Risk factors for treatment failure of fracture-related infections

Mismatch Rate of Empirical Antimicrobial Treatment in Fracture-Related Infections

OBJECTIVES

To evaluate the current standard of care regarding empirical antimicrobial therapy in fracture-related infections (FRIs).

METHODS

DESIGN

Retrospective cohort study.

SETTING

Level I Trauma Center.

PATIENT SELECTION CRITERIA

Adult patients treated for FRI with surgical debridement and empirical antibiotics between September 1, 2014, and August 31, 2022. Patients were excluded if less than 5 tissue samples for culture were taken, culture results were negative, or there was an antibiotic-free window of less than 3 days before debridement.

OUTCOME MEASURES AND COMPARISONS

FRI microbial etiology, antimicrobial resistance patterns (standardized antimicrobial panels were tested for each pathogen), the mismatch rate between empirical antimicrobial therapy and antibiotic resistance of causative microorganism(s), and mismatching risk factors.

RESULTS

In total, 75 patients were included [79% (59/75) men, mean age 51 years]. The most prevalent microorganisms were Staphylococcus aureus (52%, 39/75) and Staphylococcus epidermidis (41%, 31/75). The most frequently used empirical antibiotic was clindamycin (59%, 44/75), followed by combinations of gram-positive and gram-negative covering antibiotics (15%, 11/75). The overall mismatch rate was 51% (38/75) [95% confidence interval (CI), 0.39-0.62] and did not differ between extremities [upper: 31% (4/13) (95% CI, 0.09-0.61), lower: 55% (33/60) (95% CI, 0.42-0.68, P = 0.11)]. Mismatching empirical therapy occurred mostly in infections caused by S. epidermidis and gram-negative bacteria. Combination therapy of vancomycin with ceftazidime produced the lowest theoretical mismatch rate (8%, 6/71). Polymicrobial infections were an independent risk factor for mismatching (OR: 8.38, 95% CI, 2.53-27.75, P < 0.001).

CONCLUSIONS

In patients with FRI, a mismatching of empirical antibiotic therapy occurred in half of patients, mainly due to lack of coverage for S. epidermidis , gram-negative bacteria, and polymicrobial infections. Empirical therapy with vancomycin and ceftazidime produced the lowest theoretical mismatch rates. This study showed the need for the consideration of gram-negative coverage in addition to standard broad gram-positive coverage. Future studies should investigate the effect of the proposed empirical therapy on long-term outcomes.

LEVEL OF EVIDENCE

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

The State of Local Antibiotic Use in Orthopedic Trauma

Fracture-related infections are a challenging complication in orthopedic trauma that often necessitates multiple surgeries. Early administration of systemic antibiotics and surgical intervention remains the gold standard of care, but despite these measures, treatment failures can be as high as 35%. For these reasons, the introduction of local antibiotics at the site of at-risk fractures has increased over the past decade. This review looks at the various measures being used clinically including local antibiotic powder, polymethylmethacrylate, biodegradable substances, antibiotic-coated implants, and novel methods such as hydrogels and nanoparticles that have the potential for use in the future.

Construction and verification of risk prediction model of osteoporotic fractures in patients with osteoporosis in China

Objective

To explore the influencing factors of osteoporotic fractures (OPF) in patients with osteoporosis, construct a prediction model, and verify the model internally and externally, so as to provide reference for early screening and intervention of OPF in patients with osteoporosis.

Methods

Osteoporosis patients in the First Affiliated Hospital of Soochow University were selected, and the medical records of patients were consulted through the Hospital Information System (HIS) and the data management platform of osteoporosis patients, so as to screen patients who met the criteria for admission and discharge and collect data. SPSS 26.0 software was used for single factor analysis to screen statistically significant variables (p < 0.05). The influencing factors of OPF were determined by multivariate analysis, and a binary Logistic regression model was established according to the results of multivariate analysis. Hosmer-Lemeshow (H-L) goodness of fit and receiver operating characteristic curve (ROC) were used to test the model's efficiency, and Stata 16.0 software was used to verify the Bootstrap model, draw the model calibration curve, clinical applicability curve and nomogram.

Results

In this study, the data of modeling set and verification set were 1,435 and 580, respectively. There were 493 (34.4%) cases with OPF and 942 (65.6%) cases without OPF in the modeling set. There were 204 (35.2%) cases with OPF and 376 (64.8%) cases without OPF. The variables with statistically significant differences in univariate analysis are Age, BMI, History of falls, Usage of glucocorticoid, ALP, Serum Calcium, BMD of lumbar, BMD of feminist neck, T value of feminist neck, BMD of total hip and T value of total hip. The area under ROC curve of the risk prediction model constructed this time is 0.817 [95%CI (0.794 ~ 0.839)], which shows that the model has a good discrimination in predicting the occurrence of OPF. The optimal threshold of the model is 0.373, the specificity is 0.741, the sensitivity is 0.746, and the AUC values of the modeling set and the verification set are 0.8165 and 0.8646, respectively. The results of Hosmer and Lemeshow test are modeling set: (χ2 = 6.551, p = 0.586); validation set: [(χ2 = 8.075, p = 0.426)]. The calibration curve of the model shows that the reference line of the fitted curve and the calibration curve is highly coincident, and the model has a good calibration degree for predicting the occurrence of fractures. The net benefit value of the risk model of osteoporosis patients complicated with OPF is high, which shows that the model is effective.

Conclusion

In this study, a OPF risk prediction model is established and its prediction efficiency is verified, which can help identify the high fracture risk subgroup of osteoporosis patients in order to choose stronger intervention measures and management.

Case Report: Hip arthroplasty after fracture-related joint infection caused by extensively drug-resistant Klebsiella pneumoniae

This case-report focuses on a 23-year-old soldier suffering from a fracture-related hip joint infection (FRI) due to extensively drug-resistant Klebsiella pneumoniae and S. epidermidis. The patient underwent multiple septic revision surgeries including the removal of remaining shrapnel accompanied by last-resort antimicrobial therapy with cefiderocol and colistin. Additionally, the surgeries included repeated tissue sampling for microbiological and histopathological analysis. An antibiotic-loaded cemented filler containing cefiderocol was used to improve local antimicrobial therapy. The biopsies prior to and during hip replacement surgery confirmed successful microbe eradication. Hip arthroplasty restored hip joint function and significantly improved patient's quality of life. The utilization of a trabecular metal shell and a meta-diaphyseally anchored cementless hip stem ensured secure implant fixation and early patient mobilisation. An adjusted biofilm active oral antimicrobial therapy after arthroplasty intervention was continued to prevent early periprosthetic joint infection. This case emphasizes the difficulties of managing FRI and multidrug-resistant pathogens. It contributes valuable insight into navigating complex orthopedic cases while ensuring successful hip arthroplasty outcomes. In conclusion, early interdisciplinary collaboration, appropriate antimicrobial therapy along with tailored surgical interventions are crucial for managing such complex cases successfully.

High Nonunion and Amputations Rates With Either Early Intramedullary Nail Removal or Retention for Tibial Shaft Fracture-Related Infections

OBJECTIVES

To compare debridement, antibiotics, and implant retention (DAIR) and intramedullary nail (IMN) removal with subsequent strategy for fracture stabilization in the treatment of tibia fracture-related infections (FRIs) occurring within 90 days of initial IMN placement.

DESIGN

Retrospective case-control.

SETTING

Four academic, Level 1 trauma centers.

PATIENTS

Sixty-six patients who subsequently received unplanned operative treatment for FRI diagnosed within 90 days of initial tibia IMN.

INTERVENTION

DAIR versus IMN removal pathways.

MAIN OUTCOME MEASUREMENTS

Fracture union.

RESULTS

Twenty-eight patients (42.4%) were treated with DAIR and 38 (57.6%) via IMN removal with subsequent strategy for fracture stabilization. Mean follow-up was 16.3 months. At final follow-up, ultimate bone healing was achieved in 75.8% (47/62), whereas 24.2% (15/62) had persistent nonunion or amputation. No significant difference was observed in ultimate bone healing ( P = 0.216) comparing DAIR and IMN removal. Factors associated with persistent nonunion or amputation were time from injury to initial IMN ( P < 0.001), McPherson systemic host grade B ( P = 0.046), and increasing open-fracture grade, with Gustilo-Anderson IIIB/IIIC fractures being the worst ( P = 0.009). Fewer surgeries after initial FRI treatment were positively associated with ultimate bone healing ( P = 0.029).

CONCLUSIONS

Treatment of FRI within 90 days of tibial IMN with DAIR or IMN removal with subsequent strategy for fracture stabilization results in a high rate, nearly 1 in 4, of persistent nonunion or amputation, with neither appearing superior for improving bone healing outcomes.

LEVEL OF EVIDENCE

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

Application of Nucleic Acid-Based Strategies to Detect Infectious Pathogens in Orthopaedic Implant-Related Infection

➤

Implant-associated infection in orthopaedic surgery remains an enormous and largely unsolved clinical problem with a high rate of persistent or recurrent infection. This may be due, at least in part, to the potential for underdiagnosis by traditional microbial culture or the potential for culture to incompletely identify the microbial species present.

➤

Nucleic acid-based diagnostic techniques, focused on using the diagnostic information contained in DNA or RNA to identify microbial species, have been developing rapidly and have garnered escalating interest for both clinical and research applications.

➤

Commonly applied techniques include end-point polymerase chain reaction (PCR), quantitative PCR, Sanger sequencing, and next-generation sequencing. Understanding the specific strengths and weaknesses of each technique is critical to understanding their utility, applying the correct assessment strategy, and critically understanding and interpreting research.

➤

The best practices for interpreting nucleic acid-based diagnostic techniques include considering positive and negative controls, reads per sample, detection thresholds (for differentiating contaminants from positive results), and the primer set or targeted regions.

Escalation of antimicrobial resistance among MRSA part 2: focus on infections and treatment

INTRODUCTION

MRSA is associated with causing a variety of infections including skin and skin structure infections, catheter and device-related (e.g. central venous catheter, prosthetic heart valve) infections, infectious endocarditis, blood stream infections, bone, and joint infections (e.g. osteomyelitis, prosthetic joint, surgical site), central nervous system infections (e.g. meningitis, brain/spinal cord abscess, ventriculitis, hydrocephalus), respiratory tract infections (e.g. hospital-acquired pneumonia, ventilator-associated pneumonia), urinary tract infections, and gastrointestinal infections. The emergence and spread of multidrug resistant (MDR) MRSA clones has limited therapeutic options. Older agents such as vancomycin, linezolid and daptomycin and a variety of newer MRSA antimicrobials and combination therapy are available to treat serious MRSA infections.

AREAS COVERED

The authors discuss infections caused by MRSA as well as common older and newer antimicrobials and combination therapy for MRSA infections. A literature search of MRSA was performed via PubMed (up to September 2022), using the keywords: antimicrobial resistance; β-lactams; multidrug resistance, Staphylococcus aureus, vancomycin; glycolipopeptides.

EXPERT OPINION

Innovation, discovery, and development of new and novel classes of antimicrobial agents are critical to expand effective therapeutic options. The authors encourage the judicious use of antimicrobials in accordance with antimicrobial stewardship programs along with infection-control measures to minimize the spread of MRSA.

Outcome and risk factors for recurrence of early onset fracture-related infections treated with debridement, antibiotics and implant retention: Results of a large retrospective multicentre cohort study

INTRODUCTION

Early Fracture-Related Infections (FRIs) are a common entity in hospitals treating trauma patients and are often treated with a Debridement, Antibiotics and Implant Retention (DAIR) procedure. Aims of this study were to 1) evaluate the recurrence rate after DAIR procedures for early onset FRI, 2) establish the number of surgical procedures to gain control of the initial infection and 3) identify independent predictors for recurrence in this cohort.

METHODS

A retrospective multicentre cohort study was conducted in two level 1 trauma centres. Consecutive patients who underwent a DAIR procedure between January 1st 2015 and July 1st 2020 for confirmed FRI with an onset of <6 weeks after the latest osseous operation were included. Recorded data included patient demographics, treatment characteristics and follow-up. Univariate and multivariate logistic regression analyses were performed to assess predictors for recurrent FRI.

RESULTS

A total of 141 patients with early FRI were included in this study with a median age of 54.0 years (interquartile range (IQR) 34.5-64.0). The recurrence rate of FRI was 13% (n = 19) at one year follow-up and 18% (n = 25) at 23.1 months (IQR 15.3-36.4) follow-up. Infection control was achieved in 94% (n = 127/135) of cases. In total, 73 patients (52%) underwent at least two surgical procedures to treat the ongoing initial episode of FRI, of whom 54 patients (74%) required two to three procedures and 17 patients (23%) four to five procedures. Predictors for recurrent FRI were use of an intramedullary nail during index operation (odds ratio (OR) 4.0 (95% confidence interval (CI) 1.1-13.8)), need for additional surgical procedures to treat ongoing infection during the treatment period following the first presentation of early FRI (OR 1.9 (95% CI 1.1-3.5)) and a decreased Injury Severity Score (ISS) (inverted OR 1.1 (95% CI 1.0-1.1)).

CONCLUSION

The recurrence rate after treatment of early onset FRI in patients treated with a DAIR procedure was 18% at 23.1 months follow-up. At least two surgical procedures to gain control of the initial infection were needed in 52% of patients. Independent predictors for recurrent FRI were the use of an intramedullary nail during index operation, need for additional surgical procedures and a decreased ISS.

Antimicrobial potency, prevention ability, and killing efficacy of daptomycin-loaded versus vancomycin-loaded β-tricalcium phosphate/calcium sulfate for methicillin-resistant Staphylococcus aureus biofilms

Growing evidence has shown that the efficacy of systemic administration of daptomycin for the treatment of methicillin-resistant Staphylococcus aureus (MRSA)-related infections is satisfactory. However, the clinical efficacy of the local administration of daptomycin for the management of osteoarticular infections remains unclear. This in vitro study compared the efficacy of daptomycin and vancomycin against MRSA biofilms. The elution kinetics of daptomycin and vancomycin, combined with gentamicin and loaded with either β-tricalcium phosphate/calcium sulfate or calcium sulfate, in the presence of MRSA infection, was assessed. Their efficacy in preventing biofilm formation and killing pre-formed biofilms was assessed using colony-forming unit count and confocal laser scanning microscopy. In addition, the efficacy of daptomycin, vancomycin, and gentamicin in prophylaxis and eradication of MRSA biofilms was also evaluated. Daptomycin + gentamicin and vancomycin + gentamicin displayed similar antimicrobial potency against MRSA, by either β-tricalcium phosphate/calcium sulfate or calcium sulfate. In the prevention assays, both daptomycin + gentamicin and vancomycin + gentamicin showed similar efficacy in preventing bacterial colony formation, with approximately 6 logs lower colony-forming units than those in the control group at both 1 and 3  days. The killing effect on pre-formed biofilms showed significant decreases of approximately 4 logs at 1 and 3  days following treatment with daptomycin + gentamicin and vancomycin + gentamicin. In addition, the confocal laser scanning microscopy results support the colony-forming unit data. Moreover, single use of vancomycin and gentamicin showed similar efficacies in preventing and killing MRSA biofilms, both of which were better than that of gentamicin. Our study demonstrated that vancomycin + gentamicin and daptomycin + gentamicin loaded with β-tricalcium phosphate/calcium sulfate or calcium sulfate showed similar prophylactic and killing effects on MRSA biofilms, implying a potential indication of local administration daptomycin for the treatment of MRSA-associated osteoarticular infections, especially if vancomycin administration presents limitations.

Prior use of antibiotics and immunosuppression are risk factors for fracture-related infection during the COVID-19 pandemic period: a Brazilian prospective cohort study

Background

Little is known about the role of COVID-19 pandemic period on the epidemiology of fracture-related infection (FRI). The present study summarizes the changes in the prevalence, microbiology, and risk factors of FRI during this period.

Methods

A prospective single-center cohort study assessed in the setting of COVID-19 pandemic (2020–2021), clinical, microbiological aspects, and independent risk factors (RF) of FRI. RFs were estimated by bivariate and multivariable analyses using prevalence ratio (PR) with significance at P < 0.05. Kaplan–Meier analysis was performed to evaluate treatment outcomes.

Results

Overall, 132 patients were analyzed, with patients with age over 65 years accounting 65.1%. FRI was diagnosed in 21(15.9%) patients. Independent RFs for FRI were recent and preoperative use of systemic antibiotics (PR: 7.0, 95% confidence interval (95% CI): 2.2 – 22.4, p = 0.001) and cancer (PR: 9.8, 95% CI: 2.0 – 48.8, p = 0.005). Cultures yielded Gram-negative bacteria in 77.8%, 33.3% were MDR.

Conclusions

We found higher rates of FRI, predominating in the elderly with closed femoral fractures during the COVID-19 pandemic. Prior use of antibiotics and immunosuppression conditions were independent factor for FRI. Our outcomes provide evidence to avoid the empirical use of antibiotics prior to surgery for fracture stabilization.

Fracture Related Infections and Their Risk Factors for Treatment Failure—A Major Trauma Centre Perspective

Fracture related infections (FRI) are debilitating and costly complications of musculoskeletal trauma surgery that can result in permanent functional loss or amputation. Surgical treatment can be unsuccessful, and it is necessary to determine the predictive variables associated with FRI treatment failure, allowing one to optimise them prior to treatment and identify patients at higher risk. The clinical database at a major trauma centre was retrospectively reviewed between January 2015 and January 2021. FRI treatment failure was defined by infection recurrence or amputation. A univariable logistic regression analysis was performed, followed by a multivariable regression analysis for significant outcomes between groups on univariable analysis, to determine risk factors for treatment failure. In total, 102 patients were identified with a FRI (35 open, 67 closed fractures). FRI treatment failure occurred in 24 patients (23.5%). Risk factors determined by our multivariate logistic regression model were obesity (OR 2.522; 95% CI, 0.259–4.816; p = 0.006), Gustilo Anderson type 3c (OR 4.683; 95% CI, 2.037–9.784; p = 0.004), and implant retention (OR 2.818; 95% CI, 1.588–7.928; p = 0.041). Given that FRI treatment in 24 patients (23.5%) ended up in failure, future management need to take into account the predictive variables analysed in this study, redirect efforts to improve management and incorporate adjuvant technologies for patients at higher risk of failure, and implement a multidisciplinary team approach to optimise risk factors such as diabetes and obesity.