Risk factors for infectious complications after open fractures; a systematic review and meta-analysis

High-Grade Limbs Open Fractures: Time to Find Milestones in the Emergency Setting

(1) Background: The Gustilo-Anderson (G/A) grading system is a universally accepted tool used to classify high-grade limb open fractures. The purpose of this study is to find early independent predictors of amputation in emergency settings. (2) Methods: A retrospective analysis involving patients treated at our center between 2010 and 2016 was conducted. Patients with at least one G/A grade III fracture or post-traumatic amputation were included. Three groups were identified: G/A IIIA (A group), G/A IIIB-C (BC group), and Amputation group (AMP group). Each group was further divided into two subgroups considering timing of coverage (early vs. delayed). Univariate and multivariate logistic regression models were developed to identify independent predictors of the limb's outcome. (3) Results: One-hundred-six patients with G/A III A-B-C fractures or amputation of the affected limb were selected from the Niguarda Hospital Trauma Registry. The patients were divided into the A group (26), BC group (66), and AMP group (14). The rate of infectious complications following early or delayed coverage was evaluated: A group, 9.1% vs. 66.7% (p > 0.05); BC group, 32% vs. 63.6% (p = 0.03); and AMP group, 22% vs. 18.5% (p > 0.05). After further recategorization, the BC subgroups were analyzed: multivariate logistic regression model identified systolic blood pressure (SBP) <90 mmHg (p = 0.03) and Mangled Extremity Severity Score MESS ≥ 7 (p = 0.001) were determined to be independent predictors of limb amputation. (4) Conclusion: MESS and SBP serve as predictors of amputation. Based on the results, we propose a new management algorithm for mangled extremities. Early coverage is related to lower rates of infectious complications. Referral to high-volume centers with specific expertise is mandatory to guarantee the best results.

Radiotherapy-induced bone deterioration is exacerbated in diabetic rats treated with streptozotocin

Following radiotherapy, patients have decreased bone mass and increased risk of fragility fractures. Diabetes mellitus (DM) is also reported to have detrimental effects on bone architecture and quality. However, no clinical or experimental study has systematically characterized the bone phenotype of the diabetic patients following radiotherapy. After one month of streptozotocin injection, three-month-old male rats were subjected to focal radiotherapy (8 Gy, twice, at days 1 and 3), and then bone mass, microarchitecture, and turnover as well as bone cell activities were evaluated at 2 months post-irradiation. Micro-computed tomography results demonstrated that DM rats exhibited greater deterioration in trabecular bone mass and microarchitecture following irradiation compared with the damage to bone structure induced by DM or radiotherapy. The serum biochemical, bone histomorphometric, and gene expression assays revealed that DM combined with radiotherapy showed lower bone formation rate, osteoblast number on bone surface, and expression of osteoblast-related markers (ALP, Runx2, Osx, and Col-1) compared with DM or irradiation alone. DM plus irradiation also caused higher bone resorption rate, osteoclast number on bone surface, and expression of osteoclast-specific markers (TRAP, cathepsin K, and calcitonin receptor) than DM or irradiation treatment alone. Moreover, lower osteocyte survival and higher expression of Sost and DKK1 genes (two negative modulators of Wnt signaling) were observed in rats with combined DM and radiotherapy. Together, these findings revealed a higher deterioration of the diabetic skeleton following radiotherapy, and emphasized the clinical importance of health maintenance.

Facilitating the Approval Process of Anti-Infective Technologies and Advancing Them to the Market: Insights from an FDA Workshop on Orthopaedic Device-Related Infections

Orthopaedic device-related infection is one of the most devastating complications in orthopaedic and trauma surgery. With increasing life expectancies as well as the lifelong risk of bacterial seeding on an implant, the prevention and treatment of device-related infection remains an important area for research and development. To facilitate information exchange and enhance collaboration among various stakeholders in the orthopaedic community, the U.S. Food and Drug Administration (FDA) Center for Devices and Radiological Health (CDRH) organized an inaugural workshop on orthopaedic device-related infections, exploring the regulatory challenges that are faced when proceeding from the bench level to marketing and clinical implementation of new infection-control devices and products. This article summarizes the perspectives of scientists, clinicians, and industry partners on the current regulatory approval process for orthopaedic anti-infective technologies as well as the proposed strategies to overcome these regulatory challenges.

Outcomes following the delayed management of open tibial fractures

AIMS

National guidelines set standards for the definitive management of open fractures within 72 h. This study aims to investigate our outcomes where this timeline was unachievable for most cases due to a split-site orthoplastic service.

PATIENTS & METHODS

116 consecutive Gustilo-Anderson grade IIIB & IIIC open tibial fractures presenting to our major trauma centre (MTC) between September 2012 and April 2018 were reviewed. The mean follow up was 46 months (17 to 88). 110 (95%) were grade IIIB and 6 (5%) grade IIIC. The most common injury mechanism included road traffic accidents (59%) and falls (28%). Primary outcomes were recorded according to; timing of initial debridement and definitive cover, rates of superficial and deep infection, non-union and amputation. Subgroups were statistically analysed according to time to initial debridement, definitive soft-tissue cover and injury severity score (ISS).

RESULTS

The mean time to initial debridement was 11.3 h (2.9 to 38.9) and definitive soft-tissue cover 9.9 days (0 to 37). We recorded rates of: superficial infection; 42 cases (36%), deep infection; 14 cases (12%) and non-union requiring revision; 19 cases (16%). There were 20 amputations (17%) with 9 (8.6%) performed early and 11 (9.5%) delayed. Subgroup analysis showed higher rates of superficial infection (50%, p = 0.002) and amputation (26.6%, p = 0.01) for those debrided <12 h. A greater presenting ISS related to a delay to definitive cover >7 days (p = 0.05). Primary outcomes trended worse for those covered >7 days but did not reach significance.

CONCLUSION

Major trauma patients are particularly vulnerable to poor outcomes resulting from the delay in definitive management of open fractures. MTC's need resources and a co-located orthoplastic service to achieve national standards and better outcomes. Current guidelines do not advise for the management of patients where a delay in definitive surgery is anticipated.

The epidemiology of fracture-related infections in Germany

The epidemiology of fracture-related infection (FRI) is unknown, which makes it difficult to estimate future demands and evaluate progress in infection prevention. Therefore, we aimed to determine the nationwide burden’s development over the last decade as a function of age group and gender. FRI prevalence as a function of age group and gender was quantified based on annual ICD-10 diagnosis codes from German medical institutions between 2008 through 2018, provided by the Federal Statistical Office of Germany (Destatis). The prevalence of FRI increased by 0.28 from 8.4 cases per 100,000 inhabitants to 10.7 cases per 100,000 inhabitants between 2008 and 2018. The proportion of fractures resulting in FRI increased from 1.05 to 1.23%. Gender distribution was equal. Patients aged 60–69 years and 70–79 years comprised the largest internal proportion with 20.2% and 20.7%, respectively, whereby prevalence increased with age group. A trend towards more diagnoses in older patients was observed with a growth rate of 0.63 for patients older than 90 years. Increasing rates of fracture-related infection especially in older patients indicate an upcoming challenge for stakeholders in health care systems. Newly emerging treatment strategies, prevention methods and interdisciplinary approaches are strongly required.

A Machine Learning Algorithm to Identify Patients with Tibial Shaft Fractures at Risk for Infection After Operative Treatment

BACKGROUND

Risk stratification of individual patients who are prone to infection would allow surgeons to monitor high-risk patients more closely and intervene early when needed. This could reduce infection-related consequences such as increased health-care costs. The purpose of this study was to develop a machine learning (ML)-derived risk-stratification tool using the SPRINT (Study to Prospectively Evaluate Reamed Intramedullary Nails in Patients with Tibial Fractures) and FLOW (Fluid Lavage of Open Wounds) trial databases to estimate the probability of infection in patients with operatively treated tibial shaft fractures (TSFs).

METHODS

Patients with unilateral TSFs from the SPRINT and FLOW trials were randomly split into derivation (80%) and validation (20%) cohorts. Random forest algorithms were used to select features that are relevant to predicting infection. These features were included for algorithm training. Five ML algorithms were trained in recognizing patterns associated with infection. The performance of each ML algorithm was evaluated and compared based on (1) the area under the ROC (receiver operating characteristic) curve (AUC), (2) the calibration slope and the intercept, and (3) the Brier score.

RESULTS

There were 1,822 patients included in this study: 170 patients (9%) developed an infection that required treatment, 62 patients (3%) received nonoperative treatment with oral or intravenous antibiotics, and 108 patients (6%) underwent subsequent surgery in addition to antibiotic therapy. Random forest algorithms identified 7 variables that were relevant for predicting infection: (1) Gustilo-Anderson or Tscherne classification, (2) bone loss, (3) mechanism of injury, (4) multitrauma, (5) AO/OTA fracture classification, (6) age, and (7) fracture location. Training of the penalized logistic regression algorithm resulted in the best-performing prediction model, with AUC, calibration slope, calibration intercept, and Brier scores of 0.75, 0.94, 0.00, and 0.076, respectively, in the derivation cohort and 0.81, 1.07, 0.09, and 0.079, respectively, in the validation cohort.

CONCLUSIONS

We developed an ML prediction model that can estimate the probability of infection for individual patients with TSFs based on patient and fracture characteristics that are readily available at hospital admission.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

A Reevaluation of the Risk of Infection Based on Time to Debridement in Open Fractures: Results of the GOLIATH Meta-Analysis of Observational Studies and Limited Trial Data

BACKGROUND

Open fractures are one of the leading causes of disability worldwide. The threshold time to debridement that reduces the infection rate is unclear.

METHODS

We searched all available databases to identify observational studies and randomized trials related to open fracture care. We then conducted an extensive meta-analysis of the observational studies, using raw and adjusted estimates, to determine if there was an association between the timing of initial debridement and infection.

RESULTS

We identified 84 studies (18,239 patients) for the primary analysis. In unadjusted analyses comparing various "late" time thresholds for debridement versus "early" thresholds, there was an association between timing of debridement and surgical site infection (odds ratio [OR] = 1.29, 95% confidence interval [CI] = 1.11 to 1.49, p < 0.001, I2 = 30%, 84 studies, n = 18,239). For debridement performed between 12 and 24 hours versus earlier than 12 hours, the OR was higher in tibial fractures (OR = 1.37, 95% CI = 1.00 to 1.87, p = 0.05, I2 = 19%, 12 studies, n = 2,065), and even more so in Gustilo type-IIIB tibial fractures (OR = 1.46, 95% CI = 1.13 to 1.89, p = 0.004, I2 = 23%, 12 studies, n = 1,255). An analysis of Gustilo type-III fractures showed a progressive increase in the risk of infection with time. Critical time thresholds included 12 hours (OR = 1.51, 95% CI = 1.28 to 1.78, p < 0.001, I2 = 0%, 16 studies, n = 3,502) and 24 hours (OR = 2.17, 95% CI = 1.73 to 2.72, p < 0.001, I2 = 0%, 29 studies, n = 5,214).

CONCLUSIONS

High-grade open fractures demonstrated an increased risk of infection with progressive delay to debridement.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instruction for Authors for a complete description of the levels of evidence.

Locally delivered adjuvant biofilm-penetrating antibiotics rescue impaired endochondral fracture healing caused by MRSA infection

Infection is a devastating complication following an open fracture. We investigated whether local rifampin-loaded hydrogel can combat infection and improve healing in a murine model of methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis. A transverse fracture was made at the tibia midshaft of C57BL/6J mice aged 10-12 weeks and stabilized with an intramedullary pin. A total of 1 × 106 colony-forming units (CFU) of MRSA was inoculated. A collagen-based hydrogel containing low-dose (60 μg) and high-dose (300 μg) rifampin was applied before closure. Postoperative treatment response was assessed through bacterial CFU counts from tissue and hardware, tibial radiographs and microcomputed tomography (μCT), immunohistochemistry, and histological analyses. All untreated MRSA-infected fractures progressed to nonunion by 28 days with profuse MRSA colonization. Infected fractures demonstrated decreased soft callus formation on safranin O stain compared to controls. Areas of dense interleukin-1β stain were associated with poor callus formation. High-dose rifampin hydrogels reduced the average MRSA load in tissue (p < 0.0001) and implants (p = 0.041). Low-dose rifampin hydrogels reduced tissue bacterial load by 50% (p = 0.021). Among sterile models, 88% achieved union compared to 0% of those infected. Mean radiographic union scale in tibia scores improved from 6 to 8.7 with high-dose rifampin hydrogel (p = 0.024) and to 10 with combination local/systemic rifampin therapy (p < 0.0001). μCT demonstrated reactive bone formation in MRSA infection. Histology demonstrated restored fracture healing with bacterial elimination. Rifampin-loaded hydrogels suppressed osteomyelitis, prevented implant colonization, and improved healing. Systemic rifampin was more effective at eliminating infection and improving fracture healing. Further investigation into rifampin-loaded hydrogels is required to correlate these findings with clinical efficacy.

Impact of duration of perioperative antibiotic prophylaxis on development of fracture-related infection in open fractures

INTRODUCTION

Infection is a common complication of open fractures potentially leading to nonunion, functional loss, and even amputation. Perioperative antibiotic prophylaxis (PAP) is standard practice for infection prevention in the management of open fractures. However, optimal duration of PAP remains controversial. The objectives were to assess whether PAP duration is independently associated with infection in open fractures and if administration of PAP beyond the commonly-recommended limit of 72 h has any effect on the infection rate.

MATERIALS AND METHODS

Over a 14-year period from 2003 to 2017, 530 skeletally-mature patients with operatively-treated, non-pathologic, long-bone open fractures were treated at one institution. Twenty-eight patients were excluded because of death or loss to follow-up and the remaining 502 patients (with 559 open fractures) who completed a 24-month follow-up were included in this retrospective study. The outcome was fracture-related infection (FRI), defined by the criteria of a recent consensus definition. A logistic generalized estimating equations regression model was conducted, including PAP duration and variables selected by a least absolute shrinkage and selection operator (LASSO) method, to assess the association between PAP duration and FRI. Propensity score analysis using a 72-h cut-off was performed to further cope with confounding.

RESULTS

PAP duration, adjusted for the LASSO selected predictors, was independently associated with FRI (OR: 1.11 [95%CI, 1.04-1.19] for every one-day increase in PAP duration, p = 0.003). PAP duration longer than 72 h did not significantly increase the odds for FRI compared to shorter durations (p = 0.06, analysis adjusted for propensity score).

CONCLUSIONS

This study found no evidence that administration of prophylactic antibiotics beyond 72 h in patients with long-bone open fractures is warranted. Analyses adjusted for known confounders even revealed a higher risk for FRI for longer PAP. However, this effect cannot necessarily be considered as causal and further research is needed.

The induced membrane technique for the management of long bone defects

AIMS

The purpose of this study was to: review the efficacy of the induced membrane technique (IMT), also known as the Masquelet technique; and investigate the relationship between patient factors and technique variations on the outcomes of the IMT.

METHODS

A systematic search was performed in CINAHL, The Cochrane Library, Embase, Ovid MEDLINE, and PubMed. We included articles from 1 January 1980 to 30 September 2019. Studies with a minimum sample size of five cases, where the IMT was performed primarily in adult patients (≥ 18 years old), in a long bone were included. Multivariate regression models were performed on patient-level data to determine variables associated with nonunion, postoperative infection, and the need for additional procedures.

RESULTS

A total of 48 studies were included, with 1,386 cases treated with the IMT. Patients had a mean age of 40.7 years (4 to 88), and the mean defect size was 5.9 cm (0.5 to 26). In total, 82.3% of cases achieved union after the index second stage procedure. The mean time to union was 6.6 months (1.4 to 58.7) after the second stage. Our multivariate analysis of 450 individual patients showed that the odds of developing a nonunion were significantly increased in those with preoperative infection. Patients with tibial defects, and those with larger defects, were at significantly higher odds of developing a postoperative infection. Our analysis also demonstrated a trend towards the inclusion of antibiotics in the cement spacer having a protective effect against the need for additional procedures.

CONCLUSION

The IMT is an effective management strategy for complex segmental bone defects. Standardized reporting of individual patient data or larger prospective trials is required to determine the optimal implementation of this technique. This is the most comprehensive review of the IMT, and the first to compile individual patient data and use regression models to determine predictors of outcomes. Cite this article: Bone Joint J 2020;102-B(12):1723-1734.

Risk Factors Associated With Infection in Open Fractures of the Upper and Lower Extremities

Introduction:

Open fractures are associated with a high risk of infection. The prevention of infection is the single most important goal, influencing perioperative care of patients with open fractures. Using data from 2,500 participants with open fracture wounds enrolled in the Fluid Lavage of Open Wounds trial, we conducted a multivariable analysis to determine the factors that are associated with infections 12 months postfracture.

Methods:

Eighteen predictor variables were identified for infection a priori from baseline data, fracture characteristics, and surgical data from the Fluid Lavage of Open Wounds trial. Twelve predictor variables were identified for deep infection, which included both surgically and nonoperatively managed infections. We used multivariable Cox proportional hazards regression analyses to identify the factors associated with infection. Irrigation solution and pressure were included as variables in the analysis. The results were reported as adjusted hazard ratios (HRs), 95% confidence intervals (CIs), and associated P values. All tests were two tailed with alpha = 0.05.

Results:

Factors associated with any infection were fracture location (tibia: HR 5.13 versus upper extremity, 95% CI 3.28 to 8.02; other lower extremity: HR 3.63 versus upper extremity, 95% CI 2.38 to 5.55; overall P < 0.001), low energy injury (HR 1.64, 95% CI 1.08 to 2.46; P = 0.019), degree of wound contamination (severe: HR 2.12 versus mild, 95% CI 1.35 to 3.32; moderate: HR 1.08 versus mild, 95% CI 0.78 to 1.49; overall P = 0.004), and need for flap coverage (HR 1.82, 95% CI 1.11 to 2.99; P = 0.017).

Discussion:

The results of this study provide a better understanding of which factors are associated with a greater risk of infection in open fractures. In addition, it can allow for surgeons to better counsel patients regarding prognosis, helping patients to understand their individual risk of infection.

How Successful Is Antibiotic Treatment for Superficial Surgical Site Infections After Open Fracture? A Fluid Lavage of Open Wounds (FLOW) Cohort Secondary Analysis

BACKGROUND

Although many studies report the incidence and prevalence of surgical site infections (SSIs) after open fractures, there is limited information on the treatment and subsequent outcomes of superficial SSIs in patients with open fractures. Additionally, clinical studies describing the factors that are associated with persistent infection after nonoperative treatment with antibiotics for patients with superficial SSIs are lacking.

QUESTIONS/PURPOSES

Therefore, we asked: (1) What proportion of patients with superficial SSIs after open fracture treatment developed persistent infection after nonoperative treatment (that is, treatment with antibiotics alone)? (2) What risk factors are associated with SSIs that do not resolve with nonoperative (antibiotic) treatment? As a secondary objective, we planned to analyze the microbiological information about participants wound cultures, when these were available, and the proportion of positive cultures for patients whose SSIs were not resolved by antibiotics alone.

METHODS

This is a secondary analysis of the Fluid Lavage of Open Wounds (FLOW) trial dataset. The FLOW trial included 2445 patients with operatively managed open fractures. FLOW participants who had a nonoperatively managed superficial SSI diagnosed in the 12 months post-fracture were included in this analysis. Superficial SSIs were diagnosed in 168 participants within 12 months of their fracture. Of these, 83% (139) had their superficial SSI treated with antibiotics alone. Participants were grouped into two categories: (1) 97 participants whose treatment with antibiotics alone resolved the superficial SSI and (2) 42 participants whose treatment with antibiotics alone did not resolve the SSI (defined as undergoing surgical management or the SSI being unresolved at latest follow-up [12-months post-fracture for the FLOW trial]). Of the participants whose treatment with antibiotics alone resolved the SSI, 92% (89 of 97) had complete follow-up, 6% (6 of 97) were lost to follow-up before 12 months, 1% (1 of 97) withdrew consent from the study before 12 months, and 1% (1 of 97) experienced mortality before 12 months. Of the participants whose treatment with antibiotics alone did not resolve the SSI, 90% (38 of 42) had complete follow-up, 7% (3 of 42) were lost to follow-up before 12 months, and 2% (1 of 42) withdrew consent from the study before 12 months. A logistic binary regression analysis was conducted to identify factors associated with persistent infection despite superficial SSI antibiotic treatment. Based on biologic rationale and previous evidence, we identified a priori 13 potential factors (corresponding to 14 levels) to be included in the regression model.

RESULTS

The antibiotic treatment resolved the superficial SSI in 70% (97 of 139) of patients and did not resolve the SSI in 30% (42 of 139). After controlling for potential confounding variables, such as age, fracture severity, and time from injury to initial surgical irrigation and débridement, superficial SSIs diagnosed later in follow-up were associated with antibiotics not resolving the SSI (odds ratio 1.05 [95% CI 1.004 to 1.009] for every week of follow-up; p = 0.03). Sex, fracture pattern, and wound size were not associated with antibiotics not resolving the SSI.

CONCLUSIONS

Our secondary analysis of prospectively collected FLOW data suggests that antibiotics alone can be an appropriate treatment option when treating superficial SSIs after an open fracture wound, especially when promptly diagnosed. Further research with longer follow-up time is needed to better identify the natural history of superficial SSIs and possibly some dormant or subclinical infections to help clinicians in the treatment decision-making process.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Reduction of pin tract infections during external fixation using cadexomer iodine

PURPOSE

Knee joint distraction (KJD) is a joint-preserving treatment for younger osteoarthritis patients. KJD has shown positive results in regular care, but the external fixation frame often caused pin tract skin infections. Therefore, the use of cadexomer iodine was included in the wound care protocol. The goal of this cross-sectional study was to evaluate whether use of this ointment reduced the number of patients with infections during KJD treatment.

METHODS

Patients treated with KJD in regular care were included if they gave consent for use of their data and completed treatment with the newest distraction device before 2020. All patients followed a wound care protocol, which since March 2019 included using cadexomer iodine ointment. The number of patients experiencing pin tract infections was compared between patients who did (March 2019-December 2019) and did not (November 2017-March 2019) use the ointment.

RESULTS

Sixty-seven patients were included; 34 patients used cadexomer iodine and 33 patients did not. Patient who did not use cadexomer iodine experienced twice as many infections (64% vs 32%;p = 0.010). There was a significant difference in the number of patients with serious infections, requiring more antibiotics than the standard 7-day oral antibiotics (30% without vs 6% with cadexomer iodine; p = 0.009).

CONCLUSIONS

The use of cadexomer iodine ointment during KJD results in a significant reduction of the number of patients experiencing pin tract infections during treatment. Use of this ointment should be considered standard protocol during KJD treatment and could be of value in general external fixator usage as well.

Microbiological diagnosis of intramedullary nailing infection: comparison of bacterial growth between tissue sampling and sonication fluid cultures

BACKGROUND

Intramedullary nailing (IMN) has been frequently indicated to treat long bone open and closed fractures, but IMN infection (IMNI) may have devastating consequences. Sonication has been regarded as an important add-on for microbial identification on a variety of orthopaedic implant-associated infections, but its role in the IMNI is poorly studied. We aim at evaluating the accuracy obtained by conventional peri-implant tissue culture (TC) samples with sonication fluid cultures (SCs) of IMNI.

METHODS

Longitudinal prospective cohort study ongoing since June 2014, which included patients with indication for IMN removal due to any reason. Clinical diagnosis of INMI was defined according to publication addressing fracture-related infections. Minimal of two samples from TC were cultured. SCs followed the protocol previously published. Statistical analysis was performed using McNemar's test for related proportions.

RESULTS

We included 54 patients submitted to IMN retrieval, of whom 47 presenting clinical signs of IMNI. Sensitivity for detecting microorganisms using TC and SC was 89.4% (42/47) and 97.6% (40/41), and specificity was 71.4% (5/7) for both TC and SC (p = 1.00). Positive and negative predictive values for TC and SC were 95.5% (42/44), 95.2% (40/42), 50% (5/10), and 83.3% (5/6), respectively. The most frequent organisms isolated in both TC and SC were Staphylococcus aureus, S. epidermidis, and Enterococcus sp. Polymicrobial infection was diagnosed in 14.8% (8/54) and 25% (12/48) by TC and SC, respectively (p = 0.19).

CONCLUSION

Sonication fluid and tissue samples presented similar accuracy on the diagnosis of IMNI, but SC was advantageous of detecting polymicrobial infection.

Nuclear imaging for diagnosing fracture-related infection

Purpose

Fracture-related infection (FRI) is a complication of surgical fracture treatment and can be challenging to diagnose. Recent studies show promising results for the use of either FDG-PET/CT or WBC/anti-granulocyte scintigraphy. The purpose of this pictorial essay is to outline recent developments in nuclear imaging techniques to diagnose FRI.

Methods

The current literature on this topic is reviewed. Additionally, three examples of patients who underwent nuclear imaging as part of their clinical work-up and surgical treatment for FRI are presented.

Results

Based on recent retrospective studies, FDG-PET/CT (accuracy 0.83) and WBC scintigraphy with SPECT/CT (accuracy 0.92) both have a good diagnostic accuracy for diagnosing fracture-related infection. Nuclear imaging contributes to a correct diagnosis in patients with FRI.

Conclusion

Retrospective studies show promising results for both FDG-PET/CT and WBC scintigraphy with SPECT/CT in diagnosing FRI. A prospective, multicenter study (IFI trial), directly comparing MRI, FDG-PET/CT, and WBC scintigraphy with SPECT/CT in patients with suspected FRI, is currently in progress.

Hardware considerations in infection and nonunion management: When and how to revise the fixation

The occurrence of both nonunion and fracture-related infection provides challenges for both the patient and the treating orthopaedic surgeon, with the potential need for complex reconstructive procedures to achieve union and/or eradicate infection. In addition to addressing the multiple different factors that often contribute to nonunion, surgeons are often forced to deal with difficult hardware issues at the time of revision surgery including infected hardware, loose or failing hardware, malaligned hardware, or inappropriate hardware constructs. This article reviews common causes of nonunions with emphasis on infection management and provides indications and techniques for hardware removal in the context of an algorithmic approach to nonunion management with illustrative case examples.

Single-stage "Fix and Flap" gives Good Outcomes in Grade 3B/C Open Tibial Fractures: A Prospective Study

Introduction:

Grade 3B/C open tibial fractures with grossly contaminated degloving injuries have poor outcomes, with or without vascular injuries. Treatment decision oscillates between limb salvage and amputation. The standard protocol of repeated debridement and delayed wound cover is a challenge in developing countries due to overcrowded emergencies and limited operating room availability. We present results of our modified protocol involving primary stabilisation with external fixation and immediate wound cover as an aggressive modality of treatment.

Material and Methods:

Thirty-three patients with severe open tibial shaft fractures were managed using a standardised protocol of emergent debridement, external fixation and immediate wound cover with free distant/local rotational muscle flaps and fasciocutaneous flaps, and with vascular repair in Grade 3C fractures. Intra-articular fractures were excluded. Patients were followed for a minimum of three years, with an assessment of clinical, radiological and functional outcomes.

Results:

Wound cover was achieved with 24 distant free muscle flaps, four local rotational muscle flaps and five fasciocutaneous flaps. All fractures united with an average time to union of 40.3 weeks (16-88). Fifteen patients (45.4%) underwent only a single major surgery using primary definitive external fixation. Deep infection was seen in four patients (12.1%). Nineteen patients had excellent to good outcomes, six were fair, and eight were poor.

Conclusion:

“Fix and Flap” in the same sitting, using immediate wound cover and external fixation, has given good results in our hands despite the delayed presentation, the neurovascular deficit and the degloving injury. This may be a better management strategy in overcrowded tertiary care centres of developing countries, with a single surgical procedure in almost half the cases.

Smoking and alcohol drinking and risk of non-union or delayed union after fractures: A protocol for systematic review and dose-response meta-analysis

INTRODUCTION

To the best of our knowledge, there is no consensus on dose-response between smoking, alcohol drinking, and bone healing. The aim of the present study is to conduct a comprehensive systematic review and dose-response meta-analysis of studies to estimate the influence of smoking and alcohol use on the success of non-pathologic bone fracture healing in adult patients.

METHODS

A systematic search will be performed using MEDLINE, EMBASE and Cochrane CENTRAL, CINAHL, and AMED databases to identify randomized controlled trials and observational studies which have assessed the effect of smoking or alcohol drinking on fracture healing. Primary outcomes include delayed union or nonunion rate and time to union. Secondary outcomes are common complications which occur during bone healing including malunion and wound infection. Risk of bias will be evaluated using the Quality In Prognosis Studies (QUIPS) tool for quality assessment of each study. Dose-response meta-analysis will be performed between smoking, alcohol drinking, and bone healing. Evaluation of the quality of evidence will be conducted using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

RESULTS

The present study will assess the effects of smoking and alcohol drinking on non-pathologic bone fracture healing in adult patients.

CONCLUSION

We hope that this systematic review and dose-response meta-analysis will provide high quality evidence on dose-response between smoking, alcohol drinking, and bone fracture healing.

PROSPERO REGISTRATION NUMBER

CRD42019131454.

Osteomyelitis Risk Factors Related to Combat Trauma Open Upper Extremity Fractures: A Case-Control Analysis

OBJECTIVE

To determine risk factors for osteomyelitis in US military personnel with combat-related, extremity long bone (humerus, radius, and ulna) open fractures.

DESIGN

Retrospective observational case-control study.

SETTING

US military regional hospital in Germany and tertiary care military hospitals in the United States (2003-2009).

PATIENTS/PARTICIPANTS

Sixty-four patients with open upper extremity fractures who met diagnostic osteomyelitis criteria (medical record review verification) were classified as cases. Ninety-six patients with open upper extremity fractures who did not meet osteomyelitis diagnostic criteria were included as controls.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASUREMENTS

Multivariable odds ratios (ORs; 95% confidence interval [CI]).

RESULTS

Among patients with surgical implants, osteomyelitis cases had longer time to definitive orthopaedic surgery compared with controls (median: 26 vs. 11 days; P < 0.001); however, there was no significant difference with timing of radiographic union. Being injured between 2003 and 2006, use of antibiotic beads, Gustilo-Anderson [GA] fracture classification (highest with GA-IIIb: [OR: 22.20; CI: 3.60-136.95]), and Orthopaedic Trauma Association Open Fracture Classification skin variable (highest with extensive degloving [OR: 15.61; CI: 3.25-74.86]) were independently associated with osteomyelitis risk. Initial stabilization occurring outside of the combat zone was associated with reduced risk of osteomyelitis.

CONCLUSIONS

Open upper extremity fractures with severe soft-tissue damage have the highest risk of developing osteomyelitis. The associations with injuries sustained 2003-2006 and location of initial stabilization are likely from evolving trauma system recommendations and practice patterns during the timeframe.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Clinical outcome of conversion from external fixation to definitive internal fixation for open fracture of the lower limb

INTRODUCTION

Few reports have examined the outcomes and complications of temporary bridging external fixation (EF) in open fracture of the lower limb followed by conversion to open reduction internal fixation (ORIF). The purpose of this study was to evaluate healing rates and complications in patients treated with conversion from external fixation to definitive internal fixation for open fracture of the lower limb.

METHOD

Patients who underwent temporary bridging EF and subsequent conversion to internal fixation (IF) for open fracture of the lower limb, with follow-up period ≥12 months were included in this study. Demographic data, Gustilo-Anderson classification, fracture type, duration to definitive surgery, surgical procedure, perioperative complications, and additional procedures for cases with complications were obtained.

RESULTS

In total, 58 patients (43 males, 15 females), 63 fractures were included in this study. Four fractures (6.3%) were Gustilo grade I, 11 fractures (17.5%) were grade II, 34 fractures (54.0%) were grade IIIa, 12 fractures (19.0%) were grade IIIb, and two fractures (3.2%) were grade IIIc. Mean duration of the application of EF was 12.4 days (range, 3-45 days) until conversion to definitive IF. Rates of deep infection and nonunion were both 9.5%, with two cases showing concomitant infection and nonunion. Rates of infection were 8.8% (3/34) in grade IIIa and 25% (3/12) in grade IIIb. Rates of nonunion were 9.1% (1/11) in grade II, 2.9% (1/34) in grade IIIa and 33% (4/12) in grade IIIb.

CONCLUSION

Temporary EF for open fracture of the lower limb followed by conversion to IF, as early as soft tissue and general condition permit, may be a safe and effective procedure for patients with lower-limb open fracture of Gustilo grade IIIa or less.

LEVEL OF EVIDENCE

Level IV, Case series.

Pathogenesis and management of fracture-related infection

BACKGROUND

Both fracture-related infections (FRIs) and periprosthetic joint infections (PJIs) include orthopaedic implant-associated infections. However, key aspects of management differ due to the bone and soft tissue damage in FRIs and the option of removing the implant after fracture healing. In contrast to PJIs, research and guidelines for diagnosis and treatment in FRIs are scarce.

OBJECTIVES

This narrative review aims to update clinical microbiologists, infectious disease specialists and surgeons on the management of FRIs.

SOURCES

A computerized search of PubMed was performed to identify relevant studies. Search terms included 'Fracture' and 'Infection'. The reference lists of all retrieved articles were checked for additional relevant references. In addition, when scientific evidence was lacking, recommendations are based on expert opinion.

CONTENT

Pathogenesis, prevention, diagnosis and treatment of FRIs are presented. Whenever available, specific data of patients with FRI are discussed.

IMPLICATIONS

Management of patients with FRI should take into account FRI-specific features. Treatment pathways should implement a multidisciplinary approach to achieve a good outcome. Recently, international consensus guidelines were developed to improve the quality of care for patients suffering from this severe complication, which are highlighted in this review.

Duration of antibiotic treatment and risk of recurrence after surgical management of orthopaedic device infections: a multicenter case-control study

Background

Device-related infections in orthopaedic and trauma surgery are a devastating complication with substantial impact on morbidity and mortality. Systemic suppressive antibiotic treatment is regarded an integral part of any surgical protocol intended to eradicate the infection. The optimal duration of antimicrobial treatment, however, remains unclear. In a multicenter case-control study, we aimed at analyzing the influence of the duration of antibiotic exposure on reinfection rates 1 year after curative surgery.

Methods

This investigation was part of a federally funded multidisciplinary network project aiming at reducing the spread of multi-resistant bacteria in the German Baltic region of Pomerania. We herein used hospital chart data from patients treated for infections of total joint arthroplasties or internal fracture fixation devices at three academic referral institutions. Subjects with recurrence of an implant-related infection within 1 year after the last surgical procedure were defined as case group, and patients without recurrence of an implant-related infection as control group. We placed a distinct focus on infection of open reduction and internal fixation (ORIF) constructs. Uni- and multivariate logistic regression analyses were employed for data modelling.

Results

Of 1279 potentially eligible patients, 269 were included in the overall analysis group, and 84 contributed to an extramedullary fracture-fixation-device sample. By multivariate analysis, male sex (odds ratio [OR] 2.06, 95% confidence interval [CI] 1.08 to 3.94, p = 0.029) and facture fixation device infections (OR 2.05, 95% CI 1.05 to 4.02, p = 0.036) remained independent predictors of reinfection. In the subgroup of infected ORIF constructs, univariate point estimates suggested a nearly 60% reduced odds of reinfection with systemic fluoroquinolones (OR 0.42, 95% CI 0.04 to 2.46) or rifampicin treatment (OR 0.41, 95% CI 0.08 to 2.12) for up to 31 days, although the width of confidence intervals prohibited robust statistical and clinical inferences.

Conclusion

The optimal duration of systemic antibiotic treatment with surgical concepts of curing wound and device-related orthopaedic infections is still unclear. The risk of reinfection in case of infected extramedullary fracture-fxation devices may be reduced with up to 31 days of systemic fluoroquinolones and rifampicin, although scientific proof needs a randomized trial with about 1400 subjects per group. Concerted efforts are needed to determine which antibiotics must be applied for how long after radical surgical sanitation to guarantee sustainable treatment success.

Osteomyelitis Risk Factors Related to Combat Trauma Open Femur Fractures: A Case-Control Analysis

OBJECTIVES

To identify the risk factors for osteomyelitis development in US military personnel with combat-related, open femur fractures?

DESIGN

Retrospective observational case-control study.

SETTING

US military regional hospital in Germany and tertiary care hospitals in United States (2003-2009).

PATIENTS/PARTICIPANTS

One hundred three patients with open femur fractures who met diagnostic osteomyelitis criteria (medical record review verification) were classified as cases. Sixty-four patients with open femur fractures who did not meet osteomyelitis diagnostic criteria were included as controls.

MAIN OUTCOME MEASUREMENTS

The main outcome measurements were multivariable odds ratios (ORs) and 95% confidence interval (CI).

RESULTS

Among patients with surgical implants, osteomyelitis cases had significantly longer time to definitive orthopaedic surgery compared with controls (median: 21 vs. 13 days). Independent predictors for osteomyelitis risk were Gustilo-Anderson classification (transfemoral amputation OR: 19.3; CI: 3.0-123.0) and Orthopaedic Trauma Association Open Fracture Classification for muscle loss (OR: 5.7; CI: 1.3-25.1) and dead muscle (OR: 32.9; CI: 5.4-199.1). Being injured between 2003 and 2006, antibiotic bead use, and foreign body plus implant(s) at fracture site were also risk factors.

CONCLUSIONS

Patients with open femur fractures resulting in significant muscle damage have the highest osteomyelitis risk. Foreign body contamination was only significant when an implant was present. Increased risk with antibiotic bead use is likely a surrogate for clinical suspicion of contamination with complex wounds. The timeframe association is likely due to changing trauma system patterns around 2006-2007 (eg, increased negative pressure wound therapy, reduced high-pressure irrigation, decreased crystalloid use, and delayed definitive internal fixations).

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

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.

Insights into treatment and outcome of fracture-related infection: a systematic literature review

INTRODUCTION

Standardized guidelines for treatment of fracture-related infection (FRI) are lacking. Worldwide many treatment protocols are used with variable success rates. Awareness on the need of standardized, evidence-based guidelines has increased in recent years. This systematic literature review gives an overview of available diagnostic criteria, classifications, treatment protocols, and related outcome measurements for surgically treated FRI patients.

METHODS

A comprehensive search was performed in all scientific literature since 1990. Studies in English that described surgical patient series for treatment of FRI were included. Data were collected on diagnostic criteria for FRI, classifications used, surgical treatments, follow-up protocols, and overall outcome. A systematic review was performed according to the PRISMA statement. Proportions and weighted means were calculated.

RESULTS

The search yielded 2051 studies. Ninety-three studies were suitable for inclusion, describing 3701 patients (3711 fractures) with complex FRI. The population consisted predominantly of male patients (77%), with the tibia being the most commonly affected bone (64%), and a mean of three previous operations per patient. Forty-three (46%) studies described FRI at one specific location. Only one study (1%) used a standardized definition for infection. A total of nine different classifications were used to guide treatment protocols, of which Cierny and Mader was used most often (36%). Eighteen (19%) studies used a one-stage, 50 (54%) a two-stage, and seven (8%) a three-stage surgical treatment protocol. Ten studies (11%) used mixed protocols. Antibiotic protocols varied widely between studies. A multidisciplinary approach was mentioned in only 12 (13%) studies.

CONCLUSIONS

This extensive literature review shows a lack of standardized guidelines with respect to diagnosis and treatment of FRI, which mimics the situation for prosthetic joint infection identified many years ago. Internationally accepted guidelines are urgently required to improve the quality of care for patients suffering from this significant complication.

Diagnostic accuracy of serum inflammatory markers in late fracture-related infection: a systematic review and meta-analysis

AIMS

To assess the diagnostic value of C-reactive protein (CRP), leucocyte count (LC), and erythrocyte sedimentation rate (ESR) in late fracture-related infection (FRI).

MATERIALS AND METHODS

PubMed, Embase, and Cochrane databases were searched focusing on the diagnostic value of CRP, LC, and ESR in late FRI. Sensitivity and specificity combinations were extracted for each marker. Average estimates were obtained using bivariate mixed effects models.

RESULTS

A total of 8284 articles were identified but only six were suitable for inclusion. Sensitivity of CRP ranged from 60.0% to 100.0% and specificity from 34.3% to 85.7% in all publications considered. Five articles were pooled for meta-analysis, showing a sensitivity and specificity of 77.0% and 67.9%, respectively. For LC, this was 22.9% to 72.6%, and 73.5% to 85.7%, respectively, in five articles. Four articles were pooled for meta-analysis, resulting in a 51.7% sensitivity and 67.1% specificity. For ESR, sensitivity and specificity ranged from 37.1% to 100.0% and 59.0% to 85.0%, respectively, in five articles. Three articles were pooled in meta-analysis, showing a 45.1% sensitivity and 79.3% specificity. Four articles analyzed the value of combined inflammatory markers, reporting an increased diagnostic accuracy. These results could not be pooled due to heterogeneity.

CONCLUSION

The serum inflammatory markers CRP, LC, and ESR are insufficiently accurate to diagnose late FRI, but they may be used as a suggestive sign in its diagnosis.

[Primary soft tissue management in open fracture]

OBJECTIVE

Debridement of soft tissue and bone in an open fracture situation to minimize infection risk and achieve primary skin closure, or to provide conditions for early soft tissue coverage.

INDICATIONS

Indications are Gustilo-Anderson grade I-III A-C open fractures.

CONTRAINDICATIONS

Contraindications are injuries requiring amputation, burns, and life-threatening injuries which make appropriate treatment temporarily impossible.

SURGICAL TECHNIQUE

Removal of gross contamination and macroscopic contaminants; debridement of the wound; complete resection of contaminated and dirty tissue; sparse step-by-step resection of contaminated or non-vital wound and bone margins until vital, bleeding tissue begins; low-pressure irrigation with isotonic irrigation fluid; diagnostic biopsies for microbiological testing; reduction of dead space by interpositioning of muscle or cement spacers loaded with local antibiotics; primary wound closure if tension-free closure possible; otherwise, if resources and knowhow permit and satisfactory clean debridement was achieved, local flap; if flap impossible, debridement not satisfactory, secondary tissue necrosis likely, potential remaining contamination or contamination with fecal matter, then vacuum-assisted closure therapy.

POSTOPERATIVE MANAGEMENT

Wound inspection on the second postoperative day, generous indication for second-look surgery after 36-48 h, wound inspection on the second postoperative day, wound inspection every other day, primary antibiotic prophylaxis with a first- or second-generation cephalosporin (e. g., cefuroxime), and adaptation of antibiotic therapy according to susceptibility screening.

RESULTS

Infection rates of 2-4.7% are reported for immediate primary wound closure in Gustilo-Anderson grade I, II, and III A open fractures. For Gustilo-Anderson grade III B, good wound healing, bony consolidation, and no need for secondary surgery was reported in 86.7% when primary wound closure was achieved.

Osteomyelitis Risk Factors Related to Combat Trauma Open Tibia Fractures: A Case-Control Analysis

OBJECTIVES

We assessed osteomyelitis risk factors in US military personnel with combat-related open tibia fractures (2003-2009).

METHODS

Patients with open tibia fractures who met the diagnostic criteria of osteomyelitis were identified as cases using Military Health System data and verified through medical record review. Controls were patients with open tibia fractures who did not meet osteomyelitis criteria. The Gustilo-Andersen fracture classification scheme was modified to include transtibial amputations (TTAs) as the most severe level. Logistic regression multivariable odds ratios [ORs; 95% confidence intervals (CI)] were assessed.

RESULTS

A total of 130 tibia osteomyelitis cases and 85 controls were identified. Excluding patients with TTAs, osteomyelitis cases had significantly longer time to radiographic union compared with controls (median: 210 vs. 165 days). Blast injuries, antibiotic bead utilization, ≥ Gustilo-Andersen-IIIb fractures [highest risk with TTA (OR: 15.10; CI: 3.22-71.07)], and foreign body at the fracture site were significantly associated with developing osteomyelitis. In a separate model, the Orthopaedic Trauma Association Open Fracture Classification muscle variable was significant with increasing risk from muscle loss (OR: 5.62; CI: 2.21-14.25) to dead muscle (OR: 8.46; CI: 3.31-21.64). When TTAs were excluded, significant risk factors were similar and included sustaining an injury between 2003 and 2006.

CONCLUSIONS

Patients with severe blast trauma resulting in significant muscle damage are at the highest risk for osteomyelitis. The period association coincides with a time frame when several trauma system practice changes were initiated (eg, increased negative pressure wound therapy, decreased high-pressure irrigation, and reduced crystalloid use).

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Microbiological profile and susceptibility pattern of surgical site infections related to orthopaedic trauma

BACKGROUND

Understanding the epidemiology of microorganisms associated with surgical site infections related to orthopaedic trauma (SSI-ROT) is important in establishing treatment protocols. The aim of this study was to evaluate the etiology and susceptibility pattern of SSIs related to orthopaedic trauma in a Brazilian reference hospital for trauma.

METHODS

Patients with SSI-ROT in a Brazilian reference hospital for trauma were retrospectively analyzed. All patients with orthopaedic trauma who underwent a surgical procedure and developed SSI within one year were included. All patients had culture samples from the surgical site obtained from biopsy of bone or soft tissue. Clinical and epidemiological data of the patients were collected.

RESULTS

A total of 147 patients with trauma-related infection were included in the analysis. The mean time to infection was 55.5 days, and the mean duration of hospitalization was 20.0 days. The in-hospital mortality rate after infection was 5.4%. Cultures were obtained from all patients, with 104 samples obtained from soft tissues and 43 samples from bone. The positivity rate was 93.2%. Among the isolates, 56.5% (77 patients) were gram-negative bacteria and 43.8% (60 patients) were gram-positive bacteria. Staphylococcus aureus was identified in 34%, Enterobacter spp. in 14.9%, and Pseudomonas aeruginosa in 11.6%. Staphylococcus aureus presented a higher positivity in bone samples (odds ratio, 1.29; 95% CI, 1.01-1.70; p = 0.04). Few microorganisms were multi-resistant.

CONCLUSION

SSI in orthopaedic trauma can be associated with gram-negative bacilli, the susceptibility profile of which suggested that most infections occur after discharge. Staphylococcus aureus infections were commonly caused by methicillin-susceptible isolates, and this susceptibility to oral antibiotic options helps in the dehospitalization of patients.

Limited Predictive Value of Serum Inflammatory Markers for Diagnosing Fracture-Related Infections: results of a large retrospective multicenter cohort study

Introduction: Diagnosing Fracture-Related Infections (FRI) based on clinical symptoms alone can be challenging and additional diagnostic tools such as serum inflammatory markers are often utilized. The aims of this study were 1) to determine the individual diagnostic performance of three commonly used serum inflammatory markers: C-Reactive Protein (CRP), Leukocyte Count (LC) and Erythrocyte Sedimentation Rate (ESR), and 2) to determine the diagnostic performance of a combination of these markers, and the additional value of including clinical parameters predictive of FRI.

Methods: This cohort study included patients who presented with a suspected FRI at two participating level I academic trauma centers between February 1^st 2009 and December 31^st 2017. The parameters CRP, LC and ESR, determined at diagnostic work-up of the suspected FRI, were retrieved from hospital records. The gold standard for diagnosing or ruling out FRI was defined as: positive microbiology results of surgically obtained tissue samples, or absence of FRI at a clinical follow-up of at least six months. The diagnostic accuracy of the individual serum inflammatory markers was assessed. Analyses were done with both dichotomized values using hospital thresholds as well as with continuous values. Multivariable logistic regression analyses were performed to obtain the discriminative performance (Area Under the Receiver Operating Characteristic, AUROC) of (1) the combined inflammatory markers, and (2) the added value of these markers to clinical parameters.

Results: A total of 168 patients met the inclusion criteria and were included for analysis. CRP had a 38% sensitivity, 34% specificity, 42% positive predictive value (PPV) and 78% negative predictive value (NPV). For LC this was 39%, 74%, 46% and 67% and for ESR 62%, 64%, 45% and 76% respectively. The diagnostic accuracy was 52%, 61% and 80% respectively. The AUROC was 0.64 for CRP, 0.60 for LC and 0.58 for ESR. The AUROC of the combined inflammatory markers was 0.63. Serum inflammatory markers combined with clinical parameters resulted in AUROC of 0.66 as opposed to 0.62 for clinical parameters alone.

Conclusion: The added value of CRP, LC and ESR for diagnosing FRI is limited. Clinicians should be cautious when interpreting the results of these tests in patients with suspected FRI.