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Volume 101-B, Issue SUPP_14 December 2019 European Bone and Joint Infection Society (EBJIS) meeting, Antwerp, Belgium, September 2019.

K. Vanhouteghem C. Olyslaegers Y. Fortems E. van Eynde P. Willems J. van Schaeren B. Vanherendael

Aim

Microbiological culture of intraoperative periprosthetic tissue samples (IPTS) is one of the main criteria in diagnosing prosthetic joint infections (PJI) as stated by different guidelines. The current techniques are labor-intensive, prone for contamination and show low sensitivity. The aim of this study was to evaluate the added value of beadmill processing of IPTS and culturing in blood culture bottles (BCBs) over the conventional method of standard agar and broth alone.

Method

We conducted a single-center prospective study from May 2017 to January 2018 at the GZA Hospitals, a secondary care hospital (1012 beds) in Antwerp, Belgium. IPTS from patients undergoing revision arthroplasty were consecutively processed. Each IPTS was aseptically divided in two equal parts: one was processed by direct inoculation on agar and in broths (non-homogenized method); the other was transferred in a sterile vial with saline solution and glass beads (EOLabs), homogenized using a mechanic cell disruptor for 30s (Disruptor genie, Scientific Industries), 2mL of the suspension was inoculated in (an)aerobic BCBs, agar plates and broths (homogenized method). Agar plates were incubated for 4d; broths and BCBs in BacT/Alert (bioMerieux) for 14d. Micro-organisms were identified using MALDI-TOF MS (Bruker). Sensitivity (Se) and specificity (Sp) were calculated against the IDSA definition of PJI for different culture sets: non-homogenized and agar/broth; homogenized processing and agar/broth, agar/broth/BCB, agar/BCB. Ethics committee approved the study.


N. Renz P. Schulz C. Dlaska A. Trampuz

Aim

Surgical and antimicrobial treatment of periprosthetic joint infections (PJI) depends largely on the causative pathogen. We assessed the pathogen detection rates and the concordance of preoperative synovial fluid culture and culture of intraoperative samples harvested during revision surgery in patients with PJI.

Method

Culture-positive PJI cases treated at our institution from 02/2011 to 07/2018, for which culture results from preoperative (synovial fluid) and intraoperative samples (periprosthetic tissue, synovial or sonication fluid) were available, were retrospectively assessed. For organisms belonging to the resident skin flora (coagulase-negative staphylococci, cutibacteria and corynebacteria) significant growth was considered, if the identical pathogen grew in ≥2 samples or >50 cfu/ml sonication fluid. For other pathogens (S. aureus, streptococci, enterococci, fungi and gram-negative rods) or patients under antimicrobials, any growth was considered positive. We determined the pathogen detection rate in preoperative and intraoperative cultures and compared it in different subgroups using Fisher's exact test. Furthermore, we assessed the concordance of preoperative and intraoperative cultures.


J. Goosen A. Jacobs P. Heesterbeek S. Susan F. Bovendeert J. Meis

Aim

Currently, despite a thorough diagnostic work up, around ten percent of the presumed aseptic revisions turn out to have unexpected positive cultures during the revision procedure. The purpose of this study was to evaluate the negative predictive value (ruling out) of the automated multiplex PCR Unyvero i60 implant and tissue infection (ITI) cartridge (U-ITI) system for the detection of microorganisms in synovial fluid obtained intraoperatively.

Methods

A prospective study was conducted with 200 patients undergoing a one-stage knee or hip revision. In all patients six intraoperative tissue cultures were taken and a sample of synovial fluid which was analyzed as a culture and with the multiplex PCR U-ITI system. The primary outcome measure was the negative predictive value (NPV) of the multiplex PCR U-ITI system compared to the intraoperative tissue cultures to reliable rule out an infection.


A. Suda N. Landua T. Miethke

Aim

Diagnostics of orthopedic implant infection remains challenging and often shows false negative or inadequate results. Several methods have been described to improve diagnostic methods but most of them are expensive (PCR) or not accessible for all hospitals (sonication). Aim of this study was to evaluate the results of incubation of orthopedic explants compared to biopsies and punction fluid using conventional microbiological methods.

Method

In this prospective study, we included patients who received septic or aseptic orthopedic implant removal in a single University hospital between July and December 2018. A part of the explant as well as minimum 2 tissue biopsies or additional punction fluid were put in a bouillon and incubated for 11 days. Patient´s records with co-morbidities, use of antibiotics and demographic data were evaluated. The results were analyzed. The study was approved by the ethical committee.


A. Jean-David M. L. Corvec M. Antoine G. Xavier D. Claire H. Sylvie G. Claudie H. Emmanuel B. L. Goff J. Sandrine J. Bernard S. Olivier G. Pascal O. Loreal

Background

Septic arthritis diagnostic is an emergency which implies a treatment with antibiotics and hospitalization. The diagnosis is based on the cytobacteriological examination of the synovial fluid (SF), but direct bacteriological examination is insensitive, and the result of the culture is obtained only after several days. Therefore, there is still a need for a rapid, simple and reliable method for the positive diagnosis of septic arthritis. Such method must allow avoiding both unrecognized septic arthritis leading to major functional consequences, and overdiagnosis that will induce unnecessary expensive hospitalization and unjustified treatment. Mid-infrared (MIR) spectroscopy, that gives a metabolic profiling of biological fluids, has been proposed for early and fast diagnosis.

Objectives

To confirm the MIR spectroscopy to discriminate SF samples from patients with septic arthritis from other causes of joint effusion.


A. Cör K. Šuster

Background

Currently, the gold standard for the microbiological diagnosis remains the culturing of preoperative aspirated joint fluid and intraoperative periprosthetic tissue samples, which give false negative results in about 7 % of cases. Lytic bacteriophages are viruses that specifically infect and lyse bacteria within their replication cycle.

Aim

The aim of our study was to explore possibilities for the use of bacteriophage K for the detection of live Staphylococcus spp. bacteria in sonicate fluid of infected prosthetic joints, to possibly contribute to the development of a faster, more sensitive, specific and at the same time economical and handy method for the establishment of the right diagnosis.


T. A. Barbosa A. D. Carvalho A. Ribau L. Barros D. E. Soares M. Abreu R. Sousa

Aim

Treatment of complicated wound healing after total joint arthroplasty is controversial. What exactly constitutes prolonged wound drainage is matter of debate and recommendations to manage it vary considerably. Nonoperative measures are often recommended. If drainage persists, surgery may be indicated. To further intricate decision-making, differentiating superficial from deep surgical site infection is also controversial and inherently complex. Specific cutoffs for synovial fluid leukocyte count and blood C-reactive protein (CRP) in the acute stage have been suggested as a way to superficial infection requiring superficial wound washout from deep infection requiring a formal debridement, antibiotics and implant retention (DAIR) procedure. The goal of this study is to analyze clinical and laboratory findings of an institutional protocol of “aggressively” proceeding with formal DAIR in all patients with complicated wound healing

Method

Our indications for DAIR in suspected acute postoperative periprosthetic joint infection (PJI) are: 1)prolonged wound drainage and CRP upward trend after day-3; 2)persistent wound drainage by day-10 regardless of CRP; 3)wound healing disturbance (e.g. “superficial” infection, “superficial” skin necrosis) anytime in early postoperative weeks. We retrospectively evaluated patients undergoing DAIR in the first 60 postoperative days between 2014–2018. Patients without multiple deep tissue cultures obtained intraoperative were excluded. Deep infection was defined by at least two positive deep tissue cultures or one positive deep culture and positive leukocyte count (>10,000 cells/mL or >90% PMN).


D. Morcillo I. Pastor C. Detrembleur H. Poilvache M. van Cauter J. Yombi O. Cornu

Background

DAIR is an attractive treatment for PJI. The purpose of this study is to determine predictive factors of failure.

Materials and Methods

We reviewed all DAIR procedures for hip PJI performed between 2002–2017 (n=69). Data recorded included all factors correlated with treatment failure. KLIC score and an adapted McPherson score (sum of three criteria where the lower score is three for 3 A and the higher is 9 for 3 C) were analyzed.


B. Villain A. Thes A. Roux T. Begue T. Bauer

Introduction

Success rate after Debridement-Irrigation, Antibiotic Therapy and Implant Retention (DAIR) for treatment of Acute Haematogenous (AH) and Early Post-surgical (EP) periprosthetic joint infection (PJI) varies widely among published studies. Prosthesis exchange is recommended to treat PJI after a failed DAIR. However, no early postoperative prognostic factors permitting to identify future failures have been described.

Aim

Identify early prognostic factor of failure after DAIR in order to propose efficient treatment before onset of chronic PJI.


C. Löwik J. Parvizi P. Jutte W. Zijlstra B. Knobben C. Xu K. Goswami R. Sousa A. D. Carvalho A. Soriano M. Wouthuyzen-Bakker

Aim

Treatment success of debridement, antibiotics and implant retention (DAIR) is in early periprosthetic joint infection (PJI) is largely dependent on the presence or absence of a mature biofilm. In what time interval a mature biofilm develops is still unclear, and therefore, the time point at which DAIR should be disrecommended remains to be established. This large multicenter trial evaluated the failure rates of DAIR for different time intervals from index arthroplasty to DAIR in early PJI.

Method

We retrospectively evaluated patients with early PJI treated with DAIR between 1996 and 2016. Early PJI was defined as a PJI that developed within 90 days after index arthroplasty. Patients with hematogenous infections, arthroscopic debridements and a follow-up less than one year were excluded. Treatment failure was defined as 1) any further surgical procedure related to infection 2) PJI-related death, or 3) long-term suppressive antibiotics, all within one year after DAIR.


J. van Oldenrijk B. van der Ende M. Reijman P. Croughs L. van Steenbergen J. Verhaar K. Bos

Aim

Debridement Antibiotics and Implant Retention(DAIR) is a procedure to treat a periprosthetic joint infection(PJI) after Total Hip Arthroplasty(THA) or Total Knee Arthroplasty(TKA). The timing between the primary procedure and the DAIR is likely a determinant for its successful outcome. There are few retrospective studies correlating timing of a DAIR with success (1,2). However, the optimal timing of a DAIR and the chance of success still remains unclear. We aimed to assess the risk of re-revision within one year after a DAIR procedure and to evaluate the timing of the DAIR in primary THA and TKA. An estimation of the chance of a successful DAIR will help clinicians and patients in their decision-making process in case of an acute postoperative PJI.

Method

We used data from the Dutch Arthroplasty Register(LROI) and selected all primary THA and TKA in the period 2007–2016 who underwent a DAIR within 12 weeks after primary procedure. A DAIR was defined as a revision for infection in which only modular parts were exchanged. A DAIR was successful if not followed by a re-revision within 1 year after DAIR. The analyses were separated for THA and TKA procedures.


E. J. McPherson J. Castillejos M. Chowdhry M. V. Dipane

Aim

We outline a treatment protocol for subjects with chronic periprosthetic joint infections (PJI) who elected not to have surgery. We developed a method of serial “fluid-depleting” aspirations with intra-articular gentamycin injections to affect the population of the biofilm community. We have experienced many treatment failures, as expected, but have also had a group of subjects who responded exceptionally well, requiring no surgical intervention. Our longest follow-up is 10 years.

Method

From June 2009 to December 2018, 372 clinical cases of chronic PJI involving primary and revision TKA and THA were treated. Of these, 25 subjects were treated with an active suppression protocol, in lieu of surgery. The protocol entailed frequent aspirations and intra-articular antibiotic injections to quell the PJI inflammatory response. All aspirations were performed by the treating surgeon in the orthopaedic clinic without fluoroscopic guidance. Based on a subject's response to the protocol, he/she was identified as 1 of 3 classifications: 1) Ongoing Treatment – Biofilm Trained (OTBT), 2) Ongoing Treatment – Biofilm Untrained (OTBU), and 3) Treatment Failure (TF). OTBT subjects showed no clinical signs of infection. Serum biomarkers (CRP, ESR) remained consistently normal and subjects were not on oral suppressive antibiotics. Aspiration analysis and cultures remained negative. Maintenance treatment consisted of a fluid-depleting aspiration with an intra-articular gentamycin injection every 12–16 weeks. OTBU subjects showed improved clinical symptoms, lowered serum biomarkers, and lowered WBC counts, but still demonstrated objective signs of infection. TF subjects did not respond to the protocol and showed unchanged/worsening clinical symptoms.


Ø. E. Karlsen F. Snorrason M. Westberg

Aim

Debridement, antibiotics and implant retention (DAIR) has become the preferred treatment in early prosthetic joint infections (PJI) and acute haematogenous PJI, but the success rates have been varying. The aim of this study was to evaluate the outcome of a high quality DAIR procedure performed according to a consistently applied surgical protocol in early PJI's and acute haematogenous PJI's in hip and knee.

Methods

We performed a prospective multicentre study in 8 hospitals in Norway. A standardized DAIR protocol was used in all patients. An empirical intravenous regimen containing cloxacillin and vancomycin was given until definitive microbiological results were known. Antibiotics were given in total for 6 weeks. The primary outcome measure was infection control. Factors that could affect the outcome were also studied.


F.R.H.A. Nurmohamed B. van Dijk E. S. Veltman M. Hoekstra R. J. Rentenaar H. Weinans B. C. H. van der Wal H. C. Vogely

Aim

To retrospectively evaluate infection eradication rate of DAIR procedures performed in our tertiary referral center. We analyzed whether the outcome was influenced by time of infection after arthroplasty, previous surgery or causative pathogen.

Methods

We retrospectively collected data of 81 patients treated with DAIR for periprosthetic joint infections after hip (n=48) and knee (n=33) arthroplasty between 2011 and 2017. Patients were divided into 3 groups: acute early infections (occurring <4 weeks, 29 cases), late chronic infections (occurring >4 weeks postoperative, 49 cases) and acute haematogenous infections (occuring >3 months after surgery with symptoms less than 4 weeks, 3 cases). Primary outcome was successful infection eradication after treatment within one year. Eradication failure was determined as unplanned subsequent surgery because of persistent infection, use of suppressive antibiotics or signs of infection at one year follow-up.


Z. Minhas A. Palmer A. Alvand A. Taylor B. Kendrick

Introduction

Antibiotic loaded absorbable calcium sulphate beads (ALCSB) are an increasingly popular adjunct in the treatment of musculoskeletal infections including osteomyelitis and peri-prosthetic joint infections (PJI). Limited data exist regarding the clinical indications and biochemical outcomes of ALCSB in PJI cases.

Aims

To determine the proportion of organisms that were sensitive to the gentamicin and vancomycin that we add to the ALCSB as a part of our treatment protocol and to determine the prevalence of postoperative hypercalcaemia when used for treatment of hip and knee DAIR (debridement and implant retention) and revision arthroplasty for PJI.


M. Clauss C. Hunkeler I. Manzoni P. Sendi

Aim

Debridement and implant retention (DAIR) is a valuable option for treating periprosthetic joint infection (PJI), provided that the criteria of the Infectious Diseases Society of America guidelines are fulfilled. The inflammation caused by infection and the surgical impact of DAIR may influence implant stability. In this study, we investigated the sequelae of DAIR on implant survival after total hip arthroplasty (THA).

Method

THAs from our database implanted between 1984 and 2016 were included in a retrospective double-cohort study. THAs were exposed (DAIR cohort) or not exposed to DAIR (control cohort). The control cohort comprised patients matched 3:1 to the DAIR cohort. The outcome—implant failure over time—was evaluated for (i) revision for any reason, (ii) aseptic loosening of any component, and (iii) radiographic evidence of loosening.


L. Wang M. Di Luca T. Tkhilaishvili M. Gonzalez-Moreno A. Trampuz

Aim

Ciprofloxacin is recommended as anti-biofilm therapy for gram-negative periprosthetic joint infection. With ciprofloxacin monotherapy, resistance in gram-negative bacteria was observed. Therefore, we evaluated in vitro synergistic activity of fosfomycin, ciprofloxacin and gentamicin combinations against biofilms formed by E. coli and P. aeruginosa strains.

Method

E. coli ATCC 25922, P. aeruginosa ATCC 27853 and 15 clinical isolates were used for this study. MIC values were determined by Etest. Biofilms were formed on porous sintered glass beads for 24h and exposed to antibiotics for further 24h. Viability of bacteria on the glass beads after antibiotic treatment was detected by cfu counting of the sonicated beads. The minimum biofilm eradication concentration (MBEC) was defined as the lowest concentration of antibiotic required to kill biofilm cells. Synergistic activity against biofilm was evaluated by calculation of the fractional inhibitory concentration index (FICI).


H. Bezstarosti P.D. Croughs M.J.B. van der Hurk K. Kortram E. van Lieshout M.H.J. Verhofstad

Aim

Fracture-related infection (FRI) is a serious complication after trauma. More often resistant micro-organisms are cultured. Gentamicin covers a wide variety of causative agents for FRI. A bio-absorbable antibiotic carrier, Cerament-G®, combines dead space management with local release of gentamicin in a one-stage approach. The achieved tissue concentrations of locally applied antibiotics are 4–8 thousand times higher than after systemic administration. Does Cerament-G® have antimicrobial activity towards bacteria that are not susceptible to systemic gentamicin administration.

Method

The four most often cultured bacterial species found in FRI were used; Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Enterobacter cloacae. For each species, four different isolates were obtained, each with a different susceptibility for gentamicin. This susceptibility, expressed in the minimal inhibitory concentration (MIC), varied from completely susceptible (MIC 0,064 mg/L – 4mg/L), minimal resistance (4mg/L – 16mg/L), moderate resistance (8 mg/L – 96 mg/L) to high resistance (24 mg/L - >1024 mg/L), depending on each different organism. Antimicrobial activity of Cerament-G® was determent by a Kirby-Bauer test, according to the EUCAST disc protocol. Each test was done in five-fold for each of the 16 cultured isolates, four of each species. The zone of inhibition (ZOI), obtained by the test, was compared between each bacterial isolate and within each of the four separate species.


C. Duportail M. Gerard C. Kathleen G. Putzeys L. Thorrez

Aim

Allograft bone chips used in complex bone reconstruction procedures are associated with an increased infection risk. The perioperative use of systemic cefazolin is standard to prevent infection, but is less effective in the presence of avascular bone grafts. Bone chips have been described as a carrier for local delivery of antibiotics, but impregnation with cefazolin in a prophylactic setting has not been described. We aimed to obtain a prolonged cefazolin release from bone chips to maximize the prophylactic effect.

Method

Three types of bone chips were evaluated: fresh frozen, decellularized frozen and decellularized lyophilized. Bone chips were incubated with 20 mg/ml cefazolin or treated with liquid hydrogel containing either 1 mg/ml fibrin or 1 mg/ml collagen and 20 mg/ml cefazolin. The cefazolin hydrogel was distributed in the porous structure by short vacuum treatment. Bone chips with cefazolin but without hydrogel were incubated for 20 min- 4h under atmospheric pressure or under vacuum. Cefazolin elution of bone chips was carried out in fetal bovine serum and analyzed by Ultra Performance Liquid Chromatography – Diode Array Detection.


P. E. Hanberg A. R. J⊘rgensen M. Stilling M. Thomassen M. Bue

Aim

Cefuroxime is a time-dependent antibiotic widely used as intravenous perioperative prophylaxis in spine surgery. A previous study has indicated that a single dose of cefuroxime provided insufficient spine tissue concentrations for spine procedures lasting more than 2–3 hours. Due to the fact that postoperative pyogenic spondylodiscitis is associated with prolonged antimicrobial therapy and high relapse rates, we aimed to evaluate if a twofold increase of standard dosage of 1.5g cefuroxime given as one double dose or two single doses with 4-hours intervals will lead to sufficient cefuroxime spine tissue concentrations throughout the dosing interval.

Method

This is preliminary data for 8 out of 16 female pigs. Data from all 16 pigs will be included for the conference. Eight pigs were randomized into two groups: Group A received one double dose of cefuroxime (3g) as a bolus, and Group B received two single doses of cefuroxime (2×1.5g) with 4-hours intervals. Measurements were obtained from plasma, subcutaneous tissue (SCT), vertebral cancellous bone and the intervertebral disc (IVD) for 8-hours thereafter. Microdialysis was applied for sampling in solid tissues. The cefuroxime concentrations were determined using ultra-high performance liquid chromatography.


M. Dagnelie P. Bemer L. R. d'Epenoux S. Corvec

Aim

Cutibacterium acnes (CA) is one of the crucial actors in spine instrumentation or shoulder prosthesis. Its population is subdivided into 6 major phylotypes: IA1, IA2, IB, IC, II and III. Recent methods for discriminating subpopulations within CA phylotypes highlight the predominance of SLST types H1 to 6 or K1 to 20 in bone and joint infection (BJI). The impact of their ability to produce a biofilm during the development of the infection (with resistance / tolerance to antibiotics used for treatment) remains little studied.

Method

The purpose of this study was to determine whether the ability to establish a biofilm varied according to the different subtypes of clinical strains of CA previously characterized and involved in BJI (hip, knee and shoulder prosthesis). The BioFilm ring test (BioFilm Control®) method with index determination, called BFI (BioFilm Index) inversely proportional to the level of biofilm production was used (BFI = 0.00 indicates a high production of biofilm versus BFI = 20.00 indicates zero production). The BFI was determined after 3 h (T3) and 6 h (T6) incubation. The strains used came from patients, 5 belonging to the IA1 phylotype (SLST A1 and D1 types) and 4 to different phylotypes (IA2, IB, II and III).


M. Veloso M. Bernaus F. Angles L. Gómez Y. L. Cubillos S. Soto L. Font-Vizcarra

Aim

To evaluate bacterial adhesion and biofilm formation to metallic cerclage wire versus polymer cerclage system (SuperCable®)

Methods

Experimental in vitro study to evaluate quantitative bacterial adherence to different cerclage wire materials. Two types of cerclage wires were compared: a metallic versus a polymer based wire (SuperCable®).

A two-centimeter cerclage wire piece of each material was included in 2 mL of tryptic soy broth (TSB) culture media, inoculated with 10 microliters of a 0.5 McFarland of a Staphylococcus epidermidis strain and cultivated at 37°C during 2h for adhesion and 48h for biofilm formation. After this time, the cerclages were washed using a 1% phosphate buffered saline (PBS) and sonicated in new culture medium. After sonication, dilutions of each culture were spread in TSB agar and incubated 37°C during 24h. The number of colonies were counted and the cfu/cm2 was calculated.


H. Poilvache A. Ruiz-Sorribas H. Rodriguez-Villalobos G. Sakoulas O. Cornu F. van Bambeke

Aim

Irrigation is a major step during debridement surgery in the context of Prosthetic Joint Infections (PJI), but its effects on biofilms are poorly described.

The present study aims at evaluating the effect of PW alone or followed by antibiotics on MSSA and MRSA biofilms grown on Ti6Al4V coupons in-vitro.

Method

Strains: 1 reference (MSSA: ATCC25923; MRSA: ATCC33591) and 2 clinical MSSA and MRSA isolated from PJI.

Biofilm culture: Coupons were incubated for 24h at 37°C with bacteria (starting inoculum ∼6.6Log10CFU/mL in TGN [TSB + 1% glucose + 2% NaCl]), under shaking at 50rpm.

Treatment: Half of the coupons were irrigated with 50mL physiological serum from 5cm using a Stryker Interpulse; the coupons were then either analysed (ControlT0 and PWT0) or reincubated for 24h in TGN or TGN containing flucloxacillin (MSSA) or vancomycin (MRSA) at MIC or 20mg/L.

Analysis: Coupons were rinsed twice with PBS. Biomass was measured by crystal violet (CV) assay. CFUs were counted after recovering bacteria from coupons using sonication and TSA plating.


M. E. Butini G. Abbandonato C. Di Rienzo A. Trampuz M. D. Luca

Aim

Most orthopedic infections are due to the microbial colonization of abiotic surfaces, which evolves into biofilm formation. Within biofilms, persisters constitute a microbial subpopulation of cells characterized by a lower metabolic-activity, being phenotipically tolerant to high concentrations of antibiotics. Due to their extreme tolerance, persisters may cause relapses upon treatment discontinuation, leading to infection recalcitrance hindering the bony tissue regeneration. Using isothermal microcalorimetry (IMC), we aimed to evaluate in vitro the presence of persisters in a methicillin-resistant Staphylococcus aureus (MRSA) biofilm after treatment with high concentrations of vancomycin (VAN) and their ability to revert to a normal-growing phenotype during incubation in fresh medium without antibiotic. Moreover, the ability of daptomycin to eradicate the infection by killing persisters was also investigated.

Method

A 24h-old MRSA ATCC 43300 biofilm was exposed to 1024 µg/ml VAN for 24h. Metabolism-related heat of biofilm-embedded cells, either during or after VAN-treatment, was monitored in real-time by IMC for 24 or 48h, respectively. To evaluate the presence of VAN-derived “persisters” after antibiotic treatment, beads were sonicated and detached free-floating bacteria were further challenged with 100xMIC VAN (100 µg/ml) in PBS+1% Cation Adjusted Mueller Hinton Broth (CAMHB).. Suspensions were plated for colony counting. The resumption of persister cells' normal growth was analysed by IMC on dislodged trated cells for 15h in CAMHB. Activity of 16 µg/ml daptomycin was assessed against persister cells by colony counting.


L. de Vor K. Van Kessel C. De Haas P. Aerts M. Viveen E. Boel A. Fluit B. van Dijk C. Vogely B. van der Wal J. van Strijp H. Weinans S. Rooijakkers

Aim

“Implant associated Staphylococcus aureus or S. epidermidis infections are often difficult to treat due to the formation of biofilms on prosthetic material. Biofilms are bacterial communities adhered to a surface with a self-made extracellular polymeric substance that surrounds resident bacteria. In contrast to planktonic bacteria, bacteria in a biofilm are in an adherent, dormant state and are insensitive to most antibiotics. In addition, bacteria in a biofilm are protected from phagocytic cells of the immune system. Therefore, complete surgical removal and replacement of the prosthetic implant is often necessary to treat this type of infections. Neutrophils play a crucial role in clearing bacterial pathogens. They recognize planktonic bacteria via immunoglobulin (Ig) and complement opsonisation. In this project, we aim to evaluate the role of IgG and complement in the recognition and clearance of staphylococcal biofilms by human neutrophils. Furthermore, we evaluate if monoclonal antibodies (mAbs) targeting biofilm structures can enhance recognition and clearance of staphylococcal biofilms by the human immune system.”

Method

“We produced a set of 20 recombinant mAbs specific for staphylococcal antigens. Using flow cytometry and ELISA-based methods we determined the binding of these mAbs to planktonic staphylococci and in vitro staphylococcal biofilms. Following incubation with IgG/IgM depleted human serum we determined whether mAbs can react with the human complement system after binding to biofilm. Confocal microscopy was used to visualize the location of antibody binding in the biofilm 3D structure.”


C. Kolenda J. Josse M. Medina C. Fevre S. Lustig T. Ferry F. Laurent

Aim

Staphylococcus aureus is the first causative agent of bone and joints infections (BJI). It causes difficult-to-treat infections because of its ability to form biofilms, and to be internalized and persist inside osteoblastic cells. Recently, phage therapy has emerged as a promising therapy to improve the management of chronic BJI. In the present study, we evaluated the efficacy of an assembly of three bacteriophages previously used in a clinical case report (Ferry, 2018) against S. aureus in in vitro models of biofilm and intracellular osteoblast infection.

Methods

Using HG001 S. aureus, the bactericidal activities of the assembly of the three bacteriophages (Pherecydes Pharma) used alone or in association with vancomycin or rifampicin were compared by quantifying the number of viable bacteria in mature biofilms and infected osteoblasts after 24h of exposure.


C. Triffault-Fillit M. Eugenie C. Karine A. Becker B. Evelyne T. Michel S. Goutelle M. Fessy C. Dupieux F. Laurent S. Lustig C. Chidiac T. Ferry F. Valour

Aim

The use of piperacillin/tazobactam with vancomycin as empirical antimicrobial therapy (EAT) for prosthetic joint infection (PJI) has been associated with an increased risk of acute kidney injury (AKI), leading to propose cefepim as an alternative since 2017 in our reference center. The present study compared microbiological efficacy and tolerance of these two EAT strategies.

Method

All patients with PJI empirically treated by vancomycin-cefepim (n=90) were prospectively enrolled in an observational study, and compared with vancomycin-piperacillin/tazobactam-treated historical controls (n=117), regarding: i) the proportion efficacious empirical regimen (i.e., at least one of the two molecules active against the identified organism(s) based on in vitro susceptibility testing); and ii) the incidence of empirical therapy-related adverse events (AE), classified according to the Common terminology criteria for AE (CTCAE).


P. Oliveira V. C. Carvalho E. S. Saconi M. Leonhardt K. E. Kojima J. S. Silva A. L. l. M. Lima

Aim

To compare outcomes and incidence of adverse events (AE) of colistin versus tigecycline for treatment of patients with carbapenem-resistant Acinetobacter baumannii (CRAB) osteomyelitis.

Method

Retrospective study. Records of 111 patients with microbiologically confirmed CRAB osteomyelitis were analyzed. Colistin (34 cases) and tigecycline (31 cases) were the main drugs used for treatment of extremely-drug resistant (XDR) isolates. Patients who received these two antimicrobials were compared according to baseline features (sex, age, length of hospital stay, Charlson index, presence of comorbidities or immunosuppression, previous renal disease, smoking, alcoholism or use of illicit drugs, previous orthopedic surgery on affected limb, topography of infection, classification of osteomyelitis, ASA score, infection related to pressure ulcer or neuropathic foot, presence of implant, need for soft tissue repair or negative pressure therapy and previous antimicrobial use), clinical outcome after 12 months of treatment (remission of infection was considered the favorable outcome; recurrence of infection, amputation and death were considered unfavorable outcomes; loss of follow-up was analyzed separately) and AE during treatment (impaired renal function; liver abnormalities; nausea; skin rash; neurological abnormalities and other events in general). Quantitative variables were described using summary measures and compared using Student's t or Mann-Whitney tests. Qualitative characteristics were described with absolute and relative frequencies and compared using chi-square or exact tests (Fisher's exact or likelihood ratio test).


S. Karbysheva S. Cabric D. Margaryan A. Trampuz

Aim

We evaluated the efficacy and safety of treatment regimens in a pathogen and surgery specific mode according to a standardized algorithm for the treatment of periprosthetic joint infection (PJI) based on combinations with 15g/d intravenous fosfomycin followed by oral antibiotics for totally 12 weeks.

Method

Consecutive patients with PJI caused by at least one of the following isolates were prospectively included: staphylococci (MIC ≤32 mg/l), streptococci (MIC ≤128 mg/l), enterococci (MIC ≤128 mg/l), Enterobacteriaceae (MIC ≤32 mg/l) and Pseudomonas spp. (MIC ≤128 mg/l). PJI was defined by the proposed European Bone and Joint Infection Society (EBJIS) criteria. Follow up with clinical (joint function and quality of life scores), laboratory and radiological evaluation at 3, 12 and 24 months after last surgery is performed. Infection outcome was assessed as the proportion of infection-free patients. The probability of infection-free survival was estimated using the Kaplan-Meier survival method.


J. Goosen P. Heesterbeek L. Beekman D. Telgt F. Vos C. van der Velden

Aim

Long term use of antibiotics following surgical debridement are the cornerstone of PJI treatment. Due to increasing resistance of bacteria for many first line antibiotics new options are needed. One such option is linezolid known for its low percentage of resistance against many Gram positive bacteria causing PJI. Success rates up to 86% have been reported. At the same time many adverse events (AE) have been described including anemia, thrombocytopenia, gastrointestinal effects and sometimes neuropathy, e.g. irreversible vision loss [1, 2]. Therefore, linezolid use is advised to be limited to a maximum of 28 days. Literature about the effects of prolonged use is currently lacking and therefore this study will aim to determine the safety of long-term (>28 days) linezolid use in patients with orthopedic infections.

Methods

We performed a retrospective descriptive study on patient records of orthopedic patients who were treated with linezolid between January 2014 and January 2019 for >28 days. Data were collected from medical charts including co-morbidities, pre-existing liver/kidney dysfunctions, diagnosis, treatment, type of prosthesis, pathogens, adverse events associated with linezolid use and follow up laboratory data.


I. Gabriela A. L. Costache F. Lacassin-Beller B. Loutfi C. Hoskovec P. Mathieu M. Acra M. J. Rogero D. Mondon

Aim

bone and joint infection (BJI) in aging population, continues to be associated with significant morbi-mortality. In western Europeans countries, the Gram positive BJI are preponderant. Vancomycin was the “gold standard” and the full treatment requires prolonged antibiotic therapy. Dalbavancin is a semi-synthetic lipoglycopeptideanalog of teicoplanin class of antibiotics with bactericidal activity and a long half-life. The use of dalbavancin in BJI could be an option

Methods

during November 2017 and April 2019, Dalbavancin was used in monotherapy as salvage option in BJI: 1500 mg, 1st (D1) and 8th day (D8), repeated if needed. The clinical and biological follow up was for 6 months if osteomyelitis or BJI without prosthesis and 1 year if prosthesis (PJI).


R. Bandeira T. M. F. de Lima T. C. N. Freitas R. M. B. d. Silva R. O. D. d. Araujo T. C. Ribeiro M. d. C. Melo M. Salles

Aim

Infection is one of the worst complications following total joint arthroplasty, which is often associated with significant morbidity and increased medical costs. Although Gram–positive bacteria remains the most prevalent causative agents, an increase in prosthetic joint infections (PJI) due to gram-negative bacteria (GNB) has been reported. Additionally, the emergence of multidrug resistant resistance (MDR) in GNB impacts the therapeutic options and may increase the rate of treatment failure and drug toxicity adverse effects due the prescription of harmful and toxics antimicrobial schemes. The purpose of the present study was to describe the predisposing factors associated to PJI caused by MDR-GNB in a specialized orthopedic reference hospital in Brazil from 2014 through 2018.

Method

Retrospective case-control analysis of patients treated for MDR-GNB PJI over a four-year period (2014–2018). Data were collected from medical, surgical and laboratory records. PJI were defined according the criteria of MSIS. MDR was defined as non-susceptibility to at least one agent in three or more antimicrobial categories. Patients with prosthetic infection with at least two positive tissue cultures for MDR-GNB were selected. Univariate and multivariate logistic regression models were used to determine the independent risk factors associated with MDR-GNB PJI. Controls: patients with PJI with at least two positive tissue culture for non MDR- GNB


M. S. Martos I. K. Sigmund M. McNally

Aim

Calcaneal osteomyelitis is an uncommon and challenging condition. In this systemic review we aim to analyse the concomitant use of bone debridement and soft tissue management for patients diagnosed with calcaneal osteomyelitis

Method

A complete computerised and comprehensive literature search of Pubmed and Cochrane database was undertaken from January 2000 to October 2018. During the review, studies were screened for information about the surgical and antimicrobial treatment, the complications, the reinfection rate and the functional outcome of patients with calcaneal osteomyelitis.


F. Sanders M. van Hul T. Schepers

Aim

Since surgical site infections (SSIs) remain among the most common complications of orthopedic (trauma) surgery, there has been unwavering attention for potential predictors of a SSI.

Specifically in surgical fields with a high complication rate, such as foot/ankle surgery, risk factor identification is of great importance. Recently, some studies have suggested environmental factors such as season to be of influence on the number of SSI. Specifically patients operated on in the summer are reported to have a higher incidence of SSIs, compared to other seasons. The aim of this study is to identify if “seasonality” is a significant predictor for SSI in a cohort of (trauma) surgical foot and ankle procedures.

Method

This retrospective cohort study included all patients undergoing trauma related surgery (fracture fixation, arthrodesis, implant removal and tendon repair) of the lower leg, ankle and foot. Procedures were performed at a single Level 1 Trauma Center in the Netherlands between September 2015 until February 2019. Potential risk factors/ confounders for SSI were identified using univariate analysis (Chi-Square/Mann-Whitney U). Procedures were divided in two groups: 1) performed in summer (June, July or August), 2) not performed in summer (September-May). The number of SSIs was compared between the 2 groups, correcting for confounders, using multivariate regression.


L. Orioli F. Hammer B. V. Berg D. C. Putineanu D. Maiter J. Yombi O. Cornu V. Bernard

Aim

Our study aimed to analyze 1) the prevalence of peripheral arterial disease (PAD) and infection in diabetic patients with and without Charcot foot (CF), 2) the characteristics of PAD in these 2 groups, 3) the prognosis of patients with CF and PAD and/or infection.

Method

We retrospectively reviewed the medical and radiological records of 172 hospitalized patients in our diabetic foot unit between 2010 and 2014. These patients were identified using the ICD-9-CM. The CF group and the diabetic foot (DF) group included 56 and 116 patients, respectively. All statistical analyses were performed using SPSS 25.0.01. A p <0.05 was considered as statistically significant.


M. Depypere C. Moonen R. Alaerts H. Hoekstra A. Sermon S. Nijs W. Metsemakers

Aim

Negative-pressure wound therapy (NPWT) is often propagated as treatment option for fracture-related infection (FRI). After surgical debridement and repeated NPWT dressing changes, the wounds are often closed by free flaps. Sometimes even healing by secondary intention seems an alternative. Recently, concerns have been raised on the long-term use of NPWT as it could be related to bacterial overgrowth and possible re-infection. The purpose of this study was to conduct a retrospective evaluation of the influence of long-term NPWT on tissue culture results and outcome in FRI patients

Method

Between January 1st, 2015 and December 31st, 2018, a total of 852 patients were treated with NPWT for different indications on the Department of Trauma Surgery. Inclusion criteria for this study were patients with a closed fracture, stabilized with osteosynthetic fixation and complicated with a confirmed FRI according to the FRI consensus definition. Patients were included when they received at least three NPWT dressing changes in the operating room. Exclusion criteria were patients younger than 18 years, or the absence of cultures results from dressing changes.


B. Sluga I. Gril A. Fischinger

Aim

Post traumatic distal tibia osteomyelitis (DTOM) with an upper ankle joint involvement is a serious complication after primary osteosynthesis and can be a nightmare for the patient and the surgeon as well. Our aim was to identify mayor complications during treatment and to find the way to prevent or treat them.

Method

It is a retrospective analysis of eight patients with DTOM and an upper ankle joint involvement treated in our institution from 2012 to 2018. The average size of a bone defect after a debridement was 9 centimeters (4–15). Patients were treated in two stages. First stage was segmental bone resection, external fixation and soft tissue envelope reconstruction if necessary. At second stage a distraction frame was applied and proximal corticotomy performed. In all but one case a circular frame was used.


J. K. Kouamé J. Manon L. Fonkoue M. Kodo C. Detrembleur O. Cornu

Introduction

The management of patients with open leg fracture in Ivory Coast does not meet the standards of developed countries due to socio-economic conditions, accessibility and organization of care. However, is this care problematic? Is it associated with more post-traumatic infection or mechanical complications and are these correlated with the delay for treatment and the method of treatment?

Material and Methods

This is a single-center prospective study conducted on between January 2018 and May 2018 at Bouaké University Hospital. The observed parameters included factors related to patient, fracture and treatment conditions and were correlated with the rates of complications by multivariate analysis.


A. Loro G. Galiwango A. Hodges

Aim

Vascularized fibula flap is one of the available options in the management of bone loss that can follow cases of severe haematogenous osteomyelitis. The aim of this study was to evaluate the outcomes of this procedure in a pediatric population in a Sub-saharan setting.

Method

The retrospective study focuses on the procedures done in the period between October 2013 and December 2016. Twenty-eight patients, 18 males and 10 females, were enrolled. The youngest was 2 years old, the oldest 13. The bones involved were tibia (13), femur (7), radius (5) and humerus (3). In 5 cases the fibula was harvested with its proximal epiphysis, whereas in 17 cases the flap was osteocutaneous and osseous in 6 cases. In most cases, operations for eradication of the infection were carried out prior to the graft. The flap was stabilized mainly with external fixators, rarely with Kirschner's wires or mini plate. No graft augmentation was used


S. Y. Traore C. Yacaria I. Amadou Y. Coulibaly

Objectives

Our objectives were to describe the therapeutic aspects and assess the prognosis of chronic osteomyelitis in children.

Materials and methods

We made a retrospective study from January 2007 to December 2016. The study concerned children from 0 to15 years, treated for chronic osteomyelitis and monitored in the pediatric surgery department of the teaching hospital Gabriel Toure, Bamako (Mali). The other types of bone infections, osteitis and bone tumors were not included in the study.

In 10 years we received and treated 215 children with chronic osteomyelitis. This represented 3.56% of all the hospitalizations. The mean age was 8.8 (± 6.67) years with extremes of 28 days and 15 years. The patients were first seen by the traditional healer in 165 (76.7%) cases. The sex ratio was 1.26. The major clinical feature was local swelling associated with pain in 110 cases (51.2%). In 135 cases (62.8%) the staphylococcus aureus was found in direct examination or culture. After a year we performed a functional and morphological assessment according to the method of DIMEGLIO.


F. Loïc F. O. Ngongang M. A. N. Yamben U. Tambekou L. J. Bitang

Aim

Bone and joint infections are frequent in African countries and their prevention and treatment remain a great challenge. This study aimed to determine the bacterial ecology and sensitivity of isolates to locally available antibiotics in orthopedic unit of a tertiary care hospital in Cameroun.

Method

During a 12 months period, all the patients presenting with osteomyelitis or septic arthritis irrespective of the mechanism and the location were enrolled in this study. Intraoperative samples (biopsies) were taken and sent for microbiological analysis, and all strains isolated were tested for antibiotic sensitivity according to conventional methods.


L. Mora

Aim

Intramedullary osteomyelitis remains a challenge in the treatment of bone infections, requires organized, sequential and effective management to prevent its spread and subsequent recurrence. Errors are often made in the comprehensive treatment of this type of infection classified as type 1 of Cierny-Mader, where you can perform an insufficient treatment or in some cases perform very extensive and unnecessary bone resections. A rigorous protocol is proposed, by stages to achieve the total eradication of the infection and a surgical tactic that avoids diffusion of the infection or recurrences

Method

In the prospective case series study, 16 patients with type 1 intramedullary infection of Cierny Mader, diagnosed by radiology, TAC or MRI were included.

The microbiological protocol is carried out, with the germ typing and the corresponding antibiogram, at least 3 samples of deep tissues, the biofilm and segments of dead bone are taken. In the surgical tactic, intramedullary sequestrations are resected, the intramedullary canal is cleaned by stages, initially in the most inflammatory focus detected, the medullary canal is accessed through a planned and defined bone window, with round edges to avoid fractures and allowing access To the flexible reamer and cleaning guides, an additional window is made that avoids the blood dissemination of the infection, the septic embolisms or the contamination of the underlying soft tissues. It is defined if it requires stabilization of the bone with internal or external devices, therapies are applied locally to avoid recolonization, using Bioglass or absorbable substitutes with selective antibiotic. The treatment is associated with intravenous antibiotic therapy between 2 and 6 weeks according to the type of germ and if it is multiresistant.

It guarantees skin coverage and protection of structures at risk such as nerves, tendons and exposed bone.


R. Corrigan M. Dudareva M. McNally J. Lomascabeza

Aim

Skeletal tuberculosis (TB) accounts for up to one third of cases of extra-pulmonary TB but comprises a minority of osteoarticular infection in areas with low TB incidence. Consequently, unexpected cases may receive surgical management targeted at non-tuberculous orthopaedic infections. This study reviewed treatment and outcomes of non-spinal osteoarticular TB to assess outcomes from modern surgical techniques.

Method

All patients with a diagnosis of non-spinal osteoarticular TB between 2009–2017 from one tertiary referral centre were included. Retrospective review of surgical intervention, antibiotic treatment and outcome was conducted.


A. Menon R. Bhadiyadra V. Kuntwad R. Soman C. Rodrigues A. Shetty V. Agashe

Aim

Management of infection after osteosynthesis (IAO) poses a significant challenge in the setting of multidrug resistant organisms (MDRo). We have analysed whether IAO with MDRo has an adverse outcome.

Method

We have retrospectively analysed patients with IAO from January 2001 to November 2016 with a minimum follow up of 12 months after the discontinuation of antibiotics.


M. Huard C. Detrembleur H. Poilvache M. van Cauter R. Driesen J. Yombi J. Neyt O. Cornu

Aim

Apart from other biomarkers isolated in the synovial fluid, alpha-defensin appears to be a promising diagnostic tool to confirm a periprosthetic joint infection (PJI) in the hip or knee. The purpose of this study was to evaluate the sensitivity and specificity of an alpha defensin lateral flow (ADLF) test compared to usual standard classifications in the diagnostic management of PJI.

Method

This investigation was set up as a multicenter prospective cohort study. Synovial fluid was obtained by means of joint aspiration or intra-operative tissue biopsies. A presumptive PJI diagnosis was made according to criteria outlined by the Musculoskeletal Infection Society (MSIS), the Infectious Diseases Society of America (IDSA) and the European Bone and Joint Infection Society (EBJIS). The intention to treat by the surgeon was logged. Sensibility and specificity for the ADLF test was plotted for each aforementioned diagnostic algorithm. Spearman correlations between all scores were analyzed. Multiple logistic regression was used to determine the contribution of independent variables to the probability of PJI.


L. G. Cardoso J. Rocha L. Jorge J. Matos M. Carneiro B. Bassetti K. Morejon M. E. Graf C. Pilati R. P. Leme M. Salles

Aim

Over the past three years, roughly 100,000 hip and knee replacements have been performed by the Brazilian Public Healthcare System. Prosthetic joint infection (PJI) is expected to range between 1% to 10% after primary and revisions joint arthroplasties, respectively. So far, there have been no published national PJI data which would be helpful at developing local preventive strategies and guide surgeons and clinicians. We aimed at describing the epidemiological, clinical and microbiological PJI results of a national and collaboration study among infectious diseases specialists and orthopaedic surgeons, including academic, public and private institutions.

Method

We prospectively enrolled patients with PJI in a national cohort study among 12 hospitals from 6 different States to describe host, pathogens, diagnosis, surgery strategies adopted (according to the standard hospital-based guideline) and outcome after 1- and 2-years follow-up. PJI was defined using the IDSA criteria (Osmon D, et al. Clin Infect Dis. 2013). Patients were enrolled from July 2013 to December 2015.


L. Vermuyten E. J. McPherson J. Neyt

Aim

At present, a variety of clinical guidelines for treatment of periprosthetic joint infections (PJI) inevitably lead to a variety in outcomes by differing case management. Ideally a treatment algorithm should incorporate all components contributing to the decision-making process for a patient tailored solution in PJI. We aim to present a comprehensive and reproducible treatment algorithm based on a validated staging system, a thorough understanding of the host, the causative microbiome and implant complexity.

Method

The diagnosis of a PJI was defined according to major and minor criteria following revised International Consensus Symposium algorithm

The validated McPherson staging system was used in our university hospital from January 2015 until January 2019 in referred PJI patients. Standardised preoperative and postoperative survey documents were completed in order to register data from the patient's medical, social and surgical history. The complexity of the infected implant was taken into consideration, including quantity of preceding procedures, residual bone stock, type of fixation, magnitude of prosthetic components and presence or absence of reconstructive options. Further, preoperatively obtained bacteriological information by means of arthrocentesis or tissue/bone biopsies was categorized according to the mono- or polybacterial nature and to the qualification of virulence and difficulties to treat. Social and professional history, financial impediments and patient's functional outcome wishes were included in the joint decision making.


R. Afonso M. X. Baptista M. R. da Costa C. Sá-Barros B. D. Santos P. Varanda J. B. Tinoco E. B. Rodrigues

Aim

This study aims to describe our department experience with single stage revision (SSR) for chronic prosthetic-joint infection (PJI) after total hip arthroplasty (THA) between 2005 and 2014 and to analyze success rates and morbidity results of patients submitted to SSR for infected THA according to pathogen.

Method

We retrospectively reviewed our 10 years of results (2005–2014) of patients submitted to SSR of the hip combined with IV and oral antibiotic therapy for treatment of chronic PJI (at least 4 weeks of symptoms), with a minimum follow-up of four years (n=26). Patients were characterized for demographic data, comorbidities, identified germ and antibiotic therapy applied (empiric and/or targeted). Outcomes analyzed were re-intervention rate (infection-related or aseptic), success rate (clinical and laboratory assessment), length of stay, morbidity and mortality outcomes.


G. Giordano G. Krin Y. Portet A. Bouige C. Fourcade E. Bonnet

Aims

To evaluate the place of the massive prostheses in the most complex periprosthetic infections cases (PJis).

Method

Between 2011 and 2017, 516 hip and knee revisions for periprosthetic infections had been performed in our hospital by the same senior surgeon. We report a prospective series of 58 patients treated between 2011 and the end of 2017. 26 males and 32 females with on average 69,4 years old (38–86). Infection involved TKA in 39 cases (26 TKA revisions, 11 primary TKA), THA in 18 cases (10 revisions, 7 primary THA), a femoral pseudoarthrosis with posttraumatic gonarthrosis in one case and a septic humeral pseudoarthrosis in one case.

We used one stage procedures in 38 cases (14 hips, 23 knees, 1 shoulder) and 20 two stages surgeries (16 knees and 4 hips). Additional technics used with massive prostheses, all for TKA PJis: 4 massive extensor systemallografts performed two times in a one stage procedure, two local flaps (medial gastronecmienmuscle). Two perioperative hyperbaric procedures used to limit the risks of wound complications.


G. Ullmark D. Sotiriou H. Stigbrand

Introduction

Periprosthetic joint infection (PJI) represents the costliest complication in Orthopedics. Studies of mixing vancomycin to bone graft at Impaction Bone Grafting (IBG) have shown high local concentration for 3 weeks.

Patients and methods

55 consecutive revisions PJI, age 68 (SD 10.9), (9 one-stage and 46 two-stage) were retrospectively analyzed. All cases were revised using IBG. Most cases had vancomycin mixed in graft or added locally in joint. All had bone cement containing Gentamycin and Vancomycin. Follow up 2–16 years included clinical Merle d'Aubigne-Postel score, radiology and laboratory tests. We analyzed surgical time, bleeding, hospitalization time, infection eradication and prosthetic survival for one- and two-stage revision procedures. One patient was lost to follow up and 6 died (2 one- and 4 2-stage) before 2 years. Values are mean and SD. Analyses done by students t-test.


S. Karbysheva K. Yermak A. Trampuz

Aim

To evaluate the analytical performance of synovial fluid D-lactate test for the diagnosis of PJI.

Method

Consecutive patients undergoing diagnostic joint aspiration of prosthetic joint were prospectively included. PJI was diagnosed according to the proposed European Bone and Joint Infection Society (EBJIS) definition criteria. Synovial fluid was collected for culture, D-lactate measurement (by spectrophotometry, λ = 570 nm) and leukocyte count and differential (by flow cytometry). The receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance of D-lactate and leukocyte count.


H. Yildiz O. Cornu P. d'Abadie J.C. Yombi

Aim

Staphylococcus aureus bacteremia (SAB) is associated with significant morbidity and mortality, 20–30 % risk of infection in patient with implant related infection (IRI) .18F-FDG PET/CT is helpful in the management of SAB, leading to detection of more metastatic foci and treatment modification and finally decrease relapses and mortality rate. Our objective was to analyze mortality in high risk SAB patients undergoing 18F-FDG PET/CT and to see whether it's use in patients with IRI reduced their mortality.

Method

We performed a retrospective study at a university hospital in Belgium. All cases of high risk adult SAB between January 2014 and June 2017 were reviewed. We collected the clinical characteristics including presence of metastatic foci on 18F-FDG PET/ CT, mortality at 1 year.


W.Z. Stone C. F. Gray H. K. Parvataneni M. Al-Rashid R. G. Vlasak H. Prieto

Aim

Diagnosing periprosthetic joint infection after total joint arthroplasty is often challenging. The alpha defensin test has been recently reported as a promising diagnostic test for periprosthetic joint infection. The goal of this study was to determine the diagnostic accuracy of alpha defensin testing.

Method

One hundred and eighty-three synovial alpha defensin and synovial fluid C-reactive protein (CRP) tests performed in 183 patients undergoing evaluation for periprosthetic joint infection were reviewed. Results were compared with the Musculoskeletal Infection Society (MSIS) criteria for periprosthetic joint infection.


A. Ribau A. D. Carvalho T. A. Barbosa M. Abreu D. E. Soares R. Sousa

Aim

C-reactive protein(CRP) and erythrocyte sedimentation rate(ESR) are non-specific markers with variable reported accuracy in the diagnosis of prosthetic joint infection(PJI). They are often used as a part of the initial diagnostics as they are widely available and inexpensive. Given its high false-negative rate, CRP is an insufficient screening tool for PJI especially in low virulence microorganisms. Nevertheless, many advocate ESR offers no added advantage and is useless in this setting. Our goal is to determine if the combined measurement of ESR and CRP offers increased sensitivity for the preliminary screening of PJI over isolated CRP measurement.

Method

We retrospectively evaluated every single- or first-stage for presumed aseptic or known infected revision total hip/knee arthroplasty procedures between 2013–2018. Cases without preoperative CRP and ESR measurement as well those without synovial fluid for differential leukocyte count and/or no multiple cultures including sonication of removed implant obtained during surgery were excluded. Diagnostic accuracy was compared against two different PJI definitions: 2013 International Consensus Meeting and ProImplant Foundation definitions.


S. Klim G. Glehr F. Amerstorfer L. Leitner R. Krassnig A. Leithner G. Bernhardt M. Glehr

Aim

In the diagnosis of prosthetic joint infection (PJI), many biomarkers have shown a sound performance in terms of accuracy, sensitivity and specificity. In this study we aimed to test the frequently used serum biomarkers C-reactive Protein (CRP), Fibrinogen, Leukocytes, Interleukin-6 (IL-6), Interferon alpha (IF-alpha) and Procalcitonin (PCT) regarding these qualities. Following that, the optimal multi-biomarker combination was calculated to further improve the diagnostic performance.

Method

124 knee or hip revision arthroplasty procedures were prospectively investigated focusing on preoperative serum blood levels of CRP, Fibrinogen, Leukocytes, IL-6, IF-alpha and PCT. The presence of PJI was determined by a blinded researcher. Logistic regression with lasso-regularization was used for the biomarkers and all their ratios. Following cross-validation on a training sample set to get optimal performance estimates, we performed the final model on a test set (25% of all samples).


M. Loppini C. F. Bruno F. L. Camera C. Favazzi M. Casana M. C. Ferrari G. Grappiolo

Aims

The purpose of this study was to evaluate the infection-free outcome of patients underwent revision of total joint arthroplasty (TJA) for presumed aseptic causes, with positive intra-operative cultures.

Patients and Methods

A retrospective cohort study was assembled with 130 patients undergoing revision knee (21 cases) or hip arthroplasty (109 cases) for presumed aseptic causes. For all patients five to seven separate intra-operative cultures were obtained and prosthesis sonication was done. Patients were diagnosed with a previously unsuspected prosthetic joint infection (PJI) if two or more cultures were

positive or a positive prosthesis sonication. Data were reviewed for demographic details, preoperative laboratory results and culture results. The endpoint was infection-free implant survival at 24 months.


H. Bezstarosti E. van Lieshout L.W. Voskamp P.D. Croughs K. Kortram M.A. McNally W. Metsemakers M.H.J. Verhofstad

Aim

The aim of this systematic review was to determine all cultured bacteria, antibiotic strategies, and their outcome from literature describing treatment of FRI patients between 1990 and 2018.

Methods

A systematic literature search was performed on treatment and outcome of FRI. All studies in English that described surgical patient series for treatment of FRI were included, using Medline, Embase, Web of Science, Cochrane, and Google Scholar. Publications before 1990 and studies that did not describe FRI patient treatment or did not report original data (e.g., reviews or meta-analyses) were excluded. Study selection and data collection were done by two authors independently. Main collected parameters were preoperative cultures, use of local antibiotics, postoperative antibiotic protocol, cultured microorganisms, and overall outcome of treatment, i.e., eradication of infection and bony union, recurrence, amputations, revisional surgery, and number of complications. Dichotomous data were pooled using Medcalc, and weighted means were calculated for continuous data using Excel.


A. Khajuria P. Fenton D. Bose

Aim

To evaluate clinical outcomes for patients with osteomyelitis at a major trauma centre limb reconstruction unit.

Method

We prospectively evaluated 137 patients on the limb reconstruction database with long bone osteomyelitis. Data on initial diagnosis, management (bone resection, use of external fixation, dead space and soft tissue management), microbiology and 2-year outcomes were collated. 11 patients' data was incomplete and 9 underwent primary amputations; these were excluded from microbiology data analysis. The patient data was categorised into microbiological culture negative or culture positive groups. Inter-group comparisons were made to evaluate two-year outcomes and percentage failure rate.


E. Giannitsioti M. Salles A. Mavrogenis D. Rodríguez-Pardo C. Pigrau A. Ribera J. Ariza D. D. Toro S. Nguyen E. Senneville E. Bonnet M. Chan M. B. Pasticci S. Petersdorf A. Soriano N. Benito N. O' Connell A. B. García G. Skaliczki P. Tattevin Z. K. Tufan N. Pantazis P. D. Megaloikonomos P. Papagelopoulos A. Papadopoulos

Aim

Gram negative bacteria (GNB) are emerging pathogens in chronic post-traumatic osteomyelitis. However, data on multi-drug (MDR) and extensively drug resistant (XDR) GNB are sparse.

Methods

A multi-centre epidemiological study was performed in 10 countries by members of the ESGIAI (ESCMID Study Group on Implant Associated Infections). Osteosynthesis-associated osteomyelitis (OAO) of the lower extremities and MDR/XDR GNB were defined according to international guidelines. Data from 2000 to 2015 on demographics, clinical features, microbiology, surgical treatment and antimicrobial therapy were retrospectively analyzed. Cure was assessed after the end of treatment as the absence of any sign relevant to OAO. Factors associated with cure were evaluated by regression analysis.


A. Hotchen M. Dudareva J. Ferguson I. Rombach M. Scarborough M. McNally

Aim

Bone and joint infections are a serious complication of trauma, surgery and soft tissue infections. However, there are few data presenting patient reported outcome measures for osteomyelitis. A recently proposed method for classification of osteomyelitis, BACH, stratifies patients into ‘uncomplicated’ and ‘complex’, based on four key inter-disciplinary components: Bone involvement, Anti-microbial options, soft-tissue Coverage and Host status. We aim to correlate the classification severity with patient reported outcomes following osteomyelitis surgery.

Method

Seventy-one patients with long-bone osteomyelitis, confirmed using a validated composite protocol, were included. Patients received a single-stage procedure at a specialist bone infection unit. Euro-Qol EQ-5D-3L questionnaires and Visual Analogue Scores (VAS) (0–100) were collected prospectively at baseline, 14 days, 6 weeks, 4 months and 1 year post-operatively. The EQ-5D-3L index score, a composite measure of performance of daily activities, was calculated from the 5 domains of the EQ-5D-3L. BACH was applied retrospectively by two independent clinicians blinded to all patient outcomes.


A. Joensson A. Joensson S. Vikstroem N. Fagerberg C. Olsen

Aim

To retrospectively investigate the clinical outcome after surgical, single-stage treatment of orthopaedic infections using antibiotics delivered locally by a calcium sulphate/hydroxyapatite biocomposite.

Method

In order to identify the patients, we retrospectively searched several patient associated hospital-based databases using free text search with the term “Cerament” between November 2015 and November 2018.

58 cases with confirmed osteomyelitis and in which the bone substitute loaded with Gentamicin and/or Vancomycin had been used were identified and further evaluated.


M. Rupp S. Kern C. Biehl G. Knapp T. E. Khassawna C. Heiß V. Alt

Introduction

Polymicrobial infections are expected to complicate the treatment of bone and joint infections. Septic nonunions often occur after initial open fractures, which prophylactically receive broad-spectrum antibiotics. However, no data that describes frequencies of polymicrobial infections and pathogens evident in course of the treatment of septic nonunions is published. Therefore, this study aims at investigating the frequency and pathogen types in polymicrobial infections.

Methods

Surgically treated Patients with long bone septic nonunion admitted between January 2010 and March 2018 were included in the study. Following parameters were examined: age, gender, American Society of Anesthesiologists (ASA) score, body mass index (BMI), and anatomical location of the infected nonunion. Microbiological culture data, polymerase-chain-reaction results of tissue samples, sonication, and joint fluid of the initial and follow-up revision surgeries were assessed. No exclusion criteria were determined.


P-E. Schwab N. Varady A. Chen

Aim

Traditionally, serum white blood count (WBC), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) have been utilized as markers to evaluate septic arthritis (SA). Recently, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been identified as prognostic factors for treatment failure, mortality and morbidity in various clinical settings. To date, these markers have not been utilized for evaluating outcomes after hip and knee SA.

Thus, the purpose of this study was to determine the ability of admission NLR and PLR to predict treatment failure and postoperative 90-day mortality in hip and knee SA.

Method

A retrospective study was performed using our institutional research patient database to identify 235 patients with native hip and knee septic arthritis from 2000–2018. Patient demographics, comorbidities and social factors (alcohol intake, smoking and intravenous drug use) were obtained, and NLR and PLR were calculated based on complete blood count values (absolute neutrophil, lymphocyte and platelet count) on admission. Treatment failure was defined as any reoperation or readmission within 90 days after surgery. Receiver operating curves were analyzed, and optimal thresholds for NLR and PLR were determined using Youden's test. Univariate and multivariate analyses were performed to determine if these ratios were independent predictors of treatment failure and 90-day mortality after surgery. These ratios were compared to serum WBC, CRP, and ESR.


A. Fischbacher O. Borens

Aim

There is a constant increase of total joint arthroplasties to improve the quality of life of an aging population. Prosthetic-joint infections are rare, with an incidence of 1–2%, but they represent serious complications in terms of morbidity and mortality. Different therapeutic options exist, but the role of the surgeon's experience has never been investigated. The aim of this retrospective study is to assess the infection eradication success rate depending on the involvement of a septic surgeon.

Method

Patients having a prosthetic-joint infection at Lausanne University Hospital (Switzerland) between 2006 and 2018 were included. The success rate depending on type of surgeon (septic vs non-septic) and type of surgical procedure was analyzed.


J. Ferguson M. McNally D. Stubbs

Aims

Infective complications following implant related orthopaedic surgery or fracture related infection are associated with high costs and increased length of stay (LOS). However, the economic burden of disease before, during and after definitive osteomyelitis surgery is not well quantified. The Hospital Episode Statistics (HES) database captures all admissions, outpatient appointments and emergency department attendances at NHS hospitals in England. We identified all patients with a diagnostic code of osteomyelitis and quantified the tariff costs associated with the surgical treatment of osteomyelitis. We also collected all recorded healthcare events related to osteomyelitis for two years preceding the initial osteomyelitis treatment procedure, as well as for two years after the procedure. We compared average osteomyelitis treatment costs in England against a dedicated specialist multidisciplinary bone infection centre.

Methods

We interrogated the HES database for all patients given a diagnostic code of osteomyelitis (M86) between April 2013 and January 2017. We excluded all cases with a diagnosis of osteomyelitis and an index procedure of an amputation for diabetes or arterial disease. Of the remaining 104,622 patients there were 24,408 cases who had their index procedure for osteomyelitis in this time period. Of these we compared a subset of 575 cases treated in a specialist bone infection centre.


C. Berberich P. Sanz-Ruiz

Aim

There is an ongoing controversy whether the observed benefit of infection risk reduction by ALBC outweighs the risk of possible antimicrobial resistance development.

Methods

The scientific & clinical literature in PubMed, Medline and Embase has been systematically reviewed with the keywords “antibiotic resistance”, “antibiotic loaded bone cement”, “local antibiotics”, “bacterial colonization” and “joint infection”. In total 28 relevant publications were found with the majority of them reporting laboratory results. Only 7 papers focused on clinical septic situations & patient data


H. Scheper R. van der Wal R. Mahdad S. Keizer N. Delfos J. van der Lugt K. E. Veldkamp M. L. Hall E. van Elzakker M. G. J. D. Boer L. G. Visser R. Nelissen

Aims

Current antibiotic treatment strategies for prosthetic joint infection (PJI) are based mostly on observational retrospective studies. High-quality data from prospective cohorts using identical treatment strategies may improve current clinical practice. We developed a regional network of collaborating hospitals and established a uniform treatment protocol. Data from all patients diagnosed with a PJI are prospectively registered in a an online database. With this quality registry we aim to study the outcome of antibiotic and surgical strategies while adhering to a pre-established treatment protocol.

Methods

A working group of orthopaedic surgeons, infectious disease specialists and microbiologists was established. The working group reached consensus on definition of PJI and a uniform treatment protocol, based on current guidelines and expert-based clinical experience. A website was built to communicate information to colleagues and patients (www.protheseinfectie.nl). In each participating hospital weekly multidisciplinary meetings were started to discuss all PJI cases. All patients are included in an online quality registry and followed for at least two years. We aim to enroll >600 patients with a knee or hip PJI. Research will focus on the duration of antibiotic treatment, antibiotic suppressive therapy and comparison of different oral antibiotic treatment strategies in relation to successful treatment outcomes.


E. T. Sandbakken E. Witsoe B. Sporsheim K. W. Egeberg O. Foss L. Hoang G. Bjerkan K. Bergh

Aim

In cases of prosthetic joint infections the sensitivity of bacterial cultivation of tissue samples is not 100%. In fact, the reported sensitivity based on standardized criteria and rigorous tissue sampling technique probably differs between 86 to 89%. It has been claimed that sonication of explanted prostheses with subsequent culturing of sonication fluid can increase the sensitivity of the test compared to culturing of tissue samples. To what degree bacteria embedded in biofilm is dislodged during the sonication process has to our knowledge not been fully elucidated. We studied the effect of sonication as a method to dislodge biofilm embedded Staphylococcus epidermidis in vitro.

Method

46 steel plates were colonized with biofilm forming S. epidermidis ATCC 35984 in TSB with 1% glucose aerobically at 37°C for 24 hours. Plates were cleansed for non-adherent bacteria before microscopy. Biofilm embedded bacteria were stained with LIVE/DEAD ™ BacLight ™ Bacterial Viability Kit for microscopy and visualized under vital conditions using EVOS™ FL Auto 2 Imaging System (epifluorescence) and an inverse confocal laser scanning microscope LSM510 (CLSM). All steel plates were subjected to epifluorescence microscopy before and after sonication. CLSM and SEM were used to confirm the presence of biofilm embedded bacteria after sonication. Pictures from epifluorescence microscopy were processed for image analysis with help of a macro application (Fiji) and the data was expressed as biofilm coverage rate (BCR). The sonication was performed using a BactoSonic® Bandolin sonicator and the applied effect in each glass test tube (40 kHz, 800W) was measured with a Bruel og Kjær 8103 hydrophone. The amount of bacteria in the sonication fluid was quantified by counting the number of colony forming units (CFU).

Three steel plates acted as negative controls.


O. Grossi R. Lamberet S. Touchais S. Corvec P. Bemer

Aim

Cutibacterium acnes is a significant cause of late-onset spinal implant infection (SII). In addition, usual preoperative prophylactic measures may be insufficient to prevent C. acnes operating site colonisation and infection, as demonstrated for prosthetic shoulder surgery. However, little information is available regarding risk factors for SII due to this microorganism. The aims of this study were to determine the characteristics of and risk factors for C. acnes SII.

Method

we conducted a retrospective unmatched case-control study including all adult patients treated for mono and polymicrobial C. acnes SII during 2010–2015. Controls were randomly selected among patients diagnosed with SII due to other microorganisms during the same period.


G. Cacciola F. D. Meo A. Bruschetta P. Cavaliere

Aim

Periprosthetic joint infections (PJI) are a severe complications after hip arthroplasty. The infections rate ranges from 0.7 to 1.3 depending on different reports. The aim of the present study is to evaluate the radiological and clinical outcome of patients that underwent two-stage revision for the treatment of periprosthetic joint infection of the hip when an extended trochanteric osteotomy (ETO) was necessary to remove the femoral stem.

Methods

We retrospectively analyzed data from 84 patients that underwent two-stage revision of the hip between January 2006 and December 2010 at our institution. In forty-nine patients (Group A, 58.3%), the femoral stem was removed without an ETO, while in the remaining thirty-five patients (Group B, 41.7%) an ETO was necessary. In each case a metallic cerclage was used to closure of the flap. The average age for patients in group A was 64.3 years, while the average age in patients in group B was 66.4 years. The mean follow-up was respectively 117 months in group A and 122 months in group B. Eight patients died before the last follow-up, and data from six patients were incomplete. Complications, radiological and clinical outcome were. Mann Whitney U Test and Chi Square Test were used respectively to analyze continues and categorical variables. Cumulative survival of the implants was calculated for reinfection and mechanical complications with Kaplan-Meyer curves.


E. Denes F. Fiorenza E. Toullec F. Bertin S. E. Balkhi

Aim

Local concentration of antibiotic at the site of infection is a major parameter for its efficiency. However, bone diffusion is poor leading either to their non-use (ex: gentamicin) or the use of high concentration (ex: vancomycin). Local administration could optimize their local concentration combined with lower side effects. We report the clinical experience and pharmacological results of an antibiotic loaded porous alumina used to replace infected bone in 4 patients.

Method

Two patients had a destroyed sternum following mediastinitis; one presented a femoral chronic osteomyelitis due to MRSA and one had an infected ankle arthroplasty. The ceramic was loaded with gentamicin in three cases and vancomycin for the ankle infection. Local dosages thanks to Redon's drain and blood samples were performed. Loading was done to protect the device while implanted in an infected area and was combined with conventional antibiotic therapy.


C. Yeung P. Lichstein N. Varady B. Bonner C. Carrier P. Schwab J. Maguire A. Chen D. Estok

Aim

Knee arthrodesis (KA) and above knee amputation (AKA) have been used for salvage of failed total knee arthroplasty (TKA) in the setting of periprosthetic joint infection (PJI). The factors that lead to a failed fusion and progression to AKA are not well understood. The purpose of our study was to determine factors associated with failure of a staged fusion for PJI and predictive of progression to AKA.

Method

We retrospectively reviewed a single-surgeon series of failed TKA for PJI treated with two-stage KA between 2000 and 2016 with minimum 2-year follow-up. Patient demographics, comorbidities, surgical history, tissue compromise, and radiographic data were recorded. Outcomes were additional surgery, delayed union, Visual Analog Pain scale (VAS) and Western Ontario and McMaster Activity score (WOMAC). No power analysis was performed for this retrospective study. Medians are reported as data were not normally distributed.


A. D. Carvalho A. Ribau T. A. Barbosa C. Santos M. Abreu D. E. Soares R. Sousa

Aim

Antibiotic loaded spacers are often used during a two-stage exchange for periprosthetic joint infections (PJI) both for its mechanical properties and as a means for local antibiotic delivery. The main goal of this study is to compare the rate of positive cultures during reimplantation with the use of different antibiotic loaded spacers: aminoglycoside only vs. combined glycopeptide/aminoglycoside vs. combined glycopeptide/carbapenem/aminoglycoside.

Method

We retrospectively evaluated every two-stage exchange procedures for infected hip/knee arthroplasty between 2012–2018. Microbiological findings in the first and second stage were registered as well as the type of spacer and antibiotic(s) used. Cases in whom no cultures were obtained during reimplantation and cases without sufficient data on antibiotic(s) used in cement spacers were excluded.


I. Pastor H. Poilvache D. Morcillo M. van Cauter H. Rodriguez-Villalobos J. Yombi O. Cornu

Aim

We wonder what the results of two stage procedures were in terms of morbidity (amputation, dead) and infection recurrence. We also seek to identify risk factors for failure and see if the results of a second two stage surgery were not even worse.

Material and Methods

We retrospectively reviewed 140 prosthetic joint infection (PJI) treated with a two stage procedure. Patient data has been reviewed to determine which factors would be predictive for failure.


W. Boot A. Foster T. Schmid M. D'este S. Zeiter D. Eglin G. Richards F. Moriarty

Aim

Implant-associated osteomyelitis is a devastating complication with poor outcomes following treatment, especially when caused by antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA). A large animal model of a two-stage revision to treat MRSA implant-associated osteomyelitis has been developed to assess novel treatments. A bioresorbable, thermo-responsive hyaluronan hydrogel (THH) loaded with antibiotics has been developed and our aim was to investigate it´s in vivo efficacy as a local antibiotic carrier compared to the current standard of care i.e. antibiotic-loaded polymethylmethacrylate (PMMA) bone cement.

Method

12 female, 2 to 4 year old, Swiss Alpine Sheep were inoculated with MRSA at the time of intramedullary nail insertion in the tibia to develop chronic osteomyelitis. After 8 weeks sheep received a 2-stage revision protocol, with local and systemic antibiotics. Group 1 received the gold standard clinical treatment: systemic vancomycin (2 weeks) followed by rifampicin plus trimethoprim/sulfamethoxazole (4 weeks), and local gentamicin/vancomycin via PMMA. Group 2 received local gentamicin/vancomycin delivered via THH at both revision surgeries and identical systemic therapy to group 1. Sheep were euthanized 2 weeks following completion of antibiotic therapy. At euthanasia, soft tissue, bone, and sonicate fluid from the hardware was collected for quantitative bacteriology.


I. L. Torres P. S. Ruiz J. Matas-Díaz A. Fraguas F. Navarro-García J. Vaquero

Aim

The demonstration of the in vivo bactericidal efficacy of a new bone cement with rifampicin contained in microcapsules and its intra-articular release profile.

Method

Fifteen New Zealand White rabbits were employed to reproduce periprosthetic infection by intra-articular inoculation of 105 CFU/mL of Staphylococcus aureus ATCC® 29213 using as a target implant a 3D printed stainless steel tibial insert. 7 days after inoculation, the first stage of the two stage exchange was carried out and at this time the animals were divided into two study groups: group C (7 rabbits) that received a spacer with gentamicin and group R (8 rabbits) that received a spacer with gentamicin and rifampicin microcapsules. Response to infection was monitored by clinical (weight and temperature), hematological (leukocyte, lymphocyte and platelet counts) and biochemical (erythrocyte sedimentation rate) analyses at the time of inoculation, at the first stage of exchange, 4 days after first stage and weekly until the fourth week when animals were euthanized. Microbiological counts were performed at the first stage of exchange and at the end of the study.


L. K. Jensen S. A. Blirup B. Aalbæk T. Bjarnsholt K. N. Kragh H. Gottlieb M. Bue H. E. Jensen

Aim

To study the antimicrobial effect of a gentamicin loaded bio-composite bone void filler in relation to a limited or extensive debridement of osteomyelitis lesions, respectively.

Methods

Nine pigs were inoculated into the right proximal tibial bone with a high virulent gentamicin sensitive strain of Staphylococcus aureus (104 CFU). Seven days after inoculation, Group A pigs (n=3) were exposed to a limited debridement of the bone lesion, whereas Group B pigs (n=3) were exposed to an extensive debridement. The bone defects of Groups A and B were filled with (2–5 ml) of an absorbable gentamicin (175 mg/10 mL) loaded bio-composite. The animals of Group A and B were euthanized 12 days after revision surgery. Group C animals did not undergo revision surgery and were euthanized seven (n=1) or nineteen (n=2) days post inoculation in order to follow the development of the untreated infection. None of the animals were treated with systemic antimicrobials. All bones were exposed to a post mortem CT scan and rigours pathological examinations. The surrounding bone tissue and the bio-composite were sampled for microbiology.


J. Pützler M. Alexander J. Everding M. J. Raschke D. Arens S. Zeiter G. R. Richards F. T. Moriarty

Aim

Focused high energy extracorporeal shockwave therapy (fhESWT) is used to support fracture healing in non-union cases and has been shown to have antibacterial effects. We trialed fhESWT as an adjunct to conventional treatment in a clinically relevant rabbit model of fracture related infection.

Method

A complete humeral osteotomy was performed in 31 rabbits and fixed with a 7-hole-LCP. A fracture-related infection (FRI) was established with Staphylococcus aureus. After two weeks, a revision surgery was performed with debridement, irrigation and implant retention. Rabbits then received: no further treatment (controls); shockwaves (at day 2 and 6 after revision, 4'000 Impulses each time with 23kV); systemic antibiotics (rifampin and nafcillin) over one week in weight adjusted dosages; or the combination of antibiotics and shockwaves. Treatments were applied over one week. Blood cultures were taken before and after shockwave sessions. After an additional week without treatment, rabbits were euthanized, and quantitative bacteriology was performed on implants and tissues to determine infection burden. Indicator organs (brain, heart, liver, lungs, kidneys and spleen) were cultured to assess possible bacteraemia due to fhESWT.


D. Arens S. Zeiter T. Paulin N. Ranjan V. Alt

Aim

Silver is known for its excellent antimicrobial activity, including activity against multiresistant strains. The aim of the current study was to analyze the biocompatibility and potential influence on the fracture healing process a silver-coating technology for locking plates compared to silver-free locking plates in a rabbit model.

Methods

The implants used in this study were 7-hole titanium locking plates, and plasma electrolytic oxidation (PEO) silver coated equivalents. A total of 24 rabbits were used in this study (12 coated, 12 non-coated). An osteotomy of the midshaft of the humerus was created with an oscillating saw and the humerus stabilized with the 7 hole locking plates with a total of 6 screws. X-rays were taken on day 0, week 2, 4, 6, 8, and 10 for continuous radiographical evaluation of the fracture healing. All animals were euthanized after 10 weeks and further assessment was performed using X-rays, micro-CT, non-destructive four-point bending biomechanical testing and histology. Furthermore, silver concentration was measured in the kidney, liver, spleen and brain.


M. Thomassen P. E. Hanberg M. Stilling K. Kjær K. S⊘balle L. Krag C. H⊘jskov M. Bue

Aim

Local treatment with gentamicin may be an important tool in the prevention and treatment of surgical site infections in high-risk procedures and patients. The aim of this study was to evaluate the pharmacokinetic profile of gentamicin in bone and surrounding tissue, released from a controlled application of a GentaColl sponge in a porcine model.

Method

In 8 female pigs, a GentaColl sponge of 10×10 cm (1.3 mg gentamicin/cm2) was placed in a cancellous bone cavity in the proximal tibia. Microdialysis was used for sampling of gentamicin concentrations over 48 hours from the cavity with the implanted GentaColl sponge, cancellous bone parallel to the cavity over and under the epiphyseal plate, cortical bone, the intramedullary canal, subcutaneous tissue, and the joint cavity of the knee. Venous blood samples were obtained as reference.


S. Maurer A. Moter L. Kursawe S. P. Kuster B. Bartik S. Rahm A. Zinkernagel R. Zbinden P. Zingg Y. Achermann

Aim

Periprosthetic joint infections (PJI) are increasing due to our elderly population with the need of a joint prosthesis. These infections are difficult to treat, because bacteria form biofilms within one day on the orthopedic implant surface. Notably, most of the current available antibiotics do not penetrate the biofilm or are not active against the sessile forms of bacteria. Therefore, prevention is key. In the current paradigm, bacteria from the skin surface or dermis - such as Staphylococcus aureus, coagulase-negative staphylococci, or Cutibacterium sp. – contaminate the periimplant tissue during surgery. Cutibacterium avidum, which has increasingly been reported in hip PJIs, colonizes the skin in the groin area in 32.3%. We were wondering if standard skin antisepsis before hip arthroplasty is effective to eliminate C. avidum colonization in the surgical field.

Method

In a single-center, prospective study, we preoperatively screened all patients undergoing a hip arthroplasty through a direct anterior approach for different skin bacteria in the groin area. Only in patients colonized with C. avidum, we intraoperatively searched for persistent bacterial growth during and after triple skin antisepsis with povidone-iodine/alcohol. For that, we collected skin scrapings after first and third antisepsis and biopsies from the dermis at the surgical incision and evaluated bacterial growth and species. In addition, thin sections of the dermis biopsies were submitted to Fluorescence in situ Hybridization (FISH) using pan-bacteria probe EUB338.


A. B. Hesselvig A. Odgaard M. Arpi T. Bjarnsholt F. Madsen

Aim

The primary aim of this study was to examine whether the use of iodine impregnated incision drape (IIID) decreased the risk of periprosthetic joint infections (PJIs). The secondary aim was to investigate whether intraoperative contamination could predict postoperative infection.

PJI is a devastating incident for the patients and in a population that is getting older and the incidence of arthroplasty surgery is rising it is vital to keep the infection rate as low as possible. Despite prophylactic measures as pre-operative decontamination, antisepsis and prophylactic antibiotics the infection rate has been constant at 1–2%.

Method

We performed a transregional, prospective, randomized two arm study (IIID vs control group) of 1187 patients undergoing primary knee arthroplasty surgery. A database with patient demographics and surgical observations was established with the purpose of following the patients for ten years. Patients, who developed an infection within the first year of surgery were analyzed for correlation with the intraoperative bacterial findings and the use of IIID.


R. L. Roerdink A. W. Plat R. P. van Hove A. C. A. P. Leenders B. C. van der Zwaard

Aim

Wound leakage has been shown to increase the risk of prostetic joint infections (PJIs) in primary total hip (THA) and knee arthroplasty (unicondylar and total knee arthroplasty; KA). The aim of this study is to determine whether the addition of a continuous subcuticular bonding stitch to a conventional 3-layer closure method reduces the incidence of prolonged wound leakage and PJIs after THA and KA.

Method

This retrospective cohort study included all patients receiving a THA or KA. Patients in the control group with a 3-layer closure method had surgery between November 1st 2015 and 2016, and were compared to the study group with a 4-layer closure method that had surgery between January 1st 2017 and 2018. The primary outcome was incidence of prolonged wound leakage longer than 72 hours. Differences were evaluated using logistic regression. Incidence of PJIs was the secondary outcome.


T. Kramer C. Schröder U. Noeth R. Krause B. Schmidt D. Stephan E. Scheller F. Jahn P. Gastmeier

Aim

Periprosthetic joint infections (PJI) and surgical site infections (SSI) are one of the most severe complications in joint arthroplasty. Decolonization measures prior to elective orthopedic surgeries have shown to reduce the risk of infection especially in patient identified as carriers of S. aureus. However additional screening measures can be difficult to implement in daily routine.

The objective was to study the influence of universal decolonization with polihaxanid on SSI rates.

Method

Between January 2017 and December 2018 patients scheduled for hip or knee joint arthroplasty in 5 participating orthopedic centers received polyhexanid containing decolonization set consisting of oral, nasal and wipes. Patients were instructed to perform a 5 day decolonization regimen 4 days prior to surgery. SSIs were recorded according to modified CDC criteria for a surveillance period of 90days after surgery.


T. Wik E. Wits⊘

Aim

The incidence of early periprosthetic joint infection (PJI) after total hip arthroplasty (THA) and total knee arthroplasty (TKA) is between 1 and 2 percent. In our department approximately 700 primary THAs and TKAs are performed annually. In 2015 and 2016 the incidence of early PJIs was nearly 3%. The aim of this study was to see if it was possible to reduce the incidence of infection by employing a bundle of measures by involving staff from all aspects of patient flow and addressing preventing measures in every step of the patients´ course throughout the hospital.

Method

The Arthroplasty surgeon team reviewed the Proceedings of the International Consensus Meeting on Periprosthetic Joint Infection of 2013. Issues where literature had shown a significant effect on prevention of PJI was identified and written in an action plan. An interdisciplinary team with staff from all aspects of patient flow was established. In January 2017 the action plan was presented to the interdisciplinary team. The team discussed in what way the different issues could be solved, and issues that could be addressed without extra costs were implemented immediately. The issues addressed in the meeting were: preoperative risk factors, preoperative skin preparation, perioperative antibiotics, reducing particle amount and reducing traffic in the surgical theatre.


R. Trebse T. Kanalec K. Angelini S. Baljak T. Filipič V. Levašic

Aim

”There is not a lot of data of the frequency and impact of unwanted events including glove perforation, contamination of the surgical field (drape perforation, laceration, detachment, bone bounced back from an unsterile object), unsterile object in the surgical field (hair, sweat droplet…), defecation, elevated air temperature, and others. Mishaps occur in every surgical theatre. These events should influence the surgical site infection rate but it is not clear to what extent. We wanted to calculate the frequency and measure the impact of these events on the infection and revision rate of the relative patients.”

Method

”In our institution, scrub nurses prospectively record untoward events in the theatres. Surgeons register complications before discharge. Stratified failures are recorded since 2002 within a registry. We analysed the respective databases and compared the revision and infection rate in the group with untoward effects with the outcome of all arthroplasty patients within the same time period. Two tailed Z statistical test was used for analysis.”


M. A. Burch K. Thompson U. Eberli D. Arens A. Milstrey V. Stadelmann G. Richards F. Moriarty

Aim

Non-steroidal anti-inflammatory drugs (NSAIDs) are a cornerstone of perioperative pain management in orthopedic trauma surgery, although concerns persist regarding the potential impact of these drugs on fracture healing. Furthermore, NSAIDs may also exert an influence on host immune defenses, which may also be important in the context of infection treatment. However, this has been very much under-investigated in the clinical and scientific literature. The aim of this study was to determine the impact of NSAIDs on the course of an orthopedic device-related infection (ODRI) and its response to antibiotic therapy in a rat model.

Method

A polyetheretherketone (PEEK) screw was inserted in the proximal tibia of 48 skeletally mature female Wistar rats: 12 control animals received a sterile screw, of which 6 also received NSAID therapy (carprofen, 5 mg/kg s.c. once daily); 36 rats received a Staphylococcus epidermidis-inoculated screw, of which 18 received NSAID therapy. Antibiotic therapy was administered from day 7–21 in 9 animals from all groups receiving S. epidermidis-inoculated screws (cefazolin: 30 mg/kg; s.c., b.i.d. plus rifampin: 25 mg/kg; s.c., b.i.d.). Bone histomorphometric changes were monitored using longitudinal microCT scanning, performed postoperatively, and at 3, 6, 9, 14, 20 and 28 days (euthanasia). Quantitative bacteriology of the implant, bone and overlying soft tissue was performed to assess infection status of individual animals.


M. D. Luca A. Materazzi A. Klatt D. Bottai A. Tavanti A. Trampuz

Aim

To investigate the ability of the bacteriophage Sb-1 to treat and prevent implant-associated infections due to methicillin-resistant Staphylococcus aureus (MRSA) in Galleria mellonella larvae implanted with a K-wire.

Method

The stability of Sb-1 in G. mellonella larvae was investigated by injecting a phage titer of 108 PFU and evaluating the presence of Sb-1 in hemolymph at different time points. For infection experiments, sterile stainless-steel K-wires (4 mm, 0.6 mm Ø) were implanted into larvae. Two days after implant, larvae were infected with MRSA ATCC 43300 (1×105 CFU) and incubated at 37°C for further 2 days. Implanted-infected larvae were thus treated for 2 days (3×/day) with 10µL of: i) PBS; ii) Sb-1 (107 PFU); iii) Daptomycin (4mg/kg), iv) PBS (24h)/Daptomycin(24h); v) Sb-1(24h)/Daptomycin(24h). To evaluate the prophylactic efficacy of Sb-1, an experiment based on phages or vancomycin (10mg/kg) administration, followed by MRSA infection of implanted larvae was performed. Both two days post-infection and post-treatment, K-wires were explanted, and the material was sonicated and plated for MRSA colony counting.


H. Freischmidt N. Titze C. Rothhaas T. Gühring G. Reiter P. A. Grützner L. Helbig

Aim

Treatment of infected and non-infected non-unions remain a major challenge after orthopedic fracture-related surgery. In clinical practice, several revision surgeries are usually required, including a radical debridement and exchange of implants, to control or even eradicate the infection to finally achieve bone healing. However, a clear treatment algorithm in clinical practice may be difficult to follow due to the heterogeneous patient population. Thus, so controlled settings for research purposes is better achieved in standardized animal studies.

So far, there exists no multi-stage animal model that can be realistically transferred to the clinical situation in humans. The importance of such a model is obvious in order to be able to investigate different therapy concepts for infected and non-infected non unions.

Methods

In 20 female Sprague-Dawley rats, a critical size defect by a femur osteotomy with 5 mm width was done. The periosteum at the fracture zone was cauterized proximal and distal to the osteotomy to achieve an hypovascularized situation. After randomization, 10 animals were intramedullary infected with a multisensible Staph. aureus strain (103 CFU). After 5 weeks, a second surgery was performed with removing the K-wire, debridement of the osteotomy-gap and re-osteosynthesis with an angle-stable plate. After further 8 weeks all rats were euthanized and underwent biomechanical testing to evaluate bone consolidation or delayed union, respectively. Additional micro-CT analysis, histological, and histomorphometric analysis were done to evaluate bone consolidation or delayed union, respectively, by the score of Lane and Sandhu and to quantify callus formation and the mineralized area of the callus.


H. Langvatn J. C. Schrama L. B. Engesæter G. Hallan O. Furnes E. Lingaas G. Walenkamp H. Dale

Aim

The aim of this study was to assess the influence of the true operating room (OR) ventilation on the risk of revision due to infection after primary total hip arthroplasty (THA) reported to the Norwegian Arthroplasty Register (NAR).

Method

40 orthopedic units were included during the period 2005 – 2015. The Unidirectional airflow (UDAF) systems were subdivided into small-area, low-volume, vertical UDAF (lvUDAF) (volume flow rate (VFR) (m3/hour) <=10,000 and diffuser array size (DAS) (m2) <=10); large-area, high-volume, vertical UDAF (hvUDAF) (VFR >=10,000 and DAS >=10) and Horizontal UDAF (H-UDAF). The systems were compared to conventional, turbulent ventilation (CV) systems. The association between revision due to infection and OR ventilation was assessed using Cox regression models, with adjustments for sex, age, indication for surgery, ASA-classification, method of fixation, modularity of the components, duration of surgery, in addition to year of primary THA. All included THAs received systemic, antibiotic prophylaxis.


H. Scheper J. Verhagen A. de Visser R. van der Wal J. Wubbolts L. G. Visser M. G. J. D. Boer P. H. Nibbering

Aims

Prosthetic joint infection (PJI) remains the most severe complication of arthroplasty. Failure of intensive, long-term antibiotic treatment for PJI often requires removal of the implant. Antibiotic failure is thought to be caused by biofilm and persister formation. Novel anti-biofilm and anti-persister strategies are urgently needed. Here, we investigated the effects of several antimicrobial peptides on the bacteria within antibiotic-treated biofilms in an in vitro mature biofilm model on abiotic surfaces.

Methods

On polystyrene, a mature (7 day-old) methicillin-resistant Staphylococcus aureus (MRSA) biofilm was developed. Thereafter, bacteria in the biofilm were exposed to rifampicin and ciprofloxacin (both 10× >MIC) for three days. Surviving bacteria in the antibiotic-treated biofilm, presumed to include persisters, were exposed to increasing doses of the antimicrobial peptides SAAP-148, acyldepsipeptide 4 (ADEP4), LL-37 and pexiganan. SAAP-148 was further tested on antibiotic-treated mature biofilms on titanium/aluminium/niobium (TAN) discs and prosthetic joint liners.


I. K. Sigmund M. Morgenstern M. Dudareva N. Athanasou M. McNally

Background

Preoperative diagnosis of fracture related infections can be challenging, especially when confirmatory criteria such as sinus tract and purulent discharge are absent. Although serum parameters, such as CRP and white blood cell count (WBC), showed poor accuracy in the literature, they are still often used in clinical practice. The European Bone and Joint Infection Society (EBJIS) defined evidence-based criteria for fracture related infection. Elevated serum inflammatory markers were regarded as suggestive criteria only, as the literature was of limited quality. This study assessed the diagnostic value of the serum parameters CRP, WBC and differential cell count in the diagnosis of fracture related infections defined by the EBJIS-criteria for fracture related infections.

Methods

In this retrospective cohort study, 94 patients who underwent surgical treatment for suspected infected non unions after failed fracture fixation were included. Preoperatively, blood samples including serum inflammatory markers were taken. For this study, cut-offs of 5 mg/L for CRP, 10×10⁁9 cells/L for WBC, and >70% for the percentage of neutrophils were regarded as positive for infection. All patients had intraoperative samples taken for microbiology and histology. Analysis of diagnostic accuracy was based on the receiver-operating characteristic (ROC).


L. K. Jensen N. L. Henriksen S. A. Blirup H. E. Jensen

Aim

To conduct a systematic review of non-rodent animal models (rabbit, pig, dog, goat and sheep) of bone infection. In the future, anti-infective technologies aiming to fight bone infections are depending on evaluation in reliable animal models. Therefore, it is highly relevant to evaluate the scientific quality of existing bone infection models.

Method

PubMed and Web of Science were searched systematically. To be included in the systematic review, publications had to deal with bacterial inoculation of non-rodent animals in order to model bone infections in humans. Data was extracted on study design e.g. bacterial inoculation dose and infection time, methodological quality and post-mortem evaluation with respect to registration and quantification of pathology and microbiology.


M. Honkanen E. Jämsen M. Karppelin R. Huttunen A. Eskelinen J. Syrjänen

Aim

The risk for developing a periprosthetic joint infection (PJI) as a consequence of bacteremia is not clear, except for Staphylococcus aureus bacteremia, and patient-related risk factors for it are not known. The aim of this study was to investigate the risk for developing a PJI during any bacteremia and to find out possible risk factors leading to it.

Method

All patients with a primary knee or hip joint replacement performed between September 2002 and December 2013 in a tertiary care hospital (n=14 378) were retrospectively followed up until December 2014. The mean follow-up time was 6.0 years (range 0–12 years). Positive blood culture results of the patients during the study period were obtained. PJIs during the study period were identified from several data sources. PJIs as a consequence of bacteremia were recorded and confirmed from patient records. Primary PJIs resulting in bacteremia were excluded. Binary logistic regression with univariate analysis was used to study potential risk factors for PJI among those with bacteremia.


A. Meinshausen N. Märtens S. Illiger P. Macor J. Färber C. H. Lohmann J. Bertrand

Aim

Low-grade infections cannot be easily distinguished from aseptic complications frequently leading to false negative diagnoses and late onset of anti-bacterial therapy. Therefore, there is a great need to establish biomarkers for early detection of low-grade infections.

Method

In this study, we focused on the investigation of anti-α-defensin, anti-C3, anti-C5 and anti-C9 as potential biomarkers for infection in a cohort of hip and knee septic revision cases, taking patient characteristics and comorbidities into account. Here we included 78 patients with septic (35) and aseptic (43) (woman:37, men:42, age 50 – 93 years) revision surgeries of hip and knee. CRP serum levels and leucocyte blood values were evaluated. Patient characteristics, including age, number of prior revision surgeries and comorbidities were recorded. Periprosthetic tissue was stained histologically with Hematoxylin/Eosin and immunohistologically with different antibodies.