Pathogens in FRI - Do bugs matter? - An analysis of FRI studies to assess your enemy

Fracture-related infection (FRI) is a devasting complication for both patients and their treating Orthopaedic surgeon that can lead to loss of limb function or even amputation. The unique and unpredictable features of FRI make its diagnosis and treatment a significant challenge. It has substantial morbidity and financial implications for patients, their families and healthcare providers. In this article, we perform an in-depth and comprehensive review of FRI through recent and seminal literature to highlight evolving definitions, diagnostic and treatment approaches, focusing on common pathogens such as Staphylococcus aureus, polymicrobial infections and multi-drug-resistant organisms (MDRO). Furthermore, multiple resistance mechanisms and adaptations for microbial survival are discussed, as well as modern evidence-based medical and surgical advancements in treatment strategies in combating FRI.

Costs of fracture-related infection: the impact on direct hospital costs and healthcare utilisation

PURPOSE

Fracture-Related Infection (FRI) is associated with high medical costs and prolonged healthcare utilization. However, limited data is available on the financial impact. The purpose of this study was to investigate the impact of FRI on direct hospital costs and healthcare utilization.

METHODS

This was a retrospective cohort study in a level-1 trauma centre in the Netherlands. Patients ≥ 18 years, after open reduction and internal fixation of a long bone fracture between January 1st 2016 and November 1st 2021, were included. Exclusion criteria were Injury Severity Score (ISS) ≥ 16, indefinable data on costs or incomplete follow-up. Hospital costs related to fracture treatment were individually calculated based on procedure codes raised with a fixed percentage of overhead expenses, in line with hospital billing policies.

RESULTS

In total, 246 patients were included with a median follow-up of 1 year (IQR 0.6-1.8). A total of 45 patients developed FRI, of whom 15 patients had an FRI recurrence. Compared to non-FRI patients, median hospital costs from an FRI patient without and with recurrence, were respectively three (3.1) and seven (7.6) times higher. Compared to non-FRI patients, increased costs in patients with FRI or recurrent FRI are due to respectively a fivefold or even tenfold prolonged length-of-stay, two or seven additional infection-related surgeries, and 21 or 55 days of intravenous antibiotic treatment.

CONCLUSION

Direct healthcare costs of patients with single occurrence of FRI after long bone fracture treatment are three times higher compared to non-FRI patients. In case of FRI-recurrence, the differences in costs might even increase to sevenfold. To put this in perspective, cost of severely injured trauma patients were recently established at approximately 25.000 euros. Compared to non-FRI patients, increased costs in patients with FRI or recurrent FRI are due to respectively a fivefold or even tenfold prolonged length-of-stay, two or seven additional infection-related surgeries and 21 or 55 days of intravenous antibiotic treatment. Not only from patient perspective but also from a financial aspect, it is important to focus on prevention of (recurrent) FRI.

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.

What can they expect? Decreased quality of life and increased postoperative complication rate in patients with a fracture-related infection

BACKGROUND

By gaining insight into the Quality of Life (QoL) status and occurrence of complications, critical facets in the care for patients with Fracture-Related Infection (FRI) can be mitigated and measures can be taken to improve their outcome. Therefore, the aims of this study were to 1) determine the QoL in FRI patients in comparison to non-FRI patients and 2) describe the occurrence of other complications in both FRI and non-FRI patients.

METHODS

An ambidirectional cohort study was conducted in a level 1 trauma centre between January 1st 2016 and November 1st 2021. All patients who underwent surgical stabilisation of an isolated long bone fracture were eligible for inclusion. To avoid confounding, only patients with an Injury Severity Score (ISS) <16 were included. Data regarding patient demographics, fracture characteristics, treatment, follow-up and complications were collected of both non-FRI and FRI patients. QoL was assessed through the use of five-level EuroQol five-dimension (EQ-5D-5L) questionnaires twelve months post-injury.

RESULTS

A total of 134 patients were included in this study, of whom 38 (28%) FRI patients and 96 (72%) non-FRI patients. In comparison to non-FRI patients, FRI patients scored significantly worse on the QoL assessment regarding the index value (p = 0.012) and the domains mobility (p<0.001), usual activities (p = 0.010) and pain/discomfort (p = 0.009). Other postoperative complications were more often reported (p<0.001) in FRI patients (66%, n = 25/38) compared to non-FRI patients (27%, n = 26/96). During the median follow-up of 14.5 months (interquartile range (IQR) 9.5-26.5), 25 FRI patients developed a total of 49 distinctive complications besides FRI. The complications nonunion (18%, n = 9/49), infection other than FRI (e.g. line infection, urinary tract infection, pneumonia) (18%, n = 9/49) and implant failure (14%, n = 7/49) were the most frequently described in the FRI group.

CONCLUSION

Patients who suffered from an FRI have a decreased QoL in comparison to those without an FRI. Moreover, patients with an FRI have a higher rate of additional complications. These findings can help in patient counselling regarding the potential physical and mental consequences of having a complicated course of recovery due to an infection.

Surgical strategy selection and the need for early surgical intervention

The aim of this narrative review is to describe the various surgical management strategies employed in fracture-related infection (FRI), to explore how they are selected and discuss the rationale for early surgical intervention. Surgical treatment options in patients with FRI include debridement, antibiotics and implant retention (DAIR), revision (exchange) or removal. In selecting a treatment strategy, a variety of factors need to be considered, including the condition of the bone, soft tissues, host and causative microorganism. Irrespective of the selected treatment strategy, prompt surgical intervention should be considered in order to confirm the diagnosis of an FRI, to identify the causative organism, remove necrotic or non-viable tissue that can serve as a nidus for ongoing infection, ensure a healthy soft tissue envelope and to prevent the vicious cycle of infection associated with skeletal and/or implant instability. Ultimately, the objective is to prevent the establishment of a persistent infection. Urgent surgery may be indicated in case of active, progressive disease with systemic deterioration, local progression of infection, deterioration of soft tissues, or progressive fracture instability. In case of static disease, the patient should be monitored closely and surgery can be performed on an elective basis, allowing adequate time for optimisation of the host through risk factor modification, optimisation of the soft tissues and careful planning of the surgery.

Implants coating strategies for antibacterial treatment in fracture and defect models: A systematic review of animal studies

Objective

Fracture-related infection (FRI) remains a major concern in orthopaedic trauma. Functionalizing implants with antibacterial coatings are a promising strategy in mitigating FRI. Numerous implant coatings have been reported but the preventive and therapeutic effects vary. This systematic review aimed to provide a comprehensive overview of current implant coating strategies to prevent and treat FRI in animal fracture and bone defect models.

Methods

A literature search was performed in three databases: PubMed, Web of Science and Embase, with predetermined keywords and criteria up to 28 February 2023. Preclinical studies on implant coatings in animal fracture or defect models that assessed antibacterial and bone healing effects were included.

Results

A total of 14 studies were included in this systematic review, seven of which used fracture models and seven used defect models. Passive coatings with bacteria adhesion resistance were investigated in two studies. Active coatings with bactericidal effects were investigated in 12 studies, four of which used metal ions including Ag+ and Cu2+; five studies used antibiotics including chlorhexidine, tigecycline, vancomycin, and gentamicin sulfate; and the other three studies used natural antibacterial materials including chitosan, antimicrobial peptides, and lysostaphin. Overall, these implant coatings exhibited promising efficacy in antibacterial effects and bone formation.

Conclusion

Antibacterial coating strategies reduced bacterial infections in animal models and favored bone healing in vivo. Future studies of implant coatings should focus on optimal biocompatibility, antibacterial effects against multi-drug resistant bacteria and polymicrobial infections, and osseointegration and osteogenesis promotion especially in osteoporotic bone by constructing multi-functional coatings for FRI therapy.

The translational potential of this paper

The clinical treatment of FRI is complex and challenging. This review summarizes novel orthopaedic implant coating strategies applied to FRI in preclinical studies, and offers a perspective on the future development of orthopaedic implant coatings, which can potentially contribute to alternative strategies in clinical practice.

[Treatment strategies for fracture-related infections with concurrent soft tissue damage]

Fracture-related infections are the predominant complication following surgical fracture treatment. The distal lower leg, e.g., in pilon tibial fractures, is at a high risk of infection due to poor soft tissue coverage, particularly in cases of open fractures in this area. Fracture-related infections with significant soft tissue damage require special attention alongside treatment of the infection itself. In general, the principle is that healing of fracture-related infection is not possible without sufficient soft tissue coverage. Therefore, it is crucial to integrate both soft tissue damage and fracture-related infection into a comprehensive treatment plan from the beginning. An interdiscpilinary treatment approach between trauma and plastic surgery is often necessary and beneficial. In cases, where fracture fixation devices or bone is exposed, mid- or long-term use of vacuum-assisted wound therapy is not advisable due to a higher risk of reinfection. Hence, an interdisciplinary treatment strategy involving trauma and plastic surgery should prioritize early soft tissue closure, referred to as the "orthoplastic approach". If this cannot be done in the own hospital, early patient transfer is indicated to ensure optimal interdisciplinary therapy with early soft tissue closure and simultaneous trauma surgical treatment to control the infection and enable bone healing. Free fasciocutaneous or muscle flap techniques in combination with adequate trauma surgical and antibiotic therapy lead to good reliable results in these situations.

A practical definition of pin site infection

Pin Site Infection (PSI) is the most common complication of external fixation treatment. Several classifications and diagnostic approaches have been used with reported incidences varying widely from 1 to 100 %. The quality of the existing literature is limited by the absence of a definition. This renders comparing literature and developing evidence-based algorithms for prevention, diagnostics, and treatment difficult to impossible. Similar problems were identified with prosthetic joint infection (PJI) and fracture-related infection (FRI) in recent years, resulting in new, validated definitions. PSI is complicated by the complexity of the issue. Numerous factors in PSI need consideration. Factors may be related to the patient, the surgical technique, the pin-bone interface, the pin-skin interface, the choice of external fixation device and/or the material used and its properties. Reliably diagnosing PSI is one of the most pressing issues. New definitions for FRI or PJI have diagnostic criteria which can be either confirmatory or suggestive. Any positive finding of a confirmatory criterion constitutes an infection. Although PSI resembles PJI and FRI, distinct differences are present. The skin is never closed, and bacterial colonization is inevitable along the treatment duration. The external fixator is only temporarily in place; thus, the goal of all measures is to continue the external fixator until the intended indication is reached. This paper proposes the principles of a definition of PSI. This definition is not designed to guide any treatment of PSI. Its purpose is to create common ground for clinical investigations and publishing further research.

[Diagnostic and therapeutic work-up of infected tibial nonunion]

BACKGROUND

The failure of bone fracture healing is one of the major complications of fracture treatment, especially of the tibia due to its limited soft tissue coverage and high rate of open injuries. Although implant development is constantly progressing and modern surgical techniques are continuously improving, infected tibial nonunion plays a decisive role in terms of its variable clinical presentation.

OBJECTIVE

This article provides guidelines for the successful surgical treatment of infected tibial nonunion.

MATERIAL AND METHOD

Strategies are presented to identify infection as a cause of failure of fracture healing and to achieve infection and bone healing.

RESULTS

A significant amount of tibial nonunions primarily thought to be aseptic ultimately turn out to be infected nonunions.

CONCLUSION

The treatment of infected tibial nonunion requires extensive clinical, radiological and laboratory diagnostics as well as a profound biomechanical and biological understanding of the bone situation. This is the only way to achieve rapid osseous healing with as few revision interventions as possible.

Diagnostic Performance of a telephone questionnaire for fracture-related infections (FRIs) in open tibia fracture patients in Tanzania

INTRODUCTION

Fracture-related infections (FRIs) are a major cause of trauma-associated morbidity worldwide. In 2018, an expert group supported by the AO Foundation, European Bone and Joint Infection Society developed a consensus definition of FRI. Still, there is limited knowledge on the applicability of this definition in low- and middle-income countries (LMICs). Given the unique barriers that cause low follow-up rates for orthopaedic trauma patients in LMICs, this study aims to evaluate the diagnostic performance of a telephone questionnaire in identifying patients with FRIs after open tibia fracture fixation in Tanzania.

MATERIALS AND METHODS

Patients from a randomized controlled trial investigating the infection prevention benefit of locally applied gentamycin for open tibial fractures were included. Patients completed FRI based telephone questionnaires 7-10 days prior to scheduled follow-ups at 6 weeks, 3 months, 6 months, 9 months, and 1 year. The questionnaire included two "confirmatory" criteria questions for FRI (i.e., open wound and purulent drainage) and three "suggestive" criteria questions (i.e., wound drainage, fever, and warmth). Contingency tests were performed to identify the sensitivity and specificity between answers and adjudicated FRI diagnoses at the corresponding in-person follow-up. Data was analysed using STATA version 15.0 and MedCalc's online diagnostic test calculator.

RESULTS

There were a total of 234 complete questionnaires and 85 unique patients included. The sensitivity and specificity of having any positive answer in the questionnaire was highest at 6 months (100 % and 92.5 %, respectively). For all time-points pooled, sensitivity was 71.4 % and specificity was 93.0 %. Drainage had the highest sensitivity (71.4 %) while fever had the highest specificity (99.6 %). For confirmatory criteria, sensitivity was 14.3 % and specificity was 96.0 %. Contrastingly, the sensitivity for suggestive criteria was higher (71.4 %), with a similar specificity (93.8 %).

CONCLUSION

Our study indicates that telephone questionnaires have adequate diagnostic performance when assessing FRIs. The presence of drainage identified the majority of patients with FRI, and specificities were high across confirmatory and suggestive criteria. Our study is one of the first to evaluate telephone questionnaires as a diagnostic tool for FRIs in patients with open tibia fractures in a LMIC hospital and validates the FRI consensus definition criteria.

Key aspects of soft tissue management in fracture-related infection: recommendations from an international expert group

A judicious, well-planned bone and soft tissue debridement remains one of the cornerstones of state-of-the-art treatment of fracture-related infection (FRI). Meticulous surgical excision of all non-viable tissue can, however, lead to the creation of large soft tissue defects. The management of these defects is complex and numerous factors need to be considered when selecting the most appropriate approach. This narrative review summarizes the current evidence with respect to soft tissue management in patients diagnosed with FRI. Specifically we discuss the optimal timing for tissue closure following debridement in cases of FRI, the need for negative microbiological culture results from the surgical site as a prerequisite for definitive wound closure, the optimal type of flap in case of large soft tissue defects caused by FRI and the role of negative pressure wound therapy (NPWT) in FRI. Finally, recommendations are made with regard to soft tissue management in FRI that should be useful for clinicians in daily clinical practice.Level of evidence Level V.

Alginate microbeads and hydrogels delivering meropenem and bacteriophages to treat Pseudomonas aeruginosa fracture-related infections

Bacteriophage (phage) therapy has shown promise in treating fracture-related infection (FRI); however, questions remain regarding phage efficacy against biofilms, phage-antibiotic interaction, administration routes and dosing, and the development of phage resistance. The goal of this study was to develop a dual antibiotic-phage delivery system containing hydrogel and alginate microbeads loaded with a phage cocktail plus meropenem and evaluate efficacy against muti-drug resistant Pseudomonas aeruginosa. Two phages (FJK.R9-30 and MK.R3-15) displayed enhanced antibiotic activity against P. aeruginosa biofilms when tested in combination with meropenem. The antimicrobial activity of both antibiotic and phage was retained for eight days at 37 °C in dual phage and antibiotic loaded hydrogel with microbeads (PA-HM). In a mouse FRI model, phages were recovered from all tissues within all treatment groups receiving dual PA-HM. Moreover, animals that received the dual PA-HM either with or without systemic antibiotics had less incidence of phage resistance and less serum neutralization compared to phages in saline. The dual PA-HM could reduce bacterial load in soft tissue when combined with systemic antibiotics, although the infection was not eradicated. The use of alginate microbeads and injectable hydrogel for controlled release of phages and antibiotics, leads to the reduced development of phage resistance and lower exposure to the adaptive immune system, which highlights the translational potential of the dual PA-HM. However, further optimization of phage therapy and its delivery system is necessary to achieve higher bacterial killing activity in vivo in the future.

Treatment of bone infections in children in low-income countries - A practical guideline based on clinical cases

In low-income countries (LIC), the management of bone infections is a huge challenge. A high number of patients are in the pediatric age group. Children and adolescents exhibit good bone healing potential offering treatment options that mainly rely on the biological response of the infected bone. The purpose of this article is to highlight treatment options for these patients in LIC, which is based on clinical cases that illustrate the principles of the treatment, focusing on bone reaction and healing potential. First, identification of emergency cases is of importance. Sepsis of the patient due to bone infections is a life-threatening disease that requires immediate surgical attention with abscess incision. It should be tailored to the surgeon's experience and local conditions to avoid unwanted complications, such as excessive bleeding, fracture or bone loss. In non-septic patients, uncomplicated cases should be distinguished from complicated cases as the first might often require only abscess incision, particularly in small children, without any other major surgical intervention. Biomechanical stability and bone formation capacity, soft tissue conditions and joint involvement are decisive factors differentiating uncomplicated from complicated cases. Central treatment column is the immobilization of the infected bone with simple methods, such as plaster of Paris, braces or external fixation. This is intended to provide sufficient stability to allow for new bone formation that subsequently downsizes the infection site and that can bridge previously infected non-union sites or bone defects. In most cases, antibiotic treatment is not performed as antibiotics are not available or affordable. Severe soft tissue defects remain a major challenge as microvascular surgical experience is often required for reliable coverage, for which referral to one of the very few specialized centers is recommended. Major bone defects should also be treated in centers with sufficient expertise for bone reconstruction procedures. Regular follow-ups are important to ensure healing and to avoid aggravation of the disease. Encouraging success rates can be achieved by these treatment principles. However, it should not be forgotten that poverty in these countries, including limited access to health care, remains one of the world's most important problems.

A fluorogenic micrococcal nuclease-based probe for fast detection and optical imaging of Staphylococcus aureus in prosthetic joint and fracture-related infections

PURPOSE

Staphylococcus aureus is the most common and impactful multi-drug resistant pathogen implicated in (periprosthetic) joint infections (PJI) and fracture-related infections (FRI). Therefore, the present proof-of-principle study was aimed at the rapid detection of S. aureus in synovial fluids and biofilms on extracted osteosynthesis materials through bacteria-targeted fluorescence imaging with the 'smart-activatable' DNA-based AttoPolyT probe. This fluorogenic oligonucleotide probe yields large fluorescence increases upon cleavage by micrococcal nuclease, an enzyme secreted by S. aureus.

METHODS

Synovial fluids from patients with suspected PJI and extracted osteosynthesis materials from trauma patients with suspected FRI were inspected for S. aureus nuclease activity with the AttoPolyT probe. Biofilms on osteosynthesis materials were imaged with the AttoPolyT probe and a vancomycin-IRDye800CW conjugate (vanco-800CW) specific for Gram-positive bacteria.

RESULTS

38 synovial fluid samples were collected and analyzed. Significantly higher fluorescence levels were measured for S. aureus-positive samples compared to, respectively, other Gram-positive bacterial pathogens (p < 0.0001), Gram-negative bacterial pathogens (p = 0.0038) and non-infected samples (p = 0.0030), allowing a diagnosis of S. aureus-associated PJI within 2 h. Importantly, S. aureus-associated biofilms on extracted osteosynthesis materials from patients with FRI were accurately imaged with the AttoPolyT probe, allowing their correct distinction from biofilms formed by other Gram-positive bacteria detected with vanco-800CW within 15 min.

CONCLUSION

The present study highlights the potential clinical value of the AttoPolyT probe for fast and accurate detection of S. aureus infection in synovial fluids and biofilms on extracted osteosynthesis materials.

Relevance of a bone and joint registry for fracture-related infections

The UK Bone and Joint Infection Registry (BAJIR) is a national project established in 2018 with the aim of collecting information about demographics, co-morbidities, pathogens, treatment strategies and outcomes on all patients who are diagnosed with, and treated for, a bone or joint infection in the UK with the objective of providing an understanding of the burden of disease. In time these data will be used to inform best practice, direct research and provide information for commissioners of healthcare. In this fracture-related infection special edition article, we discuss the registry's development, relevance and how we see it directing our practice in the future. Equally, we have highlighted some potential limitations and lessons learned.

Proposal for a multicentre regional registry

Postoperative bone infection is a severe complication in the treatment of fractures. The management of this pathology is challenging, but recent advances have been made to achieve standardization that can help diagnosis and decision-making. However, we are unaware of studies validating these models in Latin America. Therefore, this study aims to collect data from patients with fracture-related infections treated in different institutions in Latin America to create a registry that will assist in future clinical decision-making regarding the diagnostic process and the surgical and medical treatment of these patients.

Gentamicincoated tibial nail is an effective prevention method for fracture-related infections in open tibial fractures

Fracture-related infection (FRI) is a common complication following open tibia fracture (OTF), especially in patients with high-energy trauma or comorbidities. The use of gentamicin-coated nail (GCN) has been proposed as a local adjuvant to prevent FRI in high-risk patients.

HYPOTHESIS

The incidence of FRI is expected to be lower in OTF treated with a GCN, alongside with no detrimental effects on fracture healing time.

OBJECTIVES

This study aimed to evaluate the effectiveness of GCNs as a definitive fixation method and prophylaxis for FRI in OTFs. Secondary outcomes included non-union rates and time to healing.

METHODS

The study design was a mixed cohort, including a prospective group of patients treated with GCN (Expert Tibial Nail PROtect™, Depuy Synthes, Johnson&Johnson Company Inc, New Jersey, USA) and a retrospectively evaluated group treated with non-gentamicin-coated nail (NGCN). Patients with at least 12 months of follow-up were included. The treatment protocol consisted of timely administration of antibiotics, surgical debridement, and early soft-tissue coverage. Exclusion criteria included protocol infringement, traumatic amputation, and loss of follow-up. Statistical analysis was performed using Stata v14.0, with a significance level of p < 0.05.

RESULTS

The study included 243 patients, 104 in GCN group and 139 NGCN group. External Fixator use was higher in the NGCN group, but this did not significantly affect the FRI rate. GCN use was associated with a significantly lower incidence of FRI (2.88% GCN group vs. 15.83% NGCN group, OR 0.16, p < 0.01). Furthermore, GCN use was found to be a protective factor against tibial non-union (OR 0.41, p = 0.03). There were no adverse effects attributed to locally administered gentamycin. The NGCN cohort had a higher incidence of polytrauma, although the difference was not statistically significant. A longer time to heal as well as more FRI and Non-union according to the progression in Gustilo-Anderson classification was observed in the GCN group.

CONCLUSION

Our findings suggest that GCN is an effective prophylactic method to reduce the risk of FRI in open tibial fractures at 12-month follow-up, as well as, probably derived from this protective effect, leading to lower fracture consolidation times when compared with cases treated without GCN.

Risk factors for fracture-related infection after ankle fracture surgery

INTRODUCTION

Ankle fracture surgery comes with a risk of fracture-related infection (FRI). Identifying risk factors are important in preoperative planning, in management of patients, and for information to the individual patient about their risk of complications. In addition, modifiable factors can be addressed prior to surgery. The aim of the current paper was to identify risk factors for FRI in patients operated for ankle fractures.

METHODS

A cohort of 1004 patients surgically treated for ankle fractures at Haukeland University Hospital in the period of 2015-2019 was studied retrospectively. Patient charts and radiographs were assessed for the diagnosis of FRI. Binary logistic regression was used in analyses of risk factors. Regression coefficients were used to calculate the probability for FRI based on the patients' age and presence of one or more risk factors.

RESULTS

FRI was confirmed in 87 (9%) of 1004 patients. Higher age at operation (p < .001), congestive heart failure (CHF), p = 0.006), peripheral artery disease (PAD, p = 0.001), and current smoking (p = .006) were identified as risk factors for FRI. PAD and CHF were the risk factors displaying the strongest association with FRI with an adjusted odds ratio of 4.2 (95% CI 1.8-10.1) and 4.7 (95% CI 1.6-14.1) respectively.

CONCLUSION

The prevalence of FRI was 9% after surgical treatment of ankle fractures. The combination of risk factors found in this study demonstrate the need for a thorough, multidisciplinary, and careful approach when faced with an elderly or frail patient with an ankle fracture. The results of this study help the treating surgeons to inform their patients of the risk of FRI prior to ankle fracture surgery.

LEVEL OF EVIDENCE

Level III retrospective case-control study.

Fracture-related infections

Fracture-related infection is a serious complication which can occur following musculoskeletal injury and is associated with significant morbidity. These complications can be challenging to recognise, and experts have provided a clearer definition of fracture-related infection to help with the diagnosis and detection of these infections. This system includes clinical, radiological and laboratory-based diagnostic features which are either confirmatory or suggestive of fracture-related infection. Treatment requires a multifaceted approach with multidisciplinary involvement, and generally a combination of surgical techniques and prolonged antibiotics, the timing and choice of which should be optimised. This article provides an evidence-based review of the British Orthopaedic Association Standards for Trauma for the diagnosis and management of fracture-related infections.

Treatment and outcome of fracture-related infection of the clavicle

INTRODUCTION

The number of operatively treated clavicle fractures has increased over the past decades. Consequently, this has led to an increase in secondary procedures required to treat complications such as fracture-related infection (FRI). The primary objective of this study was to assess the clinical and functional outcome of patients treated for FRI of the clavicle. The secondary objectives were to evaluate the healthcare costs and propose a standardized protocol for the surgical management of this complication.

METHODS

All patients with a clavicle fracture who underwent open reduction and internal fixation (ORIF) between 1 January 2015 and 1 March 2022 were retrospectively evaluated. This study included patients with an FRI who were diagnosed and treated according to the recommendations of a multidisciplinary team at the University Hospitals Leuven, Belgium.

RESULTS

We evaluated 626 patients with 630 clavicle fractures who underwent ORIF. In total, 28 patients were diagnosed with an FRI. Of these, eight (29%) underwent definitive implant removal, five (18%) underwent debridement, antimicrobial treatment and implant retention, and fourteen patients (50%) had their implant exchanged in either a single-stage procedure, a two-stage procedure or after multiple revisions. One patient (3.6%) underwent resection of the clavicle. Twelve patients (43%) underwent autologous bone grafting (tricortical iliac crest bone graft (n = 6), free vascularized fibular graft (n = 5), cancellous bone graft (n = 1)) to reconstruct the bone defect. The median follow-up was 32.3 (P₂₅-P₇₅: 23.9-51.1) months. Two patients (7.1%) experienced a recurrence of infection. The functional outcome was satisfactory, with 26 out of 28 patients (93%) having full range of motion. The median healthcare cost was € 11.506 (P₂₅-P₇₅: € 7.953-23.798) per patient.

CONCLUSION

FRI is a serious complication that can occur after the surgical treatment of clavicle fractures. In our opinion, when treated adequately using a multidisciplinary patient-specific approach, the outcome of patients with an FRI of the clavicle is good. The median healthcare costs of these patients are up to 3.5 times higher compared to non-infected operatively treated clavicle fractures. Although not studied individually, we consider factors such as the size of the bone defect, condition of the soft tissue, and patient demand important when it comes to guiding our surgical decision making in cases of osseous defects.

The value of sonication in the differential diagnosis of septic and aseptic femoral and tibial shaft nonunion in comparison to conventional tissue culture and histopathology: a prospective multicenter clinical study

BACKGROUND

Septic and aseptic nonunion require different therapeutic strategies. However, differential diagnosis is challenging, as low-grade infections and biofilm-bound bacteria often remain undetected. Therefore, the examination of biofilm on implants by sonication and the evaluation of its value for differentiating between femoral or tibial shaft septic and aseptic nonunion in comparison to tissue culture and histopathology was the focus of this study.

MATERIALS AND METHODS

Osteosynthesis material for sonication and tissue samples for long-term culture and histopathologic examination from 53 patients with aseptic nonunion, 42 with septic nonunion and 32 with regular healed fractures were obtained during surgery. Sonication fluid was concentrated by membrane filtration and colony-forming units (CFU) were quantified after aerobic and anaerobic incubation. CFU cut-off values for differentiating between septic and aseptic nonunion or regular healers were determined by receiver operating characteristic analysis. The performances of the different diagnostic methods were calculated using cross-tabulation.

RESULTS

The cut-off value for differentiating between septic and aseptic nonunion was ≥ 13.6 CFU/10 ml sonication fluid. With a sensitivity of 52% and a specificity of 93%, the diagnostic performance of membrane filtration was lower than that of tissue culture (69%, 96%) but higher than that of histopathology (14%, 87%). Considering two criteria for infection diagnosis, the sensitivity was similar for one tissue culture with the same pathogen in broth-cultured sonication fluid and two positive tissue cultures (55%). The combination of tissue culture and membrane-filtrated sonication fluid had a sensitivity of 50%, which increased up to 62% when using a lower CFU cut-off determined from regular healers. Furthermore, membrane filtration demonstrated a significantly higher polymicrobial detection rate compared to tissue culture and sonication fluid broth culture.

CONCLUSIONS

Our findings support a multimodal approach for the differential diagnosis of nonunion, with sonication demonstrating substantial usefulness.

LEVEL OF EVIDENCE

Level 2 Trial registration DRKS00014657 (date of registration: 2018/04/26).

Femoral shaft fractures in eldery patients - An epidemiological risk analysis of incidence, mortality and complications

OBJECTIVES

This work aimed at answering the following research questions: (1) What is the incidence of femoral shaft fractures in the geriatric population in the U.S.? (2) What is the rate of mortality, mechanical complications, nonunion and infection, and what are the associated risk factors?

STUDY DESIGN AND SETTING

In this cross-sectional study, femoral shaft fractures occurred between January 1, 2009, and December 31, 2019, were identified from Medicare records. Rates of mortality, nonunion, infection, and mechanical complications were calculated with the Kaplan-Meier method with Fine and Gray sub-distribution adaptation. Semiparametric Cox regression was applied with twenty-three covariates to determine risk factors.

RESULTS

Between 2009 through 2019 the incidence of femoral shaft fractures decreased by 12.07% to 40.8/100,000 inhabitants (p = 0.549). The 5-year mortality risk was 58.5%. Male sex, age over 75 years, chronic obstructive pulmonary disease, cerebrovascular disease, chronic kidney disease, congestive heart failure, diabetes mellitus, osteoporosis, tobacco dependence, and lower median household income were significant risk factors. The infection rate was 2.22% [95%CI: 1.90-2.58] and the union failure rate 2.52% [95%CI: 2.17-2.92] after 24 months.

CONCLUSION

An early assessment of individual patient risk factors may be beneficial in the care and treatment of patients with these fractures.

Radiographic parameters associated with fracture-related infection in high energy bicondylar tibial plateau fractures managed with two-stage treatment: Identifying the bad actors

INTRODUCTION

High energy tibial plateau fractures are fraught with complications, particularly fracture-related infection (FRI). Previous studies have evaluated patient demographics, fracture classification, and injury characteristics as risk factors for FRI in patients with these injuries. This study evaluated the relationship between radiographic parameters (fracture length relative to femoral condyle width (FLF ratio), initial femoral displacement (FD ratio), and tibial widening (TW ratio)) and fracture-related infection following internal fixation in high energy bicondylar tibial plateau fractures.

METHODS

225 patients treated for bicondylar tibial plateau fractures at two level I trauma centers were retrospectively reviewed. Patient characteristics, fracture classification, and radiographic measurements were analyzed to determine association with FRI.

RESULTS

The rate of FRI was 13.8%. Increased fracture length, FLF ratio, FD ratio, TW ratio, and fibula fracture were each associated with FRI on regression analysis, independent of clinical variables. Cutoff values were identified for each parameter and patients were risk stratified based on these radiographic parameters. High-risk patients had a 2.68- and 12.36-times risk of FRI compared to medium and low-risk patients, respectively.

DISCUSSION

This study is the first to examine the relationship between radiographic parameters and FRI in high energy bicondylar tibial plateau fractures. Fracture length, FLF ratio, FD ratio, TW ratio, and fibula fracture were identified as radiographic parameters associated with FRI. More importantly, risk stratifying patients based on these parameters accurately identified patients at increased risk of FRI. Not all bicondylar tibial plateau fractures are created equal and radiographic parameters can be utilized to help identify the bad actors.

Implant retention with serial debridement and use of antibiotic-loaded calcium sulfate beads in acute fracture-related infection (FRI) after pelvic ring or acetabular fractures: A retrospective case series of 7 cases

BACKGROUND

The development of a pelvic wound infection in the presence of hardware after open reduction and internal fixation presents a clinical dilemma and there is little literature to aid in decision-making. The purpose of this study was to describe the possibility of debridement, antibiotic pearls and retention of the implant (DAPRI) procedure to eradicate the infection.

METHODS

Tumor-like debridement, antibiotic pearls and retention of the implant (DAPRI) aimed to remove the biofilm allowing a higher and prolonged local antibiotic concentration by using calcium sulfate antibiotic-added beads. Wound status, radiological signs of bone healing, gait and functional activity of the patient were evaluated.

RESULTS

Seven patients underwent this technique. The mean follow up time was nine months (range: 6 -16 months). Complete wound healing was achieved in all the patients with no major complications. Average time of bony union was 4.3 months (range: 3-6 months) with no need for implant removal.

CONCLUSION

The DAPRI technique might represent a safe and more conservative treatment for management of early fracture-related infections (FRI) of the pelvis and acetabulum.

Intrawound application of vancomycin reduces the proportion of fracture-related infections in high-risk tibial plateau fractures

INTRODUCTION

Despite the improvements in surgical techniques and the use of prophylactic intravenous antibiotics, the fracture-related infection (FRI) incidence after high-risk tibial plateau fractures remains high. This study aimed to evaluate the clinical effect of the intrawound application of vancomycin on the FRI after high-risk tibial plateau fracture surgery.

METHODS

A total of 243 patients who underwent high-risk tibial plateau fracture surgery from May 2013 to June 2021 were retrospectively reviewed. Of these, 233 cases were enrolled. Considering the preoperative patient condition, surgeons applied vancomycin powder directly into the surgical site before wound closure in 105 cases (intrawound application of vancomycin powder with preoperative intravenous cephalosporin). The remaining 128 cases served as the control group (preoperative intravenous cephalosporin alone). Clinical data and surgical details were recorded. The Cox proportional hazards regression analysis was used to assess risk factors for FRI. The Kaplan-Meier method and the log rank test illustrated the infection status of patients based on the application of intrawound vancomycin. The primary outcome was an FRI within one year. Secondary outcomes included bacterial culture and vancomycin-related complications.

RESULTS

Our study demonstrated a significant difference in the incidence of FRI between the vancomycin group and the control group (3.8% versus 10.9%; p=0.041). Multivariable Cox regression showed the intrawound application of vancomycin powder decreased the rate of FRI. There were no complications related to intrawound vancomycin observed during follow-up. The presence of Gram-positive FRI was higher in the control group compared with the vancomycin group.

CONCLUSIONS

Intrawound application of vancomycin was associated with a significant lower rate of FRI after high-risk tibial plateau fracture surgery compared to the control group.

Analyzing risk factors for treatment failure in fracture-related infection

INTRODUCTION

Fracture-related infection (FRI) represents a challenging clinical scenario. Limited evidence exists regarding treatment failure after initial management of FRI. The objective of our investigation was to determine incidence and risk factors for treatment failure in FRI.

MATERIALS AND METHODS

We conducted a retrospective review of patients treated for FRI between 2011 and 2015 at three level 1 trauma centers. One hundred and thirty-four patients treated for FRI were identified. Demographic and clinical variables were extracted from the medical record. Treatment failure was defined as the need for repeat debridement or surgical revision seven or more days after the presumed final procedure for infection treatment. Univariate comparisons were conducted between patients who experienced treatment failure and those who did not. Multivariable logistic regression was conducted to identify independent associations with treatment failure.

RESULTS

Of the 134 FRI patients, 51 (38.1%) experienced treatment failure. Patients who failed were more likely to have had an open injury (31% versus 17%; p = 0.05), to have undergone implant removal (p = 0.03), and additional index I&D procedures (3.3 versus 1.6; p < 0.001). Most culture results identified a single organism (62%), while 15% were culture negative. Treatment failure was more common in culture-negative infections (p = 0.08). Methicillin-resistant Staphylococcus aureus (MRSA) was the most common organism associated with treatment failure (29%; p = 0.08). Multivariate regression demonstrated a statistically significant association between treatment failure and two or more irrigation and debridement (I&D) procedures (OR 13.22, 95% CI 4.77-36.62, p < 0.001) and culture-negative infection (OR 4.74, 95% CI 1.26-17.83, p = 0.02).

CONCLUSIONS

The rate of treatment failure following FRI continues to be high. Important risk factors associated with treatment failure include open fracture, implant removal, and multiple I&D procedures. While MRSA remains common, culture-negative infection represents a novel risk factor for failure, suggesting aggressive treatment of clinically diagnosed cases remains critical even without positive culture data.

LEVEL OF EVIDENCE

Retrospective cohort study; Level III.

Fracture-related infection: Prevalence and application of the new consensus definition in a cohort of 1004 surgically treated ankle fractures

BACKGROUND

Surgical treatment of ankle fractures comes with a substantial risk of complications, including infection. An unambiguously definition of fracture-related infections (FRI) has been missing. Recently, FRI has been defined by a consensus group with a diagnostic algorithm containing suggestive and confirmatory criteria. The aim of the current study was to report the prevalence of FRI in patients operated for ankle fractures and to assess the applicability of the diagnostic algorithm from the consensus group.

PATIENTS AND METHODS

Records of all patients with surgically treated ankle fractures from 2015 to 2019 were retrospectively reviewed for signs of postoperative infections. Patients with suspected infection were stratified according to confirmatory or suggestive criteria of FRI. Rate of FRI among patients with confirmatory and suggestive criteria were calculated.

RESULTS

Suspected infection was found in 104 (10%) out of 1004 patients. Among those patients, confirmatory criteria were met in 76/104 (73%) patients and suggestive criteria were met in 28/104 (27%) at first evaluation. Patients with clinical confirmatory criteria (N = 76) were diagnosed with FRI. Patients with suggestive criteria were further examined with either bacterial sampling at the outpatient clinic, revision surgery including bacterial sampling, or a wait-and-see approach. Eleven (39%) of the 28 patients had positive cultures and were therefore diagnosed as having FRI at second evaluation. In total 87 (9%) patients were diagnosed with FRI according to the consensus definition. Only 73 (70%) of the 104 patients with suspected FRI had adequate bacterial sampling.

CONCLUSION

The prevalence of FRI, applying the FRI-consensus criteria, for patients with surgically treated ankle fractures was 9%. Twenty-two percent of patients who met the confirmatory criteria had negative bacterial cultures. The current study shows that we did not have a systematic approach to patients with suspected FRI as recommended by the consensus group. A systematic approach to adequate bacterial sampling when FRI is suspected is paramount. The consensus definition of FRI and its diagnostic algorithm facilitates such an approach.

LEVEL OF EVIDENCE

Level III - retrospective cohort study.

Comparative analysis of pathogen distribution in patients with fracture-related infection and periprosthetic joint infection: a retrospective study

BACKGROUND

The purpose of this study is to investigate the microbial patterns of periprosthetic joint infection (PJI) and fracture-related infection (FRI), and guide for the formulation of more accurate empirical antimicrobial regimens based on the differences in pathogen distribution.

METHODS

A comparative analysis of pathogen distribution was conducted between 153 patients (76 with PJI and 77 with FRI). Predicted analyses against isolated pathogens from two cohorts were conducted to evaluate the best expected efficacy of empirical antimicrobial regimens (imipenem + vancomycin, ciprofloxacin + vancomycin, and piperacillin/tazobactam + vancomycin).

RESULTS

Our study found significant differences in pathogen distribution between the PJI and FRI cohorts. Staphylococci (61.3% vs. 31.9%, p = 0.001) and Gram-negative bacilli (GNB, 26.7% vs. 56.4%, p < 0.001) were responsible for the majority of infections both in the PJI and FRI cohorts, and their distribution in the two cohorts showed a significant difference (p < 0.001). Multi-drug resistant organisms (MDRO) were more frequently detected in the FRI cohort (29.3% vs. 44.7%, p = 0.041), while methicillin-resistant coagulase-negative Staphylococci (MRCoNS, 26.7% vs. 8.5%, p = 0.002) and Canidia albicans (8.0% vs. 1.1%, p = 0.045) were more frequently detected in the PJI cohort. Enterobacter spp. and Acinetobacter baumannii were detected only in the FRI cohort (11.7% and 8.5%, respectively).

CONCLUSIONS

Staphylococci and GNB were responsible for the majority of infections in both PJI and FRI. Empirical antimicrobial therapy should focus on the coverage of Staphylococci in PJI and GNB in FRI, and infections caused by MDROs should be more vigilant in FRI, while the high incidence of MRCoNS in PJI should be noted, which could guide for the formulation of more accurate empirical antimicrobial regimens. Targeted therapy for FRI caused by A. baumannii and PJI caused by C. albicans needs to be further investigated. Our study reports significant differences in pathogen distribution between the two infections and provides clinical evidence for studies on the mechanism of implant-associated infection.

Biofilms-What Should the Orthopedic Surgeon know?

Background

Musculoskeletal infections are a major source of morbidity for orthopedic and trauma patients, are associated with prolonged treatment times, and, unfortunately, suffer from poor functional outcomes. Further complicating the issue, antimicrobial resistance (AMR) is increasingly impacting the treatment of musculoskeletal infections with a diminishing repertoire of effective antibiotic agents for some highly resistant pathogens. Most orthopedic surgical procedures involve implants, and the formation of bacterial biofilms on these implants is now recognized as a major factor contributing to the failure of antibiotic therapy in orthopedic surgery.

Methods

This review presents an overview of the types, structure, formation, and pathogenesis of biofilms as they pertain to musculoskeletal infections. Furthermore, it describes the key concepts in the management of biofilms and future perspectives for the better treatment of patients with biofilm-related musculoskeletal infections.

Results

A bacterial biofilm is a dynamic, living conglomerate of bacteria encased in an extracapsular polysaccharide matrix (EPS). Biofilms are a natural mode of survival for virtually all bacterial species, including both Grampositive and Gram-negative bacteria, as well as fungi. The biofilm model of growth confers resistance by several well-defined mechanisms regardless of the species of the microorganism. In most cases, biofilm management often necessitates radical measures to ensure eradication including both surgical and medical interventions.

Conclusions

Orthopedic surgeons should be aware of the key concepts pertaining to biofilms, and the impact that these can have on clinical practice.

Use of negative pressure wound therapy in patients with fracture-related infection more than doubles the risk of recurrence

PURPOSE

Fracture-related infection (FRI) is one of the most serious complications in orthopedic trauma surgery. Despite its widespread use, the role of Negative Pressure Wound Therapy (NPWT) remains controversial in the management pathway of FRI. The aim of this study was to assess the relationship between the application of NPWT and its duration and recurrence of infection in operatively treated FRI patients.

PATIENTS AND METHODS

This is a retrospective cohort study based on the FRI database of three level 1 Trauma Centres. Included patients had to be at least 16 years of age and surgically treated for FRI between January 1st 2015 and September 1st 2020. Patients were subdivided in either the NPWT group, when NPWT was applied as part of the FRI treatment, or in the control group, when no NPWT had been applied. To limit confounding, patients were excluded if they (also) underwent NPWT prior to the diagnosis of FRI. The relation between the duration of NPWT during FRI treatment and the recurrence rate of infection was analyzed using a multivariable logistic regression model.

RESULTS

A total of 263 patients were included, 99 in the NPWT group and 164 in the control group. The median duration of NPWT was 18.0 (IQR 15.8) days. In the NPWT group, 28 patients (28.3%) developed a recurrent FRI. In the control group, 19 patients (11.6%) had a recurrent FRI (p = 0.001, 95% CI [0.174 - 0.635]). In the NPWT group there were no significant differences in baseline characteristics between the recurrence and non-recurrence group. The duration of NPWT was associated with a higher risk of recurrence of infection (p = 0.013, OR 1.036, 95% CI [1.008 - 1.066]).

CONCLUSION

Delayed wound closure with the application of NPWT increased the risk of recurrence of infection in patients with soft tissue defects after FRI treatment. Therefore, it is advised to consider NPWT only as a short-term (e.g. few days) necessity to bridge the period until definitive wound closure can be established.

Quality of life after fracture-related infection of the foot

BACKGROUND

Fracture related infection (FRI) of the foot is a serious hazard. Despite successful therapy, the physiological and psychological involvement seems to be high. Therefore, we aim to analyze the impact of an FRI of the foot on the quality of life after successful surgical therapy and infect eradication.

METHODS

In total, 25 patients from two German hospitals treated for FRI of the foot between March 2011 to January 2020 were retrospectively included. Quality of life was assessed by the German Short Form 36 (SF-36) and the EuroQol five-dimension three-level questionnaire (EQ-5D) as well as the ICD-10 based psychological symptom rating (ISR), and compared to a norm obtained from the general population of Germany.

RESULTS

3.0 years (range 0.7-7.9 years) following final surgery after fracture-related infection of the foot, the mean physical health component score (PCS) of the SF-36 was 35.6 ± 12.3, and the mean mental health component score (MCS) of the SF-36 reached a value of 41.3 ± 12.9. Both values were significantly lower than in the general population of Germany (p< .019). The mean scores of the ISR of the cohort crossed the threshold of mild symptom burden in total, as well as for the subscales depression and somatization. The mean EQ-5D VAS rating (62.1 ± 18.6) and the EQ-5D index value (0.66 ± 0.27) were significantly lower in comparison to a score of 72.9 ± 1.0 and 0.88 obtained from an age-matched reference population (p < .01).

CONCLUSION

FRI of the foot represents a major burden for the patient. Physical and mental well-being of affected patients is restricted albeit successful treatment in terms of infect eradication and bone union has been achieved after a mean follow-up of 3.0 years. A patient-centered treatment approach focusing on improvement of quality of life during and after treatment is therefore warranted.

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.

Individual and commercially available antimicrobial coatings for intramedullary nails for the treatment of infected long bone non-unions - a systematic review

The treatment of infected non-unions of the femur and the tibia remains difficult and requires control of the infection and successful bone healing. Antimicrobial coating of intramedullary nails promises both infection control and stabilization for subsequent bone healing. Both results for custom-made and commercially available antimicrobial coating for intramedullary nails have been published in the past mainly consisting of retrospective case series. The purpose of this work is to review the published literature on techniques and clinical outcome of antimicrobial coatings for intramedullary nails for the treatment of infected long bone non-unions. A systematic literature research in Medline, PubMed, Embase and Cochrane Library was performed in accordance to the PRISMA guidelines. Articles reporting on antimicrobial-coated intramedullary nails for the treatment of infected long bone non-unions were eligible for inclusion. In total, 22 publications were found reporting on 506 infected non-unions of the tibia and femur treated with an antimicrobial-coated nail. Most of them consisted of retrospective case series (72.7%). 469 and 37 patients were treated with an individual antibiotic-loaded PMMA-coating and commercially available gentamicin-coating for intramedullary nails, respectively. The overall infection eradication rate was 90.0% (range 68.7-100%) and the bone consolidation rate was 85.5% (range 57.9-100%). Coating specific side effects were not reported. In conclusion, the treatment of infected long bone non-unions with antimicrobial-coated nails is associated with a high infection control and bone consolidation rate and seems to be a reasonable treatment options with minimal side effects. However, scientific quality of the publications is low and randomized controlled trials are needed.

Treatment of a Gustilo-Anderson type II open tibia shaft fracture with an ultrathin silver plasma-coated plate: A case report

The treatment of open tibia fractures with plate fixation bears a high risk for the development of a fracture-related infection. Here we present a case of an 80-year-old female with a Gustilo-Anderson type II open distal tibial shaft fracture with an indwelling knee prosthesis. The case was successfully treated with a 2-stage procedure with initial external fixation and subsequent open reduction and plate fixation with a custom-made ultrathin silver plasma-coated locking plate. Plate fixation was the preferred method as the indwelling knee prosthesis prevented the use of a standard intramedullary tibia nail. The fracture healed uneventfully without any signs of infections and the patient achieved full weight-bearing with a normal gait and without any pain after three months. Radiographical full bridging of the initial fracture area was seen after 5 months without any signs of infection or fracture healing disturbances. After an overall follow-up of 12 months, there were no signs of silver associated or other adverse events. Thus, ultrathin silver plasma coating seems to be helpful in the treatment open fractures with plate fixation to prevent fracture-related infections.

Current therapeutic interventions combating biofilm-related infections in orthopaedics : a systematic review of in vivo animal studies

Aims

Biofilm-related infection is a major complication that occurs in orthopaedic surgery. Various treatments are available but efficacy to eradicate infections varies significantly. A systematic review was performed to evaluate therapeutic interventions combating biofilm-related infections on in vivo animal models.

Methods

Literature research was performed on PubMed and Embase databases. Keywords used for search criteria were “bone AND biofilm”. Information on the species of the animal model, bacterial strain, evaluation of biofilm and bone infection, complications, key findings on observations, prevention, and treatment of biofilm were extracted.

Results

A total of 43 studies were included. Animal models used included fracture-related infections (ten studies), periprosthetic joint infections (five studies), spinal infections (three studies), other implant-associated infections, and osteomyelitis. The most common bacteria were Staphylococcus species. Biofilm was most often observed with scanning electron microscopy. The natural history of biofilm revealed that the process of bacteria attachment, proliferation, maturation, and dispersal would take 14 days. For systemic mono-antibiotic therapy, only two of six studies using vancomycin reported significant biofilm reduction, and none reported eradication. Ten studies showed that combined systemic and topical antibiotics are needed to achieve higher biofilm reduction or eradication, and the effect is decreased with delayed treatment. Overall, 13 studies showed promising therapeutic potential with surface coating and antibiotic loading techniques.

Conclusion

Combined topical and systemic application of antimicrobial agents effectively reduces biofilm at early stages. Future studies with sustained release of antimicrobial and biofilm-dispersing agents tailored to specific pathogens are warranted to achieve biofilm eradication.

Cite this article: Bone Joint Res 2022;11(10):700–714.

Outcomes of two circular external fixation systems in the definitive treatment of acute tibial fracture related infections

INTRODUCTION

Acute tibial fracture-related infection (FRI) is one of the most feared and challenging complications after a tibial fracture. The most appropriate treatment in this scenario is far from a resolved topic. Circular external fixators (CEFs) offer multiplanar control and minimize soft tissue injury using temporary implants far from the infected area. This study aimed to investigate the outcomes of two different types of CEFs (Ilizarov and hexapod) in the treatment of a series of acute tibial FRIs.

MATERIAL AND METHODS

A retrospective study at two specialized limb reconstruction centres identified all patients with an acute tibial FRI (≤4 weeks after index procedure) definitively treated with a CEF from January 2015 to December 2020.

PRIMARY OUTCOMES

fracture healing and infection eradication rate with a minimum FU of 12 months after frame removal.

SECONDARY OUTCOMES

to investigate the differences between the two types of circular frames regarding final post-treatment deformity magnitude.

RESULTS

We included 31 patients with acute tibial FRIs: 18 treated with hexapod-type and 13 with Ilizarov-type CEFs. Average age was 45.5±16.56 years. Fracture healing and infection eradication were achieved in all patients (31/31) after a mean follow-up of 24.7 months (range 12.1-55.3). Patients treated with an Ilizarov-type fixator presented shorter time to fracture union (5.5±2.2 months vs. 9.2±6.0 months; p-value 0.021) and shorter duration of external fixation (p-value 0.001). Regarding residual post-treatment deformity, the hexapod system presented significantly less residual coronal translation deformity (p-value 0.034) and better callus quality. Fixator-related complications were similar when comparing the two groups. No significant differences were seen in pain (p-value 0.25), RTW rate (35% vs. 45%; p-value 0.7) or functionality (p-value 0.4).

CONCLUSIONS

Definitive circular external fixation is an excellent treatment for acute tibial FRI. Both Ilizarov and hexapod systems offer a very high rate of fracture healing and infection eradication. Although both presented very low radiological post-operative residual deformity, the hexapod system showed less residual coronal translation deformity and better callus quality.

Mid- to long-term results of single-stage surgery for patients with chronic osteomyelitis using a bioabsorbable gentamicin-loaded ceramic carrier

AIMS

Excision of chronic osteomyelitic bone creates a dead space which must be managed to avoid early recurrence of infection. Systemic antibiotics cannot penetrate this space in high concentrations, so local treatment has become an attractive adjunct to surgery. The aim of this study was to present the mid- to long-term results of local treatment with gentamicin in a bioabsorbable ceramic carrier.

METHODS

A prospective series of 100 patients with Cierny-Mader Types III and IV chronic ostemyelitis, affecting 105 bones, were treated with a single-stage procedure including debridement, deep tissue sampling, local and systemic antibiotics, stabilization, and immediate skin closure. Chronic osteomyelitis was confirmed using strict diagnostic criteria. The mean follow-up was 6.05 years (4.2 to 8.4).

RESULTS

At final follow-up, six patients (six bones) had recurrent infection; thus 94% were infection-free. Three infections recurred in the first year, two in the second year, and one 4.5 years postoperatively. Recurrence was not significantly related to the physiological class of the patient (1/20 Class A (5%) vs 5/80 Class B (6.25%); p = 0.833), nor was it significantly related to the aetiology of the infection, the organisms which were cultured or the presence of nonunion before surgery (1/10 with nonunion (10%) vs 5/90 without nonunion (5.6%); p = 0.570). Organisms with intermediate or high-grade resistance to gentamicin were significantly more likely in polymicrobial infections (9/21; 42.8%) compared with monobacterial osteomyelitis (7/79 (8.9%); p < 0.001). However, recurrence was not significantly more frequent when a resistant organism was present (1/16 for resistant cases (6.25%) vs 5/84 in those with a microbiologically sensitive infection (5.95%); p = 0.958).

CONCLUSION

We found that a single-stage protocol, including the use of a high-delivery local antibiotic ceramic carrier, was effective over a period of several years. The method can be used in a wide range of patients, including those with significant comorbidities and an infected nonunion.Cite this article: Bone Joint J 2022;104-B(9):1095-1100.

Validation of the diagnostic criteria of the consensus definition of fracture-related infection

BACKGROUND

The recently developed fracture-related infection (FRI) consensus definition, which is based on specific diagnostic criteria, has not been fully validated in clinical studies. We aimed to determine the diagnostic performance of the criteria of the FRI consensus definition and evaluated the effect of the combination of certain suggestive and confirmatory criteria on the diagnostic performance.

METHODS

A multicenter, multi-national, retrospective cohort study was performed. Patients were subdivided into an FRI or a control group, according to the treatment they received and the recommendations from a multidisciplinary team ('intention to treat'). Exclusion criteria were patients with an FRI diagnosed outside the study period, patients younger than 18 years of age, patients with pathological fractures or patients with fractures of the skull, cervical, thoracic and lumbar spine. Minimum follow up for all patients was 18 months.

RESULTS

Overall, 637 patients underwent revision surgery for suspicion of FRI. Of these, 480 patients were diagnosed with FRI, treated accordingly, and included in the FRI group. The other 157 patients were included in the control group. The presence of at least one confirmatory sign was associated with a sensitivity of 97.5%, a specificity of 100% and a high discriminatory value (AUROC 0.99, p < 0.001). The presence of a clinical confirmatory criterion or, if not present, at least one positive culture was associated with the highest diagnostic performance (sensitivity: 98.6%, specificity: 100%, AUROC: 0.99 (p < 0.001)). In the subgroup of patients without clinical confirmatory signs at presentation, specificities of at least 95% were found for the clinical suggestive signs of fever, wound drainage, local warmth and redness.

CONCLUSIONS

The presence of at least one confirmatory criterion identifies the vast majority of patients with an FRI and was associated with an excellent diagnostic discriminatory value. Therefore, our study validates the confirmatory criteria of the FRI consensus definition. Infection is highly likely in case of the presence of a single positive culture with a virulent pathogen. When certain clinical suggestive signs (e.g., wound drainage) are observed (individually or in combination and even without a confirmatory criterion), it is more likely than not, that an infection is present.

Fracture-related infection of the patella: Treatment options and outcome

BACKGROUND

Fracture-related infection (FRI) after the operative management of patella fractures is a serious complication that can result in prolonged hospitalization, multiple revision procedures and permanent functional impairment. Till today, treatment modalities and outcome of FRI of the patella are not well described. Therefore, the main objective of this retrospective cohort study was to evaluate treatment options, functional outcome and healthcare costs related to FRI of the patella.

METHODS

This study evaluated 111 consecutive patients that were surgically treated for patella fractures, at the department of trauma surgery of the University Hospitals Leuven (Belgium), between January 2015 and April 2020. Patients were excluded if they (1) were younger than 18 years at the time of injury or (2) died during follow up. The minimal follow-up for all patients was 18 months.

RESULTS

During the 5-year study period, 107 patients with 108 patella fractures were included. A total of 10 patients were diagnosed with an FRI (9.3%). Four of these were treated with a DAIR approach and three patients underwent implant removal or exchange. Finally, three patients were treated with total patellectomy. Out of the 10 patients, two were diagnosed with a recurrence of infection. Overall, we observed substantial lower scores for all Knee Injury and Osteoarthritis Outcome Score subscales in the FRI group, compared to a reference population. Moreover, our study shows that direct hospital-related healthcare costs of FRI of the patella were nine times higher compared to non-FRI cases.

CONCLUSIONS

FRI of the patella is a challenging complication and recurrence of infection not uncommon. Although multiple treatment modalities exist, a multidisciplinary patient-specific approach is crucial. An early or delayed onset infection can be managed with a DAIR approach, but only when the construct is stable and the soft tissue coverage adequate. In patients with an FRI, implant removal is preferred when the fracture has healed. A total patellectomy can be used as a salvage procedure in complex cases with acceptable functional results. Overall, FRI of the patella leads to both a negative impact on the functional status of the patient and a ninefold increase in total healthcare costs.

Treatment of an infected nonunion with additional fresh fracture of the femur with a silver-coated intramedullary nail: A case report

Infected non-unions of the femur can be difficult to treat with a high risk of reinfection and persisting nonunion. Here we demonstrate a case of a 66-year-old female with a chronic infected nonunion of the left femur. The patient fell during temporary external fixation of the infected nonunion and sustained an additional proximal femur shaft fracture. The case was successfully managed with a low-amount silver coating of a long proximal femur nail and an additional augmentation locking plate along with local and systemic antibiotics. After a follow-up of 26 months, both the fracture and also the infected nonunion healed completely without recurrence of infection and without any signs of adverse events in response to the silver coating. In conclusion, silver coated fracture fixation devices can be helpful in difficult to treat infection cases without adverse events.

Type of antibiotic but not the duration of prophylaxis correlates with rates of fracture-related infection

PURPOSE

The issue of optimal prophylactic antibiotic administration for closed and open fracture surgeries remains controversial. The purpose of this study was to assess the role of type and duration longer than 48 h of antibiotic prophylaxis on the rates of fracture-related infection (FRI).

METHODS

This is a single-center, prospective observational cohort study carried out with patients undergoing surgery for implants insertion to fracture stability. Risk estimates were calculated on the variables associated with factors for FRI and reported as a prevalence ratio (PR) with respect to the 95% confidence interval (CI).

RESULTS

Overall, 132 patients were analyzed. The global rate of FRI was 15.9% (21/132), with open and closed fractures accounting for 30.5% (11/36) and 10.4% (10/96), respectively. The FRI rates in patients undergoing orthopedic surgery for fracture stabilization who received prophylactic antibiotic for up to and longer than 48 h were 8.9% and 26.4%, respectively. This difference did not reach statistical significance (prevalence ratio [PR] = 2.6, 95% confidence interval [95% CI]: 0.9-7.3. p = 0.063).

CONCLUSIONS

Duration of antibiotic prophylaxis for surgical orthopedic fractures was not correlated with rates of FRI.

Soft-tissue reconstruction in lower-leg fracture-related infections: An orthoplastic outcome and risk factor analysis

Introduction Fracture-related infection (FRI) is a severe post-traumatic complication which is occasionally accompanied by a deficient or even avital soft-tissue envelope. In these cases, a thoroughly planned orthoplastic approach is imperative as a vital and intact soft-tissue envelope is mandatory to achieve fracture union and infection eradication. The aim of this study was, to analyse if soft-tissue reconstruction (STR) without complications is associated with a better long-term outcome compared to FRI patients with STR complications. In particular, it was investigated if primary flap failure represented a risk factor for compromised fracture union and recurrence of infection. Patients and Methods Patients with a lower leg FRI requiring STR (local, pedicled and free flaps) who were treated from 2010-18 at the University Hospital Basel were included in this retrospective analysis. The main outcome measure was the success rate of STR, further outcome measures were fracture nonunion and recurrence of infection. Results Overall, 145 patients with lower leg FRI were identified, of whom 58 (40%) received STR (muscle flaps: n = 38, fascio-cutaneous flaps: n=19; composite osteo-cutaneous flap: n = 1). In total seven patients required secondary STR due to primary flap failure. All failures and flap-related complications occurred within the first three weeks after surgery. Secondary STR was successful in all cases. A high Charlson Comorbidity Index Score was a significant risk factor for flap failure (p = 0.011). Out of the 43 patients who completed the 9-month follow-up, 11 patients presented with fracture nonunion and 12 patients with a recurrent infection. Polymicrobial infection was a significant risk factor for fracture nonunion (p = 0.002). Primary flap failure was neither a risk factor for compromised fracture consolidation (p = 0.590) nor for recurrence of infection (p = 0.508). Conclusion: A considerable number of patients with lower-leg FRI required STR. This patient subgroup is complex and rich in complications and the long-term composite outcome demonstrated a high rate of compromised fracture consolidation and recurrent infections. It appears that secondary STR should be performed, as primary flap failure was neither a risk factor for compromised fracture consolidation nor for recurrence of infection. We propose to monitor these patients closely for three weeks after STR.

Fracture-related infection in long bone fractures: A comprehensive analysis of the economic impact and influence on quality of life

OBJECTIVES

Fracture-related infection (FRI) is a feared complication with substantial clinical and economic consequences. The main objective of this study was to compare direct and indirect healthcare costs related to long bone fractures in patients with and without FRI and to assess its impact on the patient's quality of life (QoL).

PATIENTS AND METHODS

Between January 2015 and March 2019, 175 patients with FRI were treated at the University Hospitals Leuven (Belgium). Using a matched-pair analysis, patients with an FRI were matched by age, sex, and fracture location (humeral, femoral, or tibial shaft) to a non-FRI cohort treated during the same time period. Clinical and process-related variables, direct hospital-related healthcare costs, and indirect costs due to absenteeism were compared between the two groups. Furthermore, the patient's QoL was evaluated using Patient-Reported Outcomes Measurement Information System (PROMIS) physical function and pain interference.

RESULTS

After matched-pair analysis, 15 patients in both the FRI and non-FRI group were included. FRI was associated with direct hospital-related costs being eight times that of non-FRI patients (€ 47,845 [€ 43,072-€ 82,548] vs. € 5,983 [€ 4,519-€ 8,428], p < 0.001). Furthermore, FRI was associated with prolonged absenteeism (340 [340-676] vs. 86 [65-216] days, p = 0.007) and a median indirect cost that was nearly four times that of patients without FRI (€ 77,909 vs. € 19,706). Lastly, FRI patients showed significantly poorer outcomes on both physical function (35.6 vs. 48.4, p < 0.001) and pain interference (60.4 vs. 46.3, p < 0.001) PROMIS scales.

CONCLUSION

Direct hospital-related healthcare costs of FRI are eight times that of non-FRI long bone fractures. Total healthcare costs are mainly driven by hospitalisation costs, wherein FRI is associated with prolonged length of stay. To the best of our knowledge, this study is the first to demonstrate that FRI is also associated with substantial absenteeism, which is almost four times higher compared to non-FRI patients. In addition to this economic impact, FRI significantly deteriorates QoL. Generalizing the outcome of this study should be done cautiously due to the small sample size of 15 patients in both the FRI and non-FRI group after matched-pair analysis.

What is the diagnostic value of the Centers for Disease Control and Prevention criteria for surgical site infection in fracture-related infection?

BACKGROUND

Fracture-related infection (FRI) remains one of the most challenging complications in orthopaedic trauma surgery. An early diagnosis is of paramount importance to guide treatment. The primary aim of this study was to compare the Centers for Disease Control and Prevention (CDC) criteria for the diagnosis of organ/space surgical site infection (SSI) to the recently developed diagnostic criteria of the FRI consensus definition in operatively treated fracture patients.

METHODS

This international multicenter retrospective cohort study evaluated 257 patients with 261 infections after operative fracture treatment. All patients included in this study were considered to have an FRI and treated accordingly ('intention to treat'). The minimum follow-up was one year. Infections were scored according to the CDC criteria for organ/space SSI and the diagnostic criteria of the FRI consensus definition.

RESULTS

Overall, 130 (49.8%) FRIs were captured when applying the CDC criteria for organ/space SSI, whereas 258 (98.9%) FRIs were captured when applying the FRI consensus criteria. Patients could not be classified as having an infection according to the CDC criteria mainly due to a lack of symptoms within 90 days after the surgical procedure (n = 96; 36.8%) and due to the fact that the surgery was performed at an anatomical localization not listed in the National Healthcare Safety Network (NHSN) operative procedure code mapping (n = 37; 14.2%).

CONCLUSION

This study confirms the importance of standardization with respect to the diagnosis of FRI. The results endorse the recently developed FRI consensus definition. When applying these diagnostic criteria, 98.9% of the infections that occured after operative fracture treatment could be captured. The CDC criteria for organ/space SSI captured less than half of the patients with an FRI requiring treatment, and seemed to have less diagnostic value in this patient population.

Epidemiology and microbiology of fracture-related infection: a multicenter study in Northeast China

Objective

This study aimed to explore the epidemiological and microbiological characteristics of fracture-related infection (FRI), analyze the drug resistance characteristics of major pathogens, and provide timely and relatively complete clinical and microbiological data for antimicrobial treatment of FRI.

Methods

The clinical and microbiological data of patients with FRI from January 1, 2011, to December 31, 2020, were collected from three tertiary hospitals in Northeast China. The automatic microbial analysis system was used for strain identification and drug susceptibility testing, and the drug susceptibility results were determined in accordance with the latest Clinical and Laboratory Standards Institute (CLSI) criteria (as applicable each year).

Results

A total of 744 patients with FRI were enrolled. The incidence of FRI was about 1.5%, and 81.7% were male patients, with an average age of 48.98 ± 16.01 years. Open fractures accounted for 64.8%. Motor crush (32.8%) and falling (29.8%) were the main causes of injuries. The common sites of infection were the tibia and fibula (47.6%), femur (11.8%), foot (11.8%), and hand (11.6%). A total of 566 pathogenic bacteria were cultured in 378 patients with positive bacterial cultures, of which 53.0% were Gram-positive bacteria and 47.0% were Gram-negative bacteria. The most common pathogen at all sites of infection is Staphylococcus aureus. Staphylococcus aureus had a high resistance rate to penicillin (PEN), erythromycin (ERY), and clindamycin (CLI), exceeding 50%. Methicillin-resistant Staphylococcus aureus (MRSA) was more than 80% resistant to CLI and ERY.

Conclusions

The incidence of FRI in Northeast China was at a low level among major medical centers nationwide. Staphylococcus aureus was still the main pathogen causing bone infections, and the proportion of MRSA was lower than reported abroad, but we have observed an increase in the proportion of infections. Enterobacteriaceae have a higher resistance rate to third-generation cephalosporins and quinolones. For Enterobacteriaceae, other sensitive treatment drugs should be selected clinically.

Fracture biomechanics influence local and systemic immune responses in a murine fracture-related infection model

Biomechanical stability plays an important role in fracture healing, with unstable fixation being associated with healing disturbances. A lack of stability is also considered a risk factor for fracture-related infection (FRI), although confirmatory studies and an understanding of the underlying mechanisms are lacking. In the present study, we investigate whether biomechanical (in)stability can lead to altered immune responses in mice under sterile or experimentally inoculated conditions. In non-inoculated C57BL/6 mice, instability resulted in an early increase of inflammatory markers such as granulocyte-colony stimulating factor (G-CSF), keratinocyte chemoattractant (KC) and interleukin (IL)-6 within the bone. When inoculated with Staphylococcus epidermidis, instability resulted in a further significant increase in G-CSF, IL-6 and KC in bone tissue. Staphylococcus aureus infection led to rapid osteolysis and instability in all animals and was not further studied. Gene expression measurements also showed significant upregulation in CCL2 and G-CSF in these mice. IL-17A was found to be upregulated in all S. epidermidis infected mice, with higher systemic IL-17A cell responses in mice that cleared the infection, which was found to be produced by CD4+ and γδ+ T cells in the bone marrow. IL-17A knock-out (KO) mice displayed a trend of delayed clearance of infection (P=0.22, Fisher’s exact test) and an increase in interferon (IFN)-γ production. Biomechanical instability leads to a more pronounced local inflammatory response, which is exaggerated by bacterial infection. This study provides insights into long-held beliefs that biomechanics are crucial not only for fracture healing, but also for control of infection.

Summary: Physical movement between bone fragments after a fracture influence healing, and are shown here, for the first time, to influence immune responses and infection.

Comparative diagnostic accuracy of respective nuclear imaging for suspected fracture-related infection: a systematic review and Bayesian network meta-analysis

BACKGROUND

The aim of this study was to compare the accuracy of available nuclear imaging modalities in the diagnosis of suspected fracture-related infection (FRI).

METHODS

We conducted a comprehensive literature search of PubMed, EMBASE and the Cochrane Library to retrieve diagnostic accuracy studies in which FRI was investigated using different nuclear imaging modalities. The pooled sensitivity, specificity, likelihood ratios and diagnostic odds ratios were constructed using the bivariate meta-analysis framework, while the superior index was pooled using Bayesian network meta-analysis.

RESULTS

22 eligible studies (1,565 patients) were included in the quantitative analysis. A broad overlapping confidence interval (CI) of pooled sensitivity was observed among bone scintigraphy (0.94; 95% CI 0.85-0.98), ¹⁸F-FDG PET and PET/CT (0.91; 95% CI 0.85-0.94) and leukocyte scintigraphy (0.86; 95% CI 0.53-0.97). Bone scintigraphy (0.34; 95% CI 0.08-0.75) seemed to be less specific than all the other modalities, while leukocyte scintigraphy (0.96, 95% CI 0.92-0.98) was notably more specific than ¹⁸F-FDG PET and PET/CT (0.78; 95% CI 0.69-0.85). Based on the superiority index, ¹⁸F-FDG PET/CT (3.78; 95% CI 0.14-11.00), ¹⁸F-FDG PET (2.98; 95% CI 0.14-9.00) and leukocyte scintigraphy (1.51; 95% CI 0.11-7.00) all achieved high accuracy in detecting FRI.

CONCLUSION

Bone scintigraphy is a highly sensitive nuclear imaging technique but lacks the specificity needed to unequivocally differentiate among various conditions suspected to be FRI. Leukocyte scintigraphy, ¹⁸F-FDG PET/CT and PET all present good satisfactory accuracy for the diagnosis of FRI, but their costs should be further reduced to promote their wide application.

Risk factors for treatment failure of fracture-related infections

OBJECTIVE

Infection after fracture fixation is a potentially devastating outcome, and surgical management is frequently unsuccessful at clearing these infections. The purpose of this study is to determine if factors can be identified that are associated with treatment failure after operative management of a deep surgical site infection.

METHODS

We retrospectively reviewed the billing system at a Level I trauma center between March 2006 and December 2015. We identified 451 patients treated for deep surgical site infection after fracture fixation at our center. A multivariate regression analysis was then performed to evaluate for factors associated with treatment failure.

RESULTS

Mean follow-up was 2.3 years. One hundred fifty-six patients (35%) failed initial surgical management. Risk factors associated with treatment failure included initial culture results positive for polymicrobial organisms (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.0-2.4), removal of implants (OR, 1.9; 95% CI, 1.2-2.9), or Gustilo-Anderson IIIB/IIIC injury (OR, 2.0; 95% CI, 1.1-3.7). Increased body mass index and fulfilling the criteria to have a methicillin-resistant Staphylococcus aureus (MRSA) nasal swab screening showed a trend toward increased risk of failure.

CONCLUSION

Treatment failure after deep surgical site infection was relatively common. Three distinct factors (polymicrobial infection, removal of implants, and IIIB/C fracture) were associated with failure to eradicate the infection in the first series of surgeries and antibiotics. These data might help guide clinicians as they counsel patients on the risk of treatment failure and might focus efforts to improve treatment toward patients at higher risk of treatment failure.