Aim

To compare outcomes of PJI in relation to treatment method versus classification using the JS-BACH system.

Method

Patients having surgery for EBJIS Criteria Confirmed PJI between 2010–2015 were included. Index surgical procedures were 1-stage or 2-stage revision or debridement and implant retention (DAIR). Patients completed the EuroQol EQ-5D-3L questionnaire and were followed clinically to a median of 4.7 years (IQR 2.7–6.7 years). Patients were stratified using the JS-BACH classification1 into either ‘Uncomplicated’, ‘Complex’ or having ‘Limited treatment options’, by two separate classifiers, blinded to clinical outcome.

Aim

Rifampicin as a biofilm-active antibiotic drug has a significant role in the treatment of periprosthetic joint infection (PJI). However, rifampicin resistance is an increasing threat to PJI treatment. This study aimed to evaluate the prevalence of rifampicin resistant staphylococci over time and its association with infection-free survival after PJI in a single centre in Sweden.

Methods

We included 238 PJIs in 238 patients who had undergone PJI revision surgery from 2001 to 2020 on whom the causative bacteria were staphylococci, and the agent was tested for rifampicin resistance. Data regarding agents, rifampicin resistance, treatment and outcome was obtained. Kaplan-Meier survival analysis and a Cox regression model with adjustment for age, sex, localisation (hip or knee) and type of prosthesis (primary or revision) were used to calculate infection-free survival rates and adjusted risk ratios (HRs) of the risk of treatment failure. Treatment failure was defined as any reoperation or suppression treatment with antibiotics due to prolonged infection.

Aim

Prosthetic joint infection (PJI) due to Candida spp. is a severe complication of arthroplasty but is little reported. This study describes Candida PJI epidemiology, management, and outcome.

Method

We performed a retrospective, observational multinational study with support of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID). Patients diagnosed with PJI due to Candida spp. between 1990 and 2021 were included. Demographic, clinical, laboratory, imaging, medical/surgical treatment, and outcome data were collected within a standardized database. Treatment failure was defined either as a Candida infection recurrence, superinfection, or death due to infection.

Aim

Prosthetic joint infection (PJI) is a devastating complication of joint replacement, having an impact on morbimortality but also on national health systems and their budgets. The current situation of PJI-related hospitalizations in Spain and their changes over time are unknown. Therefore, we aimed to analyze the hospitalization burden of PJI, including costs and trends in recent decades.

Methods

Retrospective observational study including data from the National Surveillance System for Hospital Data, which includes more than 98% of Spanish hospitals. During the period 2000–2015, hospitalizations due to PJI (ICD-9-CM 996.66) as main diagnosis were included. Epidemiological trends were evaluated during four periods: P1, 2000–2003; P2, 2004–2007; P3, 2008–2011; P4, 2012–2015. Annual hospitalization rates per 100,000 inhabitants and trends were also calculated.

Aim

The aim of this investigation was to compare risk of infection in both cemented and cementless hemiarthroplasty (HA) as well as total hip arthroplasty (THA) following femoral neck fracture.

Methods

Data collection was performed using the German Arthroplasty Registry (EPRD) In HA and THA following femoral neck fracture fixation method was divided into cemented and cementless protheses and paired according to age, sex, body mass index (BMI), and the Elixhauser score using Mahalanobis distance matching.

Aim

Currently, gram-negative bacteria (GNB), including multidrug-resistant (MDR-GNB) pathogens, are gaining importance in the aetiology of prosthetic joint infection (PJI). To characterize the antimicrobial resistance patterns of Gram-negative bacteria (GNB) causing hip prosthetic joint infections in elderly patients treated at a Brazilian tertiary academic hospital.

Method

This is a retrospective, cross-sectional study of patients over 60 years of age undergoing hip arthroplasty from 2018 to 2023 at a tertiary academic trauma, which were diagnosed with hip prosthetic joint infection. PJI diagnosed was based on EBJIS criteria, in which intraoperative tissue cultures identified the pathogens. Demographics, reason for arthroplasty, type of implant and susceptibility patterns using disk diffusion method were analysed.

Aim

Two-stage replacement is a frequent procedure in patients with chronic PJI. However, results in the literature after this procedure differ, ranging from 54% to 100% of infection eradication. Positive cultures at reimplantation, when performing the second stage, are perceived as a risk factor for reinfection. This study aims to determine the impact of positive cultures during the second stage on the outcome of patients undergoing a 2-stage septic replacement and the impact of antibiotic holidays between the first and the second stage.

Method

We systematically searched four databases from inception to May 31, 2022. We combined terms related to PJI, joint replacement and culture results. We analysed the risk of failure when positive cultures at second stage and performed a subgroup analysis by antibiotic holiday period.

Aim

Mega-endoprosthesis over the last two decades have played a significant role in management of non-neoplastic cases for limb salvage for a variety of indications involving bone loss, infection, fracture and failed revision surgery. This is a retrospective case control study comparing outcomes of Mega-Endoprosthesis (MEP) in non-neoplastic cases with periprosthetic joint infections (PJI), with previous history of PJI and aseptic revision. Failure was defined as persistence/recurrence of infection, all cause revision, and antibiotic suppression during the follow up period. Secondary aims were identification of causative organisms, resistance profile and causative factors for revision surgery.

Method

A total of 122 patients undergoing 133 MEPs were identified between January 2012 and December 2020. 60 procedures were categorised as group 1 (infection; 50%), 20 as group 2 (previous history of infection; 16.7%), and 53 controls (no infection; 44.2%). Mean age of the cohort was 70.97 years (37.16–94.17), with a mean follow-up of 44.5 months (0.2–179) including patients lost to follow up.

Aim

Perioperative myocardial infarction/injury (PMI) is a common complication in noncardiac surgery, contributing to postoperative morbidity and mortality. We aimed to identify the risk for PMI in periprosthetic joint infection (PJI) in comparison to primary hip (THA) and knee arthroplasty (TKA) and to non-PJI revision surgery.

Methods

Patients undergoing primary/revision THA/TKA at a University Hospital who were eligible for the institutional PMI screening and response program were prospectively included. Revision arthroplasties were divided into 2 groups (PJI revision and non-PJI revision). PJI was defined according to the EBJIS criteria, and included DAIR, one-stage and two-stage revisions. Non-PJI revisions included partial and/or complete exchange of components. The primary endpoint was PMI, secondary endpoints were major adverse cardiovascular events (MACE) and all-cause mortality within 120 days.

Aim

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.

Method

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.

Aims

Fracture-Related Infection (FRI) is a severe complication caused by microbial infection of bone. It is imperative to gain more insight into the potentials and limitations of Debridement, Antibiotics and Implant Retention (DAIR) to improve future FRI treatment. The aims of this study were to: 1) determine how time to surgery affects the success rate of DAIR procedures of the lower leg performed within 12 weeks after the initial fracture fixation operation and 2) evaluate whether appropriate systemic antimicrobial therapy affects the success rate of a DAIR procedure.

Methods

This multinational retrospective cohort study included patients of at least 18-years of age who developed an FRI of the lower leg within 12 weeks after the initial fracture fixation operation, between January 1st 2015 to July 1st 2020. DAIR success was defined by the absence of recurrence of infection, preservation of the affected limb and retention of implants during the initial treatment. The antimicrobial regimen was considered appropriate if the pathogen(s) was susceptible to the given treatment at the correct dose as per guideline. Logistic regression modelling was used to assess factors that could contribute to the DAIR success rate.

Aim

To determine mortality and outcomes of patients diagnosed with fracture-related infections (FRIs).

Method

FRI patients treated at a trauma centre between 2001 and 2020 were analysed. The primary outcome was 1-year mortality; mortality associations with FRI organism, depth of involvement, and temporality were investigated with multivariable survival analysis. Healthcare-associated and serological outcomes were reported as secondary outcomes.

Aim

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.

Method

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.

Aim

infected segmental bone defect (ISBD) is frequent in developing countries. The aim of this study was to assess the efficacy of the Masquelet technique in the treatment of ISBD in a low-resource setting.

Patients and Method

We performed a prospective cohort study during the period from 2018 to 2022. Patients with infected bone defect of long bones were included. Management protocol consisted of two stages in all patients. The first stage consisted in debridement, tissues biopsy for microbiological culture, stabilization with external fixator and defect filling with gentamicin cement spacer. The second stage consisted of reconstruction using a cancellous bone autograft alone, or a mixture of autograft with allograft (demineralized bone matrix + tricalcium phosphate) and 1 gram of vancomycin powder. All patients were followed-up for at least one year. The results were assessed based on both objective (clinical and radiographic evaluation) and subjective (limb function and patient satisfaction) criteria. Main outcomes were bone union, reoperation and failure rates, union time, and limb function.

Aim

Treatment algorithms for fracture-related nonunion depend on the presence or absence of bacterial infection. However, the manifestation of septic nonunion varies. Low-grade infections, unlike manifest infections, lack clinical signs of infection and present similarly to aseptic nonunion. The clinical importance of low-grade infection in nonunion is not entirely clear. Therefore, the aim of this study was to evaluate the clinical relevance of low-grade infection in the development and management of femoral or tibial nonunion.

Method

A prospective, multicenter clinical study enrolled patients with nonunion and regular healed fractures. Preoperatively, complete blood count without differential, C-reactive protein (CRP), and procalcitonin were obtained, clinical signs of infection were recorded, and a suspected septic or aseptic diagnosis was made based on history and clinical examination. During surgical nonunion revision or routine implant removal, tissue samples were collected for microbiology and histopathology, and osteosynthesis material for sonication. Nonunion patients were followed for 12 months. Definitive diagnosis of “septic” or “aseptic” nonunion was made according to diagnostic criteria for fracture-related infection, considering the results of any further revision surgery during follow-up.

Aim

Debridement, Antibiotics, Irrigation, and implant Retention (DAIR) is a surgical treatment protocol suitable for some patients with fracture related infection (FRI). Clinically relevant pre-clinical models of DAIR are scarce and none have been developed in large animals. Therefore, this project aimed to develop a large animal model for FRI including a DAIR approach and compare outcomes after 2 or 5 weeks of infection.

Method

Swiss Alpine sheep (n=8), (2–6 years, 50–80 kg) were included in this study. This study was approved by cantonal Ethical authorities in Chur, Switzerland. A 2 mm osteotomy was created in the tibia and fixed with a 10-hole 5.5 mm steel plate. Subsequently, 2.5 mL of saline solution containing 10⁶ CFU/mL of Staphylococcus aureus MSSA (ATCC 25923) was added over the plate. Sheep were observed for 2 (n=3) or 5 weeks (n=5) until revision surgery, during which visibly infected or necrotic tissues were removed, and the wound flushed with saline. All samples were collected for bacterial quantification. After revision surgery, the sheep were treated systemically for 2 weeks with flucloxacillin and for 4 weeks with rifampicin and cotrimoxazole. After 2 further weeks off antibiotics, the animals were euthanized. Bacteriological culture was performed at the end of the study. Bone cores were isolated from the osteotomy site and processed for Giemsa & Eosin and Brown and Brenn staining. A radiographical examination was performed every second week.

Aim

Pin site infection (PSI) is a common complication of external fixators. PSI usually presents as a superficial infection which is treated conservatively. This study investigated those rare cases of PSI requiring surgery due to persistent osteomyelitis (OM), after pin removal.

Method

In this retrospective cohort study we identified patients who required surgery for an OM after PSI (Checketts-Otterburn Classification Grade 6) between 2011 and 2021. We investigated patient demographics, aetiology of the OM, pathogen and histology, treatment strategies and complications. Infection was confirmed using the 2018 FRI Consensus Definition. Successful outcome was defined as an infection-free interval of at least 24 months following surgery, which was defined as minimum follow-up.

Aim

There are no studies in literature that analyze the effectiveness of closed-incisional negative pressure wound therapy (ciNPWT) in the treatment of bone and joint infections (BJI). The aim of the study was to evaluate the efficacy and the safety of the application of ciNPWT in the postsurgical wound management of patients with osteoarticular infections.

Method

We conducted a perspective single-center study on patients with BJI treated between 01/2022 and 10/2022 with ciNPWT dressing application at the end of the surgical procedure. All patients were treated by a multidisciplinary team (MDT) approach and operated by the same surgical equipe. Inclusion criteria were: presence of periprosthetic joint infection (PJI), fracture-related infection (FRI), osteomyelitis (OM), septic arthritis (SA) surgically treated, after which ciNPTW was applied over the closed surgical wound. 30 patients (19M, 11F) have been analyzed with mean age of 56,10±17,11 years old; BJIs were all localized in the lower limb (16 PJI, 12 FRI, 1 SA, 1 OM).

Aim

To classify Fracture-related Infection (FRI) allowing comparison of clinical studies and to guide decision-making around the main surgical treatment concepts.

Method

An international group of FRI experts met in Lisbon, June 2022 and proposed a new FRI classification. A core group met during the EBJIS Meeting in Graz, 2022 and on-line, to determine the preconditions, purpose, primary factors for inclusion, format and the detailed description of the elements of an FRI Classification.

Aim

Staphylococcus aureus (SA) can cause various infections and is associated with high morbidity and mortality rates of up to 40%. Antibiotic treatment often fails to eradicate SA infections even if the causative strain has been tested susceptible in vitro. The mechanisms leading to this persistence is still largely unknown. In our work, we to reveal SA interactions with host cells that allow SA to persist at the site of infection.

Method

We established a sampling workflow to receive tissue samples from patients requiring surgical debridement due to SA bone-and joint or soft-tissue infections. We developed a multiplex immunofluorescent staining protocol which allowed us to stain for SA, leukocytes, neutrophils, macrophages, B-cells, T-cells, DAPI and cytoplasmatic marker on the same sample slide. Further, distance of SA to cell nuclei was measured. Interaction of immune cells and SA on a single cell level was investigated with high-resolution 3D microscopy. We then validated our findings applying fluorescence-activated cell sorting (FACS) on digested patient samples. Finally, we aimed to reproduce our ex vivo patient results in an in vitro co-culture model of primary macrophages and clinical SA strains, where we used live cell microscopy and high-resolution microscopy to visualize SA-immune cell interactions and a gentamicin protection assay to assess viability of SA.

Aim

To make an inoculum for induction of Implant-Associated Osteomyelitis (IAO) in pigs based on bacterial aggregates resembling those found on the human skin, i.e. aggregates of 5–15 µm with low metabolic activity. The aggregates were evaluated and compared to a standard planktonic bacterial inoculum.

Method

The porcine Staphylococcus aureus strain S54F9 was cultured in Tryptone Soya Broth for seven days. Subsequently, the culture was filtered through cell strainers with pore sizes of 15 µm and 5 µm, respectively. The fraction of 5–15 µm aggregates in the top of the 5 µm filter was collected as the aggregate-inoculum. The separation of aggregates into different size fractions was evaluated by light microscopy. The metabolism of the aggregate-inoculum and a standard overnight planktonic inoculum was evaluated with isothermal microcalorimetry. In total, six female minipigs were allocated into three groups (n=2), receiving different inoculums. Group A: overnight planktonic inoculum; 10⁴ CFU S. aureus (S54F9), Group B: seven days old 5–15 µm aggregate-inoculum; 10⁴ CFU S. aureus (S54F9), Group C: saline. All inoculums were placed in a pre-drilled implant cavity in the right tibia of the pig and a sterile stainless-steel implant was inserted. The pigs were euthanized seven days after surgery. Postmortem macroscopic pathology, microbiology, computed tomography and histopathology were performed.

Aim

Polypropylene (PPE) synthetic mesh is increasingly used in knee arthroplasty surgery to salvage a disrupted extensor mechanism. Despite its clinical success, it is associated with a high rate of periprosthetic joint infection (PJI), which is hypothesized to be caused by bacterial biofilm. The purpose of the current study is to describe the progression of PPE-based biofilm formation over time and to determine if intraoperative antiseptic solutions could be used to effectively remove biofilm when treating PJI.

Method

Commercially available knotted monofilament PPE mesh¹ was cut into 10mm circular shape, immersed in tryptic soy broth (TSB) with methicillin-sensitive staphylococcus aureus and cultured individually in 48-well plates for 10 days to elucidate the biofilm grown on mesh over time. At every 24 hours, a triplicate of samples was retrieved and biofilm on the mesh was dislodged by sonicating at 52 kHz for 15 minutes and quantified by counting colony-forming units (CFUs) after overnight growth. The biofilm growth was also verified using scanning electron microscopy.

The effect of saline and antiseptic solutions was verified by exposing 1) 0.05% chlorohexidine gluconate², 2) acetic acid-based mixture³, 3) diluted povidone-iodine (0.35%), 4) undiluted povidone-iodine (10%)⁴, and 5) 1:1 combination of 10% povidone-iodine & 3% hydrogen peroxide on immature and mature biofilms for 3 minutes, created by culturing with bacteria for 24 hours and 72 hours respectively. All experiments were performed in quintuples and repeated. Antiseptic treatments that produced a three-log reduction in CFU counts compared to controls were considered clinically significant.

Title

Longitudinal Intravital Imaging to Quantify the “Race for the Surface” Between Host Immune Cell and Bacteria for Orthopaedic Implants with S. aureus Colonization in a Murine Model

Aim

To assess S. aureus vs. host cell colonization of contaminated implants vis intravital multiphoton laser scanning microscopy (IV-MLSM) in a murine model.

Aim

Infections represent a serious threat to the successful utilization of implants in modern medicine. Implant-associated infections are difficult to treat, because they involve biofilms that protect bacteria from the immune system and harbour antibiotic-tolerant persister cells.

In this work, we developed an antibody-drug conjugate (ADC) containing the anti-neoplastic drug mitomycin C (MMC) as a novel treatment paradigm for implant-associated infections. MMC was chosen as it is a potent antimicrobial against biofilms and its synthesis into an ADC was chosen to alleviate toxicity. Following development and synthesis of the ADC, stability and release of MMC was measured. We then used the ADC to kill bacteria in suspension and in biofilms, in vitro and in vivo.

Method

Mitomycin C was conjugated to a commercially available antibody against S. aureus via a disulfide linkage, with a drug release occurred via thiol-disulfide exchange.

ADC as tested against S. aureus under various growth conditions (planktonic, persisters and biofilm). In vitro toxicity of ADC vs MMC was measured using a human cell line (MOLT-4).

Finally, two independent in vivo experiments were performed in a murine implant-associated osteomyelitis model. In experiment one ADC treatment was compared NaCl, vancomycin and vancomycin + ADC (n=10 for all groups). Subsequently, ADC was compared to NaCl, the antibody used in the ADC construction, MMC and a novel ADC constructed with a non-S. aureus antibody (n=10 for all groups). All treatments were started day 7 post inoculation and were administered for 3 days. CFU enumeration was done following sonication to quantify bacterial load.

Aim

Osteomyelitis (OM) is a debilitating infection of the bone that originates from hematogenous spreading of microbes or contamination after surgery/fracture. OM is mainly caused by the opportunistic bacterium Staphylococcus aureus (SA), which can evade the host immune response, acquire antibiotic resistance and chronically colonize the musculoskeletal tissue ^1,2, yet the underlying molecular and cellular processes are largely unclear. This study aimed to characterize the pathogenetic mechanisms of SA-OM with a focus on the long pentraxin 3 (PTX3), a soluble pattern recognition molecule and bone tissue component that is emerging as a new player in osteoimmunology ³ and a diagnostic marker of periprosthetic joint infections, a common form of OM⁴.

Method

A murine model of OM based on intra-bone injection of SA was developed that closely mimicked surgery/trauma-related OM in humans and allowed addressing the role of PTX3 in gene-modified (Ptx3^-/-) animals. Local and systemic infection and inflammation were assessed via microbiology, flow cytometry, histochemistry and microCT techniques.

Aim

Antibiotics have limited activity in the treatment of multidrug-resistant or chronic biofilm-associated infections, in particular when implants cannot be removed. Lytic bacteriophages can rapidly and selectively kill bacteria, and can be combined with antibiotics. However, clinical experience in patients with surgical infections is limited. We investigated the outcome and safety of local application of bacteriophages in addition to antimicrobial therapy.

Method

8 patients (2 female and 6 male) with complex orthopedic and cardiovascular infections were included, in whom standard treatment was not feasible or impossible. The treatment was performed in agreement with the Article 37 of the Declaration of Helsinki. Commercial or individually prepared bacteriophages were provided by ELIAVA Institute in Tbilisi, Georgia. Bacteriophages were applied during surgery and continued through drains placed during surgery three times per day for the following 5–14 days. Follow-up ranged from 1 to 28 months.

Aim

Bacteriophages are remerging as alternative and adjunctive therapy for fracture-related infection (FRI). However, current administration protocols involve prolonged retention of a percutaneous draining tube with potential risk of developing superinfection. In this study, we applied a cocktail of in vitro evolved biofilm-targeting phages for Methicillin-resistant Staphylococcus aureus (MRSA) in a hydrogel platform co-delivering vancomycin. In vitro synergy and antibiofilm activity was assessed and a subsequent in vivo study was performed in a mouse FRI model with MRSA.

Method

Two evolved bacteriophages (MRSA-R14 and COL-R23) with improved antibiofilm activity against a clinical isolate (MRSA3) were tested in combination with vancomycin and a carboxymethylcellulose (CMC) hydrogel in vitro and in vivo. MRSA3 bacterial biofilms were formed on sterile 4 mm sintered porous glass beads at 37 °C for 24 h. Biofilms were exposed to i-phage cocktail (10⁷ PFU/ml), ii-vancomycin at concentrations of 0.5, 1, 10 and 100 times the MIC, or iii-combination of phage cocktail and vancomycin. Recovered biofilm cells, were quantified by colony counting. The stability and release profiles of phage cocktail and vancomycin in co-delivery hydrogel were assessed in vitro for 8 days and 72 hrs, respectively, and subsequently tested in the treatment of 5-day-old MRSA3 infection of a femoral plate osteotomy in mice.

Aim

Antibacterial activity of coatings based on metal and metal oxide nanoparticles (NPs) often depends on materials and biotic targets resulting in a material-specific killing activity of selected Gram-positive and Gram-negative bacteria, including drug-resistant strains. In this perspective, the NPs loading amount, the relative elemental concentration inside the nanogranular building blocks and the deposition method are of paramount importance when the goal is to widen the antimicrobial spectrum, but at the same time to avoid high levels of metal content to limit undesired toxic effects. Aim of the present study was evaluation of the antimicrobial properties of two multielement nanogranular coatings composed of Titanium-Silver and Copper and of Magnesium-Silver and Copper.

Method

Ti-Ag-Cu and Mg-Ag-Cu NPs were deposited on circular cover glasses (VWR) by Supersonic Cluster Beam Deposition. Biofilm-producer strains of Staphylococcus aureus (methicillin susceptible and resistant), Staphylococcus epidermidis (methicillin susceptible and resistant), Escherichia coli (fully susceptible and producer of extended spectrum beta lactamases), and Pseudomonas aeruginosa (susceptible and multidrug-resistant) were selected. The abilities of the selected strains to adhere, colonize and produce biofilm on the discs coated with Ti-Ag-Cu or Mg-Ag-Cu NPs were compared to uncoated circular cover glasses which were used as growth control. Cytotoxicity was also evaluated in order to assess the biocompatibility of the newly synthesized NPs.

Aim

The use of medical devices has grown significantly over the last decades, and has become a major part of modern medicine and our daily life. Infection of implanted medical devices (biomaterials), like titanium orthopaedic implants, can have disastrous consequences, including removal of the device. For still not well understood reasons, the presence of a foreign body strongly increases susceptibility to infection. These so-called biomaterial-associated infections (BAI) are mainly caused by Staphylococcus aureus and Staphylococcus epidermidis. Formation of biofilms on the biomaterial surface is generally considered the main reason for these persistent infections, although bacteria may also enter the surrounding tissue and become internalized within host cells. To prevent biofilm formation using a non-antibiotic based strategy, we aimed to develop a novel permanently fixed antimicrobial coating for titanium devices based on stable immobilized quaternary ammonium compounds (QACs).

Method

Medical grade titanium implants (10×4×1 mm) were dip-coated in a solution of 10% (w/v) hyperbranched polymer, subsequently in a solution of 30% (w/v) polyethyleneimine and 10 mM sodium iodide, using a dip-coater, followed by a washing step for 10 min in ethanol. The QAC-coating was characterized using water contact angle measurements, scanning electron microscopy, FTIR, AFM and XPS. The antimicrobial activity of the coating was evaluated against S. aureus strain JAR060131 and S. epidermidis strain ATCC 12228 using the JIS Z 2801:2000 surface microbicidal assay. Lastly, we assessed the in vivo antimicrobial activity in a mouse subcutaneous implant infection model with S. aureus administered locally on the QAC-coated implants prior to implantation to mimic contamination during surgery.

Aim

Prosthetic joint infections pose a major clinical challenge. Developing novel material surface technologies for orthopedic implants that prevent bacterial adhesion and biofilm formation is essential. Antimicrobial coatings applicable to articulating implant surfaces are limited, due to the articulation mechanics inducing wear, coating degradation, and toxic particle release. Noble metals are known for their antimicrobial activity and high mechanical strength and could be a viable coating alternative for orthopaedic implants [1]. In this study, the potential of thin platinum-based metal alloy coatings was developed, characterized, and tested on cytotoxicity and antibacterial properties.

Method

Three platinum-based metal alloy coatings were sputter-coated on medical-grade polished titanium discs. The coatings were characterized using optical topography and scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS). Ion release was measured using inductively coupled plasma optical emission spectrometry (ICP-OES). Cytotoxicity was tested according to ISO10993-5 using mouse fibroblasts (cell lines L929 and 3T3). Antibacterial surface activity, bacterial adhesion, bacterial proliferation, and biofilm formation were tested with gram-positive Staphylococcus aureus ATCC 25923 and gram-negative Escherichia coli ATCC 25922. Colony forming unit (CFU) counts, live-dead fluorescence staining, and SEM-EDS images were used to assess antibacterial activity.

Aim

In this study we investigated the effects of non-steroidal anti-inflammatory drugs (NSAIDs) with different cyclooxygenase (COX) selectivity on orthopaedic device-related infections (ODRIs) in a rat model. Specifically, we aimed to measure the impact of NSAID therapy on bone changes, bacterial load, and cytokine levels after treatment with antibiotics. In addition, we compared the effects of long vs short-term celecoxib (a COX-2 inhibitor) treatment on the same outcomes.

Method

Skeletally mature female Wistar rats were implanted with Staphylococcus epidermidis-contaminated polyetheretherketone (PEEK) screws (1.5 × 10⁶ CFU per screw) in the proximal right tibia and monitored for 7 days. All animals received subcutaneous antibiotics (rifampicin plus cefazolin) for two weeks from day 7 to 21. In phase I of the study, rats were randomly assigned to receive 28 days of oral treatment with acetylsalicylic acid, ibuprofen, celecoxib, or vehicle control. In phase II, an additional group received seven days of celecoxib treatment from day 0 to 7. After implantation, bone changes were monitored using in vivo micro-CT and histology. Quantitative bacteriology was performed at euthanasia. Plasma samples were collected to measure cytokine levels at four time points (day 0, 6, 20, and 28).

Aim

Deep infection following endoprosthetic replacement (EPR) of long bones is a devastating complication occurring in 15% of musculoskeletal tumour patients. The recently published PARITY Trial demonstrated that extending antibiotic prophylaxis from 24 hours to 5 days does not reduce infection rates. However, questions remain about the optimal antibiotic choice and dose.

Method

A 23-question multiple-choice questionnaire was designed and piloted through an iterative feedback process until the final version was agreed by all authors. Open and closed-ended questions were used to gather information on practice and Likert-type scale responses were used to grade responses to ascertain surgeon perceptions and preferences. The online survey was sent to all surgeon delegates of the 34th Annual Meeting of the European Musculo-Skeletal Oncology Society in London in October 2022.

Aim

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.

Method

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.

Aim

The origin of surgical site and biomaterial-associated infection is still elusive. Microorganisms contaminating the wound may come from the air, the surgical team, or from the skin of the patient. Prior to surgery the skin of patients is disinfected, but bacteria deeper in the skin (e.g. in sweat glands or sebaceous glands), may not be reached. This study aims to assess a potential role of this intracutaneous bacterial reservoir in biomaterial-associated infection.

Method

To study if cutaneous microbiota colonize the wound when released from the skin upon cutting, we isolated, quantified and identified aerobic and anaerobic bacteria from the skin of 99 patients undergoing trauma surgery, before and after skin disinfection, from the knife blades and from the wound directly after the first cut.

Purpose

Intra-articular corticosteroid injection is widely used for symptomatic relief of knee osteoarthritis. However, if pain is not improved which consequences a total knee arthroplasty (TKA), there is a potential risk of post-operative periprosthetic joint infection (PJI). The aim of this study is to investigate whether the use of preoperative intra-articular corticosteroid injection increases the risk of PJI and to investigate a time frame in which the risk of subsequent infection is significantly increased.

Methods

A systematic search was performed in PubMed (Medline), Scopus, and the Cochrane Library. Inclusion criteria were original studies investigating the rate of PJI in patients receiving pre-operative intra-articular corticosteroid injection compared to controls.

Aim

To describe the risk factors, microbiology and treatment outcome polymicrobial prosthetic joint infections (PJI) compared to monomicrobial PJI.

Methods

Between January 2011 and December 2021, a total of 536 patients were diagnosed with PJI at our institution. Clinical records were revised, and 91(16.9%) had an isolation of two or more pathogens. Age, sex, previous conditions, Charlson comorbidity score, previous surgery, PJI diagnosis and surgical and antibiotic treatment, from the index surgery onwards were reviewed and compared between groups.

Aim

The aim of this paper is to analyse the cause of neuropathic diabetic foot ulcers and discuss their preventive measures.

Methods

Review of patients with foot ulcers managed in our diabetic MDT clinics since Feb 2018 were analysed. Based on this observation and review of pertinent literature, following observations were made.

Aim

To describe a 2-stage treatment pathway for managing neuropathic forefoot ulcers and the safety and efficacy of percutaneous tendo-Achilles lengthening (TAL) in out-patient clinics.

Methods

Forefoot ulcers in patients with diabetic neuropathy are a result of factors that result in increased forefoot plantar pressure. Plantar flexed metatarsal heads secondary to progressive claw toe deformity and hindfoot equinus from changes within the gastrocnemius-soleus-tendo-Achilles complex, with additional contraction of tibialis posterior and peroneal longus, secondary to motor neuropathy results in progressive increase in forefoot plantar pressures.

Consecutive patients, who presented to our Diabetic Foot clinic since February 2019 with forefoot ulcers or recurrent forefoot callosity were treated with TAL in the first instance, and in patients with recurrent or non-healing ulcers, by proximal dorsal closing wedge osteotomy; a 2-stage treatment pathway.

Patients were followed up at 3, 6, and 12 months to assess ulcer healing and recurrence.

Aim

Calcaneal osteomyelitis remains a difficult condition to treat with high rates of recurrence and below knee amputation; particularly in cases of severe soft tissue destruction. This study assesses the outcomes of combined ortho-plastics treatment of complex calcaneal osteomyelitis.

Method

A retrospective review was performed of all patients who underwent combined single stage ortho-plastics treatment of calcaneal osteomyelitis (2008- 2022). Primary outcome measures were osteomyelitis recurrence and BKA. Secondary outcome measures included flap failure, operative time, complications, length of stay.

Aim

Antibiotic concentration at the infected site is a relevant information to gain knowledge about deep-seated infections. The combination of antibiotic therapy and debridement is often indicated to treat these infections. At University Hospital Basel the most frequently administered antibiotic before debridement is amoxicillin in combination with clavulanic acid. Amoxicillin is a fragile beta-lactam antibiotic that brings multiple challenges for its quantification.

As for many sample materials only little material is available, the aim of this work was to establish a sensitive and reliable quantification method for amoxicillin that only requires a small sample mass. We did not quantify clavulanic acid as we focused on the drug with antibiotic action.

Method

Usually discarded sample material during debridement was collected and directly frozen. The thawed tissues were prepared using simple protein precipitation and manual homogenization with micro pestles followed by a matrix cleanup with online solid-phase extraction. Separation was performed by HPLC followed by heated electrospray ionization and tandem mass spectrometry.

Background and aim

Implant-associated osteomyelitis is one of the most feared complications following orthopedic surgery. Although the risk is low it is crucial to achieve adequate antibiotic concentrations proximate to the implant for a sufficient amount of time to protect the implant surface and ensure tissue integration. The aim of this study was to assess steady-state piperacillin concentrations in the proximity of an orthopedic implant inserted in cancellous bone.

Method

Six female pigs received an intravenous bolus infusion of 4 g/0.5 g piperacillin/tazobactam over 30 min every 6 h. Steady state was assumed achieved in the third dosing interval (12–18 h). Microdialysis catheters were placed in a cannulated screw in the proximal tibial cancellous bone, in cancellous bone next to the screw, and in cancellous bone on the contralateral tibia. Dialysates were collected from time 12 to 18 h and plasma samples were collected as reference.

Abstract Background

The treatment of bone and joint infections (BJI) involving multi-drug resistant bacteria remains a challenge. MDR Staphylococcus epidermidis (MDRSE) clones, resistant to methicillin, clindamycin, levofloxacin, rifampicin and even linezolid, have been reported worldwide. The interest of delafloxacin (DFX), theoretically active on MRSA, remains to be evaluated with respect to MDRSE.

Purpose

Our objective was to evaluate during a retrospective multicenter study the DFX minimal inhibitory concentrations (MICs) and compare its efficacy between ofloxacin-susceptible and ofloxacin-resistant S. epidermidis clinical strains involved in BJI.

Aim

The β-lactam penicillin is often used in the treatment of soft tissue infections and osteomyelitis caused by penicillin susceptible Staphylococcus aureus. Oral antibiotic treatment has been shown to be non-inferior to intravenous (IV) therapy when used during the first 6 weeks in complex orthopedic infections (OVIVA trial). However, the use of oral β-lactams in osteomyelitis treatment remains a topic of debate due to low and variable bioavailability. The aim was to assess the time for which the unbound penicillin concentration exceeded targeted minimum inhibitory concentrations (fT>MIC) in cancellous bone and subcutaneous tissue after IV (penicillin G) and oral (penicillin V) treatment in a porcine microdialysis model.

Method

12 female pigs (75kg) were assigned to standard clinical regimens of either three doses of IV penicillin G (1.2g) or oral penicillin V (0.8g) every 6h over 18h. Microdialysis catheters were placed for sampling in tibial cancellous bone and adjacent subcutaneous tissue. Data was collected in the first dosing interval (0–6h; prophylactic situation) and the third dosing interval (12–18h; assumed steady state). Plasma samples were collected for reference. MIC targets of 0.125μg/mL (Staph. aureus breakpoint), 0.25μg/mL (Strep. Group A, B, C and G breakpoint) and 0.5μg/mL (4xMIC) were applied.

Aim

The objective of this systematic review is to evaluate the current evidence for or against this up-and-coming treatment modality.

Method

A comprehensive literature search in accordance with the Preferred Reporting Items for Systematic review and Meta-analysis (PRISMA) guidelines was conducted using PubMed, Embase, MEDLINE and Cochrane databases. Exclusion criteria included patients < 18 years of age, follow-up <11 months, and a score < 6 on the National Institute of Health quality assessment tool.

Aim

Local antibiotics released through a carrier is a commonly used technique to prevent infection in orthopaedic procedures. An interesting carrier in aseptic bone reconstructive surgery are bone chips impregnated with AB solution. Systemically administered Cefazolin (CFZ) is used for surgical site infection prophylaxis however in vitro study showed that fresh frozen and processed bone chips impregnated with CFZ solution completely release the CFZ within a few hours. On the other hand irradiated freeze-dried bone chips, treated with supercritical CO2 (scCO2) have been shown to be an efficient carrier for the antibiotics vancomycine or tobramycine.

With this pilot study we wanted to investigate if CFZ solution impregnation of bone chips treated with scCO2 shows a more favorable release pattern of CFZ.

Method

The bone chips were prepared using the standard scCO2 protocol and were impregnated with 100 mg/ml cefazolin at different timepoints during the process: before freeze drying (BC type A), after freeze drying (BC type B) and after gamma-irradiation. 0.5g of the impregnated bone grafts were incubated with 5ml of fetal calf serum (FCS) at 37°C. At 2, 4, 6, 8 and 24h of incubation 200µl of eluate was taken for analysis. After 24h the remaining FCS was removed, bone grafts were washed and new FCS (5ml) was added. Consecutive eluate samples were taken at 48, 72 and 96h of incubation.

The concentration of CFZ in the eluates was measured with the validated UPLC-DAD method. Analysis was performed in triplicate.

Aim

Prosthetic joint infection (PJI) is a devastating and costly complication of total joint arthroplasty (TJA). Use of extended oral antibiotic prophylaxis (EOAP) has become increasingly popular in the United States following a highly publicized study (Inabathula et al) from a single center demonstrating a significant protective effect (81% reduction) against PJI in ‘high-risk’ patients. However, these results have not been reproduced elsewhere and EOAP use directly conflicts with current antibiotic stewardship efforts. In order to study the role of EOAP in PJI prevention, consensus is needed for what defines ‘high-risk’ patients. The revision TJA (rTJA) population is an appropriate group to study due to having a higher incidence of PJI. The purpose of the current study was to rigorously determine which preoperative conditions described by Inabathula et al. (referred to as Inabathula criteria (IBC)) confer a higher rate of PJI in patients undergoing aseptic rTJA.

Method

2,256 patients that underwent aseptic rTJA at a single high-volume institution between 2016–2022 were retrospectively reviewed. Patient demographics and comorbidities were recorded to determine if they had 1 or more ‘IBC’, a long list of preoperative conditions including autoimmune diseases, active smoking, body mass index (BMI)>35, diabetes mellitus, and chronic kidney disease (CKD). Reoperation for PJI at 90-days and 1-year was recorded. Chi-squared or Fischer's exact tests were calculated to determine the association between preoperative presence/absence of IBC and PJI. Multivariable logistic regressions were conducted to determine if specific comorbidities within the IBC individually conferred an increased PJI risk.

Aim

Bone and joint infection requires antimicrobial treatment for 6 to 12 weeks. When patients are well prepared and instructed regarding their therapy, they are more likely to have less side effects and improved compliance. Although side effects are common, this coaching is often not routinely performed when oral treatment is given. We developed a monitoring and guidance program for our outpatients who are on long term antimicrobial therapy, in which we can early signal side effects and treatment failure and coach the patients in their journey of infection treatment.

Method

In our tertiary referral centre for orthopaedic infections, we started the outpatient monitoring of antimicrobial treatment (OMAT)- team for patients who will receive antimicrobial therapy for >2 weeks. Before discharge, our trained nurse gives instruction to the patient. Within 3 days after hospital discharge the patient is contacted by phone to, if necessary, clarify ambiguities in monitoring set up. During this contact, the nurse checks for side effects, addresses logistic problems regarding laboratory monitoring or future appointments and coaches patients for other questions. The patient is instructed how to recognize and who to contact in case of red flags and problems possibly related to the treatment. This is repeated after every laboratory check-up. Supervision is performed by an infectious disease specialist in close collaboration with the patient's surgeon.

Aim

Antimicrobial suppression has shown to significantly improve treatment success of streptococcal periprosthetic joint infection (PJI) compared to 12-week standard antimicrobial therapy, however, only short-term follow-up was investigated. In this study we assessed the impact of suppression on the long-term outcome of streptococcal PJI.

Method

Consecutive patients with streptococcal PJI (defined by EBJIS criteria) treated 2009–2021 were prospectively included and allocated into standard and suppression (> 6 months) treatment group. Infection-free survival was assessed with Kaplan-Meier-method and compared between the groups with log rank test. Rates of infection-free, streptococcal infection-free and relapse-free status as well as tolerability of suppression were assessed.

Aim

Dalbavancin is a lipoglycopeptide with a half-life of 14 days (range 6.1 to 18.4), significantly longer than other antimicrobials, which avoids the need for daily antibiotic dosing. This multi-centre observational study aims to describe the use of dalbavancin to facilitate discharge in treating bone and joint infections.

Method

All adult patients treated with dalbavancin from January 2017 to September 2022 in four UK bone infection units were included.

Data collected through a standardised data collection form included:

Treatment-related costs were calculated for dalbavancin and the preferred hypothetical treatment option that would have been administered for the same duration. The costs were subtracted to calculate the cost difference.

Clinical success was defined as the absence of definite failure in accordance with the OVIVA Trial protocol.

Aim

Patient quality of life (QoL) in untreated bone infection was compared to other chronic conditions and stratified by disease severity.

Method

Patients referred for treatment of osteomyelitis (including fracture related infection) were identified prospectively between 2019 and 2023. Patients with confirmed infection completed the EuroQol EQ-5D-5L questionnaire. Clinicians blinded to EQ-index score, grouped patients according to JS-BACH Classification into ‘Uncomplicated’, ‘Complex’ or ‘Limited treatment options’. A systematic review of the literature was performed of other conditions that have been stratified using EQ-index score.

Aim

This study assessed quality of life (QoL) in patients having external fixation for treatment of osteomyelitis and fracture-related infection (OM/FRI).

Method

Patients who had surgery for OM/FRI and who completed the EuroQoL EQ-5D-5L or EQ-5D- 3L questionnaires, were identified between 2010 and 2020. Patients were followed-up for 2 years after surgery. QoL was compared between patients who had either an Ilizarov frame or a monolateral external fixator with those who did not receive external fixation.

Aim

The number of periprosthetic joint infections (PJI) is increasing due to ageing population and increasing numbers of arthroplasty procedures and treatment is costly. Aim of the study was to analyze the direct healthcare costs of PJI in Europe for total hip arthroplasties (THA) and total knee arthroplasties (TKA).

Method

A systematic review in PubMed with search of direct costs of PJI in European countries was performed. Thereby the term cost* AND (infection OR PJI) AND (prosthesis OR knee OR hip OR “TKA” OR “THA” OR arthroplast*) was combined with each European country to detect relevant publications. Publications with definition of performed procedure and joint localization were included into further analysis. The mean value of direct healthcare cost was calculated for the respective joint and the respective operation performed.

Aim

Multidisciplinary team (MDT) management of complex bone and joint infections (BJI) is increasingly implemented but studies evaluating this approach are scarce. We assessed the effectiveness of our MDT by analyzing the adherence to its treatment decisions.

Method

A cohort study was conducted comprising patients with complex BJI of which the management was discussed during MDT meetings between 2015 and 2022 in a tertiary care academic hospital. Patient characteristics and MDT data were obtained from electronic patient records.

Aim

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 complications in both FRI and non-FRI patients.

Method

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 a long bone fracture were eligible for inclusion. Patients with an Injury Severity Score (ISS) ≥16 or incomplete follow-up were excluded. QoL was assessed through the use of five-level EuroQol five-dimension (EQ-5D-5L) questionnaires twelve months post-injury.

Aim

Prosthetic joint infection (PJI) is a serious complication following total hip arthroplasty (THA) entailing increased mortality, decreased quality of life, and high healthcare costs. In 2009 a nationwide, multidisciplinary infection control program was launched in Sweden, PRISS, which aimed to reduce the PJI burden by 50%.

The primary aim was to investigate whether the PRISS project reduced PJI incidence after primary THA; the secondary aim was to evaluate other possible benefits of PRISS, such as shorter time to diagnosis.

Method

We obtained data on patients undergoing primary THA in Sweden (n = 45,723 patients, 49,946 THAs), 2012–2014. Using personal identity numbers, this cohort was matched with the Swedish Prescribed Drug Registry. Medical records of patients with ≥4 weeks antibiotic consumption were reviewed to verify PJI diagnosis (n = 2240, 2569 THAs).

Aim

To investigate the impact of waiting for surgical treatment for bone and joint infection (BJI) on patient self-reported quality of life (QoL).

Method

Patients presenting to clinic between January 2019 and February 2020 completed the EuroQol EQ-5D-5L questionnaire. Patients were divided into three groups: surgery performed; on the waiting list for surgery; or decision for non-operative management. All patients were followed-up for 2 years. The EQ-index score was calculated and change from presentation to 1-year and 2-year follow-up was compared across the 3 groups. Mortality at final follow-up was measured in all groups.

Aim

The aim of this systematic review was to assess the existing published data on tuberculous arthritis involving native joints in adults aged 18 years and older. The specific research questions focused on the diagnosis and management of the disease.

Method

This study was performed in accordance with the guidelines provided in the Preferred Reporting Items for Systematic reviews and Meta-Analysis extension for Scoping Reviews (PRISMA-ScR). A systematic literature search was undertaken of Pubmed, Web of Science, Scopus and the Cochrane library. Only studies published in English since 1970 were considered. Case series involving less than 10 patients, systematic and narrative reviews, and laboratory or animal studies were excluded. We also excluded reports of TB infections not involving a “native joint” and tuberculosis of the spine. The level of evidence and strength of recommendations was performed in accordance with the GRADE system.

Aim

At our tertiary orthopaedic centre, mycobacterial cultures are routinely performed on bone and joint samples sent for bacterial culture. We have previously described the prevalence Mycobacterium tuberculosis Complex (MTBC) in these samples. Here, we describe the prevalence of non-tuberculous mycobacteria (NTM). We calculate the number needed to test to identify one previously undiagnosed mycobacterial bone or joint infection.

Methods

Samples taken during a single procedure were pooled in one BACTEC MGIT culture. From laboratory records, we ascertained the number of mycobacterial cultures performed, the number positive for MTBC or NTM, and characteristics of individuals from whom mycobacteria were isolated. We collected the same data from 100 individuals with negative mycobacterial cultures. Results presented here are from interim analysis.

Introduction

A proportion of patients with hip and knee prosthetic joint infection (PJI) undergo multiple revisions with the aim of eradicating infection and improving quality of life. The aim of this study was to describe the microbiology cultured from multiply revised hip and knee replacement procedures to guide antimicrobial therapy at the time of surgery.

Patients and Methods

Consecutive patients were retrospectively identified from databases at two specialist orthopaedic centres in the United Kingdom between 2011 and 2019. Patient were included who had undergone repeat revision total knee replacement (TKR) or total hip replacement (THR) for infection, following an initial failed revision for infection.

Aims

The aim of this study was to assess the incidence the microbiological spectrum and clinical outcome of hip and knee revision arthroplasties with unexpected-positive-intraoperative-cultures (UPIC) at a single center with minimum follow up of 2 years.

Methods

We retrospectively analyzed our prospectively maintained institutional arthroplasty registry. Between 2011 and 2020 we performed presumably aseptic rTHA (n=939) and rTKA (n= 1,058). Clinical outcome, re-revision rates and causes as well as the microbiological spectrum were evaluated.

Aims

The microbiological detection of microorganisms plays a crucial role in the diagnosis as well as in the targeted systemic and local antibiotic therapy of periprosthetic infections (PJI). Despite extensive efforts to improve the sensitivity of current culture methods, the rate of culture-negative infections is approximately 10–20% of all PJI. This study investigates an preanalytical algorithm (culture collection and direct processing in the OR) to potentially increasing culture yield in patients with PJI.

Methods

Patients undergoing staged revision arthroplasty for PJI in our hospital between October 2021 and 2022 were included in this prospective pilot study. Intraoperatively twenty tissue samples were collected and distributed among 4 groups. Tissue samples were prepared according to standard without medium and in thioglycolate medium at 3 different temperatures (room temperature, 4°C, 37° for 24h before transport to microbiology) directly in the OR. The removed implants were sonicated. Cultures were investigated on days 1, 3, 7, 12, 14 for possible growth. All grown organism, the number of positive samples and the time to positivity were recorded and compared.

Aim

The aim of this study was to investigate the clinical relevance of an isolated positive sonication fluid culture (SFC) in patients who underwent revision surgery of a prosthetic joint. We hypothesized that cases with a positive SFC have a higher rate of infection and prosthesis failure during follow-up compared to controls with a negative SFC.

Method

This retrospective multicentre observational study was performed within the European Study Group of Implant-Associated Infections (ESGIAI). All patients who underwent revision surgery of a prosthetic joint between 2013 and 2019 and had a minimum follow-up of 1 year were included. Patients with positive tissue cultures or synovial fluid cultures were excluded from the study.

Aim

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is commonly associated with serious cases of community-onset skin and musculoskeletal infections (Co-SMSI). Molecular epidemiology analysis of CA-MRSA recovered from skin and soft tissues specimens is lacking in Latin America. This study aimed to identify phenotypic and genotypic features of MRSA isolates recovered from patients presenting Co-SMSI.

Methods

Consecutive MRSA isolates recovered from Co-SMSI of patients admitted from March 2022 to January 2023 in a Brazilian teaching hospital were tested for antimicrobial resistance and characterized by their genotypic features. Identification was carried out by automated method and through MALDI-TOF MS. Antimicrobial susceptibility was tested by disk diffusion, broth microdilution and E-test strips for determination of the minimal inhibitory concentration (MIC) according to recommendations from the Brazilian Committee on Antimicrobial Susceptibility Testing (BrCAST) and European Committee on Antimicrobial Susceptibility Testing (EUCAST). Gene mecA characterization and Sccmec typing were performed by multiplex polymerase chain reaction (PCR) assay, and gene lukF detection by single PCR. Patients were prospectively followed up for two months, in order to determine their clinical characteristics and outcomes.

Aim

The localization of sequestrum in chronic osteomyelitis (COM) is crucial in preoperative planning. The identification of sequestrum on plain X-ray could be difficult. CT and MRI were reported to show the sequestrum. We aimed to analyze the sequestrum characteristics on 18F-FDG-PET-CT images.

Methods

A prospective study included all patients diagnosed with long-bone chronic osteomyelitis. All patients had preoperative 18F-FDG-PET-CT. Images were analyzed using RadiAnt DICOM Viewer. Axial cuts were used to measure the Standard Uptake Ratio (SUV)max in the Region of Interest (ROI) in the sequestrum, the surrounding area, and the normal bone in the same cut. Surgical debridement was done as standard; samples were taken for microbiology and histopathology, and the intraoperative finding was documented.

Background

The identification of novel biomarker which is highly specific and sensitive for periprosthetic joint (PJI) have the potential to improve diagnostic accuracy and ultimately improve patient outcomes. Thus, the aim of this systemic review is to identify and evaluate novel biomarkers for the preoperative diagnostics of PJI.

Methods

MEDLINE, EMBASE, PubMed and Cochrane Library databases identified from 1^st of January 2018 to 30^th of September. 2022. We used “periprosthetic joint infection” OR “prosthetic joint infection” OR “periprosthetic infection” as the diagnosis of interest and the target index applied AND “marker”. To focus on novel biomarkers already used biomarkers of the established PJI diagnostic criteria of MSIS, ICM and EBJIS were not included in the analysis. These three criteria were considered the reference standard during quality assessment.

Background

The diagnosis of periprosthetic joint infection (PJI) remains a challenge in clinical practice and the analysis of synovial fluid (SF) is a useful diagnostic tool. Recently, two synovial biomarkers (leukocyte esterase (LE) strip test, alpha-defensin (AD)) have been introduced into the MSIS (MusculoSkeletal Infection Society) algorithm for the diagnosis of PJI. AD, although promising with high sensitivity and specificity, remains expensive. Calprotectin is another protein released upon activation of articular neutrophils. The determination of calprotectin and joint CRP is feasible in a routine laboratory practice with low cost.

Purpose

Our objective was to evaluate different synovial biomarkers (calprotectin, LE, CRP) for the diagnosis of PJI.

Aim

Synovial calprotectin point-of-care test (POC) has shown promising clinical value in diagnosing periprosthetic joint infections (PJIs). However, limited data are available in unclear cases. Moreover, cut-off values for calprotectin lateral flow assay (LFA) and enzyme-linked immunosorbent assay (ELISA) need to be adapted. The aim of this study was to evaluate the performance of an upgraded and more sensitive version of a synovial calprotectin LFA along with ELISA immunoassay in patients with septic, aseptic, and unclear cases.

Methods

Overall, 206 prospectively collected periprosthetic synovial fluid samples from 169 patients (106f/63m; 38 hip/131 knee) who underwent revision surgeries were retrospectively evaluated for calprotectin concentration. The following groups were analyzed: unexpected negative cultures (UNC; 32/206), unexpected positive cultures (UPC; 28/206), and unclear cases (65/206) with conflicting clinical results. In addition, we added a true aseptic (40/206), and true septic (41/206) control groups according to the international consensus meeting (ICM) 2018 PJI classification. Calprotectin concentration was determined by a rapid quantitative LFA (n=206) (Lyfstone®, Norway), and compared to calprotectin ELISA immunoassay (171/206). For the determination of a new calprotectin cut-off value, analysis of the area under the curve (AUC) followed by Youden's J statistic were performed using the calproctectin values from clear septic and aseptic cases. Sensitivity and specificity for calprotectin were calculated. All statistical analyses were performed using IBM-SPSS® version 25 (Armonk, NY, USA).

Aim

Serum parameters continue to be a focus of research in diagnosing periprosthetic joint infections (PJI). Several workgroups have recently proposed serum Albumin-Globulin-Ratio (AGR) as a potential new biomarker. Due to controversies in the literature, its usability in clinical practice remains uncertain. The aim of this study was to assess the value of serum AGR in diagnosing PJI preoperatively, especially in comparison with the well-established marker C-reactive Protein (CRP).

Method

From January 2015 to June 2022, patients with indicated revision hip (rTHA) and knee (rTKA) arthroplasty were included in this retrospective cohort study of prospectively collected data. A standardized diagnostic workup was performed using the 2021 European Bone and Joint Infection Society (EBJIS) definition of PJI, excluding CRP. Diagnostic accuracies of serum AGR and CRP were calculated by receiver operating characteristic curve (ROC) analysis. A z-test was used to compare the area under the curves (AUC).

Aim

The diagnosis of periprosthetic joint infection (PJI) remains a clinical dilemma, since presentations of PJI usually greatly overlap with aseptic failure (AF). The aim of this study is to evaluate the values of plasma fibrinogen, individually or in combination with CRP, ESR and WBC, for distinguishing PJI from AF.

Method

We retrospectively enrolled 357 cases who underwent revision hip or knee arthroplasties in the Third Affiliated Hospital of Southern Medical University, Sun Yat-sen Memorial Hospital and the First Affiliated Hospital of Sun Yat-sen University from January 2013 to December 2021, including 197 AF, 116 PJI and 44 reimplantation. The diagnostic capacity of preoperative fibrinogen, CRP, ESR and WBC as well as their combinations for differentiating PJI from AF were assessed by ROC curves. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated according to the optimal cutoff value based on the Youden index. All biomarkers were further investigated for their potential ability to predict optimal timing of reimplantation as well as their diagnostic capacity in the subgroups of the knee and hip PJI. Furthermore, the correlations among fibrinogen, CRP and ESR in the patients with PJI and AF were analyzed to further evaluate the potential capacity of fibrinogen in the diagnosis of PJI.

Aim

Prosthetic joint infection (PJI) represents the second most frequent complication of total joint arthroplasty (TJA) with up to 20% of low-grade PJI treated as aseptic failure. Sensitive diagnostic criteria have been provided by EBJIS. However, to date there is no single test to reliably diagnose all PJIs. Studies of Mazzucco et al. and Fu et al. suggest that synovial fluid (SF) viscosity could be considered as an important marker for PJI. The primary aim of our study was to determine if SF viscosity is a more reliable diagnostic criterion of PJI than the SF cell count with differential (CCD), and the combined diagnostic value of SF viscosity and CCD.

Method

We prospectively analysed the viscosity of SF samples obtained during TJA of hip and knee revisions. We sampled 2.5–5mL of SF for viscosity and CCD. Intraoperatively, 1mL of the sample was analysed for the CCD. The remaining SF was centrifuged for 4min at 7000rpm. The viscosity of the supernatant was determined on Ostwald viscometer as the time required to pass the viscometer at 20°C. During each surgery at least 5 microbiological and multiple histopathological samples were harvested, and explant sonication was performed. The diagnosis was based on EBJIS definition. The viscosity threshold for detecting PJI was set at 65 seconds.

Aim

Diagnosis of periprosthetic shoulder infections (PSI) is difficult as they are mostly caused by low-virulent bacteria and patients do not show typical infection signs, such as elevated blood markers, wound leakage, or red and swollen skin. Ultrasound-guided biopsies for culture may therefore be an alternative for mini-open biopsies as less costly and invasive method. The aim of this study was to determine the diagnostic value and reliability of ultrasound-guided biopsies for cultures alone and in combination polymerase chain reaction (PCR), and/or synovial markers for preoperative diagnosis of PSI in patients undergoing revision shoulder surgery.

Method

A prospective explorative diagnostic cohort study was performed including patients undergoing revision shoulder replacement surgery. A shoulder puncture was taken preoperatively before incision to collect synovial fluid for interleukin-6 (IL-6), calprotectin, WBC, polymorphonuclear cells determination. Prior to revision surgery, six ultrasound-guided synovial tissue biopsies were collected for culture and two additional for PCR analysis. Six routine care tissue biopsies were taken during revision surgery and served as reference standard.

Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV; primary outcome measure), and accuracy were calculated for ultrasound-guided biopsies, and synovial markers, and combinations of these.

Background

Data regarding the diagnostic value of ultrasound (US)-determined fluid film and joint aspiration prior to revision total hip arthroplasty (THA) for suspected periprosthetic joint infections (PJIs) is limited. This study aimed to analyse (1) the value of US-determined fluid film, (2) characterisation of the pre- and intraoperative microbiological spectrum and resistance patterns and (3) the concordance between preoperative synovial fluid and intraoperative culture results.

Methods

We analysed 366 US-examinations from 340 patients prior to revision THA. Selected cases were categorized into clearly infected, non-infected and inconclusive, according to the International Consensus Meeting (ICM) 2018 Criteria. If US-determined fluid film was <1mm, no aspiration was performed based on our institutional standard protocol. Patients were grouped into no-aspiration (144/366;[39.3%]), dry-tap (21/366;[5.7%]) and a successful-tap (201/366;[54.9%]). The microbiological spectrum and antibiotic resistance patterns were determined and differences were compared between pre- and intraoperative results.

Aim

The aim of our study was to analyze putative genes for virulence factors of Cutibacterium isolates obtained from implant-associated infections.

Methods

We analyzed 64 isolates of Cutibacterium spp. (C. acnes (53/64), C. avidum (6/64), C. granulosum (4/64), C. namnetense (1/64)) using NextSeq 550 (Illumina, San Diego, CA, USA) and performed genomic analysis of 24 genes associated with virulence factors (VFs) of C. acnes previously reported in the literature. Most isolates were obtained from implant-associated infections (IAI) between 2012–2021 at the Institute of Microbiology and Immunology, Faculty of Medicine, Ljubljana. Additionally, we included the first C. namnetense isolated in our laboratory from surgical site infection.

Aim

While 16S rRNA PCR - Sanger sequencing has paved the way for the diagnosis of culture-negative bacterial infections, it does not provide the composition of polymicrobial infections. We aimed to evaluate the performance of the Nanopore-based 16S rRNA metagenomic approach using partial-length amplification of the gene, and to explore its feasibility and suitability as a routine diagnostic tool for bone and joint infections (BJI) in a clinical laboratory.

Method

Sixty-two clinical samples from patients with BJI were sequenced on MinION* using the in-house partial amplification of the 16S rRNA gene. BJI were defined based on the ICM Philly 2018 and EBJIS 2021 criteria. Among the 62 samples, 16 (26%) were culture-positive, including 6 polymicrobial infections, and 46 (74%) were culture-negative from mono- and polymicrobial infections based on Sanger-sequencing. Contamination, background noise definition, bacterial identification, and time-effectiveness issues were addressed.

Background and aim

In 2019, specific diagnostic and antibiotic treatment recommendations for diabetic foot infection (DFI) and osteomyelitis (DFO) were introduced in our institution. They include principles on numbers of biopsies to obtain for microbiological/histopathological examinations, labeling anatomic localization, and antibiotic treatment (ABT) duration based on the aforementioned findings. ABT should be stopped after complete resection of infected bone. In case of incomplete resection, treatment is continued for 4–6 weeks. Two years after the introduction of these recommendations, we investigated the degree of implementation for hospitalized patients.

Method

Adult patients with DFI/DFO undergoing surgical intervention from 01/2019–12/2021 were reviewed retrospectively. Diagnostic procedures were assigned to each episode when performed ≤30 days before surgical invention. Chi-square and Mann-Whitney-U tests were performed where appropriate.

Aim

To evaluate whether sonication of implant material and subsequent culturing add clinical relevance to culturing of tissue biopsies for improved antibiotic treatment in treatment of bone and joint infection.

Method

A retrospective examination of patients’ charts and microbiological analyses in patients who had explanted material (plates, screws, k-wires and prostheses) send for sonication between December 2020 and April 2022.

Aim

One of the surgical therapeutic options for periprosthetic joint infection (PJI) includes debridement, antibiotics, and implant retention (DAIR). Prognostically favorable criteria for DAIR include short duration of symptoms, stable implant, pathogen susceptible to a ‘biofilm-active’ antimicrobial agent, and intact soft-tissue conditions. Despite this, there is a proportion of failures after DAIR, possibly because the duration of infection is underestimated. With the hypothesis that the duration of infection correlates with the bacterial load, and hence, the bacterial load is associated with failure after DAIR, we aimed to investigate the association of bacterial load in the sonication fluid of mobile parts and clinical outcome after DAIR.

Method

From our PJI cohort (2010–2021), patients with DAIR (both palliative and curative approaches) were reviewed retrospectively. Patients with hip, knee or shoulder arthroplasties fulfilling infection definition, available sonication results, and ≥2 years follow-up were included. Sonication results were categorized in ≤ or >1000 cfu/mL. Univariate analysis was performed to identify predictors for DAIR failure.

Aim

To provide proof of concept in an in vivo animal model for the prevention of prosthetic joint infection prevention using electric fields along with conventional antibiotic prophylaxis.

Corresponding Author: Marti Bernaus

Method

First, we standardized the animal model to simulate implant contamination during the surgical procedure. We then implanted cobalt-chrome prostheses adapted to both knees of two New Zealand White rabbits, under standard aseptic measures and antibiotic prophylaxis with cefazolin. Prior to implantation, we immersed the prostheses in a 0.3 McFarland inoculum of S. aureus (ATCC 25923) for 30 seconds. In the first animal (control), the joint was directly closed after washing with saline. In the second animal (case), both prostheses were treated with electric current pulses for 30 seconds, washed with saline, and the joint was closed. After 72 hours, both animals were reoperated for the collection of periprosthetic tissue and bone samples, and prosthesis removal. In all samples, we performed quantitative cultures prior to vortexing and sonication, as well as prolonged cultures of the sonication broth. We confirmed the absence of contamination by identification with MALDI-TOF (VITEK-MS) and automated antibiotic susceptibility testing of the isolated colonies (VITEK-2).

Aim

The time to onset of symptoms after fracture fixation is still commonly used to classify fracture-related infections (FRI). Early infections (<2 weeks) can often be treated with debridement, systemic antibiotics, irrigation, and implant preservation (DAIR). Late infections (>10 weeks) typically require implant removal as mature, antibiotic-tolerant biofilms have formed. However, the recommendations for delayed infections (2–10 weeks) are not clearly defined. Here, infection healing and bone healing in early and delayed FRI is investigated in a rabbit model with a standardized DAIR procedure.

Method

Staphylococcus aureus was inoculated into 17 rabbits after plate osteosynthesis in a humerus osteotomy. The infection developed either one week (early group, n=6) or four weeks (delayed group, n=6) before a standardized DAIR procedure and microbiological analysis were performed. Systemic antibiotics were administered for six weeks (two weeks: Nafcillin+Rifampin, four weeks: Levofloxacin+Rifampin). A control group (n=5) also underwent a revision operation (debridement and irrigation) after four weeks, but received no antibiotic treatment. Rabbits were euthanized seven weeks after the revision operation. Bone healing was assessed using a modified radiographic union score for tibial fractures (mRUST). After euthanasia, a quantitative microbiological examination of the entire humerus, adjacent soft tissues, and implants was performed.

Aim

The use of bone substitutes such as calcium sulfate (CaSO4) and hydroxyapatite with local antibiotics are crucial in the treatment of osteomyelitis. They allow the treatment of the dead space and locally provide large concentrations of antibiotics. However, it is unknown whether use of local vancomycin may elute and influence on vancomycin plasma levels. The aim of this study is to assess whether the addition of vancomycin to CaSO4 with hydroxyapatite may increase vancomycin plasma concentrations in in patients with osteomyelitis and therefore alter dosage adjustments.

Method

The present study investigates the vancomycin plasma concentrations at 72–94 h post-surgery after the application of local vancomycin within CaSO4 (660mg vancomycin/10cc) and hydroxyapatite bone substitute in patients treated with empiric intravenous vancomycin and surgically treated for osteomyelitis.

Vancomycin plasma concentrations were analyzed in twelve patients with osteomyelitis surgically treated with local release of vancomycin by CaSO4 and hydroxyapatite and undergoing therapeutic drug monitoring (TDM) of their vancomycin plasma concentrations as it is routinely done in our hospital. From 2019 to 2022, demographic data, microbiology, type of osteomyelitis, amount of local vancomycin applied, alteration of renal function, and vancomycin levels were retrospectively analyzed.

Aim

Differentiation of infected (INF) nonunion from aseptic (AS) nonunion is crucial for the choice of intra- and postoperative treatment. Preoperative diagnosis of infected nonunion is challenging, especially in case of low-grade infection lacking clinical signs of infection. Standard blood markers such as C-reactive protein or leucocyte count do not aid in preoperative diagnosis. Proteomic profiling has shown promising results for differentiation of numerous chronic disease states, and in this study was applied to preoperative blood samples of patients with nonunion in an attempt to identify potential biomarkers.

Method

This prospective multicenter study enrolled patients undergoing revision surgery of femur or tibia nonunion. Patients with implant removal after regular fracture healing (HEAL) were included as a control-group. Preoperative blood samples, intraoperative tissue samples, sonication of osteosynthesis material and 1-year-follow-up questionnaire were taken. Nonunion patients were grouped into INF or AS after assessing bacterial culture and histopathology of retrieved samples. Diagnosis of infection followed the fracture related infection consensus group criteria, with additional consideration of healing one year after revision surgery. Targeted proteomics was used to investigate a predefined panel of 45 cytokines in preoperative blood samples. Statistical differences were calculated with Kruskal Wallis and Dunn's post hoc test. Cytokines with less than 80% of samples being above the lower limit of detection range (LLDR) were excluded for this study.

Aim

Debridement, antibiotics, and implant retention (DAIR) is a viable treatment option for acute periprosthetic joint infections (PJI). The landmark DATIPO trial of Bernard et al. concluded that six weeks is not non-inferior to 12-week antibiotic therapy for DAIR. However, it is unknown if suppressive antibiotic treatment (SAT) would improve patient outcomes. Therefore, our study aims to evaluate the utility of SAT after 12 weeks of therapy.

Method

We performed a retrospective study of patients with acute hip or knee PJI managed with DAIR at five institutions; in the U.S. (n=1), Netherlands (n=3), and Spain (n=1) from 2005–2020. We analyzed the effect of SAT using a Cox model among patients after 12 weeks of antibiotic treatment. The primary covariate of interest was whether the patient was on antibiotics after week 12, which was coded as a time-varying covariate. We decided a-priori to control for the clinically important risk factors such as age, sex, type of infection, modular exchange, joint, and presence of bacteremia and Staphylococcus aureus. We excluded patients who died, had treatment failure, or were lost to follow-up before 12 weeks. We defined treatment failure as infection recurrence (same or different organism), unexpected reoperation, or death due to infection.

Background

Although described as a commensal bacterium with low pathogenicity, Cutibacterium acnes involvement has been reported in many clinical entities: infections associated with devices, such as shoulder prosthetic joint infections, osteosynthesis, breast implants or cerebrospinal fluid shunts. Various studies show that C. acnes grows as a biofilm, contributing to its persistence by allowing its escape from the action of the immune system and antibiotics.

Purpose

Our aim was to assess the activity of different active substances (erythromycin, clindamycin, doxycycline and Myrtacine^®) on eight different well-characterized C. acnes strains after growth in biofilm mode.

Aim

Sepsis is a life-threatening complication of periprosthetic joint infections (PJI) that requires early and effective therapy. This study aims to investigate the epidemiology, associated risk factors, and outcome of sepsis in the context of periprosthetic joint infections (PJI).

Method

This single-center retrospective cohort study included patients treated for PJI from 2017 to 2020. Patients were classified based on the criteria of the European Bone and Joint Infection Society. The presence of sepsis was determined using the SOFA score and SIRS criteria. The cohort with PJI and sepsis (sepsis) was compared to patients with PJI without sepsis (non-sepsis). Risk factors considered were patient characteristics, affected joints, surgical therapy, microbiological findings, preexisting medical conditions, clinical symptoms, and symptom duration. Outcome parameters were mortality, length of hospital stay, and length of stay in the intensive care unit.

Aim

Musculoskeletal infection is a serious complication, however literature is lacking prospective data on its impact on mental health. The study aimed to assess mental health in patients with musculoskeletal infections and how they experience the possible mental and physical impairment.

Method

All patients treated in our unit for musculoskeletal infections between July 2020 and March 2022 were prospectively included. To assess specific patient reported outcomes the following questionnaires were used: World-Health-Organization Quality-Of-Life (WHOQOL)-BREF and the Veterans-RAND-12Item Health Survey (VR-12) for mental & physical health; Patient-Health-Questionnaire (PHQ-8) for depression symptoms; Generalized-Anxiety-Disorder-Scale-7 (GAD-7) for anxiety symptoms and Somatic-Symptom-Disorder-B Criteria Scale (SSD-12) for experience of mental & physical impairment. The surveys were conducted at baseline, 6 and 12-weeks and 1-year.

Aim

In 10% of the presumed aseptic hip or knee revisions, a low-grade infection is unexpectedly diagnosed based on the tissue samples taken during revision. Extended antimicrobial prophylaxis can possibly reduce the failure rate in cases of unexpected PJI, because the prophylaxis can be considered as early empiric treatment. In this randomized controlled study we analysed whether extended antimicrobial prophylaxis compared to a single dose is beneficial to improve the outcome of treatment in unexpected PJI in revision arthroplasty.

Method

This study was nested in a randomized clinical trial comparing single-dose cefazolin with prolonged prophylaxis (15 doses of cefazolin over 5 days) for revision arthroplasty of the hip or knee. For this analysis, patients were included if an unsuspected PJI (defined as ≥2 positive intraoperative tissue samples with the same microorganism) was diagnosed. PJI treatment consisted of 12 weeks of a rifampicin-based regimen in Staphylococcal PJI, without removal of the prosthesis. We examined Infection characteristics and success of treatment after one year, defined as the absence of signs or treatment for PJI during follow-up.

Aim

There is growing evidence that bacteria encountered in periprosthetic joint infections (PJI) form surface-attached biofilms on prostheses, as well as biofilm aggregates embedded in synovial fluid and tissues. However, models allowing the investigation of these biofilms and the assessment of their antimicrobial susceptibility in physiologically relevant conditions are currently lacking. To address this, we developed a synthetic synovial fluid (SSF) model and we validated this model in terms of growth, aggregate formation and antimicrobial susceptibility testing, using multiple PJI isolates.

Methods

17 PJI isolates were included, belonging to Staphylococcus aureus, coagulase negative staphylococci, Cutibacterium acnes, Pseudomonas aeruginosa, enterococci, streptococci, Candida species and Enterobacterales. Growth and aggregate formation in SSF, under microaerophilic or anaerobic conditions, were evaluated using light microscopy. The biofilm preventing concentration (BPC) and minimum biofilm inhibitory concentration (MBIC) of relevant antibiotics (doxycyclin, rifampicin and oxacillin) were determined for the staphylococcal strains (n=8). To this end, a high throughput approach was developed, using a fluorescent viability resazurin staining. BPC and MBIC values were compared to the minimum inhibitory concentration (MIC) obtained with conventional methods.