the other surgical aspects addressed in this review were associated with debridement and irrigation. A delay of six hours from injury to the first debridement was acceptable to 47% of surgeons, but delays were tolerable. Normal saline was the solution used most often for wound irrigation in open fractures (89%), with low-pressure irrigation being applied most commonly (55%). CONCLUSIONS: This international survey provided an overview of clinical practice in FRI prevention, particularly in open fracture cases. The treatment of these serious injuries remains heterogeneous. A major issue is the lack of consensus concerning type and duration of PAP. Furthermore, there seems to be no agreement on the indication for the use of local anti-infective agents. Overall, it is unknown what the repercussions are of this lack of internationally accepted guidelines on daily clinical practice, but it is clear that standardised treatment protocols are preferable in the current medical landscape.

Negative pressure dressings are no better than standard dressings for open fractures.

The studyEffect of negative pressure wound therapy vs standard wound management on 12-month disability among adults with severe open fracture of the lower limb: the WOLLF randomised clinical trial.Costa ML, Achten J, Bruce J, et al; UK WOLLF CollaborationPublished on 9 October 2018 JAMA 2018;319:2280-8.This project was funded by the National Institute for Health Research Health Technology Assessment Programme (project number 10/57/20).To read the full NIHR Signal, go to: https://discover.dc.nihr.ac.uk/content/signal-000655/negative-pressure-dressings-are-no-better-than-standard-dressings-for-open-fractures.

Is Bone Loss or Devascularization Associated With Recurrence of Osteomyelitis in Wartime Open Tibia Fractures?

BACKGROUND: During recent wars, 26% of combat casualties experienced open fractures and these injuries frequently are complicated by infections, including osteomyelitis. Risk factors for the development of osteomyelitis with combat-related open tibia fractures have been examined, but less information is known about recurrence of this infection, which may result in additional hospitalizations and surgical procedures. QUESTIONS/PURPOSES: (1) What is the risk of osteomyelitis recurrence after wartime open tibia fractures and how does the microbiology compare with initial infections? (2) What factors are associated with osteomyelitis recurrence among patients with open tibia fractures? (3) What clinical characteristics and management approaches are associated with definite/probable osteomyelitis as opposed to possible osteomyelitis and what was the microbiology of these infections? METHODS: A survey of US military personnel injured during deployment between March 2003 and December 2009 identified 215 patients with open tibia fractures, of whom 130 patients developed osteomyelitis and were examined in a retrospective analysis. No patients with bilateral osteomyelitis were included. Twenty-five patients meeting osteomyelitis diagnostic criteria were classified as definite/probable (positive bone culture, direct evidence of infection, or symptoms with culture and/or radiographic evidence) and 105 were classified as possible (bone contamination, organism growth in deep wound tissue, and evidence of local/systemic inflammation). Patients diagnosed with osteomyelitis were treated with débridement and irrigation as well as intravenous antibiotics. Fixation hardware was retained until fracture union, when possible. Osteomyelitis recurrence was defined as a subsequent osteomyelitis diagnosis at the original site ≥ 30 days after completion of initial treatment. This followup period was chosen based on the definition of recurrence so as to include as many patients as possible for analysis. Factors associated with osteomyelitis recurrence were assessed using univariate analysis in a subset of the population with ≥ 30 days of followup. Patients who had an amputation at or proximal to the knee after the initial osteomyelitis were not included in the recurrence assessment. RESULTS: Of 112 patients meeting the criteria for assessment of recurrence, 31 (28%) developed an osteomyelitis recurrence, of whom seven of 25 (28%) had definite/probable and 24 of 87 (28%) had possible classifications for their initial osteomyelitis diagnosis. Risk of osteomyelitis recurrence was associated with missing or devascularized bone (recurrence, 14 of 31 [47%]; nonrecurrence, 22 of 81 [28%]; hazard ratio [HR], 3.94; 1.12-13.81; p = 0.032) and receipt of antibiotics for 22-56 days (recurrence, 20 of 31 [65%]; nonrecurrence: 37 of 81 [46%]; HR, 2.81; 1.05-7.49; p = 0.039). Compared with possible osteomyelitis, definite/probable osteomyelitis was associated with localized swelling at the bone site (13 of 25 [52%] versus 28 of 105 [27%]; risk ratio [RR], 1.95 [1.19-3.19]; p = 0.008) and less extensive skin and soft tissue injury at the time of trauma (9 of 22 [41%; three definite/probably patients missing data] versus 13 of 104 [13%; one possible patient missing data]; RR, 3.27 [1.60-6.69]; p = 0.001). Most osteomyelitis infections were polymicrobial (14 of 23 [61%; two patients with missing data] for definite/probable patients and 62 of 105 [59%] for possible patients; RR, 1.03 [0.72-1.48]; p = 0.870). More of the definite/probable patients received vancomycin (64%) compared with the possible patients (41%; p = 0.046), and the duration of polymyxin use was longer (median, 38 days versus 16 days, p = 0.018). Time to definitive fracture fixation was not different between the groups. CONCLUSIONS: Recurrent osteomyelitis after open tibia fractures is common. In a univariate model, patients with an intermediate amount of bone loss and those treated with antibiotics for 22 to 56 days were more likely to experience osteomyelitis recurrence. Because only univariate analysis was possible, these findings should be considered preliminary. Osteomyelitis recurrence rates were similar, regardless of initial osteomyelitis classification, indicating that diagnoses of possible osteomyelitis should be treated aggressively. LEVEL OF EVIDENCE: Level III, therapeutic study.

Antibiotic Prophylaxis in the Management of Open Fractures: A Systematic Survey of Current Practice and Recommendations.

BACKGROUND: Evidence with regard to antibiotic prophylaxis for patients with open fractures of the extremities is limited. We therefore conducted a systematic survey addressing current practice and recommendations. METHODS: We included publications from January 2007 to June 2017. We searched Embase, MEDLINE, CINAHL, the Cochrane Central Registry of Controlled Trials (CENTRAL), and the Cochrane Database of Systematic Reviews for clinical studies and surveys of surgeons; WorldCat for textbooks; and web sites for guidelines and institutional protocols. RESULTS: We identified 223 eligible publications that reported 100 clinical practice patterns and 276 recommendations with regard to systemic antibiotic administration, and 3 recommendations regarding local antibiotic administration alone. Most publications of clinical practice patterns used regimens with both gram-positive and gram-negative coverage and continued the administration for 2 to 3 days. Most publications recommended prophylactic systemic antibiotics. Most recommendations suggested gram-positive coverage for less severe injuries and administration duration of 3 days or less. For more severe injuries, most recommendations suggested broad antimicrobial coverage continued for 2 to 3 days. Most publications reported intravenous administration of antibiotics immediately. CONCLUSIONS: Current practice and recommendations strongly support early systemic antibiotic prophylaxis for patients with open fractures of the extremities. Differences in antibiotic regimens, doses, and durations of administration remain in both practice and recommendations. Consensus with regard to optimal practice will likely require well-designed randomized controlled trials. CLINICAL RELEVANCE: The current survey of literature systematically provides surgeons' practice and the available expert recommendations from 2007 to 2017 on the use of prophylactic antibiotics in the management of open fractures of extremities.

Prehospital Antibiotic Prophylaxis for Open Fractures: Practicality and Safety.

OBJECTIVE: Early antibiotic administration has been associated with a significant decrease in infection following open fractures. However, antibiotics are most effective at a time when many patients are still being transported for care. There is limited evidence that antibiotics may be safely administered for open fractures when being transported by life-flight personnel. No such data exists for ground ambulance transport of patients with open fractures. The purpose of the study was to assess the safety and feasibility of prophylactic antibiotic delivery in the prehospital setting. METHODS: We performed a prospective observational study between January 1, 2014 and May 31, 2015 of all trauma patients transferred to a level 1 trauma center by a single affiliated ground ambulance transport service. If open fracture was suspected, the patient was indicated for antibiotic prophylaxis with 2 g IV Cefazolin. Exclusion criteria included penicillin allergy, higher priority patient care tasks, and remaining transport time insufficient for administration of antibiotics. The administration of antibiotics was recorded. Patient demographics, associated injuries, priority level (1 = life threatening injury, 2 = potentially life threatening injury, 3 = non-life threatening injury), and timing of transport and antibiotic administration were recorded as well. RESULTS: EMTs identified 70 patients during the study period with suspected open fractures. Eight reported penicillin allergy and were not eligible for prophylaxis. The patient's clinical status and transport time allowed for administration of antibiotic prophylaxis for 32 patients (51.6%). Total prehospital time was the only variable assessed that had a significant impact on administration of prehospital antibiotics (<30 minutes = 29% vs. >30 minutes = 66%; p < 0.001). There were no allergic reactions among patients and no needle sticks or other injuries to EMT personnel related to antibiotic administration. CONCLUSIONS: EMT personnel were able to administer prehospital antibiotic prophylaxis for a substantial portion of the identified patients without any complications for patients or providers. Given the limited training provided to EMTs prior to implementation of the antibiotic prophylaxis protocol, it is likely that further development of this initial training will lead to even higher rates of prehospital antibiotic administration for open fractures.

Children with open tibial fractures show significantly lower infection rates than adults: clinical comparative study.

PURPOSE: The purpose of this study is to investigate and compare the surgical site infection (SSI) rates of children and adults after open tibia fracture at a single medical centre. METHODS: A retrospective study was performed on patients who sustained open tibia fractures and who received treatment at our hospital from 2012 to 2016. Data on age, gender, fracture site, Gustilo-Anderson grade, treatment management, and culture results from the infection site were recorded. RESULTS: Overall, 37 children with a mean age of 7.19 ± 2.28 years and 89 adults with a mean age of 40.38 ± 13.53 years were enrolled. The rate of SSIs was 13.5% (6/37) in children, which was significantly lower than the 21.3% (19/89) rate in adults (p < 0.001). The mean number of days to discharge was 12.86 ± 10.25 in children, which was significantly lower than the mean of 28.67 ± 16.92 days in adults (p < 0.001). Furthermore, the average waiting time for soft tissue recovery before definitive surgery was 1.41 ± 1.79 and 8.42 ± 4.38 days in children and in adults, respectively, and the difference was significant (p < 0.001). Early infection occurred more frequently in adults (5/19) than in children (0/6). Staphylococcus aureus was the most commonly found pathogen in both groups. CONCLUSION: The SSI rate of paediatric patients after open tibia fracture fixation is significantly lower than that of adults, and the prognosis of the former is superior. The results indicate a superior ability of soft tissue recovery and infection resistance after open tibia fracture fixation among children.

Controlled Release of Vancomycin and Tigecycline from an Orthopaedic Implant Coating Prevents Staphylococcus aureus Infection in an Open Fracture Animal Model.

INTRODUCTION: Treatment of open fractures routinely involves multiple surgeries and delayed definitive fracture fixation because of concern for infection. If implants were made less susceptible to infection, a one-stage procedure with intramedullary nailing would be more feasible, which would reduce morbidity and improve outcomes. METHODS: In this study, a novel open fracture mouse model was developed using Staphylococcus aureus (S. aureus) and single-stage intramedullary fixation. The model was used to evaluate whether implants coated with a novel "smart" polymer coating containing vancomycin or tigecycline would be colonized by bacteria in an open fracture model infected with S. aureus. In vivo bioluminescence, ex vivo CFUs, and X-ray images were evaluated over a 42-day postoperative period. RESULTS: We found evidence of a markedly decreased bacterial burden with the local release of vancomycin and tigecycline from the PEG-PPS polymer compared to polymer alone. Vancomycin was released in a controlled fashion and maintained local drug concentrations above the minimum inhibition concentration for S. aureus for greater than 7 days postoperatively. Bacteria were reduced 139-fold from implants containing vancomycin and undetected from the bone and soft tissue. Tigecycline coatings led to a 5991-fold reduction in bacteria isolated from bone and soft tissue and 15-fold reduction on the implants compared to polymer alone. Antibiotic coatings also prevented osteomyelitis and implant loosening as observed on X-ray. CONCLUSION: Vancomycin and tigecycline can be encapsulated in a polymer coating and released over time to maintain therapeutic levels during the perioperative period. Our results suggest that antibiotic coatings can be used to prevent implant infection and osteomyelitis in the setting of open fracture. This novel open fracture mouse model can be used as a powerful in vivo preclinical tool to evaluate and optimize the treatment of open fractures before further studies in humans.

Intrawound Vancomycin Powder Reduces Bacterial Load in Contaminated Open Fracture Model.

OBJECTIVES: To compare the effectiveness of both vancomycin powder and antibiotic bead placement to irrigation and debridement alone in prevention of infection in a contaminated open fracture model in rats. METHODS: In a previously described model of contaminated open fractures, 45 rats had simulated open fractures created, stabilized, and contaminated with Staphylococcus aureus. They were then treated 6 hours later with 3 interventions: irrigation and debridement alone (control group) or in combination with placement of polymethyl methacrylate beads containing vancomycin and tobramycin powders (antibiotic bead group) or placement of 10 mg of intrawound vancomycin powder (powder group). Rats were allowed to recover and then killed 14 days later for harvest of femurs and plates. Femurs and plates were both incubated overnight, and bacterial colonies were counted in each group for comparison. RESULTS: Quantitative counts of bacteria in bone showed significantly reduced growth in both bead and powder groups when compared with control group (P < 0.0001). Quantitative counts of bacteria in plates showed significantly reduced growth in both bead and powder groups when compared with control group (P < 0.0003; 0.029). No significant differences were seen in bacterial growth between bead and powder groups for either bones (P = 0.13) or plates (P = 0.065). CONCLUSIONS: When compared with irrigation and debridement alone, placement of intrawound vancomycin powder significantly decreased bacterial load in a contaminated open fracture model in rats similar to placing antibiotic beads. This may provide an additional adjuvant treatment that does not require a secondary surgery for bead removal.

The microbiota of traumatic, open fracture wounds is associated with mechanism of injury.

Open fractures are characterized by disruption of the skin and soft tissue, which allows for microbial contamination and colonization. Preventing infection-related complications of open fractures and other acute wounds remains an evolving challenge due to an incomplete understanding of how microbial colonization and contamination influence healing and outcomes. Culture-independent molecular methods are now widely used to study human-associated microbial communities without introducing culture biases. Using such approaches, the objectives of this study were to (1) define the long-term temporal microbial community dynamics of open fracture wounds and (2) examine microbial community dynamics with respect to clinical and demographic factors. Fifty-two subjects with traumatic open fracture wounds (32 blunt and 20 penetrating injuries) were enrolled prospectively and sampled longitudinally from presentation to the emergency department (ED) and at each subsequent inpatient or outpatient encounter. Specimens were collected from both the wound center and adjacent skin. Culture-independent sequencing of the 16S ribosomal RNA gene was employed to identify and characterize microbiota. Upon presentation to the ED and time points immediately following, sample collection site (wound or adjacent skin) was the most defining feature discriminating microbial profiles. Microbial composition of adjacent skin and wound center converged over time. Mechanism of injury most strongly defined the microbiota after initial convergence. Further analysis controlling for race, gender, and age revealed that mechanism of injury remained a significant discriminating feature throughout the continuum of care. We conclude that the microbial communities associated with open fracture wounds are dynamic in nature until eventual convergence with the adjacent skin community during healing, with mechanism of injury as an important feature affecting both diversity and composition of the microbiota. A more complete understanding of the factors influencing microbial contamination and/or colonization in open fractures is a critical foundation for identifying markers indicative of outcome and deciphering their respective contributions to healing and/or complication.