Infecção de sítio cirúrgico após fixação de fraturas fechadas e expostas – Incidência e perfil microbiológico

Surgical site infection in severe trauma patients in intensive care: epidemiology and risk factors

BACKGROUND

Severe trauma is the leading cause of disability and mortality in the patients under 35 years of age. Surgical site infections (SSI) represent a significant complication in this patient population. However, they are often inadequately investigated, potentially impacting the quality of patient outcomes. The aim of this study was to investigate the epidemiology of SSI and risk factors in severe trauma patients.

METHODS

We conducted a multicenter retrospective cohort study screening the severe trauma patients (STP) admitted to two intensive care units of an academic institution in Marseille between years2018 and 2019. Those who underwent orthopedic or spinal surgery within 5 days after admission were included and classified into two groups according to the occurrence of SSI (defined by the Centers for Disease Control (CDC) international diagnostic criteria) or not. Our secondary goal was to evaluate STP survival at 48 months, risk factors for SSI and microbiological features of SSI.

RESULTS

Forty-seven (23%) out of 207 STP developed an SSI. Mortality at 48-months did not differ between SSI and non-SSI patients (12.7% vs. 10.0%; p = 0.59). The fractures of 22 (47%) severe trauma patients with SSI were classified as Cauchoix 3 grade and 18 (38%) SSI were associated with the need for external fixators. Thirty (64%) severe trauma patients with SSI had polymicrobial infection, including 34 (72%) due to Gram-positive cocci. Empirical antibiotic therapy was effective in 31 (66%) cases. Multivariate analysis revealed that risk factors such as low hemoglobin, arterial oxygenation levels, hyperlactatemia, high serum creatinine and glycemia, and Cauchoix 3 grade on the day of surgery were associated with SSI in severe trauma patients. The generated predictive model showed a good prognosis performance with an AUC of 0.80 [0.73-0.88] and a high NPV of 95.9 [88.6-98.5] %.

CONCLUSIONS

Our study found a high rate of SSI in severe trauma patients, although SSI was not associated with 48-month mortality. Several modifiable risk factors for SSI may be effectively managed through enhanced perioperative monitoring and the implementation of a patient blood management strategy.

Infection after intramedullary nailing of femoral and tibial diaphyseal fractures

PURPOSE

Management of fracture-related infection (FRI) after intramedullary fixation (IF) is a challenge. The aim of the present study is to describe a series of 26 patients with FRI after IF and to evaluate factors possibly related to the outcome.

METHODS

Baseline variables were obtained at the time of IF: age, sex, body mass index, affected bone, open fracture, substance abuse, use of an external fixator, type of nail, reaming, soft-tissue reconstruction and surveillance culture result. After diagnosis of the infection, information was obtained about the time interval between IF and diagnosis and classification according to both the Willeneger and Roth and Makridis systems. Treatment modalities were grouped and analysed according to: use of antimicrobials, surgical debridement, nail removal or retention and spacer use. Cultures of bone or deep soft tissues were performed. Patients were followed up for 12 months, and outcomes (remission, relapse, death and loss of follow-up) were evaluated, as well as fracture consolidation.

RESULTS

Remission was observed in 42.3% of patients. There was no significant association between any baseline variable and outcome. There was a significant association between Makridis stage 2 classification and recurrence or death. Treatment strategy was not significantly associated with outcome, and 65.4% of cases had positive culture results, with Enterobacter cloacae as the predominant agent. Consolidation was observed in 81.8% of patients and was not significantly related to the outcome.

CONCLUSION

There was a significant association between Makridis classification and the outcome. Consolidation rate was not associated with the outcome regarding the treatment of the infection.

Do Intrawound Antibiotics Reduce the Incidence of Surgical Site Infections in Pelvic and Lower-Limb Trauma Surgery? A Systematic Review and Meta-analysis

OBJECTIVES

To analyze the efficacy of intraoperative topical antibiotics in reducing the incidence of postoperative surgical site infections in pelvic and lower-limb trauma orthopaedic surgery.

DATA SOURCES

A search of Ovid MEDLINE, PubMed, and Embase was conducted for English language studies published from 1946 through September 3, 2021, using relevant keywords.

STUDY SELECTION

Included studies were randomized controlled trials, cohort studies, or case-control studies reporting on the rate of surgical site infections in adult patients (age 16 and older) who underwent surgical fixation of lower-limb or pelvic traumatic fractures, including both open and closed fractures, with topical intraoperative antibiotics applied to the surgical site before wound closure.

DATA EXTRACTION

Studies were evaluated using the Joanna Briggs Institute Critical Appraisal Checklist for analytical cross-sectional studies. The risk of bias was assessed using the ROBINS-I and Cochrane risk-of-bias tools.

DATA SYNTHESIS

A meta-analysis was conducted using the inverse variance method and random-effects model to assess effect significance and study heterogeneity.

CONCLUSIONS

Seven studies were included in the systematic review. Results of the meta-analysis suggested a potential 23% reduction in the odds of developing a deep surgical site infection in patients treated with intraoperative antibiotic powder compared with those managed with intravenous antibiotics alone (odds ratio 0.77, 95% confidence interval 0.52-1.13), although the results did not reach statistical significance. Further powered studies including randomized controlled trials would be of great value to validate the results suggested in this study and inform best practice intraoperative antibiotic prophylaxis in pelvic and lower-limb trauma surgery.

LEVEL OF EVIDENCE

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

Controlled and Local Delivery of Antibiotics by 3D Core/Shell Printed Hydrogel Scaffolds to Treat Soft Tissue Infections

Soft tissue infections in open fractures or burns are major cause for high morbidity in trauma patients. Sustained, long-term and localized delivery of antimicrobial agents is needed for early eradication of these infections. Traditional (topical or systemic) antibiotic delivery methods are associated with a variety of problems, including their long-term unavailability and possible low local concentration. Novel approaches for antibiotic delivery via wound coverage/healing scaffolds are constantly being developed. Many of these approaches are associated with burst release and thus seldom maintain long-term inhibitory concentrations. Using 3D core/shell extrusion printing, scaffolds consisting of antibiotic depot (in the core composed of low concentrated biomaterial ink 3% alginate) surrounded by a denser biomaterial ink (shell) were fabricated. Denser biomaterial ink (composed of alginate and methylcellulose or alginate, methylcellulose and Laponite) retained scaffold shape and modulated antibiotic release kinetics. Release of antibiotics was observed over seven days, indicating sustained release characteristics and maintenance of potency. Inclusion of Laponite in shell, significantly reduced burst release of antibiotics. Additionally, the effect of shell thickness on release kinetics was demonstrated. Amalgamation of such a modular delivery system with other biofabrication methods could potentially open new strategies to simultaneously treat soft tissue infections and aid wound regeneration.

Preventing Staphylococcus aureus stainless steel-associated infections in orthopedics. A systematic review and meta-analysis of animal literature

Surgical site infection in the presence of orthopedic implants poses significant healthcare and socioeconomic burden. To assess the potential of various prevention strategies against Staphylococcus-induced stainless steel-associated infections, a review of animal evidence was designed. The databases of PubMed, Embase, and CENTRAL were searched until March 10, 2020, for articles including animal models with stainless steel instrumentation and techniques to prevent Staphylococcus infection. We conducted a random-effects meta-analysis of standardized mean differences (SMD) with subgroup analysis linked to various protection strategies and we recorded complications. Quality was assessed with the SYRCLE's risk of bias tool. Twenty-five studies were included. Combined active coating (featuring organic antibacterial compound release) and degradable passive finishing (lipid- or polymer-based structure modification reducing bacterial adhesion) was favored over untreated controls (SMDs for methicillin-sensitive Staphylococcus aureus [MSSA] and methicillin-resistant Staphylococcus aureus [MRSA] were -3.46, 95% CI [-4.53 to -2.4], p < .001 [n = 4 head-to-head comparisons]; and -6.67, 95% CI [-10.53 to -3], p < .001 [n = 5 head-to-head comparisons], respectively). Systemic vitamin D supplementation and systemic antibiotic administration with or without local antibiotics demonstrated favorable outcomes against MSSA infection. On the contrary, no benefit was seen following vaccination. Of note, no side effects were documented. On the basis of data gathered from eight studies, which comprised 294 animals, a bioresorbable polymer- or lipid-based surface modification supplemented with organic coating yielded improved infection-related outcomes against MSSA and MRSA stainless steel infections, and therefore, this strategy could be further investigated in human research.

Antibiotic resistance: still a cause of concern?

Antibiotic resistance remains a global public health concern with significant patient morbidity and tremendous associated health care costs. Drivers of antibiotic resistance are multifaceted and differ between developing and developed countries. Under evolutionary pressure, microbes acquire antibiotic tolerance through a variety of mechanisms at the cellular level. Patients after orthopaedic trauma are vulnerable to drug-resistant pathogens, particularly after open fractures. Traumatologists practicing appropriate antibiotic prophylaxis and treatment regimens mitigate infection and propagation of antibiotic resistance.

Review of calcium-sulphate-based ceramics and synthetic bone substitutes used for antibiotic delivery in PJI and osteomyelitis treatment

Infection in orthopaedic and trauma surgery remains a destructive complication with particularly challenging diagnosis and treatment due to bacterial antibiotic resistance and biofilm formation.

Along with surgical debridement and systemic antibiotics, an important type of adjuvant therapy is local antibiotic delivery, with the purpose of eliminating bacterial colonization and biofilm development.

Calcium sulphate, as a synthetic absorbable biomaterial used for local antibiotic delivery, has experienced an increasing popularity during the last decade, with multiple promoted advantages such as predictable antibiotic elution kinetics, complete and quick biodegradation, good biocompatibility, and limited associated complications.

A series of commercially available antibiotic-delivery systems based on calcium sulphate are under investigation and in clinical use, with different presentations, compositions, and application techniques.

The current article presents the main available calcium-sulphate-based products and the existing data about the clinical and preclinical research results, stemming from their implementation as local antibiotic carriers for surgical site and implant-associated infections treatment and prevention.

Cite this article: EFORT Open Rev 2021;6:297-304. DOI: 10.1302/2058-5241.6.200083

Timing and Management of Surgical Site Infections in Patients With Open Fracture Wounds: A Fluid Lavage of Open Wounds Cohort Secondary Analysis

BACKGROUND

Many studies report on the incidence or prevalence of fracture-related surgical site infections (SSIs) after open fractures; however, few studies report on their timing and management outcomes. To address this gap, we used data from the Fluid Lavage of Open Wounds trial to determine timing of diagnosis, management, and resolution of SSIs.

METHODS

All participants included in this analysis had an SSI after an open fracture. Participants were assigned to a group based on the type of SSI as follows: (1) those who developed a superficial SSI and (2) those who had either a deep or organ/space SSI. Descriptive statistics characterized the type, timing, and management of each SSI.

RESULTS

Of the 2445 participants in the Fluid Lavage of Open Wounds trial, 325 (13.3%) had an SSI. Superficial SSIs were diagnosed significantly earlier [26.5 days, interquartile range (IQR) 12-48] than deep or organ/space SSIs (53 days, IQR 15-119). Of the 325 patients with SSIs, 174 required operative management and 151 were treated nonoperatively. For SSIs managed operatively, median time for infection resolution was 73 days (IQR 28-165), and on average, 1.73 surgeries (95% confidence interval 1.58-1.88) were needed during the 12 months follow-up. There were 24 cases whose SSIs were not resolved at the time of the final follow-up visit (12 months).

CONCLUSIONS

Based on this study's findings and in contradistinction to the Centers for Disease Control and Prevention guidelines, after an open fracture, superficial SSIs were diagnosed at one month and deep/organ/space SSIs at 2 months. This information can allow for earlier infection detection. In addition, the knowledge that approximately 50% of the SSIs in our study required a reoperation and 3 months at a minimum to resolve will assist orthopaedic surgeons when counseling their patients.

LEVEL OF EVIDENCE

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

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.

Antibacterial coating of implants: are we missing something?

Implant-related infection is one of the leading reasons for failure in orthopaedics and trauma, and results in high social and economic costs. Various antibacterial coating technologies have proven to be safe and effective both in preclinical and clinical studies, with post-surgical implant-related infections reduced by 90% in some cases, depending on the type of coating and experimental setup used. Economic assessment may enable the cost-to-benefit profile of any given antibacterial coating to be defined, based on the expected infection rate with and without the coating, the cost of the infection management, and the cost of the coating. After reviewing the latest evidence on the available antibacterial coatings, we quantified the impact caused by delaying their large-scale application. Considering only joint arthroplasties, our calculations indicated that for an antibacterial coating, with a final user's cost price of €600 and able to reduce post-surgical infection by 80%, each year of delay to its large-scale application would cause an estimated 35 200 new cases of post-surgical infection in Europe, equating to additional hospital costs of approximately €440 million per year. An adequate reimbursement policy for antibacterial coatings may benefit patients, healthcare systems, and related research, as could faster and more affordable regulatory pathways for the technologies still in the pipeline. This could significantly reduce the social and economic burden of implant-related infections in orthopaedics and trauma. Cite this article: C. L. Romanò, H. Tsuchiya, I. Morelli, A. G. Battaglia, L. Drago. Antibacterial coating of implants: are we missing something? Bone Joint Res 2019;8:199-206. DOI: 10.1302/2046-3758.85.BJR-2018-0316.

Incidence and risk factors associated with infection after intramedullary nailing of femoral and tibial diaphyseal fractures: Prospective study

BACKGROUND

Diaphyseal fractures of femur and tibia are prominent due to its high incidence and high economic and social impact. Intramedullary nailing (IN) is the surgical procedure of choice. Surgical site infection (SSI) related to this procedure is considered a difficult to treat complication.

AIMS

Determine the incidence of SSI after IN of femoral and tibial diaphyseal fractures and evaluate possible risk factors.

METHODS

Prospective observational cohort study. SSI was defined according to CDC-NHSN criteria and surveillance period for the occurrence of infection was 12 months. Incidence of SSI was calculated as the ratio between the number of patients with SSI and total number of patients. Analysis of potential risk factors included patients-related factors (age, gender, body mass index, active foci of infection, immunosuppressive conditions, ASA score, alcohol or illicit drug abuse, smoking, polytrauma, etiology of fracture, type of fracture if closed or open, classification of fracture according to Müller AO, Tcherne classification for closed fractures, Gustilo-Anderson classification for open fractures, previous surgical manipulation, use of blood products); environmental and surgical-related factors (surgical wound classification, duration of surgery, hair removal, intraoperative contamination, antimicrobial use, presence of drains, hypothermia or hypoxia in the perioperative period, type of IN used, reaming, need for soft tissue reconstruction, use of negative pressure therapy) and microbiota-related factors (cultures of nasopharyngeal swabs forStaphylococcus aureus and axillary/inguinal/perineal swab for Acinetobacter baumannii).

RESULTS

221 patients were included and completed the 12-month follow-up period. Incidence of SSI was 11.8%. In the initial analysis by unadjusted logistic regression, following factors were associated SSI: Müller AO classification of the fracture morphology groups 2 or 3, previous use of external fixator, presence of drains, use of negative pressure therapy and need for muscle or skin flap repair. In the multiple logistic regression-adjusted analysis, previous use of external fixator and need for muscle or skin flap repair remained associated with SSI.

CONCLUSIONS

Incidence of SSI associated with IN for femoral and tibial diaphyseal fractures was 11.8%. Previous use of external fixators and need for muscle or skin flap repair were factors associated with occurrence of infection.

Immunotherapy synergizes with debridement and antibiotic therapy in a murine 1-stage exchange model of MRSA implant-associated osteomyelitis

Methicillin-resistant Staphylococcus aureus (MRSA) reinfection following revision surgery remains a major orthopaedic problem. Toward the development of immunotherapy with anti-glucosaminidase monoclonal antibodies (anti-Gmd), we aimed to: (i) develop a murine 1-stage exchange model of bioluminescent MRSA (USA300LAC::lux) contaminated femoral implants; and (ii) utilize this model to demonstrate the synergistic effects of combination vancomycin and anti-Gmd therapy on reinfection and bone healing. Following an infection surgery, the original plate and two screws were removed on day 7, and exchanged with sterile implants. Mice were randomized to five groups: (i) no infection control; (ii) infected placebo; (iii) anti-Gmd; (iv) vancomycin; and (v) combination therapy. Bioluminescent imaging (BLI) was performed on days 0, 1, 3, 5, 7, 8, 10, 12, and 14. Mice were euthanized on day 14 (day 7 post-revision), and efficacy was assessed via colony forming units (CFU) on explanted hardware, micro-CT, and histology. As monotherapies, anti-Gmd inhibited Staphylococcus abscess communities, and vancomycin reduced CFU on the implants. However, only combination therapy prevented increased BLI post-revision surgery, with a significant 6.5-fold reduction on day 10 (p < 0.05 vs. placebo), and achieved sterile implant levels by day 12. Synergistic effects were also apparent from reduced osteolysis and increased new bone formation around the screws only observed following combination therapy. Taken together, we find that: (i) this murine femoral plate 1-stage revision model can efficiently evaluate therapies to prevent reinfection; and (ii) immunotherapy plays a distinct role from antibiotics to reduce reinfection following revision surgery, such that synergy to achieve osseointegration is possible. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1590-1598, 2018.

FACTORS ASSOCIATED WITH THE DEVELOPMENT OF EARLY INFECTION AFTER SURGICAL TREATMENT OF FRACTURES

OBJECTIVE

Infection after the internal fixation of fractures is a major complication. Early infection is particularly challenging, because it occurs when the fracture is not yet united. The objective of this study is to identify possible factors related to the development of early infection in patients treated with internal fixation for fractures.

METHOD

This retrospective observational study analyzed 24 patients with long bone fractures who underwent internal fixation and developed infections in the post-operatory period. The infections were classified as early (diagnosis in the first two weeks after surgery) or late (diagnosis after 2 weeks).

RESULTS

Of the 24 patients studied, 11 (46%) developed early infections and 13 (54%) were diagnosed with late infections. The early infection group was significantly younger (37.8 versus 53.1 [p = 0.05]) and underwent more surgeries prior to internal fixation (1.2 versus 0.2 [p < 0.00]).

CONCLUSION

Risk factors for the development of early infection in the postoperative period should be considered when treating patients with internal fracture fixation in order to diagnose this condition as early as possible. Level of Evidence IV; Case series.

Fast-resorbable antibiotic-loaded hydrogel coating to reduce post-surgical infection after internal osteosynthesis: a multicenter randomized controlled trial

BACKGROUND

Infection is one of the main reasons for failure of orthopedic implants. Antibacterial coatings may prevent bacterial adhesion and biofilm formation, according to various preclinical studies. The aim of the present study is to report the first clinical trial on an antibiotic-loaded fast-resorbable hydrogel coating (Defensive Antibacterial Coating, DAC®) to prevent surgical site infection, in patients undergoing internal osteosynthesis for closed fractures.

MATERIALS AND METHODS

In this multicenter randomized controlled prospective study, a total of 256 patients in five European orthopedic centers who were scheduled to receive osteosynthesis for a closed fracture, were randomly assigned to receive antibiotic-loaded DAC or to a control group (without coating). Pre- and postoperative assessment of laboratory tests, wound healing, clinical scores and X-rays were performed at fixed time intervals.

RESULTS

Overall, 253 patients were available with a mean follow-up of 18.1 ± 4.5 months (range 12-30). On average, wound healing, clinical scores, laboratory tests and radiographic findings did not show any significant difference between the two groups. Six surgical site infections (4.6%) were observed in the control group compared to none in the treated group (P < 0.03). No local or systemic side-effects related to the DAC hydrogel product were observed and no detectable interference with bone healing was noted.

CONCLUSIONS

The use of a fast-resorbable antibiotic-loaded hydrogel implant coating provides a reduced rate of post-surgical site infections after internal osteosynthesis for closed fractures, without any detectable adverse event or side-effects.

LEVEL OF EVIDENCE

2.