Aim

Late acute prosthetic joint infections (PJI) treated with surgical debridement and implant retention (DAIR) have a high failure rate. The aim of our study was to evaluate treatment outcome in late acute PJIs treated with DAIR versus implant removal.

Method

In a large multicenter study, late acute PJIs were retrospectively evaluated. Failure was defined as: PJI related death or the need for prosthesis removal or suppressive antibiotic therapy because of persistent or recurrent signs of infection. Late acute PJI was defined as < 3 weeks of symptoms more than 3 months after the index surgery.

Aim

Prosthetic Joint Infection (PJI) remains one of the leading cause for revision arthroplasty.^1,2 Early recognition and appropriate initial treatment of early PJI with debridement, antibiotics and implant retention (DAIR) can eradicate infection on first attempt and prevent implant failure. We evaluated the outcome after one year of patients who were treated for an early PJI after primary total knee arthroplasty (TKA) or total hip arthroplasty (THA) with DAIR. Furthermore, we determined preoperative infection markers, microbiology, and treatment factors related to treatment failure after DAIR procedure.

Method

A retrospective cohort study was assembled with 91 patients undergoing DAIR after primary TKA or THP with a high suspicion of an early PJI. For all patients intraoperative cultures were obtained. Records were reviewed for demographic details, preoperative laboratory results, microbiological data, given treatment and postoperative follow-up. The primary outcome measure was infection-free implant survival at one year. Repeated DAIR was not considered as treatment failure.

Aim

Debridement, antibiotics and implant retention (DAIR) is a widely used treatment modality for early acute prosthetic joint infection (PJI). A preoperative risk score was previously designed for predicting DAIR failure, consisting of chronic renal failure (K), liver cirrhosis (L), index surgery (I), cemented prosthesis (C) and C-reactive protein >115mg/L (KLIC). The aim of this study was to validate the KLIC score in an external cohort.

Method

We retrospectively evaluated patients with early acute PJI treated with DAIR between 2006 and 2016 in three Dutch hospitals. Early acute PJI was defined as less than 21 days of symptoms and DAIR performed within 90 days after index surgery. Failure was defined as the need for 1) second DAIR, 2) implant removal, 3) suppressive antimicrobial treatment or 4) infection-related death within 60 days after debridement.

Aim

S. aureus and coagulase-negative staphylococci are the most frequent bacteria responsible for PJI. In patients with acute PJI (i.e. <1 month following the implantation), DAIR with exchange of removal components followed by a combination of antibiotics that includes rifampin (particularly rifampin+fluoroquinolone) are recommended. Unfortunately, some patients could not receive rifampin due to drug-drug interaction or stopped it due to an adverse event. Finally, it was unclear if the dose and the duration of rifampin influenced the prognosis.

Method

We performed a retrospective cohort study in 4 hospitals and included patients with staphylococcal acute post-operative (< 1 month) PJI treated with DAIR in 2011–2016 period. Univariate and multivariate Cox analysis and Kaplan Meier curves were used to determine the risk factors for treatment failure (persistence of clinical signs, new surgery w/o persistence or superinfection, infection-related death).

Aim

There is a theoretical advantage for immediate postoperative start of rifampicin after debridement, antibiotics and implant retention (DAIR). Anti-biofilm treatment may be mostly needed during the first postoperative days in order to prevent new biofilm formation. However, there are concerns with regard to development of rifampicin resistance if rifampicin is started too early. Rifampicin monotherapy will rapidly result in rifampicin resistance, but this may not occur when prescribed as part of combination antimicrobial therapy and after thorough surgical debridement. We hypothesized that in this setting the probability of development of rifampicin resistance is very low. We evaluated the frequency of development of rifampicin resistance in patients with acute staphylococcal PJI who were treated with DAIR followed by immediate postoperative start of rifampicin in combination with a betalactam or glycopeptide.

Method

During 2003–2014, all patients with an acute staphylococcal PJI were treated with five days of high-dose rifampicin (600mg bid) in combination with at least 6 weeks of betalactam or glycopeptide antibiotics, both started immediately postoperative after DAIR. Clinical outcome and development of rifampicin resistance in patients who failed were monitored. Susceptibility testing for rifampicin was performed by Vitek 2 (Biomerieux). Until 2014, Clinical and Laboratory Standards Institute (CLSI) criteria for rifampicin resistance were applied (S ≤ 1), from 2014 EUCAST criteria (S ≤ 0.06) were applied.

Aim

Diagnosing or excluding a chronic prosthetic joint infection (PJI) prior to revision surgery can be a clinical challenge. To enhance accuracy of diagnosis, several biomarkers were introduced in recent years, but most are either expensive or not available as a rapid test. We compared the diagnostic accuracy of leucocyte esterase (€0.20 per sample), calprotectin (€20 per sample) and alpha defensin (€200 per sample).

Method

We prospectively evaluated PJI patients with chronic pain with or without prosthetic loosening between 2017 and 2018. Synovial fluid was collected prior to revision surgery. Leucocyte esterase was measured using a reagent strip (2+ considered as positive), and calprotectin and alpha defensin were measured using a lateral flow immunoassay. Intraoperative cultures (5 periprosthetic tissue samples, synovial fluid and sonication fluid) incubated for 9 days, were used as gold standard. At least two positive cultures of low-grade microorganisms with the same antibiogram were required to diagnose PJI.

Aim

Revision surgery and debridement and implant retention are recognised approaches for managing prosthetic joint infections (PJI) but may not always be indicated. If the patient is unable to have or declines surgery, prolonged suppressive antibiotic therapy (PSAT) is an option. This study aims to define outcomes of PSAT from a single unit.

Method

A retrospective study was performed. All cases of PJI involving the hip or knee between 2012 and 2017 were identified from our institutional database and cross referenced with patient notes. One hundred and seventy eight cases were identified. Of these, 23 (12.9%) (10 hips, 13 knees) were treated with PSAT. Infection was diagnosed based on the MSIS criteria in all cases and all cases were managed by a multidisciplinary team which included specialist microbiologists.

One case of long term antifungal therapy was additionally identified. Co-morbidity was assessed using the Charlson co-morbidity index.

Exacerbations of infection and need for further surgery were recorded.

Aim

Dexamethasone is often used as part of multimodal analgesia to prevent postoperative nausea and vomiting (PONV) and also to reduce postoperative pain. Because glucocorticoids have immunosuppressive and glucose-rising effects, the aim of current study was to examine if dexamethasone may be used safely in arthroplasty surgery.

Methods

All consecutive total primary and revision hip and knee arthroplasties performed in the Hospital District of Helsinki and Uusimaa, Peijas Hospital were analyzed (n=18 872). Emergency operations, for example total hip arthroplasties for femur fractures, were also included. Prospective surveillance for postoperative infections was performed. All infections meeting the Musculoskeletal Infection Society definition for prosthetic joint infection (PJI) were included.

Aim

Virulent bacteriophages are known to be an effective therapy against various human bacterial infections. The aims of the study are to evaluate i) the killing activity of an antistaphylococcal phage lysate (ASPL), available in the Czech Republic for topical application, against Staphylococcal aureus (Sa) strains isolated in orthopedic infections; ii) the antimicrobial activity of ASPL against biofilm-embedded cells of a methicillin-resistant Sa (MRSA) standard strain.

Method

The susceptibility of 25 MRSA and 18 methicillin-sensitive Sa (MSSA) strains to the ASPL was evaluated by spot assay. In addition, susceptibility of four laboratory MRSA strains, including ATCC 43300, ATCC 33591, Mu3 (MRSA/hetero vancomycin intermediate resistant Sa) and Mu50 (MRSA/vancomycin-resistant Sa) was also tested. The activity of ASPL against planktonic and biofilm-embedded MRSA ATCC 43300 was evaluated in real-time by isothermal microcalorimetry. The minimum heat inhibitory concentrations (MHIC) was defined as the lowest antimicrobial concentration leading to the lack of heat flow production after 24h for both planktonic and biofilm-embedded cells. The viability of bacterial cells was assessed by plating and colony counting. The minimum bactericidal concentration (MBC) was defined as the lowest antimicrobial concentration leading the reduction of 3 log CFU compared to the untreated control.

Aim

Treatment of enterococcal periprosthetic joint infections (PJI) is challenging due to heterogeneous pathogenesis, non-standardized management strategies and lack of biofilm-active antibiotics. Previous studies report treatment success from 50–76%. We evaluated the characteristics and outcome of enterococcal PJI, in particular the influence of antimicrobial treatment regimens.

Method

Consecutive patients with enterococcal PJI treated at two specialized orthopaedic institutions were retrospectively included from 2010 to 2017. PJI was defined by the proposed European Bone and Joint Infection Society (EBJIS) criteria. Adequate antimicrobial treatment was considered when the antibiotic was appropiate for the treatment of enterococcal bone infections (activity, dose, oral bioavailability, bone penetration). The treatment success (defined as no relapse of enteroccal infection) and clinical success(i.e. infection-free status) was evaluated and compared using Fishers exact test.

Aim

The B.A.C.H. system is a new classification for long bone osteomyelitis. It uses the four key inter-disciplinary components of osteomyelitis, namely, bone involvement, anti-microbial options, soft tissue status and host status. This study aims to assess the inter-user reliability of using the B.A.C.H. classification system.

Method

We identified 20 patients who had a diagnosis of long bone osteomyelitis using a previously validated composite protocol. For each patient, osteomyelitis history, past-medical history, clinical imaging (including radiology report), photographs of the affected limb and microbiology were presented to clinical observers on an online form. Thirty observers, varying in clinical experience (training grades and consultants, with a variety of exposure to osteomyelitis) and specialty (orthopaedic surgery, infectious diseases and plastic surgery) were asked to rate the twenty cases of osteomyelitis. Before rating, an explanation of how to use the classification system was given to the observers, in a structured ‘user key’. The responses were assessed by accuracy against a reference value and Fleiss' kappa value (Fκ).

Aim

Determine the incidence of surgical site infections (SSI) after intramedullary nailing (IN) of femoral and tibial diaphyseal fractures and evaluate possible risk factors.

Method

Prospective observational cohort study. SSI was defined according to CDC-NHSN criteria and surveillance period for the occurrence of infection was 12 months instead of the 90 days currently recommended. Incidence was calculated as the ratio between the number of patients with SSI and total number of patients. Analysis of potential risk factors included patients-related factors (age, gender, body mass index, active foci of infection, immunosuppressive conditions, ASA score, alcohol or illicit drug abuse, smoking, polytrauma, etiology of fracture, type of fracture if closed or open, classification of fracture according to Müller AO, Tcherne classification for closed fractures, Gustilo-Anderson classification and duration of bone exposure for open fractures, previous stay in other healthcare services, use of external fixator, previous surgical manipulation at same topography of fracture, use of blood products); environmental and surgical-related factors (surgical wound classification, duration of surgery, hair removal, intraoperative contamination, antimicrobial use, presence of drains, hypothermia or hypoxia in the perioperative period, type of IN used, reaming, need for muscle or skin flap repair, use of negative pressure therapy) and microbiota-related factors (presence of preoperative colonization by Staphylococcus aureus or Acinetobacter baumannii).

Aim

The incidence of deep infections after internal fixation of ankle and lower leg fractures is estimated 1 to 2%. Hindfoot arthrodesis by retrograde intramedullary nailing (IMN) is a potential alternative to external fixation for post-infectious ankle destruction. The aim of this study was to evaluate the clinical results, complications and effects of soft tissue management with this treatment modality.

Method

This is a single-center retrospective review of routine hospital data from 21 patients (15 men, 6 women, median age 65 [range, 21 to 87] years) undergoing IMN arthrodesis of the hindfoot for post-traumatic infections between January 1st, 2012 and March 15, 2018. We observed four bimalleolar, eight trimalleolar, three pilon fractures, and six distal lower leg fractures. Six and three patients had sustained second- and third degree open fractures, respectively. Early- and late-onset surgical infections were observed in 8 and 13 cases. Four participants had diabetes mellitus, two arterial occlusive disease, and four had both. Six patients were smokers.

Aim

Fracture-related infection (FRI) is an important complication following surgical fracture management. Key to successful treatment is an accurate diagnosis. To this end, microbiological identification remains the gold standard. Although a structured approach towards sampling specimens for microbiology seems logical, there is no consensus on a culture protocol for FRI. The aim of this study is to evaluate the effect of a structured microbiology sampling protocol for fracture-related infections compared to ad-hoc culture sampling.

Method

We conducted a pre-/post-implementation cohort study that compared the effects of implementation of a structured FRI sampling protocol. The protocol included strict criteria for sampling and interpretation of tissue cultures for microbiology. All intraoperative samples from suspected or confirmed FRI were compared for culture results. Adherence to the protocol was described for the post-implementation cohort.

Aim

Current guidelines for the diagnosis of prosthetic joint infection (PJI) recommend collecting 4–5 independent tissue specimens, with isolation of indistinguishable organisms from two or more specimens. The same principle has been applied to other orthopaedic device-related infections (DRI) including fracture-related infections. However there are few published data validating this approach in DRI other than PJI. We evaluated the performance of different diagnostic cutoffs and varying numbers of tissue specimens for microbiological sampling in fracture-related infections.

Method

We used standard protocols for tissue sample collection and laboratory processing, and a standard clinical definition of fracture-related infection. We explored how tissue culture sensitivity and specificity varied with the number of tissue specimens obtained; and with the number of specimens from which an identical isolate was required (diagnostic cutoff). To model the effect of the number of specimens taken we randomly sampled n specimens from those obtained at each procedure, excluding procedures from which less than n specimens were collected, and calculated sensitivity and specificity based on this sample. For each value of n we repeated this process 100 times to estimate the mean sensitivity and specificity for n specimens.

Aim

Duration of perioperative antimicrobial prophylaxis (PAP) remains controversial in prevention of fracture-related infection (FRI) – with rates up to 30% - in open fracture (OF) management. Objectives were to investigate the impact of the PAP duration exclusively in or related to long bone OF trauma patients and the influence of augmented renal clearance (ARC), a known phenomenon in trauma patients, as PAP consists of predominantly renally eliminated antibiotics.

Method

Trauma patients with operatively treated OF, admitted between January 2003 and January 2017 at the University Hospitals Leuven, were retrospectively evaluated. FRI was defined following the criteria of the consensus definition of FRI. A logistic regression model was conducted with FRI as outcome. Results were considered statistically significant when p< 0.05.

Aim

Prosthetic joint infections (PJI) are devastating complications after hip arthroplasty and infection rates varies internationally between 0.76% to 1.24%. Hemi-arthroplasty (HA) is the gold standard treatment for dislocated femoral neck fractures. Recently, total hip arthroplasty (THA) has been suggested to generate even better outcomes. However, little is known about PJIs after hip fractures. The purpose of this study was to investigate PJIs after femoral neck fracture in a population-based sample.

Methods

Clinical databases were harvested for all THA or HA procedures done for the treatment of femoral neck fractures at our hospital district (HUS) of 1.6 million inhabitants. Altogether, 3693 arthroplasty procedures for hip fractures were performed between 2011 to 2015. The original patient records of each case were reviewed. Complication(s) leading to readmission(s), the microbe(s), and the treatment protocol of each infection was recorded until the closing date (31.12.2016). The definition of PJI according to Musculosceletal Infection Society modified at the International Consensus meeting was used.

Aim

The purpose of this study was to report on outcomes after stabilization of large skeletal defects following radical debridement of hip or knee infections and staged reimplantation using segmental antibiotic mega-spacers.

Method

From 1998–2018, 39 patients (18 male, 21 female) were treated for musculoskeletal infections at the hip (14) or knee (25). Patients were treated for infection after a procedure related to oncology (20), arthroplasty (16), or trauma (3). Following debridement, defects were stabilized with antibiotic impregnated PMMA and intramedullary nails. All patients underwent a standardized protocol: 6 weeks of intravenous antibiotics followed by 6 weeks of oral antibiotics guided by intraoperative cultures. After a 6-week holiday of antibiotics, repeat intraoperative cultures and inflammatory markers were analysed for infection resolution. Success was defined by reimplantation without additional infection-related complications or requirement of suppressive antibiotics at latest follow-up.

Background

Periprosthetic joint infection (PJI) after knee arthroplasty surgery remains a serious complication. Yet, there is no international consensus on the surgical treatment of PJI. The purpose was to assess the prosthesis survival rates, risk of re-revision, and mortality rate following the different surgical strategies (1-stage or 2-stage implant revision, and irrigation and debridement (IAD) with implant retention) used to treat PJI.

Methods

The study was based on 653 total knee arthroplasties (TKAs) revised due to PJI in the period 1994 to 2016. Kaplan-Meier (KM) and multiple Cox regression analyses were performed to assess the survival rate of these revisions and the risk of re-revisions. We also studied the mortality rates at 90 days and 1 year after revision for PJI.

Aim

Radiologic signs such as radiolucent lines around the implant, hardware fracture or displacement and periosteal reaction have been considered suggestive of implant-associated infection. The goal of this study is to assess the correlation of these signs with confirmed internal fixation-associated infection evaluated in a prospective cohort.

Method

We evaluated the radiologic appearance of preoperative standard x-ray images in 421 surgeries performed in 380 patients with internal fixation device in place (56.8% male, mean age 53 ± 17 years). This prospective study was performed in a large single center for musculoskeletal surgery from 2013–2017. Infection was suspected preoperatively in only 23.8% of the surgeries. The most common indications for surgeries in which infection was not suspected were nonunion (84 cases) and symptomatic hardware (57 cases). All removed implants were sent to sonication for biofilm removal and detection. In addition, several peri-implant tissue samples were collected. Radiographs were analyzed in a blinded fashion for signs of radiolucent lines around the implant before removal, hardware fracture or displacement, and soft periosteal reactions suggestive of infection. Diagnosis was established according to the IDSA criteria for PJI. Contingency tables were constructed to determine sensitivity and specificity, and to perform Chi-square tests to compare the presence of infection with radiological signs of infection.

Aim

A number of orthopaedic strategies have been described for limb salvage following periprosethic joint infection (PJI). However, this is often only possible with concomitant soft tissue reconstruction in the form of flap coverage. The purpose of this study was to determine the long-term clinical outcome of patients who underwent pedicled gastrocnemius flap coverage as part of their treatment for knee PJI.

Method

We performed a retrospective review of all patients undergoing gastrocnemius muscle transfer with split thickness skin grafting as part of their treatment for knee PJI at a tertiary referral centre between 1994 and 2015. Data recorded included patient characteristics, orthopaedic procedure, microbiology result and antimicrobial management. Outcome measures included flap failure, infection recurrence, amputation, functional outcome (Oxford knee score; OKS) and mortality.

Aim

Simultaneous use of Ilizarov techniques with transfer of free muscle flaps is not current standard practice. This may be due to concerns about duration of surgery, clearance of infection, potential flap failure or coordination of surgical teams. We investigated this combined technique in a consecutive series of complex tibial infections.

Method

A single centre, consecutive series of 45 patients (mean age 48 years; range 19–85) were treated with a single stage operation to apply an Ilizarov frame for bone reconstruction and a free muscle flap for soft-tissue cover.

All patients had a segmental bone defect in the tibia, after excision of infected bone and soft-tissue defects which could not be closed directly or with local flaps. We recorded comorbidities, Cierny-Mader and Weber-Cech classification, the Ilizarov method used, flap type, follow-up duration, time to union and complications.

Aim

Soft tissue defects of the lower leg can be closed - following the reconstructive ladder - with a pediculated fasciocutaneous suralis flap, but a free flap is gold standard in most of the cases. Aim of the study was to evaluate complications, risk factors for failure and the reasonableness of this procedure.

Method

91 patients (92 flaps, 70 males, 21 females) with a mean Age of 55 years (16 to 87) were included in the study. The patients had mean four surgical procedures before the flap, the follow-up was mean 407 days. 70 patients were classified ASA I or ASA II.

Aim

Infection rates after management of open fractures are still high. Existing guidelines regarding prevention of this complication are inhomogeneous. A survey directed to orthopaedic trauma surgeons worldwide aims to give an overview of current practices in the management of open fractures.

Method

An international group of trauma surgeons and infection specialists with experience in the field of musculoskeletal infections developed a questionnaire that was distributed via email to all AOTrauma members worldwide. Descriptive statistical analysis was performed.

Aim

The aim of this systematic review was to determine the reported treatment strategies, their individual success rates, and other outcome parameters in the management of critical-sized bone defects in Fracture-Related Infection (FRI) patients between 1990 and 2018.

Method

We performed a systematic literature search on treatment and outcome of critical-sized bone defects in FRI. Treatment strategies identified were, autologous cancellous grafts, autologous cancellous grafts combined with local antibiotics, the induced membrane technique, vascularized grafts, bone transport, and bone transport combined with local antibiotics. Studies describing bone defects of 1 cm or greater were included. Outcomes were bone healing and infection eradication after primary surgical protocol and recurrence of FRI and amputations at the end of study period.

Aim

Infected segmental defects are one of the most feared complications of open tibial fractures. This may be due to prolonged treatment time, permanent functional deficits and high reinfection and non-union rates. Distraction osteogenesis techniques such as Ilizarov acute shortening with bifocal relengthening (ASR) and bone transport (BT) are effective surgical treatment options in the tibia. The aim of this study was to compare ASL with bone transport in a consecutive series of complex tibial infected non-unions and osteomyelitis, for the reconstruction of segmental defects created at surgical resection of the infection.

Method

In this single centre series, all patients with a segmental defect (>2cm) of the tibia after excision of infected non-union or osteomyelitis were eligible for inclusion. Based on clinical features, bone reconstruction was achieved with either ASR or BT using an Ilizarov fixator. We recorded the external fixation time (months), the external fixation index (EFI), comorbidities, Cierny-Mader or Weber-Cech classification, follow-up duration, time to union, number of operations and complications.

Aim

Orthopedic implant related surgical site infection (SSI) is a severe complication which represents an important challenge concerning to its treatment. Therefore, gram-negative orthopedic infections have recently become a global concern.

Method

Retrospective study through searching of the SCIH (infection control service) database, concerning to the year 2016 and 2017. Cases selected were those of implant placement clean surgeries (osteosynthesis or prosthetic placement) which evolved with SSI and Gram-negative bacterial growth in bone tissue or periprosthetic cultures.

Aim

Surgical site infections caused by Staphylococcus aureus (S. aureus) are associated with considerable clinical and economic burden. Studies assessing this burden in Germany have been limited to specific institutions, selected patient groups or not specific to S. aureus infections (SAI). This study was undertaken to further understand the burden of SAI following orthopedic surgeries in Germany.

Method

All patients with at least one spine, endoprosthetic hip or knee surgery between 2012 and 2015 captured in the AOK PLUS claims database were included in this analysis. SAI were identified using S. aureus-specific ICD-10 codes following surgery. Exclusion criteria included: younger than 18, SAI in the 90 days preceding index, any surgery in the 180 days preceding index, surgery at the same body location as index in the preceding 365 days, or more than one surgery of interest during index hospitalization.

Cumulative incidence and incidence density were used to assess SAI. Mortality, healthcare resource utilization and costs were compared between SAI and non-SAI group during the 1year follow-up post index surgery. Multivariate analyses were conducted while controlling for sex, age, Charlson Comorbidity Index (CCI), location of surgery, length of index hospitalization, recent fractures, other bacterial infections during index hospitalization and outpatient prescriptions for antibiotics in the year pre-index.

Aim

Spinal implant-associated infections (SIAI) require combined surgical and antimicrobial treatment and prolonged hospital stay. We evaluated the clinical, laboratory, microbiological and radiological characteristics and treatment approaches in patients with SIAI.

Method

Consecutive adult patients with SIAI treated between 2015 and 2017 were prosepctively included. SIAI was defined by: (i) significant microbial growth from intraoperative tissue or sonication fluid, (ii) intraoperative purulence, secondary wound dehiscence or implant on view, (iii) radiographic evidence of infection and fever (>38°C) without other recognized cause, increasing back pain or neurologic impairment, (iv) peri-implant tissue inflammation in histopathology.

Aim

Data of optimal management of infections after internal fixation (IIF) is scarce and long-term follow-up results often lack. We analyzed characteristics of infections after intramedullary (IIIF) and extramedullary long bone fixation (IEIF) and evaluated their infection and functional outcome.

Method

Consecutive patients with IIF diagnosed at our institution from 01/2010-10/2017 were retrospectively included. Infection was defined as visible purulence, sinus tract, microbial growth in ≥2 independent samples or positive histopathology. The outcome was compared before and after implementation of a comprehensive surgical and antimicrobial treatment algorithm in 04/2013.

Aim

The aim of our study was to identify pathogens involved in septic knee arthritis after ACLR and to describe clinical features, treatment and outcome of infected patients.

Methods

We conducted a retrospective observational study including all patients with ACLR infection in 3 orthopedic centers sharing the same infectious disease specialists.

Aim

Cutibacterium acnes is involved in chronic/low-grade pathologies such as prosthetic joint infection (PJI) or sarcoidosis. During these diseases, granulomatous structures are frequently observed. In this study, we induced a physiological granulomatous reaction in response to different well-characterized clinical C. acnes isolates in order to investigate the cellular process during the granulomatous formation.

Method

An acne C. acnes ATCC6919 isolate (clonal complex (CC) 18, phylotype IA1), a PJI C. acnes BL clinical isolate (CC36, phylotype IB) and a sarcoidosis C. acnes S8 strain (CC28, phylotype IA₂) were included and co-culture with PBMC. Cellular aggregation was followed daily using light microscopy. At various time points of incubation (day 3 and day 7), granuloma structures were processed for microscopic observation, colony forming unit enumeration after Triton ×100 lysis to release the internalized bacteria (bacterial load within the granulomas), as well as for flow cytometric analysis (detection of CD4, CD8 and NK lymphocytes).

Aim

A two-stage exchange of an infected prosthetic joint (PJI) is considered the most effective surgical treatment of chronic PJIs, particularly in North America. However, reinfection rates are unacceptably high (10–20%). This could be the consequence of a persistent infection or a new infection introduced during the first or second stage of the exchange arthroplasty. We aimed to determine: i) the prevalence of positive cultures at reimplantation, ii) whether there is an association between positive cultures at reimplantation and reinfection during follow-up, and iii) if there is a microbiological correlation between primary infections, reimplantations and reinfections.

Method

We retrospectively evaluated all two-stage exchange procedures performed at two academic centers between 2000 and 2015. Primary culture-negative PJIs and cases in whom no intraoperative cultures were obtained during reimplantation were excluded from the analysis. One or more positive intraoperative cultures during reimplantation were considered positive for infection. Reinfection was defined as the need for additional surgical intervention after reimplantation or the need for antibiotic suppressive therapy due to persistent clinical signs of infection.

Aim

Aseptic loosening is the leading cause of revision of total hip arthroplasty (THA). It is well recognized that an occult infection is the underlying cause of some aseptic revisions. Intraoperative cultures are central to the diagnosis of prosthetic joint infection (PJI). However, the diagnostic and prognostic value of unexpected positive intraoperative cultures remains unclear.

The aim was to study whether first-time aseptic revision of a total hip arthroplasty with unexpected bacterial growth in cultures of intraoperatively taken biopsies have an increased risk of secondary revision due to all causes and increased risk of PJI revision, specifically.

Method

Cases reported as first-time aseptic loosening revisions to the Danish Hip Arthroplasty Register (DHR) performed during January 1^st, 2010, to May 15^th, 2016, were included.

DHR data were merged with the Danish Microbiology Database, which contains data from all intraoperatively obtained cultures in Denmark. Included first-time revisions were grouped based on the number of positive cultures growing the same bacteria genus: ≥2, 1 and 0 cultures. Revisions were followed until secondary revision, death, or end of follow-up period after one year. Relative risk for secondary revision due to all causes and PJI was estimated.

Aim

To assess the analytical performance and to establish the cut-off of synovial fluid D-lactate concentration for the diagnosis of prosthetic joint infection (PJI) and septic arthritis (SA) using commercial kits provided by two manufacturers (A and B).

Method

We prospectively included patients with native or prosthetic joints undergoing synovial fluid aspiration as routine diagnostic procedure. Among 224 patients with prosthetic joints, 137 patients had aseptic loosening (AL) and 87 were diagnosed with PJI. Among 71 patients with native joints, 39 were diagnosed with osteoarthrosis (OA) and 32 with SA.

Aim

To assess the effectiveness of role of frozen section in revision arthroplasty.

Method

21 patients with infected hip arthroplasties were operated in the form of one or two-staged revision hip arthroplasties. A frozen section was obtained intra-operatively and >5 PMN's/ HPF was considered as a positive indicator of infection. Fig 1 llustrating frozen section image. If the frozen section was reported negative (≤5 PMN's/HPF), the revision prosthesis was implanted after a thorough debridement and a wash. If the frozen section was reported as positive, after the debridement a non-articulating antibiotic loaded cement spacer was implanted for 8 weeks, supplemented with 3 weeks of intravenous antibiotics and 3 weeks of oral antibiotics. This was followed by an antibiotic free interval of 2 weeks. The patient was taken up for a revision surgery once the frozen section study was negative (≤5 PMN's/HPF). The patients were followed up for minimum of 1 year to a maximum of 2 years after the revision for any evidence of infection (assessed clinically and serologically, radiologically).

Aims

Microbiological diagnosis of bone and joint infections (BJIs) is pivotal. However, no consensus exists about the best choice for techniques to be used and the best indications for molecular methods. Our objectives were: (i) to compare the performance of various microbiological diagnostic methods (cultural and molecular) on synovial fluid specimens and (ii) to select an algorithm for optimizing the diagnosis of BJIs in adults.

Methods

This prospective multicentric study (in Lyon and Saint-Etienne, France) included 423 joint fluid samples, collected from 333 adult patients (median age 69 years) suspected for BJI on the basis of medical history and clinical symptoms. For each inclusion, joint fluid and blood culture were collected concomitantly. The synovial fluid was also inoculated into blood culture bottles. Cytology, culture (using 5 solid media and an enrichment broth, incubated for 15 days), universal 16S rRNA PCR and PCR targeting Staphylococcus spp, S.aureus, Streptococcus spp, S.pneumoniae, Kingella kingae, Borrelia burgdorferi and Propionibacterium acnes were systematically performed on synovial fluid.

Aim

What is the fate of revision total joint arthroplasty, when conventional tissue sample culture (TSC) is negative and sonication fluid culture (SFC) is positive, in terms of re-revision?

Method

We prospectively analyzed explanted prosthetic materials from 211 consecutive cases of total hip and knee arthroplasty revision surgery performed on any indication during a one year period. We used a sonication apparatus and protocol that was previously described [Borens et al, 2013. J Orthop Res]. Sampling of five periprosthetic tissue biopsies was performed according to the local protocol and incubated for 5 days. In our non-interventional study design, clinicians were blinded to the results from sonication-culture, which were not used for the subsequent treatment strategy.

In cases with suspected deep infection, thorough debridement was performed during revision surgery, and routine antibiotic treatment was dicloxacillin for 6–8 weeks. Patients were routinely seen in the outpatient clinic after 3 and 12 months, where clinical examination and any antibiotic treatment were documented. Minimum follow-up was 1 year. This cohort study is reported according to the STROBE guidelines.

Aim

Reveal the rate of surgical site infection (SSI) after primary hip and knee arthroplasty in patients with inflammatory joint disease and analyse if the infection rate was correlated to the given anti-rheumatic treatment. The background is that since 2006 patients operated at the orthopaedic department at Skåne University hospital, Lund, Sweden, have continued treatment with TNF-alpha inhibitors during the perioperative period.

Method

During 2006 to 2015 494 planned primary hip and knee arthroplasties were performed on 395 patients (236 hip arthroplasties and 239 knee arthroplasties). Data on age, sex, diagnosis, BMI, operation time, ASA-classification, treatment with cDMARDs (conventional disease modifying anti-rheumatic drugs) and bDMARDs (biological disease modifying antirheumatic drugs) and use of prednisolone was collected. The primary outcome variable was prosthetic joint infection (PJI) within 1 year from surgery with a secondary outcome variable being superficial SSI.

Aim

Obese patients are not only more likely to receive total joint arthroplasty, but are also more prone to postoperative complications. The most severe complication is a prosthetic joint infection (PJI), occurring two to four times more often in severely obese patients (BMI ≥ 35kg/m²) compared to non-obese patients. This higher risk for PJI may be attributed to higher glucose levels in case of diabetes mellitus, diminished wound healing or inadequate antibiotic prophylaxis. To ultimately improve the prevention measures for this specific patient category, we aimed to describe the clinical and microbiological characteristics of early acute PJI in severely obese patients.

Method

We retrospectively evaluated patients with early acute PJI of the hip and knee treated with DAIR between 2006 and 2016 in three Dutch hospitals. According to protocol, cefazolin was administered as antibiotic prophylaxis during arthroplasty and adjusted to bodyweight. PJI was diagnosed using the criteria described by the Musculoskeletal Infection Society. Early acute PJI was defined as less than 21 days of symptoms and a DAIR performed within 90 days after index surgery. Several clinical and microbiological variables were collected and analyzed. Severe obesity was defined as a BMI ≥ 35kg/m².

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 their management is still poorly standardized because of the lack of data from randomized trials. The aim of this retrospective study is to assess the infection eradication success rate, over the last ten years, using different patient adapted treatment options.

Method

Patients having a prosthetic-joint infection at Lausanne University Hospital (Switzerland) between 2006 and 2016 were included. The success rate depending on age, type of prosthesis, type of infection and type of surgical procedure was analyzed.

Aim

Bone loss is a severe problem in septic revision total knee arthroplasty (RTKA). The use of porous coated metaphyseal sleeves is a promising treatment option for extended bone defects. The currently published mid-term results remain limited and no study has been focused exclusively on septic cases. Our aim was to determine the implant survivorship (with special focus on osseointegration) and the clinical and radiological mid-term outcome of metaphyseal sleeve fixation in septic RTKA surgery (minimum follow-up of 2 years).

Method

Between January 2005 and September 2015, 57 patients underwent septic RTKA surgery using metaphyseal sleeves. In 56 patients (98,2 %) who underwent a total of 69 two stage revision procedures, clinical and radiological follow-up examinations were conducted. One patient (1,8 %) was lost to follow-up. The examinations included the American Knee Society Score (KSS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the SF-36 Health survey as well as radiographic measurement to determine if successful osseointegration had been achieved.

Aim

Early discharge of patients after joint arthroplasty leaves patients responsible for monitoring their postoperative wound by themselves. This might result in a delayed presentation of postoperative complications. The use of a mobile woundcare app by patients after arthroplasty might result in (1) earlier report of complications, (2) an increase in patient satisfaction and (3) insight in the incidence and duration of postoperative wound leakage. Therefore, the ease of use and perceived usefulness of using a postoperative mobile woundcare app in patients after joint arthroplasty was investigated.

Method

A cohort study was conducted in 2017 in 2 Dutch Hospitals. Eligible cases were all consecutive patients that received an arthroplasty and who owned a smartphone. During the first 30 postoperative days, patients filled in daily reviews of their wound and took a photo of the wound. Based on the review, an underlying algorithm calculated daily a score that prompted a mobile alert if needed, which advised patients to contact the hospital. Patients filled in a form on day 30 and day 90 in order to document occurrence of any postoperative wound complication. On day 15 and 30, patients were requested to fill in a questionnaire evaluating the perceived usefulness and the ease of use of the App.

Aim

In vivo studies have shown a preventive and curative effect of using an injectable vancomycin containing biphasic ceramic in an osteomyelitis model. No clinical long term pharmacokinetic release study has been reported. Inadequate concentration in target tissues results in treatment failure and selection pressure for antibiotic-resistant organisms.

Our hypothesis was that vancomycin in the first week would reach high local concentrations but with low systemic levels.

Method

9 patients (6 women, 3 men) with trochanteric hip fractures classified as A1 and A2 according to the AO-classification all had internal fixations. The mean age was 75.3 years (± S.D. 12.3 years, range 44–84y). An injectable ceramic with hydroxyapatite embedded in a calcium sulphate matrix containing 66mg vancomycin per mL augmented the fixation. A mean of 9.7 mL (± S.D. 0.7 mL, range 8–10mL) was used. The elution of vancomycin was followed by collecting drain fluid, blood (4 days) and urine (4 weeks)

Aim

The increasing incidence of orthopaedic methicillin-resistant Staphylococcus aureus (MRSA) infections represents a significant therapeutic challenge. Being effective against MRSA, the role of vancomycin may become more important in the orthopaedic setting in the years to come. Nonetheless, vancomycin bone and soft tissue penetration during infection remains unclear. We assessed the effect of a traumatically induced, implant-associated acute osteomyelitis on vancomycin bone penetration in a porcine model.

Method

In eight pigs, implant-associated osteomyelitis was induced on day 0, using a Staphylococcus aureus strain. Following administration of 1,000 mg of vancomycin on day 5, vancomycin concentrations were obtained with microdialysis for eight hours in the implant bone cavity, in cancellous bone adjacent to the implant cavity, in subcutaneous adipose tissue (SCT) adjacent to the implant cavity, and in healthy cancellous bone and healthy SCT in the contralateral leg. Venous blood samples were also obtained. The extent of infection and inflammation was evaluated by post-mortem computed tomography scans, C-reactive protein serum levels and cultures of blood and swabs.

Aims

Dead space management is an important element in the surgical management of chronic osteomyelitis and can be addressed with the use of a biodegradable local antibiotic carrier. We present the clinical and radiographic outcomes in two different biodegradable antibiotic carriers used in the management of chronic osteomyelitis.

Method

A single centre series reviewed between 2006–2017. The initial cohort (2006–2010) of 180 cases (Group A) had a calcium sulphate carrier containing tobramycin (Osteoset^® T, Wright Medical). The second cohort (2013–1017) of 162 cases (Group B) had a biphasic calcium sulphate, nano-crystalline hydroxyapatite carrier containing gentamicin (Cerament^TM G, Bonesupport AB).

All cases were Cierny-Mader Grade III and IV and had a minimum of one-year clinical follow-up.

Clinical outcomes reviewed included infection recurrence rate, wound leak, and subsequent fracture involving the treated segment. All cases with a minimum one-year radiographic follow-up were reviewed and bone void filling was assessed as percentage filling on the final follow-up radiograph to the nearest five percent increment.

Aim

The aim of this work was to evaluate, via foot and ankle TC scans, the outcomes of the use of a bone substitute (CERAMENT|™G) and the growth of native bone in the treatment of osteomyelitis (OM) of the diabetic foot.

Method

In nine patients from July 2014 to December 2016 we used a Calcium Sulphate Hemihydrate + Hydroxyapatite + Gentamicin Sulfate (CSH + HA + GS) compound to fill resected bone voids following surgical intervention in OM diabetic foot cases. Of these nine patients, three were female and six were male and their ages were between 49 and 72 years. Four patients had hindfoot involvement and underwent partial calcanectomy. Two patients presented a rocker-bottom Charcot foot pattern III according to Sanders and Frykberg's classification and were treated with esostectomy of the symptomatic bony prominence of the midfoot. One patient presented OM of the 3°, 4° and 5° metatarsal bones. One patient underwent partial resection of the midfoot and hindfoot with arthrodesis stabilised by an internal-external hybrid fixator. One patient with a Charcot foot pattern IV-V underwent partial talectomy and calcanectomy with arthrodesis stabilised by an internal-external hybrid fixator. In all these patients - after removal of the infected bone - we applied 10 to 20 ml CSH + HA + GS filling the residual spaces with the aim of stabilising the remaining bone fragments. The uniqueness of this product is that it induces native bone growth, while the synthetic bone disappears and antibiotic is released into the surrounding tissues. In March 2018, the above nine patients underwent foot and ankle TC scans to evaluate bone growth.

Aim

We aimed to compare the in vitro antibacterial activity of Bioactive Glass (BAG) S53P4, which is a compound showing local antibacterial activity, to that of antibiotic-loaded polymethylmethacrylate (PMMA) against multidrug resistant bacteria from osteomyelitis (OM) and prosthetic joint infection (PJI) isolates.

Method

We studied convenience samples of multidrug resistant (MDR) microorganisms obtained from patients presenting OM and prosthetic joint infection (PJI). Mixtures containing tryptic soy broth (TSB) and inert glass beads (2mm), BAG-S53P4 granules (0.5–0.8mm and <45 mm) and Gentamicin or Vancomycin-loaded PMMA beads were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MR-CoNS), Pseudomonas aeruginosa or Klebsiella pneumoniae isolates. Glass beads (2.0mm) were used as a control. Antibacterial activity was evaluated by means of time-kill curve, through seeding the strains on blood agar plates, and subsequently performing colony counts after 24, 48, 72, 96, 120 and 168 hours of incubation. Differences between groups were evaluated by means of two-way analysis of variance (ANOVA) and Bonferroni's t test.

Aim

Chronic osteomyelitis (OM) is usually treated with surgical excision of infected bone and subsequent dead space management to prevent local recurrence. We report outcome after antibiotic loaded biocomposite (ALB)¹ for management of infected bone defects.

Method

We report a consecutive series of 97 patients with chronic OM treated at one institution by a multidisciplinary team, using a single-stage revision protocol inspired by a recently published study².

The treatment protocol includes surgical debridement, tissue sampling, dead-space management using the ALB, stabilization and empirical antibiotic therapy adjusted based on culturing. Closure was performed directly, with a local flap, a free flap or secondarily.

This series includes all patients operated using the ALB at our institution, since its implementation 26 months ago. The senior author (HG) performed 65 (67%) of the operations. The remaining procedures were performed by 14 different surgeons.

Aim

In two-stage replacements for septic loosening, some studies have suggested that associate bacterial colonization of spacers had a worse result in relation to the control of the infection and a higher rate of complications after the implantation of the definitive prosthesis.

The aim of our study was to determine the reoperation rate of patients undergoing two-stage revision surgery according to the results of spacer sonication.

Method

A retrospective observational study was conducted in which 56 hip or knee spacers implanted at our center from 2010 to 2017 were analysed. Patients were grouped into three categories:

Patients with positive spacer sonication fluid culture, with or without positive cultures from the rest of the samples.

Patients with negative spacer sonication culture and negative second-stage intraoperative cultures.

Patients with negative spacer sonication culture but positive cultures of the rest of intraoperative samples.

Aim

The optimal treatment of displaced intra-articular calcaneal fractures (DIACF) remains controversial. The operative treatment group has better anatomical recovery, functional outcome scores and less pain than non operative treatment patients, but it may lead to a higher incidence of complications, such as delayed wound healing and surgical site infections. The aim of this study was to analyze the prophylactic effect using a biphasic bone substitute (BS) eluting antibiotic on calcaneal implant-related infections.

Methods

We conducted a retrospective non-randomized review of all patients with DIACF (type Sanders 2, 3, 4) from 2009 to 2017; 103 calcaneal fractures of 90 patients (13 bilaterally) were treated with plates. All cases received the same systemic antibiotic prophylaxis; BS was used on more complex cases with large bone defect and BS was added with antibiotic on higher risk patients. We collected data including complications: major (deep infections, osteomyelitis) and minor complications (wound dehiscence, superficial infection). We considered the absence of deep infections after 6 months. We compared statistically the outcomes of 3 operative groups: the first was treated with plates only (A), the second with plates and BS (B) and the third with plates added with BS eluting antibiotic (vancomicine or gentamicine) (C).

Aim

This study describes the histologic changes seen with a gentamicin-eluting synthetic bone graft substitute (BGS)(1) in managing bone defects after resection of chronic osteomyelitis (cOM).

Method

154 patients with mean follow-up of 21.8 months (12–56) underwent treatment of cOM with an antibiotic-loaded BGS for defect filling.

Nine patients had subsequent surgery, not related to infection recurrence, allowing biopsy of the implanted material. These biopsies were harvested between 19 days and two years after implantation, allowing a description of the material's remodelling over time. Samples were fixed in formalin and stained with haematoxylin-eosin. Immunohistochemistry, using an indirect immunoperoxidase technique, identified the osteocyte markers Dentine Matrix Protein-1 (DMP-1) and Podoplanin, the macrophage/osteoclast marker CD68, and the macrophage marker CD14.

Aim

The primary aim of multidisciplinary management of diabetic foot disease is limb savage. Difficulty in eradication of infection with systemic antibiotics and obliteration of dead space created by debridement, are two major stumbling blocks in achieving this. Antibiotic loaded bio composites help achieve both these objectives. The aim of this study is to report the early results of antibiotic loaded bio composites in diabetic foot disease

Method

We present early results of 16 patients with diabetic foot disease and osteomyelitis in whom we used antibiotic loaded bio composite (CERAMENT G Bone Support, Lund, Sweden) for local antibiotic delivery and dead space eradication. A multidisciplinary team managed all patients. We performed magnetic resonance and vascular imaging preoperatively and adhered to a strict protocol involving debridement, culture specific systemic antibiotics and dead space obliteration with antibiotic loaded bio composite. The wound was managed with negative pressure wound therapy and all patients were kept non-weight bearing with a plaster back slab or walking boot. Skin cover where required was undertaken by our plastic surgeons.

Aim

Antibiotic-eluting calcium compounds can be used to deliver antibiotics in the management of prosthetic joint infection (PJI). Described omplications include wound drainage, heterotopic ossification(HO) as well as hypercalcaemia which is potentially life threatening.

The aim of this study is to assess the incidence of hypercalcaemia and other complications between two calcium based antibiotic delivery systems.

Method

A retrospective study was performed. Thirty two patients treated with Stimulan or Cerament Calcium based antibiotic delivery system between August 2014 to January 2017 were included.

Seven patients received Cerament, 21 cases received Stimulan and one patient received both.

The volume used as well as pre- and post-operative serum calcium were recorded as well as any wound related complications and radiologic changes suggestive of heterotopic ossification. The postoperative serum adjusted Calcium were taken weekly during the initial post operative period.

Patients with overactive parathyroid disease and pre-existing renal disease were excluded.

Aim

Patients use antibiotics for various reasons before elective joint replacement surgery, but it is not known how common this is. The aim of this study was to investigate patients' use of oral antibiotics before elective joint replacement surgery and how this affects the risk for periprosthetic joint infection (PJI) in a one-year follow-up.

Method

Patients with a primary hip or knee replacement performed in a tertiary care hospital between September 2002 and December 2013 were identified (23 171 joint replacements, 10 200 hips and 12 971 knees). Information on oral antibiotics purchased within 90 days before the operation was gathered from a national database. The occurrence of a PJI, identified by prospective infection surveillance, in a one-year follow-up was the primary outcome. The occurrence of any surgical site infection was analyzed as a secondary outcome. The association between antibiotic use and subsequent infection was examined using a multivariable logistic regression model that included information on the operated joint, age, gender, body mass index and patients' chronic diseases (according to medication data).

Aim

Optimal strategies for surgical and antimicrobial management of Candida periprosthetic joint infections (PJI) are unclear. We present a retrospective case series of patients diagnosed with PJI caused by Candida spp.

Method

Patients treated at our institution with Candida PJI from 01/2017 to 04/2018 were retrospectively included with isolation of Candida spp. in synovial fluid, intraoperative tissue or sonication fluid culture. PJI was defined by the proposed European Bone and Joint Infection Society (EBJIS) criteria. Treatment failure was defined as relapse or persistence of infection.

Aim

As the populations of patients who have multiple prosthetic joints increase these years, the fate of a single joint periprosthetic joint infection in these patients is still unknown. Risk factors leading to a subsequent infection in another prosthetic joint are unclear. Our goal is to identify the risk factors of developing a subsequent infection in another prosthetic joint and describe the organism profile to the second prosthetic infection.

Method

We performed a retrospective cohort study of all PJI cases underwent surgical intervention at our institute, a tertiary care referral center over 11 years, during January 2006 to December 2016. We identified 96 patients with periprosthetic joint infection who had another prosthetic joint in place at the time of presentation. The comorbidity, number of prosthetic joints, date and type of each arthroplasty, times of recurrent infection at each prosthetic joint with subsequent debridement or 2-stage resection arthroplasty, organisms from every infection episode, the outcome of each periprosthetic joint infection in these patients were analyzed.

Aim

Two stage revision is the most commonly used surgical treatment strategy for periprosthetic hip infections (PHI). The aim of our study was to assess the intra- and postoperative complications during and after two stage revision using resection arthroplasty between ex- and reimplantation.

Method

In this retrospective cohort study, all patients treated with a two stage revision using resection arthroplasty for PHI were included from 2008 to 2014. During the first stage, the prosthesis was removed resulting in a resection arthroplasty without the use a PMMA spacer. During second stage, (cemented or uncemented) reimplantation of the hip prosthesis was performed. The cohort was stratified into two groups according to the length of prosthesis-free interval (≤10 weeks and >10 weeks). Data on complications during explantation, prosthesis-free interval, reimplantation, and after reimplantation was collected. The overall complication rate between both groups was compared using the chi-squared test. The revision-free and infection-free survival was estimated using Kaplan-Meier survival analysis.

Aim

Gram-negative aerobic bacteria account for 10%-17% of periprosthetic joint infection (PJI). Due to its biofilm-activity, ciprofloxacin plays a key role in the treatment of gram-negative PJI. However, data about treatment outcome of these infections are conflicting. With this retrospective study we aim at evaluating characteristics and outcome of gram-negative PJI.

Method

We retrospectively included consecutive patients with gram-negative PJI treated at our institution from 01/2013 to 03/2018. Diagnosis of PJI was defined by the proposed European Bone and Joint Infection Society (EBJIS) criteria. Growth of gram-negative aerobic bacteria was required in synovial fluid, periprosthetic tissue or sonication fluid. Clinical success (infection-free status) was defined as fulfillment of all of the following criteria: (i) unremarkable surgical site and no subsequent surgery (ii) no PJI related mortality and (iii) no long-term antimicrobial suppression therapy of >6 months.

Aim

Unexpected positive infections are distinct entity in prosthetic revision surgery. The prevalence and characteristics of unexpected positive cultures in internal fixation are however less established. The aim of this study was to describe the prevalence and characteristics of unexpected diagnosis of infection in a prospective cohort of revision surgeries following internal fixation.

Method

We reviewed the microbiological results following 356 surgeries that included partial or complete removal of internal fixation, performed in 328 patients (54% male, mean age 53 ± 17 years), in which infection was not initially suspected. This prospective study was performed in a large single center for musculoskeletal surgery from 2013–2017. The implants most commonly removed were plate and/or screws (281 cases, 78,9%), followed by intramedullary nails (64 cases, 18,0%). The main indications for surgery were nonunion (89 cases, 25%) and symptomatic hardware (70 cases, 19,7%). All removed implants were sonicated, and tissue cultures were obtained depending on the surgeon's criteria. Diagnosis of infection was established by the presence of 2 or more positive tissue cultures (1 with a highly virulent microorganism), or ≥ 50 colony-forming units found in the sonication fluid.

Aim

Diagnosis of periprosthetic joint infection (PJI) is challenging given the limitations of available diagnostic tests. Recently, several studies have shown a role of the long pentraxin PTX3 as a biomarker in inflammatory diseases and infections. This single-center prospective diagnostic study evaluated the diagnostic ability of synovial fluid and serum PTX3 for the infection of total hip arthroplasty (THA) and total knee arthroplasty (TKA).

Method

Consecutive patients undergoing revision surgery for painful THA or TKA were enrolled. Patients with antibiotic therapy suspended for less than 2 weeks prior to surgery and patients eligible for metal-on-metal implant revision or spacer removal and prosthesis re-implantation were excluded. Quantitative assessment of synovial fluid and serum PTX3 was performed with ELISA method. Musculoskeletal Infection Society (MSIS) criteria were used as reference standard for diagnosis of PJI. Continuous data values were compared for statistical significance with univariate unpaired, 2-tailed Student's t-tests. Receiver operating characteristic (ROC) curve analyses was performed to assess the ability of serum and synovial fluid PTX3 concentration to determine the presence of PJI. Youden's J statistic was used to determine optimum threshold values for the diagnosis of infection. Sensitivity (Se), specificity (Sp), positive (PPV) and negative (NPV) predictive values, positive (LR+) and negative (LR-) likelihood ratio, area under the ROC curve (AUC) were calculated.

Aim

The effectiveness of mandatory joint aspiration prior to re-implantation in patients with a cement spacer already in place is unclear.

The aim of this study was to evaluate the role of culturing articular fluid obtained by joint aspiration prior to re-implantation in patients who underwent a two stage septic revision.

Method

A retrospective observational study was conducted, assessing51 patients that underwent a two stage septic hip or knee revision from 2010 to 2017.

According to the results of intraoperative cultures, after the first stage revision each patient was treated with an antibiotic protocol for 6–8 weeks. Following two weeks without antibiotics, a culture of synovial fluid was obtained. Synovial fluid was obtained by direct joint aspiration in cases of knee spacers by and by joint aspiration guided by fluoroscopy in the theatre room in cases of hip spacers. Synovial fluid was transferred into a Vacutainer ACD^® flask. Samples were processed and analysed in the microbiology laboratory. Gram stains were performed and the sample was subsequently transferred into a BacALERT bottle (bioMérieux, France) and incubated in a BacALERT instrument for seven days.

Results of these cultures were recorded and compared with cultures obtained during re-implantation surgery.

Aim

Carbapenem-resistant Enterobacteriaceae (CRE) and vancomycin resistant Enterococci (VRE) have emerged as multi-drug resistant Gram-negative pathogens associated with Periprosthetic Joint Infections (PJI). In this study, we evaluated the efficacy of antibiotic-loaded calcium sulfate beads (ABLCB) to inhibit bacterial growth, biofilm formation and eradicate preformed biofilms of K. pneumoniae and E. faecalis.

Method

Three strains of K. pneumoniae (carbapenem resistant BAA1705, New Delhi metallo-beta-lactamase producing BAA2146 [NDM-1], a carbapenemase producing BAA2524) and a vancomycin resistant strain of E. faecalis (ATCC51299) were used. 4.8mm diameter ABLCBs (Stimulan Rapid Cure, Biocomposites) were loaded with vancomycin (VAN) & gentamicin (GEN) at 500 and 240 mg/10cc pack or VAN & rifampicin (RIF) at 1000 and 600 mg/10cc pack respectively and placed onto tryptic soy agar (TSA) plates spread with each of the four strains independently and incubated for 24 hours at 37°C. The beads were transferred daily onto fresh TSA medium spread with the test cultures. The zone of inhibition was recorded until no inhibition was observed. Biofilm prevention efficacy was investigated in 6 well plates. Bacterial cells (5×10⁵ CFU/mL in tryptic soy broth) were treated with ABLCBs. Media was removed and challenged with bacteria daily for 7 days. CFU counts were taken after 1, 2, 3 and 7 days. For biofilm killing, ABLCB were added to 3 day formed biofilms in 6 well plates. CFU counts were estimated at 1, 3 and 7 days with daily media exchange.

Aim

To investigate the local intra-operative concentration of gentamicin needed to prevent biofilm formation in a porcine model of implant-associated osteomyelitis.

Method

In total 24 pigs were allocated to six groups. Group A (n=6) was inoculated with saline. Groups B (n=6), C (n=3), D (n=3), E (n=3) and F (n=4) were inoculated with 10 μL saline containing 10⁴ CFU of Staphylococcus aureus, however, different minimal inhibitory concentrations (MIC) of gentamicin were added to the inoculum of Groups C(160xMIC), D(1600xMIC), E(16000xMIC) and F(160000xMIC). The inoculums were injected into a pre-drilled implant cavity proximally in the right tibial bone. Following inoculation, a steel implant (2 × 15 mm) was placed in the cavity. The pigs were euthanized after five days. The implants were sonicated and swabs were taken from the implant cavity for microbiological evaluation. The peri-implant tissue was analyzed by histopathology including estimation of neutrophil infiltration.

Aim

Staphylococcus aureus and Pseudomonas aeruginosa are ubiquitous pathogens often found together in polymicrobial, biofilm-associated infections. The mixed-species biofilm are significantly more resistant to antimicrobial treatment and are associated with failures. Bacteriophages present a promising alternative to treat biofilm-related infections due to their rapid bactericidal activity on multi-drug resistant bacteria. In this study, we assess the simultaneous or sequential application of phages and ciprofloxacin on the mixed-species biofilm in vitro.

Method

Ciprofloxacin was tested alone and in combination with Pyo-bacteriophage cocktail against P.aeurginosa ATCC 27853 and MRSA ATCC 43300 mixed-species biofilm. In order to evaluate the effect of combined treatment on biofilm-embedded cells, mature biofilms were grown on porous glass beads with MRSA (10⁶ CFU/ml) and P.aeruginosa (10³ CFU/ml) and incubated for 24h at 37° C in LB broth. The beads were then washed and placed in fresh LB in the presence of sub-eradicating titers/concentrations of phages and ciprofloxacin (corresponding to 1/4, 1/8, 1/16, 1/32, 1/64, 1/128 × MBEC_biofilm), respectively, simultaneous or in order (pretreated with phages for 3-6-12-24 hours) at 37°C. In all cases, heat flow produced by the viable cells still embedded in the biofilm was measured for 48 hours by isothermal microcalorimetry

Aim

To compare the performance of sonication and chemical methods (EDTA and DTT) for biofilm removal from artificial surface.

Method

In vitro a mature biofilms of Staphylococcus epidermidis (ATCC 35984) and P. aeruginosa ATCC®53278) were grown on porous glass beads for 3 days in inoculated brain heart infusion broth (BHI). After biofilm formation, beads were exposed to 0.9% NaCl (control), sonication (40 kHz, 1 min, 0.2 W/cm²), EDTA (25 mM/15 min) and DTT (1 g/L/15 min). Quantitative and qualitative biofilm analysis were performed with viable counts (CFU/ml) and microcalorimetry using time to detection (TTD), defined as the time from insertion of the ampoule into the calorimeter until the exponentially rising of heat flow signal exceeded 100 μW, which is inversely proportional to the amount of remaining bacterial biofilm on the beads. All experiments were performed in triplicate.

Aim

Aim of this study was to evaluate the ability of Sb-1 to enhance the antibiotic activity (tested in combination) degrading the biofilm matrix (impairing the freely diffusion of antimicrobials) and specifically targeting “persister” cells (biofilm sub-population tolerant to most antibiotics and responsible for the infection recalcitrance) of methicillin-resistant Staphylococcus aureus.

Method

MRSA ATCC 43300 24h-old biofilm was treated for 18h with Sb-1 titers (from 10⁴ to 10⁶ pfu/ml). Biofilm matrix was evaluated by confocal laser scanning microscopy after staining with wheat germ agglutinin conjugate with Alexafluor488 (WGA488) to label exopolysaccharide matrix and Syto 85 to label bacterial cells. Persister status was induced using two different protocols: i) by exposing stationary phase S. aureus to 400 µg/ml carbonyl cyanide m-chlorophenylhydrazone (CCCP) in PBS for 3h at 37°C and ii) by treatment of 24h old biofilm with 512 µg/ml ciprofloxacin for further 24h at 37°C. Then, induced persister cells and non-induced controls (10⁶ CFU/ml) were treated with 10⁴ PFU/ml and 10⁷ PFU/ml Sb-1 for 3h, followed by CFU counting. Alternatively, bacteria were washed and incubated in fresh BHI medium for the resumption of normal growth and the bacterial growth assessed after further 24 hours.

Aim

Leading etiology of Bone and Join infections (BJI), Staphylococcus aureus (SA) is responsible for difficult-to-treat infections mainly because of three persistence factors: (i) biofilm formation, (ii) persistence within bone cells and (iii) switch to the small colony variant (SCV) phenotype. The impact of rifampin on these mechanisms gave it a prominent place in orthopedic device-associated BJI. However, resistance emergence, intolerance and drug interactions cause significant concerns. In this context, other rifamycins – namely rifapentine and rifabutin – have poorly been evaluated, particularly toward their ability to eradicate biofilm-embedded and intracellular reservoirs of SA.

Method

This study aimed at comparing the intracellular activities of and SCV induction by rifampin, rifabutin and rifapentine in an in vitro model of osteoblast infection. Four concentrations were tested (0.1xMIC, MIC, 10xMIC, 100xMIC) against three SA strains (6850 and two clinical isolates involved in recurrent BJI)

Aims

Vancomycin may be an important drug for intravenous perioperative antimicrobial prophylaxis in spine surgery. We assessed single-dose vancomycin intervertebral disc, vertebral cancellous bone, and subcutaneous adipose tissue concentrations using microdialysis in a pig model.

Methods

8 female pigs received 1,000 mg of vancomycin intravenously as a single dose over 100 minutes. Microdialysis probes were placed in the C3-C4 intervertebral disc, C3 vertebral cancellous bone, and subcutaneous adipose tissue, and vancomycin concentrations were obtained over 8 hours. Venous blood samples were obtained as reference.

Aim

There is controversy about the need of remove implants removal in pediatric patients. One of the potential disadvantages of not doing it is potential infection. Since the orthopaedic implants (O.I.) are handled under an aseptic protocol, the expected results are the absence of germs in those devices. However, the risk of contamination and potential infection cannot be ruled out.

For these reason we wanted to determinate the percentage of colonization in the O.I. removed from pediatric patients of the H.G.G.B. in Concepción, Chile.

Method

Prospective observational study. The population consisted of 137 patients with previous osteosynthesis. 10 patients were excluded who had extruded material. The sample consisted of 127 patients in whom 331 implants were removed. The analysis unit was the cultures of the O.I. removed with aseptic techniques. The data was analyzed by descriptive statistics

Aim

Here we describe a cohort study to determine the performance of a commercially available Fluorescence In Situ Hybridization (FISH)-kit on samples of 65 consecutive patients suspected of orthopedic implant associated infections (IAI). Culture is routinely used and has a high specificity and sensitivity but requires days to more than a week for slow growing bacteria. FISH results are available within 45–60 minutes and thus specific treatment can start immediately. In addition, previous antibiotic therapy may hinder culture while bacteria may still be detected by FISH.

Method

The hemoFISH-kit from Miacom diagnostics (Dusseldorf, Germany) was used on a total of 82 joint aspirates, sonication fluids and tissue samples of 65 consecutive patients to detect and identify possible microorganisms. This FISH-kit contains a universal 16S rRNA probe and species-specific probes for bacteria commonly encountered in blood infections. FISH and culture were compared to the clinical definition of IAI. These definitions were based on the criteria described by Pro-Implant Foundation criteria for IAI after fracture fixation or prosthetic joint infection. If no criteria were described in the literature for a specific IAI then MSIS criteria were used.

Aim

White blood cell (WBC) scintigraphy for diagnosing fracture-related infections (FRIs) has only been investigated in small patient series. Aims of this study were (1) to establish the accuracy of WBC scintigraphy for diagnosing FRIs, and (2) to investigate whether the duration of the time interval between surgery and WBC scintigraphy influences its accuracy.

Method

192 consecutive WBC scintigraphies with ^99mTc-HMPAO-labelled autologous leucocytes performed for suspected peripheral FRI were included. The goldstandard was based on the outcome of microbiological investigation in case of surgery, or - when these were not available - on clinical follow-up of at least six months. The discriminative ability of the imaging modalities was quantified by several measures of diagnostic accuracy. A multivariable logistic regression analysis was performed to identify predictive variables of a false-positive or false-negative WBC scintigraphy test result.

Aim

To determine whether rep-PCR genotyping can improve the diagnosis of coagulase-negative staphylococci(CoNS)bone and joint infection relative to the standard method based on phenotypic identification.

Method

Observational study comparing diagnostic tests (January 2011-March 2015), including all orthopaedic surgery patients with clinically suspected infection and ≥2 surgical specimens culture-positive for CoNS. Data collection included epidemiologic and clinical information, current clinical signs of suspected infection, and microbiological information. Each CoNS strain was analyzed by both methods (phenotyping, VITEK and API;and genotyping, rep-PCR). In accordance with current IDSA guidelines, CoNS strains identified as identical in ≥2 samples within the same surgical episode were considered pathogenic. The results of the two techniques were compared and statistically analyzed.

Aim

We report on the performance of a simple algorithm using a combination of synovial fluid White blood cell count(WBC), C-reactive protein(CRP) and α-Defensin(AD) tests to aid in the diagnosis of prosthetic joint infections.

Methods

Sixty-six synovial fluid samples were collected prospectively in patients with suspected PJI (hip and knee). All samples were tested by: WBC counts (read manually) and CRP test (Alere-Afinion™ validated in-house); and on 37 of these with AD test.

Synovial fluid samples were collected in 5 ml ethylenediaminetetraacetic acid (EDTA) tubes. Samples that were very viscous were pre-processed by the addition of 100µl of hyaluronidase solution. Grossly blood stained and clotted samples were excluded.

A clinical diagnosis of infection was based IDSA definitions¹. Cut offs of >3000 × 10⁶ cells/L for total synovial WBC count and >12mg/L for CRP were used to define infection^2,3.

Aim

Fracture related infection (FRI) remains a challenging diagnosis in orthopedic and trauma surgery. In addition to clinical signs and imaging, serum inflammatory markers are often used to estimate the probability of FRI. To what extent serum inflammatory markers can be used to rule out and diagnose FRI remains unclear. The aim of this systematic review was to assess the diagnostic value of the serum inflammatory markers C-reactive protein (CRP), leukocyte count (LC) and erythrocyte sedimentation rate (ESR) in suspected fracture related infection.

Method

PubMed, Embase and Cochrane databases were searched for all articles focusing on the diagnostic value of CRP, LC and ESR in FRI. Studies on other inflammatory markers or other types of orthopedic infection, such as periprosthetic and diabetic foot infections, were excluded. For each serum inflammatory marker, all reported sensitivity and specificity combinations were extracted and graphically visualized. Average estimates were obtained using bivariate mixed effects models. This study utilized the QUADAS-2 criteria and was reported following the PRISMA statement.

Aim

Diagnosing fracture related infections (FRI) based on clinical symptoms alone can be challenging and additional diagnostic tools such as serum inflammatory markers are often utilized. The aims of this study were 1) to determine the individual diagnostic performance of three commonly used serum inflammatory markers: C-Reactive Protein (CRP), Leukocyte Count (LC) and Erythrocyte Sedimentation Rate (ESR), and 2) to determine the diagnostic performance of a combination of these markers and their value additionally to clinical predictors for FRI.

Method

This cohort study included patients who presented with a suspected FRI at two level I academic trauma centers between February 1^st 2009 and December 31^st 2017. The parameters CRP, LC and ESR, were obtained from hospital records when FRI was suspected. The gold standard for diagnosing or ruling out FRI was defined as: positive microbiology results of surgically obtained tissue samples, or absence of FRI at a clinical follow-up of at least six months. Separate markers were analysed using hospital thresholds, to determine current diagnostic performance, and continuously, to determine maximum possible diagnostic performance. Multivariable logistic regression analyses were performed to obtain the discriminative performance (Area Under the Receiver Operating Characteristic, AUROC) of (1) the combined inflammatory markers, and (2) the value of these markers additional to clinical parameters.

Aim

The current treatment concepts of acute and chronic osteomyelitis are associated with unsolved challenges and problems, underlining the need for ongoing medical research. The invention and prevalence of an absorbable, gentamicin-loaded ceramic bone graft, that is well injectable for orthopedic trauma and bone infections, enlarges the treatment scope regarding the rise of posttraumatic deep bony infections. This substance can be used either for infection, dead-space, or reconstruction management. The bone cement, eluting antibiotics continuously to the surrounding tissue, outperforms the intravenous antibiotic therapy and enhances the local concentration levels efficiently. This study aims to evaluate the power and practicability of bone cement in several locations of bony infections.

Method

The occurrence of posttraumatic infections with acute or chronic osteomyelitis increases in trauma surgery along with progression of high impact injuries and consecutively high incidence of e.g. open fractures. We present a case-series of 33 patients (18w/15m; 56,8±19,4 years) with posttraumatic osteomyelitis at different anatomic sites, who were treated in our level I trauma center. All of these patients received antibiotic eluting bone cement (Cerement® G) for infection and reconstruction management.

Aim

Despite advances in surgical and antibiotic therapies the treatment of chronic osteomyelitis remains complex and is often associated with a significant financial burden to the National Health Service. The aim of this review was to identify the different types of single-stage procedures being performed for this condition as well as to evaluate their effectiveness.

Method

Ovid Medline and Embase databases were searched for articles on the treatment of chronic osteomyelitis over the last 20 years. 3511 journal abstracts were screened by 3 independent reviewers. Following the exclusion of paediatric subjects, animal models, non-bacterial osteomyelitis and patients undergoing multiple surgical procedures we identified 13 studies reported in English with a minimum follow up of 12 months. Following a quality assessment of each study, data extraction was performed and the results analysed.

Aim

For which patients is bone defect reconstruction with the Masquelet-technique after the treatment of osteomyelitis suitable and which results did we have.

Methods

From 11/2011 to 4/2018 we treated 112 Patients (36f, 76m) with bone defects up 150mm after septic complications with the Masquelet-technique. We had infected-non-unions of upper and lower extremity, chronic osteomyelitis, infected knee-arthrodesis and knee- and ankle-joint-empyema. On average the patients were 52 (10–82) years old. The mean bone defect size was 48 mm (15–150). Most of our patients came from other hospitals, where they had up to 20 (mean 5.1) operations caused by the infection. Time before transfer in our hospital was on average 7,1 months (0,5–48). 77 patients received free (25) or local (52) flaps because of soft tissue-defects. 58 patients suffered a polytrauma. In 23 cases femur, in 4 cases a knee arthrodesis, in 68 cases tibia, in 1 case foot, 6 times ankle-joint arthrodesis, in 6 cases humerus, in 4 cases forearm were infected resulting in bone defects,

In most cases the indication for the Masquelet-technique was low-/incompliance due to higher grade of brain injury and polytrauma followed by difficult soft tissue conditions and problems with segmenttransport.

In 2/3 positive microbial detection succeeded at the first operation. Mainly we found difficult to treat bacteria. After treating the infection with radical sequestrectomy, removal of foreign bodies and filling the defect with antibiotic loaded cementspacer and external fixation we removed the spacer in common 6–8 weeks later and filled the defect with autologeous bone graft. Most of the patients needed an internal fixation after removing of the fixex.

All patients were examined clinically and radiologically every 4–6 weeks in our outpatient department until full weight bearing, later every 3 Months.

Aim

Previous studies had indicated that interleukin-1 beta (IL-1β) gene single nucleotide polymorphisms (SNPs) associate with different inflammatory diseases. However, potential links between these polymorphisms and susceptibility to extremity chronic osteomyelitis (COM) in Chinese population remain unclear. This study aimed to investigate relationships between IL-1β gene polymorphisms (rs16944, rs1143627, rs1143634 and rs2853550) and the risk of developing extremity COM in Chinese population.

Method

Altogether 233 extremity COM patients and 200 healthy controls were genotyped for the four tag SNPs of the IL-1β gene using the SNapShot genotyping method. Comparisons were performed regarding genotype distribution, mutant allele frequency and four genetic models (dominant, recessive, homozygous and heterozygous models) of the 4 SNPs between the two groups.

Aim

The aim of this study was to compare outcomes between patients with diabetic foot soft-tissue infection and osteomyelitis.

Methods

Medical records of patients with diabetic foot infection involving either soft-tissue (STI) or bone (OM) were retrospectively reviewed. Diagnosis was determined by bone culture, bone histopathology or imaging with magnetic resonance imaging (MRI) or single-photon emission computed tomography (SPECT/CT). Patient outcomes were recorded up to 1 year after admission.

Aim

Posttraumatic pelvic-osteomyelitis is one of the most serious complications after pelvic-fractures. The necessary extensive surgical debridement as part of interdisciplinary treatment is complicated by the possible persistence of pelvic instability. The aim of this study was to determine the outcome and outline the course of treatment after early posttraumatic pelvic bone infections due to type-C pelvic ring injuries.

Method

In a retrospective cohort study (2005–2015) all patients with pelvic-osteomyelitis within six weeks of surgical stabilization of a type-C pelvic-fracture were assessed. Microbiological results, risk factors, course of treatment and functional long-term outcome using the Orlando-Pelvic-Score were analyzed.

Aim

Bone and joint infections (BJI) are associated with a heavy morbidity and high health costs. Comorbidities, device associated infections and complicated journeys are associated with increased mortality, treatment failures and costs. For this reason, 24 referral centers (RC) have been created in 2009 in order to advise about management of “complex” BJI in weekly multidisciplinary meetings (MM). Since end of 2012, data from these meetings are gathered in a national database. We aimed to describe the data from this French registry of BJI and determine factors associated with the definition of “complex” BJI.

Method

Demographic, clinical, microbiologic and therapeutic characteristics of patients are systematically recorded in the database. Data from the first presentation in RC for each adult patients are presented. Complexity of BJI is recorded after each meeting according to 4 criteria (first failure, complex antibiotic therapy, precarious underlying conditions or complex surgical procedure). Part of unavailable data have been completed by pattern extraction from text-encoded commentaries. Factors associated with complexity were determined by multivariate logistic regression.

Aim

Diagnosing Fracture-Related Infections (FRI) is challenging. White blood cell (WBC) scintigraphy is considered the best nuclear imaging technique to diagnose FRI; a recent study by our group found a diagnostic accuracy of 92%. However, many centers use ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) which has several logistic advantages. Whether ¹⁸F-FDG-PET/CT has better diagnostic performance than white blood cell (WBC) scintigraphy is uncertain. Therefore, we aimed: 1) to determine the diagnostic performance of ¹⁸F-FDG-PET/CT for diagnosing FRI (defined as infection following an open fracture or fracture surgery) and 2) to determine cut-off values of standardized uptake values (SUV) that result in optimal diagnostic performance.

Method

This retrospective cohort study included all consecutive patients who received ¹⁸F-FDG-PET/CT to diagnose FRI in two level 1 trauma centers. Baseline demographic- and surgical characteristics were retrospectively reviewed. The reference standard consisted of at least 2 representative microbiological culture results or the presence or absence of clinical confirmatory FRI signs in at least 6 months of clinical follow-up. A nuclear medicine specialist, blinded to the reference standard, re-reviewed all scans. Additionally, SUVs were measured using the “European Association of Nuclear Medicine Research Ltd. (EARL)” reconstructed ¹⁸F-FDG-PET/CT scans. Volume of interests were drawn around the suspected- and corresponding contralateral area to obtain the absolute values (SUVmax) and the ratio between suspected and contralateral area (SUVratio). Diagnostic accuracy of the re-reviewed scans was calculated (sensitivity and specificity). Additionally, diagnostic characteristics of the SUV measurements were plotted in the area under the receiver operating characteristics curve (AUROC). The sensitivity and specificity at the optimal threshold was deducted from the AUROC with the Q-point method.

Aim

Antibiotic-loaded biomaterials are often used in dead space management after excision of infected bone. This study assessed the chronological progression of new bone formation in infected defects, filled only with an absorbable, osteoconductive bone void filler with Gentamicin (1).

Method

163 patients were treated for osteomyelitis or infected fractures with a single-stage excision, implantation of antibiotic carrier, stabilisation and wound closure. All had Cierny & Mader Type III (n=128) or Type IV (n=35) infection. No bone grafting was performed in any patient.

Patients were followed up for a minimum of 12 months (mean 21.4 months; 12–56). Bone void filling was assessed on serial digitised, standardized radiographs taken immediately after surgery, at 6 weeks, 3, 6 and 12 months and then yearly. Data on defect size, location, degree of void filling, quality of the bone-biomaterial interface and material leakage were collected.

Bone formation was calculated at final follow-up, as a percentage of initial defect volume, by determining the bone area on AP and lateral radiographs to the nearest 5%.

Aim

This study quantified changes in the microbiology of osteomyelitis in a single specialist centre within the UK. The rate of infection with multi-drug-resistant (MDR) bacteria was measured over a ten year period in 388 patients.

Method

Patients with confirmed osteomyelitis who received curative surgery from 2013–2017 were included (n=222). Microbiology was compared to patients from a cohort between 2001–2004, using the same diagnostic criteria (n=166).¹ The proportion of MDR bacterial pathogens² from deep tissue culture in these cohorts were compared. Pathogens were analysed according to aetiology and the presence of metal-work.

Aim

Staphylococcus aureus (SA) chronic bone and joint infections (BJI) are characterized by a progressive destruction of bone tissue associated to SA persistence which results in a large number of relapses (10–20%). The main factors proposed for these failures are: i) a weak diffusion of antibiotics in bone tissue, ii) formation of biofilm, iii) the bacterial internalization by the cells responsible for bone mineralization, namely the osteoblasts (OB).

Our in vitro and in vivo work aimed at providing new information on the impact of SA, more specifically of internalized SA, on bone homeostasis.

Method

Effect of SA infection (8325–4/FnBP+; DU5883/FnBP-) on the viability, differentiation and mineralization of an OB cell line was measured in vitro by MTT and Phosphatase Alcaline (PAL) activity assays and quantification of calcium deposits using Alizarin red, respectively. A gentamicin protection assay (GPA) confirmed that the effects observed are due solely to the internalized SA. In vivo, X-ray microtomography (μCT) and 3D reconstruction was used to evaluate the impact of SA infection on bone formation and bone resorption in a mouse model of femur infection.

Aim

Following clean (class I, not contaminated) surgical procedures, the rate of surgical site infection (SSI) should be less than approximately 2%. However, an infection rate of 12.2% has been reported following removal of orthopedic implants used for treatment of fractures below the knee. The objective of this trial was to evaluate the effect of a single dose of preoperative antibiotic prophylaxis on the incidence of SSIs following removal of orthopedic implants used for treatment of fractures below the knee.

Method

This multicenter, double-blind, randomized clinical trial included 500 patients from 19 hospitals with a follow-up of 6 months. Eligible were patients aged 18 to 75 years with previous surgical treatment for fractures below the knee who were undergoing removal of orthopedic implants. Exclusion criteria were an active infection or fistula, antibiotic treatment, reimplantation of osteosynthesis material in the same session, allergy for cephalosporins, known kidney disease, immunosuppressant use, or pregnancy. The intervention was a single preoperative intravenous dose of 1000 mg of cefazolin (cefazolin group, n = 228) or sodium chloride (0.9%; saline group, n = 242). Primary outcome was SSI within 30 days as measured by the criteria from the US Centers for Disease Control and Prevention. Secondary outcome measures were functional outcome, health-related quality of life, and patient satisfaction.

Aim

Alongside debridement and irrigation, soft tissue coverage and osseous stabilization, systemic antibiotic prophylaxis is considered the gold standard in the management of open fractures and considerably reduces the risk of subsequent fracture-related Infections (FRI). The direct application of antibiotics into the surgical field (local antibiotics) has been used for decades as additional prophylaxis in open fractures, although definitive evidence confirming a beneficial effect is scarce. The purpose of the present study was to review the clinical evidence regarding the effect of prophylactic application of local antibiotics in open limb fractures.

Method

A comprehensive literature search was performed in PubMed, Web-of- Science and Embase. Cohort studies investigating the effect of additional local antibiotic prophylaxis compared to systemic prophylaxis alone in the management of open fractures were included and the data were pooled in a meta-analysis.

Aim

Cutibacterium acnes, a skin commensal, is responsible for 5–10% of prosthetic joint infections (PJI). All current microbiological definitions of PJI require two or more identical commensal isolates to be recovered from the same procedure to diagnose PJI and rule out contamination. Unlike coagulase negative staphylococci, C.acnes shows a highly stereotypical susceptibility profile making impossible to phenotypically assess the clonal relationship of isolates. In order to determine the clonal relationship of multiple C.acnes isolates recovered from arthroplasty revisions, we analyzed by multi-locus sequence typing (MLST) C.acnes isolates grown from orthopedic device-related infections (ODRI) in a reference center for bone and joint infection.

Methods

Laboratory records from January 2009 to January 2014 were searched for monomicrobial C.acnes ODRI with growth of C. acnes in at least 2 intraoperative and/or preoperative samples. Clinical, biological and demographic information was collected from hospital charts. All corresponding isolates biobanked in cryovials (−80°C) were subcultured on anaerobic blood agar, and identification confirmed by MALDI-TOF-MS. C.acnes isolates were typed using the MLST scheme described by Lomholt et al. Plasmatic pre-operative C-reactive protein (CRP) levels were determined using DimensionEXL (Siemens). A threshold of 10 mg/L was used to determine serologically positive ODRIs from negatives.

Aim

Data on Prosthetic joint infection (PJI) caused by multi-drug resistant (MDR) or XDR (extensively drug resistant) Gram negative bacteria (GNB) are limited. Treatment options are also restricted. We conducted a multi-national, multi-center assessment of clinical data and factors of outcome for these infections.

Method

PJI were defined upon international guidelines. Data from 2000–2015 on demographics, clinical features, microbiology, surgical treatment and antimicrobial therapy was collected retrospectively. Factors associated with treatment success were evaluated by logistic regression analysis.

Aim

Debridement, antibiotics and implant retention (DAIR) is the recommended treatment for all acute prosthetic joint infections (PJI). However, the efficacy of DAIR and identification of risk factors for failure in patients with late acute PJI, is not well described.

Method

Patients diagnosed with late acute PJI between 2005 and 2015 were retrospectively evaluated. Late acute PJI was defined as the development of acute symptoms (≤ 3 weeks) occurring ≥ 3 months after arthroplasty. Failure was defined as: i) the need for implant removal, ii) infection related death, iii) the need for suppressive antibiotic therapy due to persistent signs of infection and/or iv) relapse or reinfection during follow-up.