Aims. This study aimed to investigate the clinical characteristics and outcomes associated with
Aims. In the absence of an identified organism, single-stage revision is contraindicated in prosthetic joint infection (PJI). However, no studies have examined the use of intra-articular antibiotics in combination with single-stage revision in these cases. In this study, we present the results of single-stage revision using intra-articular antibiotic infusion for treating
Aims. The aim of this study was to analyze the prevalence of
Aims. Removal of infected components and culture-directed antibiotics are important for the successful treatment of chronic periprosthetic joint infection (PJI). However, as many as 27% of chronic PJI patients yield negative culture results. Although culture negativity has been thought of as a contraindication to one-stage revision, data supporting this assertion are limited. The aim of our study was to report on the clinical outcomes for one-stage and two-stage exchange arthroplasty performed in patients with chronic
Background. Recent reports demonstrate that Next Generation Sequencing (NGS) facilitates pathogen identification in the context of
Aim. Identification of the causal pathogen is crucial in the management of periprosthetic joint infection (PJI) of the hip. Unfortunately, it was often difficult and negative culture could be a common findings. This situation made the treatment of PJI of the hip became more challenging. The negative culture finding resulted in a doubtful diagnosis of infection, and poses difficulty in choosing the appropriate antibiotics. Here we compared the treatment outcome of two-stage revision arthroplasty for
Periprosthetic joint infection (PJI) remains a challenging complication following Total Hip Arthroplasty (THA). It is associated with high levels of morbidity, mortality and is time consuming and expensive to treat. Our management generally relies on identification of the infecting organism(s) in order to define the appropriate treatment strategy. Patients with
Aim. To date, the value of culture results after a debridement, antibiotics and implant retention (DAIR) for early (suspected) prosthetic joint infection (PJI) as risk indicators in terms of prosthesis retention is not clear. At one year follow-up, the relative risk of prosthesis removal was determined for culture-positive and
Purpose. Unexpected-positive-intraoperative-cultures (UPIC) in presumed aseptic revision-total-knee-arthroplasties (rTKA) are common, and the clinical significance is not entirely clear. In contrast, in some presumably septic rTKA, an identification of an underlying pathogen was not possible, so called unexpected-negative-intraoperative-cultures (UNIC). The purpose of this study was to evaluate alpha defensin (AD) levels in these patient populations. Methods. In this retrospective analysis of our prospectively maintained biobank, we evaluated synovial AD levels from 143 rTKAs. The 2018-Musculoskeletal Infection Society score (MSIS) was used to define our study groups. Overall, 20 rTKA with UPIC with a minimum of one positive intraoperative culture with MSIS 2-≥6 and 14 UNIC samples with MSIS≥6 were compared to 34 septic culture-positive samples (MSIS ≥6) and 75 aseptic
Aims. The diagnosis of periprosthetic joint infection can be difficult
due to the high rate of
Pulmonary Tuberculosis (TB) can be detected by sputum cultures. However, Extra Pulmonary Spinal Tuberculosis (EPSTB), diagnosis is challenging as it relies on retrieving a sample. It is usually discovered in the late stages of presentation due to its slow onset and vague early presentation. Difficulty in detecting Mycobacterium Tuberculosis bacteria from specimens is well documented and therefore often leads to culture negative results. Diagnostic imaging is helpful to initiate empirical therapy, but growing incidence of multidrug resistant TB adds further challenges. A retrospective analysis of cases from the Infectious Disease (ID) database with Extra Pulmonary Tuberculosis (EPTB) between 1st of January 2015 to 31st of January. Two groups were compared 1) Culture Negative TB (CNTB) and 2) Culture Positive TB (CPTB). Audit number wasIntroduction
Methods
Culture negative (CN) prosthetic joint infections (PJI) account for approximately 10% of all PJIs and present significant challenges for clinicians. We aimed to explore the significance of CN PJI within a large prospective cohort study, and to compare their characteristics and outcomes with culture positive cases. The Prosthetic joint Infection in Australia and New Zealand Observational (PIANO) study is a prospective, binational, multicentre observational cohort study conducted at 27 hospitals between July 2014 and December 2017. We compared baseline characteristics and outcomes of all patients with culture negative (CN) prosthetic joint infection (PJI) from the PIANO cohort with culture positive (CP) cases. “Treatment success” was defined as absence of clinical or microbiological signs of infection, no need for ongoing antibiotics, and no need for revision or resection arthroplasty since the end of the initial treatment. We also describe PJI diagnostic criteria in the CN cohort and apply internationally recognised PJI diagnostic guidelines.Aim
Methods
To analyse the prevalence of culture negative periprosthetic joint infections (PJI) when adequate culture techniques are applied, and to evaluate the outcome of patients who were treated with antibiotics for a culture negative PJI versus those in whom treatment was withheld. A multicenter observational study in which acute and chronic PJIs diagnosed between 2013 and 2018 were analyzed. Culture negative PJIs were diagnosed according to the MSIS, ICM and EBJIS definitions.Aim
Method
Aims. This aim of this study was to analyze the detection rate of rare pathogens in bone and joint infections (BJIs) using metagenomic next-generation sequencing (mNGS), and the impact of mNGS on clinical diagnosis and treatment. Methods. A retrospective analysis was conducted on 235 patients with BJIs who were treated at our hospital between January 2015 and December 2021. Patients were divided into the no-mNGS group (microbial culture only) and the mNGS group (mNGS testing and microbial culture) based on whether mNGS testing was used or not. Results. A total of 147 patients were included in the no-mNGS group and 88 in the mNGS group. The mNGS group had a higher detection rate of rare pathogens than the no-mNGS group (21.6% vs 10.2%, p = 0.016). However, the mNGS group had lower rates of antibiotic-related complications, shorter hospital stays, and higher infection control rates compared with the no-mNGS group (p = 0.017, p = 0.003, and p = 0.028, respectively), while there was no significant difference in the duration of antibiotic use (p = 0.957). In
Aim. While 16S rRNA PCR - Sanger sequencing has paved the way for the diagnosis of
Aims. The microbiological detection of microorganisms plays a crucial role in the diagnosis as well as in the targeted systemic and local antibiotic therapy of periprosthetic infections (PJI). Despite extensive efforts to improve the sensitivity of current culture methods, the rate of
Aims. Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA). Two-stage revision has traditionally been considered the gold standard of treatment for established infection, but increasing evidence is emerging in support of one-stage exchange for selected patients. The objective of this study was to determine the outcomes of single-stage revision TKA for PJI, with mid-term follow-up. Methods. A total of 84 patients, with a mean age of 68 years (36 to 92), underwent single-stage revision TKA for confirmed PJI at a single institution between 2006 and 2016. In all, 37 patients (44%) were treated for an infected primary TKA, while the majority presented with infected revisions: 31 had undergone one previous revision (36.9%) and 16 had multiple prior revisions (19.1%). Contraindications to single-stage exchange included systemic sepsis, extensive bone or soft-tissue loss, extensor mechanism failure, or if primary wound closure was unlikely to be achievable. Patients were not excluded for
Aims. This study aimed to explore the diagnostic value of synovial fluid neutrophil extracellular traps (SF-NETs) in periprosthetic joint infection (PJI) diagnosis, and compare it with that of microbial culture, serum ESR and CRP, synovial white blood cell (WBC) count, and polymorphonuclear neutrophil percentage (PMN%). Methods. In a single health centre, patients with suspected PJI were enrolled from January 2013 to December 2021. The inclusion criteria were: 1) patients who were suspected to have PJI; 2) patients with complete medical records; and 3) patients from whom sufficient synovial fluid was obtained for microbial culture and NET test. Patients who received revision surgeries due to aseptic failure (AF) were selected as controls. Synovial fluid was collected for microbial culture and SF-WBC, SF-PNM%, and SF-NET detection. The receiver operating characteristic curve (ROC) of synovial NET, WBC, PMN%, and area under the curve (AUC) were obtained; the diagnostic efficacies of these diagnostic indexes were calculated and compared. Results. The levels of SF-NETs in the PJI group were significantly higher than those of the AF group. The AUC of SF-NET was 0.971 (95% confidence interval (CI) 0.903 to 0.996), the sensitivity was 93.48% (95% CI 82.10% to 98.63%), the specificity was 96.43% (95% CI 81.65% to 99.91%), the accuracy was 94.60% (95% CI 86.73% to 98.50%), the positive predictive value was 97.73%, and the negative predictive value was 90%. Further analysis showed that SF-NET could improve the diagnosis of
Aims. Metal particles detached from metal-on-metal hip prostheses (MoM-THA) have been shown to cause inflammation and destruction of tissues. To further explore this, we investigated the histopathology (aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL) score) and metal concentrations of the periprosthetic tissues obtained from patients who underwent revision knee arthroplasty. We also aimed to investigate whether accumulated metal debris was associated with ALVAL-type reactions in the synovium. Methods. Periprosthetic metal concentrations in the synovia and histopathological samples were analyzed from 230 patients from our institution from October 2016 to December 2019. An ordinal regression model was calculated to investigate the effect of the accumulated metals on the histopathological reaction of the synovia. Results. Median metal concentrations were as follows: cobalt: 0.69 μg/g (interquartile range (IQR) 0.10 to 6.10); chromium: 1.1 μg/g (IQR 0.27 to 4.10); and titanium: 1.6 μg/g (IQR 0.90 to 4.07). Moderate ALVAL scores were found in 30% (n = 39) of the revised knees. There were ten patients with an ALVAL score of 6 or more who were revised for suspected periprosthetic joint infection (PJI), aseptic loosening, or osteolysis. R2 varied between 0.269 and 0.369 for the ordinal regression models. The most important variables were model type, indication for revision, and cobalt and chromium in the ordinal regression models. Conclusion. We found that metal particles released from the knee prosthesis can accumulate in the periprosthetic tissues. Several patients revised for suspected
Aims. Single-stage revision is not widely pursued due to restrictive inclusion criteria. In this study, we evaluated the results of single-stage revision of chronically infected total hip arthroplasty (THA) using broad inclusion criteria and cementless implants. Patients and Methods. Between 2010 and 2016, 126 patients underwent routine single-stage revision with cementless reconstruction with powdered vancomycin or imipenem poured into the medullary cavity and re-implantation of cementless components. For patients with a
Aims. Periprosthetic joint infection (PJI) remains a challenging complication
following total hip arthroplasty (THA). It is associated with high
levels of morbidity, mortality and expense. Guidelines and protocols
exist for the management of culture-positive patients. Managing
culture-negative patients with a PJI poses a greater challenge to
surgeons and the wider multidisciplinary team as clear guidance
is lacking. Patients and Methods. We aimed to compare the outcomes of treatment for 50 consecutive
culture-negative and 50 consecutive culture-positive patients who
underwent two-stage revision THA for chronic infection with a minimum
follow-up of five years. Results. There was no significant difference in the outcomes between the
two groups of patients, with a similar rate of re-infection of 6%,
five years post-operatively.
Aims. The aim of this study was to evaluate the performance of metagenomic next-generation sequencing (mNGS) in detecting pathogens from synovial fluid of prosthetic joint infection (PJI) patients. Methods. A group of 75 patients who underwent revision knee or hip arthroplasties were enrolled prospectively. Ten patients with primary arthroplasties were included as negative controls. Synovial fluid was collected for mNGS analysis. Optimal thresholds were determined to distinguish pathogens from background microbes. Synovial fluid, tissue, and sonicate fluid were obtained for culture. Results. A total of 49 PJI and 21 noninfection patients were finally included. Of the 39 culture-positive PJI cases, mNGS results were positive in 37 patients (94.9%), and were consistent with culture results at the genus level in 32 patients (86.5%) and at the species level in 27 patients (73.0%). Metagenomic next-generation sequencing additionally identified 15 pathogens from five culture-positive and all ten
Aims. Microbiological culture is a key element in the diagnosis of periprosthetic joint infection (PJI). However, cultures of periprosthetic tissue do not have optimal sensitivity. One of the main reasons for this is that microorganisms are not released from the tissues, either due to biofilm formation or intracellular persistence. This study aimed to optimize tissue pretreatment methods in order to improve detection of microorganisms. Methods. From December 2017 to September 2019, patients undergoing revision arthroplasty in a single centre due to PJI and aseptic failure (AF) were included, with demographic data and laboratory test results recorded prospectively. Periprosthetic tissue samples were collected intraoperatively and assigned to tissue-mechanical homogenization (T-MH), tissue-manual milling (T-MM), tissue-dithiothreitol (T-DTT) treatment, tissue-sonication (T-S), and tissue-direct culture (T-D). The yield of the microbial cultures was then analyzed. Results. A total of 46 patients were enrolled, including 28 patients in the PJI group and 18 patients in the AF group. In the PJI group, 23 cases had positive culture results via T-MH, 22 cases via T-DTT, 20 cases via T-S, 15 cases via T-MM, and 13 cases via T-D. Three cases under ongoing antibiotic treatment remained
Although single-stage revision has attracted a lot of attention due to less socioeconomic cost, this technique is not widely used throughout the world due to strict indications. In this situation, we report our outcome on single-stage revision combined with selective direct intra-articular antibiotic infusion for chronic infected THA, especially for patients with
Aim. The gold standard treatment for late acute hematogenous (LAH) periprosthetic joint infection (PJI) is surgical debridement, antibiotics and implant retention (DAIR). However, this strategy is still controversial in the case of total knee arthroplasty (TKA) as some studies report a higher failure rate. The aim of the present study is to report the functional outcomes and cure rate of LAH PJI following TKA treated by means of DAIR at a long-term follow-up. Method. A consecutive prospective cohort consisting of 2,498 TKA procedures was followed for a minimum of 10 years (implanted between 2005 and 2009). The diagnosis of PJI and classification into LAH was done in accordance with the Zimmerli criteria (NEJM 2004). The primary outcome was the failure rate, defined as death before the end of antibiotic treatment, a further surgical intervention for treatment of infection was needed and life-long antibiotic treatment or chronic infection. The Knee Society Score (KSS) was used to evaluate clinical outcomes. Surgical management, antibiotic treatment, the source of infection (primary focus) and the microorganisms isolated were also assessed. Results. Among the 2,498 TKA procedures, 10 patients were diagnosed with acute hematogenous PJI during the study period (0.4%). All those 10 patients were operated by means of DAIR, which of course included the polyethylene exchange. They were performed by a knee surgeon and/or PJI surgeon. The failure rate was 0% at the 8.5 years (SD, 2.4) follow-up mark. The elapsed time between primary total knee replacement surgery and the DAIR intervention was 4.7 years (SD, 3.6). DAIR was performed at 2.75 days (SD 1.8) of the onset of symptoms. The most common infecting organism was S. aureus (30%) and E. coli (30%). There were 2 infections caused by coagulase-negative staphylococci and 2
Introduction. The burden of prosthetic joint infection (PJI) in total knee arthroplasty (TKA) has been rising in line with the number of primary operations performed. Current estimates suggest an infection rate of 1–2.4%. Two-stage revision has traditionally been considered the gold standard of treatment; however, some studies suggest comparable results can be achieved with single-stage procedures. The potential advantages include less time in hospital, a single anaesthetic, reduced costs, and greater patient satisfaction. Methods. We reviewed data for 72 patients (47 males, 25 females), with a mean age of 71 years (range, 49 to 94), who underwent single-stage revision TKA for confirmed PJI between 2006 and 2016. A standardized debridement protocol was performed with immediate single-stage exchange. All cases were discussed preoperatively at multidisciplinary team (MDT) meetings, which included input from a senior musculoskeletal microbiologist. Patients were not excluded for previous revisions,
Aim. Clear differentiation between aseptic failure and prosthetic joint infection remains one of the goals of modern orthopaedic surgery. New diagnostic methods can provide more precise evaluation of the etiology of prosthetic joint failure. With the introduction of sonication an increasing number of
Aim. Fracture-related infection (FRI) is a challenging complication. This study aims to investigate (1) microbial patterns in fracture-related infection (FRI), (2) the comparison of isolated pathogens in FRI patients with early, delayed, and late onset of infection and (3) antibiotic susceptibility profiles to identify effective empiric antibiotic therapy for FRI. Method. Patients treated for FRI from 2013 to 2020 were grouped into early (< 2 weeks), delayed (2– 10 weeks) and late (> 10 weeks) onset of infection. Pathogens detected during treatment were evaluated for pathogens. Antibiotic susceptibility profiles were examined with respect to broadly used antibiotics and antibiotic combinations. Results. In total 117 patients (early n=19, delated n=60, late n=38) were included in the study. Infection was polymicrobial in 10 cases (8.6%) and
Clear differentiation between aseptic failure and prosthetic joint infection remains one of the goals of modern orthopaedic surgery. The development of new diagnostic methods enabled more precise evaluation of the etiology of prosthetic joint failure. With the introduction of sonication an increasing number of
Aim. To compare pre-referral microbiology and previous bone excision in long bone osteomyelitis with intra-operative microbiology from a specialist centre. Method. A prospective observational cohort study of patients referred to a single tertiary centre who met the following criteria: (i) aged ≥18 years, (ii) received surgery for long bone osteomyelitis and (iii) met diagnostic criteria for long bone osteomyelitis. Patient demographics, referral microbiology and previous surgical history were collected at the time of initial clinic appointment. During surgery, a minimum of 5 intra-operative deep tissue samples were sent for microbiology. Antimicrobial options were classified from the results of susceptibility testing using the BACH classification of long bone osteomyelitis as either Ax (unknown or culture negative), A1 (good options available) or A2 (limited options available). The cultures and susceptibility of pre-referral microbiology were compared to the new intra-operative sampling results. In addition, an association between previous osteomyelitis excision and antimicrobial options were investigated. Results. 79 patients met inclusion criteria during the study period. From these, 39 (49.4%) patients had information available at referral regarding microbiology obtained from either sinus swab (n=16), bone biopsy (n=11), previous osteomyelitis excision sampling (n=7), aspiration (n=4) or blood culture (n=1). From these 39 patients, microbiology information at referral fully matched microbiology samples taken at operation in 8 cases (20.5%). Fifteen of the 39 patients (38.5%) had a different species isolated at surgery compared to referral microbiology. The remaining 16 patients (41.0%) had a
Aim. It is traditionally stated that around 80% of all periprosthetic joint infections (PJI) are caused by well-known gram-positive organisms such as Staphylococcus aureus. With the advances in diagnostic modalities and improved abilities to isolate infective organisms, we believe the organism profile causing PJI has changed over time and includes numerous other organisms that were either not recognized as pathogens and/or considered as contaminants. Method. We retrospectively reviewed the medical records of 1,363 patients with confirmed PJI (559 THA and 804 TKA) who received treatment at our institution between 2000 and 2019. Pertinent data related to demographics, microbiological findings, and outcome of treatment were collected. Organisms were differentiated using culture or confirmed by Matrix-Assisted Laser Desorption Ionization-time of flight (MALDI-tof) mass spectrometry. Statistical analysis included logistic regressions. Results. There was a total of 26 different species of organisms that resulted in PJI in our cohort. The rate of PJI caused by slow growing organisms, that are catalase negative, such as Streptococcal viridans (OR 1.244; 95% CI 1.036–1.494), Streptococcus agalactiae (OR 1.513; 95% CI 1.207–1.898), and Staphylococcus epidermidis (OR 1.321; 95% CI 1.191–1.466) has been increasing over time. In contrast, the incidence of PJI caused by coagulase-negative Staphylococcus (OR 0.954; 95% CI 0.927–0.981); resistant species (OR 0.962, 95% CI 0.931–0.995), and Gram-positive species (OR 0.94, 95% CI 0.914–0.966) decreased over time. Notably, there was a higher prevalence of Streptococcal PJI (OR 0.551, 95% CI 0.374–0.812) and
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
Aim. Metagenomic nanopore sequencing is demonstrating potential as a tool for diagnosis of infections directly from clinical samples. We have previously shown nanopore sequencing can be used to determine the causative bacterial species in prosthetic joint infections (PJI). However, to make predictions regarding antimicrobial resistance, human DNA contamination must be reduced so a greater proportion of sequence data corresponds to the microbial portion of the DNA extract. Here, we utilise selective DNA extraction from sonication fluid samples to begin to make predictions regarding antimicrobial resistance in PJI. Method. We investigated host cell DNA depletion with 5% saponin selective human cell lysis followed by nuclease digestion. Subsequently, bacterial cells were mechanically lysed before DNA extraction. Sequencing libraries from samples treated with and without saponin were prepared with a Rapid PCR Barcoding Kit. 1. and sequenced in multiplexes of 2–8 samples/flowcell on a GridION. Sequencing reads were analysed using the CRuMPIT pipeline and thresholds to indicate presence of a specific bacterial genus/species were investigated. Antimicrobial resistance determinants were detected using previously published sequences specifically for Staphylococcus aureus, as an example organism frequently causing PJI. Results. 247 DNA extracts from 115 sonication fluids plus controls were subjected to metagenomic sequencing, comprising extracts from 67 culture-positive (10 of which were culture-positive at <50 CFU/ml) and 48
Aim. Empiric antibiotic therapy for suspected pyogenic spondylodiscitis (SD) should be initiated immediately with severely ill patients and may also be necessary for
Aim. The aim of our study was to evaluate
We aim to describe the microbiological spectrum and relevant antibiotic susceptibility profile of PJI in our institution over a five-year period(2009–2013) and determine its evolution considering the preceding six years(2003–2008) thus evaluating the adequacy of our empirical antibiotic regimen. We retrospectively reviewed the records of 96 consecutive PJI (51 hips:45 knees) treated from May 2009-December 2013. Demographics, microbial species and antibiotic susceptibility were recorded. These results were then compared to those previously obtained by studying the 2003–2008 time period. Infections were polymicrobial in 27 cases(28.1%) and only two cases(2.1%) were
Introduction. Despite recent advances in the diagnosis of periprosthetic joint infection(PJI), identifying the infecting organism continues to be a challenge, with up to a third of PJIs reported to have negative cultures. Current molecular techniques have thus far been unable to replace culture as the gold standard for isolation of the infecting pathogen. Next- generation sequencing(NGS) is a well-established technique for comprehensively sequencing the entire pathogen DNA in a given sample and has recently gained much attention in many fields of medicine. Our aim was to evaluate the ability of NGS in identifying the causative organism(s) in patients with PJI. Methods. After obtaining Institutional Review Board approval and informed consent for all study participants, samples were prospectively collected from 148 revision total joint arthroplasty procedures (83 knees, 65 hips). Synovial fluid, deep tissue and swabs were obtained at the time of surgery and shipped to the laboratory for NGS analysis (MicroGenDx). Deep tissue specimens were also sent to the institutional laboratory(Thomas Jefferson University Hospital) for culture. PJI was diagnosed using the Musculoskeletal Infection Society(MSIS) definition of PJI. Statistical analysis was performed using SPSS software. Results. Fifty-five revisions were considered infected; culture was positive in 40 of these (40/55, 72.7%), while NGS was positive in 47 (47/55, 85.5%). Among the positive cultures, complete concordance between NGS and culture was observed in 33 cases (33/40, 82.5%). One case was partially discordant between NGS and culture, with culture detecting three organisms as opposed to one organism on NGS. One case showed complete discordance with NGS and culture detecting different organisms. Three patients with negative NGS results had positive cultures. In another two cases culture simply reported the gross morphology of the organism but the phenotype was not identified, while NGS was able to definitively identify an organism. Among the 15 cases of
Aims. The aim of this study was to identify the incidence of positive
cultures during the second stage of a two-stage revision arthroplasty
and to analyse the association between positive cultures and an
infection-free outcome. Patients and Methods. This single-centre retrospective review of prospectively collected
data included patients with a periprosthetic joint infection (PJI)
of either the hip or the knee between 2013 and 2015, who were treated
using a standardised diagnostic and therapeutic algorithm with two-stage
exchange. Failure of treatment was assessed according to a definition
determined by a Delphi-based consensus. Logistic regression analysis
was performed to assess the predictors of positive culture and risk
factors for failure. The mean follow-up was 33 months (24 to 48). Results. A total of 163 two-stage revision arthroplasties involving 84
total hip arthroplasties (THAs) and 79 total knee arthroplasties
(TKAs) were reviewed. In 27 patients (16.6%), ≥ 1 positive culture
was identified at re-implantation and eight (29.6%) of these subsequently
failed compared with 20 (14.7%) patients who were
Introduction. Patients with long-bone osteomyelitis are frequently referred with limited microbiological information. This study compared pre-referral microbiology in long bone osteomyelitis with intra-operative microbiology from a specialist centre. Materials and Methods. All patients referred to a single tertiary centre between February 2019 and February 2020, aged ≥18 years and received surgery for confirmed long-bone osteomyelitis were included. Patient demographics, referral microbiology and previous surgical history were collected at the time of initial clinic appointment. During surgery, a minimum of 5 intra-operative deep tissue samples were sent for microbiology. Antimicrobial options were classified from the results of susceptibility testing using the BACH classification of long bone osteomyelitis as either Ax (unknown or culture negative), A1 (good options available) or A2 (limited options available). The cultures and susceptibility of pre-referral microbiology were compared to the new intra-operative sampling results. In addition, an association between previous osteomyelitis excision and antimicrobial options were investigated. Results. 79 patients met inclusion criteria during the study period. From these, 39 (49.4%) patients had information available at referral regarding microbiology obtained from either sinus swab (n–16), bone biopsy (n–11), previous osteomyelitis excision sampling (n–7), aspiration (n–4) or blood culture (n–1). From these 39 patients, microbiology information at referral fully matched microbiology samples taken at operation in 8 cases (20.5%). Fifteen of the 39 patients (38.5%) had a different species isolated at surgery compared to referral microbiology. The remaining 16 patients (41.0%) had a
Aim. When treating periprosthetic joint infections with a two-stage procedure, antibiotic-impregnated spacers are used in the interval between removal of prosthesis and reimplantation. The spacer provides local antibiotics; however, it may also act as foreign-body that can be colonized by microorganisms. According to our experience, cultures of sonicated spacers are most often negative. The objective of our study was to investigate whether PCR analysis would improve the detection of bacteria in the spacer sonication fluid. Method. A prospective monocentric study was performed at Lausanne University Hospital from September 2014 until January 2016. Inclusion criteria were two-stage procedure for prosthetic infection and agreement of the patient to participate in the study. For a two-stage procedure the interval before reimplantation ranged between 2 and 8 weeks. Spacers were made of cement impregnated with gentamycin, tobramycin and vancomycin. Cultures of intraoperative deep tissues samples from first and second stage procedures, prosthesis sonication and spacer sonication were analyzed. Multiplex-PCR. *. , pan-bacterial PCR (16S), and a Staphylococcus-specific PCR analysis were performed on the sonicated spacer fluid. Results. 23 patients were identified (12 hip, 10 knee and 1 ankle replacements). Initial infection was caused by Staphylococcus aureus (27%), Streptococcus epidermidis (27%), S. dysgalactiae (13%), S. milleri (9%), S. pneumoniae (4%), S. capitis (4%), S. salivarus (4%), P. acnes (4%), E. faecalis (4%) and C. fetus (4%). At reimplantation, cultures of tissue samples and spacer sonication fluid were all negative. Of
Literature debates whether fluid aspirates for suspected PJI should undergo prolonged incubation for cultures. We looked at sensitivity and specificity of 14-day cultures, compared to 7-days, for aspirates from prosthetic hips and knees. Design and methods. Conducted at a quaternary referral centre for PJIs from Jan 2017 to July 2019. Suspected PJIs who underwent aspiration, incubated 14 days and later surgical intervention with minimum three tissue samples were included. Results. 176 aspirates were included. This is an increased number compared to our historic figures (average 88 Vs 48 pts/yr). 47 patients had fluid and tissue positive (true positive), 20 fluid +ive but tissue -ive (false positive), 98 fluid and tissue -ive (true negative) and 15 fluid negative but tissue +ive (False negative). Thus, sensitivity 76%, specificity 83%, positive predictive value70% and negative predictive value 87%. Of 88 positive aspirates, only 75% were within 7-day cultures. Low virulence organisms as Propionibacterium acnes and coagulase negative staph were grown later. Of 48 with only one tissue sample positive, 38 were
Optimal sampling for culture-based or molecular diagnosis remains highly contested for patients suspected of prosthetic joint infection (PJI). Most existing studies have a retrospective design without a standardized sampling strategy. Therefore, the results are difficult to translate into guidelines. We have conducted a 2-year prospective study with a sampling strategy adaptable to the specific procedure in patients with either hip or knee alloplasty. Thus, comparisons of results obtained with different specimen types and diagnostic methods are possible. The study enrolled patients with a painful hip or knee alloplasty. The sampling strategy for microbiological diagnosis included multiple specimens of each type (joint fluid, tissue biopsies, bone biopsies, and swabs taken from the prosthesis in situ), and prosthetic components (if removed). Prepacked boxes with containers and accessories for sampling, transport and storage were provided. Microbial culture and bacterial 16S rDNA screening were carried out for all specimen types. Whenever positive upon 16S rDNA screening, samples were analyzed further by sequencing. Peptide nucleic acid-fluorescence in situ hybridization (optimized using filtrations; Filter-PNA-FISH) was limited to a subset thereof. An overall completeness of ∼90% was obtained by the sampling strategy in 164 procedures (‘cases’) in 131 patients. In 58 cases PJI was suspected, and a revision was carried out. 42 cases were culture-positive, and 16 were
Introduction. Antibiotic loaded absorbable calcium sulphate beads (ALCSB) are an increasingly popular adjunct in the treatment of musculoskeletal infections including osteomyelitis and peri-prosthetic joint infections (PJI). Limited data exist regarding the clinical indications and biochemical outcomes of ALCSB in PJI cases. Aims. To determine the proportion of organisms that were sensitive to the gentamicin and vancomycin that we add to the ALCSB as a part of our treatment protocol and to determine the prevalence of postoperative hypercalcaemia when used for treatment of hip and knee DAIR (debridement and implant retention) and revision arthroplasty for PJI. Methods. A retrospective review of 160 hip and knee revisions using ALCSB performed between June 2015 and May 2018 at a tertiary unit was performed. 10–40 cc of ALCSB was used for each case containing vancomycin and gentamicin. Data recorded included patient demographics, comorbidities, indication for surgery, operative intervention, microbiological results and serum biochemistry for calcium levels. Results. The cohort consisted of 91 males and 69 females, with a mean age of 69.0 years (21.3 to 93.1) and mean BMI of 34.7(12.6 to 48.1). 56 (35%) had single-stage revision, 45 (28.1%) had first stage revision, 35 (21.9) had DAIR, 19 (11.9%) had second stage revision and 5 (3.1%) other procedures. Organisms included staphylococcus aureus (30.0%),
Aims. To identify the most common infecting organisms associated with deep infection and infected non-union of the tibia, as well as the rate of ‘culture-negative’ infections, at a tertiary referral trauma centre dealing with military and civilian trauma. Method. Between 2008 and 2010 all patients with a confirmed clinical diagnosis of implant-related infection or infected non-union of the tibia were identified retrospectively from a database and their records analysed. After a period of at least 10–14 days without antibiotics, all patients underwent surgical debridement in which ‘clean’ samples were went for microbiological analysis. Skeletal stablity was achieved with a circular frame and intravenous antibiotics were started pending culture and sensitivity results. Results. There were 31 patients; 28 male, 3 female. Mean age 41yrs. 21 patients (68%) had sustained open fractures. In 11 patients, tissue cultures were negative. In the remainder, 8 patients cultured one organism, 6 two organisms, 2 three organisms, and 2 four organisms. Only those with open fractures grew more than 2 organisms. A total of 15 different infecting organisms (all of which were bacteria) were identified. The most common organisms isolated were Staphylococcus aureus, coagulase-negative Staphylococcus, Bacillus and Enterobacter cloacae. There were 3 cases of MRSA infection, all in open fractures. The most frequently used antibiotics for definitive therapy were ciprofloxacin, rifampicin and vancomycin. Conclusions. The majority of patients had sustained open fractures. Patient with open fractures were more likely to have polymicrobial infections. There was a high rate of
Objectives. The risk of infection after type III° open fractures is high (10–50%). Preemptive antibiotic therapy may prevent posttraumatic infection and improve the outcome. Recommendations about the type and duration of antibiotic vary among the institutions and it remains unclear whether gram-negative bacilli or anaerobs need to be covered. In Europe, the most commonly recommended antibiotic is amoxicillin/clavulanic acid. We retrospectively analyzed microbiology, characteristics and outcome of patients with open type III° fractures treated at our institution. Methods. Between 01/2005 and 12/2009 we retrospectively included all type III grade open fractures of the leg at our institution classified after Gustilo (JBJS Am 1976) into type IIIA (adequate soft-tissue coverage of bone with extensive soft-tissue laceration or flaps), IIIB (extensive soft-tissue loss with periosteal stripping and bone exposure), and IIIC (requiring arterial injury repair). Demographic characteristics, clinical presentation, microbiology, surgical and antibiotic treatment and patient outcome were recorded using a standardized case-report form. Results. 30 cases of patients with type III° open fractures were included (25 males, mean age was 40.5 years, range 17–67 years). 27 fractures (90%) were located on the lower leg and 3 (10%) on the upper leg. 24 cases (80%) were high-energy and almost half of the patients (n=16, 53%) had a polytrauma. Microbiology at initial surgery was available for 19 cases (63%), of which 10 grew at least one organism (including 8 amoxicillin/clavulanic acid-resistant gram-negative bacilli [GNB], 7 amoxicillin/clavulanic acid-resistant Bacillus cereus), 11 were
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. Results. FISH and culture was done in 33 plain tissue samples, 43 sonication fluid samples and 6 joint aspirates of 65 patients. Results are shown in table 1. In clinical infections FISH provided earlier results in 7 and 2 extra for
Introduction. Next generation sequencing (NGS) has been shown to facilitate detection of microbes in a clinical sample, particularly in the setting of
This study aimed to evaluate the BioFire Joint Infection (JI) Panel in cases of hip and knee periprosthetic joint infection (PJI) where conventional microbiology is unclear, and to assess its role as a complementary intraoperative diagnostic tool. Five groups representing common microbiological scenarios in hip and knee revision arthroplasty were selected from our arthroplasty registry, prospectively maintained PJI databases, and biobank: 1) unexpected-negative cultures (UNCs), 2) unexpected-positive cultures (UPCs), 3) single-positive intraoperative cultures (SPCs), and 4) clearly septic and 5) aseptic cases. In total, 268 archived synovial fluid samples from 195 patients who underwent acute/chronic revision total hip or knee arthroplasty were included. Cases were classified according to the International Consensus Meeting 2018 criteria. JI panel evaluation of synovial fluid was performed, and the results were compared with cultures.Aims
Methods
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 pathogens. 2. from deep tissue culture in these cohorts were compared. Pathogens were analysed according to aetiology and the presence of metal-work. Results. Both cohorts had similar baseline characteristics. A median of five tissue samples were submitted for each patient. The proportions of specific pathogens remained unchanged between the two cohorts, with the exception of a decrease in the proportion of coagulase-negative Staphylococcus (CoNS) (12.7% vs 5.3%, p<0.05). Although the overall proportion of Staphylococcus aureus remained similar, the rate of MRSA infection decreased in the 2013–2017 cohort when compared to the 2001–2004 cohort (30.7% vs. 10.5% of Staphylococcus aureus, p<0.05). However, the proportion of MDR Enterococcus, Pseudomonas and Enterobacteriaceae did not differ between the two cohorts (37.3% vs. 35.7%). There were no differences in microbiology of the 2013–2017 cohort that related to presence of metal-work or aetiology of infection. A higher proportion of haematogenous osteomyelitis were
Gram-negative periprosthetic joint infection (PJI) has been poorly studied despite its rapidly increasing incidence. Treatment with one-stage revision using intra-articular (IA) infusion of antibiotics may offer a reasonable alternative with a distinct advantage of providing a means of delivering the drug in high concentrations. Carbapenems are regarded as the last line of defense against severe Gram-negative or polymicrobial infection. This study presents the results of one-stage revision using intra-articular carbapenem infusion for treating Gram-negative PJI, and analyzes the characteristics of bacteria distribution and drug sensitivity. We retrospectively reviewed 32 patients (22 hips and 11 knees) who underwent single-stage revision combined with IA carbapenem infusion between November 2013 and March 2020. The IA and intravenous (IV) carbapenem infusions were administered for a single Gram-negative infection, and IV vancomycin combined with IA carbapenems and vancomycin was applied for polymicrobial infection including Gram-negative bacteria. The bacterial community distribution, drug sensitivity, infection control rate, functional recovery, and complications were evaluated. Reinfection or death caused by PJI was regarded as a treatment failure.Aims
Methods