Knee Prosthetic Joint Infection Research Articles

CAN WE PREDICT DAIR FAILURE IN PJI? EXTERNAL VALIDATION OF THE KLIC AND CRIME80 SCORES

IntroductionDebridement, antibiotics irrigation and implant retention (DAIR) is a common management strategy for hip and knee prosthetic joint infections (PJI). However, failure rates remain high, which has led to the development of predictive tools to help determine success. These tools include KLIC and CRIME80 for acute-postoperative (AP) and acute haematogenous (AH) PJI respectively. We investigated whether these tools were applicable to a Waikato cohort.MethodWe performed a retrospective cohort study that evaluated patients who underwent DAIR between January 2010 and June 2020 at Waikato Hospital. Pre-operative KLIC and CRIME80 scores were calculated and compared to success of operation. Failure was defined as: (i) need for further surgery, (ii) need for suppressive antibiotics, (iii) death due to the infection. Logistic regression models were used to calculate the area under the curve (AUC).Results117 eligible patients underwent DAIR, 53 in the AP cohort and 64 in the AH cohort. Failure rate at 2 years post-op was 43% in the AP cohort and 59% in the AH cohort. In the AP cohort a KLIC score of <4 had a DAIR failure rate of 28.6%, while those who scored ³4 had a failure rate of 72.2% (p=0.002). In the AH cohort a CRIME80 score of <3 had a DAIR failure rate of 48% while those who scored ³3 had a 100% failure rate (p<0.001).DiscussionThis study represents the first external validation of the KLIC and CRIME80 scores for predicting DAIR failure in an Australasian population. The results indicate that both KLIC and CRIME80 scoring tools are valuable aids for the clinician seeking to determine the optimal management strategy in patients with AP or AH PJI.

A Meta-Analysis of Success Rates of One-Stage Versus Two-Stage Revisions in Knee Prosthetic Joint Infections.

Prosthetic joint infections (PJIs) pose significant challenges following total joint arthroplasties and cause profound complications. They are associated with significant morbidity and mortality. One-stage revision involves the removal of the infected implant and simultaneous re-implantation of a new prosthesis in a single surgical procedure. The two-stage approach is traditionally more common in the United States and follows a deliberate sequence: the infected implant is first removed, followed by a period of antibiotic therapy, and then a second surgery for implant reinsertion. While two-stage revisions were traditionally considered the gold standard, recent advancements have introduced one-stage revisions as a viable alternative. One-stage revision offers the advantage of being a single procedure, significantly reducing the patient's downtime without a functioning knee. Currently, there has not been a comprehensive exploration of the comparative outcomes between two-stage revisions and one-stage revisions. This systematic review and meta-analysis aimed to assess the outcomes of both one- and two-stage revisions for total knee arthroplasties (TKAs), by utilizing comparison studies as the foundation for analysis. Our search encompassed databases such as MEDLINE (Medical Literature Analysis and Retrieval System Online), Embase, and Cochrane to identify articles examining the comparative efficacy and outcomes of one- and two-stage revision procedures between January 2000 and June 2023. We employed keywords relevant to knee PJIs to identify comparative studies reporting on success rates, reinfection rates, microbiological findings, and other pertinent outcomes. Statistical analysis for this investigation was performed using Review Manager 5.4 (The Cochrane Collaboration, 2020) with a standard significance threshold set at a p-value less than .05. This meta-analysis incorporated six comparison articles and 802 patients. Two-stage revisions (547 patients) were associated with greater success rates (i.e., infection eradication) than one-stage revisions (255 patients) (p = .03). The studies did not suggest a difference in the microbiology of the infections. Two-stage revisions are associated with higher success rates than one-stage revisions in the treatment of knee PJIs. Future randomized controlled trials should evaluate the optimization of the management of these complications.

Use of thioglycolate broth as a pre-analytic transport medium in the diagnosis of prosthetic joint infection.

This study aimed to investigate whether adding tissue samples directly into thioglycolate (TG) broth yielded a greater number of anaerobic organisms than freshly sampled tissue in suspected hip and knee prosthetic joint infections (PJIs). Between January 2017 and December 2020, a total of 90 patients (46 males, 44 females; median age: 71.7 years; range, 50.8 and 87.8 years) who underwent revision hip or knee arthroplasty were included. Intraoperative samples were taken, with five placed in TG broth and five in standard containers (PC) with subsequent aerobic and anaerobic culturing conducted. Demographic and baseline data of the patients were recorded. The primary outcome was positive bacterial growth from a PJI specimen inoculated directly into TG broth at the time of collection or standard PJI specimen processing. Secondary outcomes investigated were the presence of Cutibacterium acnes (C. acnes) and the curative success of revision procedure. A total of 900 samples (450 PC and 450 TG) were taken from 90 revision arthroplasty patients (47 knees and 43 hips). There was no statistically significant difference in the number of positive bacterial growth samples between TG broth and standard processing (p=0.742). This was consistent with subgroup analysis analyzing C. acnes (p=0.666). In hip and knee arthroplasty, there is no benefit in substituting or adding TG broth as a culture medium to better identify both general bacterial species and C. acnes infections specifically. However, the use of TG may be useful in confirming a true positive result for infection.

Outcomes After Pseudomonas Prosthetic Joint Infections.

Pseudomonas species are a less common but devastating pathogen family in prosthetic joint infections (PJIs). Despite advancements in management, Pseudomonas PJIs remain particularly difficult to treat because of limited antibiotic options and robust biofilm formation. This study aimed to evaluate Pseudomonas PJI outcomes at a single institution and review outcomes reported in the current literature. All hip or knee PJIs at a single institution with positive Pseudomonas culture were evaluated. Forty-two patients (24 hips, 18 knees) meeting inclusion criteria were identified. The primary outcome of interest was infection clearance at 1 year after surgical treatment, defined as reassuring aspirate without ongoing antibiotic treatment. Monomicrobial and polymicrobial infections were analyzed separately. A focused literature review of infection clearance after Pseudomonas PJIs was performed. One-year infection clearance was 58% (n = 11/19) for monomicrobial PJIs and 35% (n = 8/23) for polymicrobial PJIs. Among monomicrobial infections, the treatment success was 63% for patients treated with DAIR and 55% for patients treated with two-stage exchange. Monotherapy with an oral or intravenous antipseudomonal agent (minimum 6 weeks) displayed the lowest 1-year clearance of 50% (n = 6/12). Resistance to antipseudomonal agents was present in 16% (n = 3/19), and two of eight patients with monomicrobial and polymicrobial PJIs developed resistance to antipseudomonal therapy in a subsequent Pseudomonas PJI. Polymicrobial infections (55%) were more common with a mortality rate of 44% (n = 10/23) at a median follow-up of 3.6 years. Pseudomonas infections often present as polymicrobial PJIs but are difficult to eradicate in either polymicrobial or monomicrobial setting. A review of the current literature on Pseudomonas PJI reveals favorable infection clearance rates (63 to 80%) after DAIR while infection clearance rates (33 to 83%) vary widely after two-stage revision.

Dyslipidaemia is associated with Cutibacterium acnes hip and knee prosthetic joint infection.

Optimization of medical factors including diabetes and obesity is a cornerstone in the prevention of prosthetic joint infection (PJI). Dyslipidaemia is another component of metabolic syndrome which has not been thoroughly investigated as an individual, modifiable risk factor. This study examined the association of dyslipidaemia with PJI caused by the lipophilic microbe Cutibacterium acnes (C. acnes). A retrospective chart review examined patients with positive C. acnes culture at hip or knee arthroplasty explantation. A control group with methicillin-sensitive Staphylococcus aureus (MSSA) positive cultures at explantation was matched for age, sex, and surgical site, as well as a second control group with no infection. A total of 80 patients were included, 16 with C. acnes, 32 with MSSA, and 32 with no infection. All patients had a lipid panel performed within oneyear of surgery. Lipid values and categories were compared using multinomial logistic regressions. High or borderline triglycerides (TG) (relative risk ratio (RRR) = 0.13; P = 0.013) and low high-density lipoprotein (HDL) (RRR = 0.13; P = 0.025) were significantly associated with C. acnes PJI compared to MSSA-PJI. High or borderline TG (RRR = 0.21; P = 0.041) and low HDL (RRR = 0.17; P = 0.043) were also associated with a greater probability of C. acnes infection compared to no infection. The presence of elevated TG and low HDL were both associated at a statistically significant level with C. acnes hip or knee PJI compared to controls with either MSSA PJI or no infection. This may represent a specific risk factor for C. acnes PJI that is modifiable.

Frequent microbiological profile changes are seen in subsequent-revision hip and knee arthroplasty for prosthetic joint infection.

A proportion of patients with hip and knee prosthetic joint infection (PJI) undergo multiple revisions with the aim of eradicating infection and improving quality of life. The aim of this study was to describe the microbiology cultured from multiply revised hip and knee replacement procedures to guide antimicrobial therapy at the time of surgery. Patients and methods: Consecutive patients were retrospectively identified from databases at two specialist orthopaedic centres in the United Kingdom between 2011 and 2019. Patient were included who had undergone repeat-revision total knee replacement (TKR) or total hip replacement (THR) for infection, following an initial failed revision for infection. Results: A total of 106 patients were identified. Of these patients, 74 underwent revision TKR and 32 underwent revision THR. The mean age at first revision was 67years (SD 10). The Charlson comorbidity index was 2 for 31 patients, 3-4 for 57 patients, and 5 for 18 patients. All patients underwent at least two revisions, 73 patients received three, 47 patients received four, 31 patients received five, and 21 patients received at least six. After six revisions, 90 % of patients had different organisms cultured compared with the initial revision, and 53 % of organisms were multidrug resistant. The most frequent organisms at each revision were coagulase-negative Staphylococcus (36 %) and Staphylococcus aureus (19 %). Fungus was cultured from 3 % of revisions, and 21 % of infections were polymicrobial. Conclusion: Patients undergoing multiple revisions for PJI are highly likely to experience a change in organism, with 90 % of patients having a different organism cultured by their sixth revision. It is therefore important to administer empirical antibiotics at each subsequent revision, taking into account known drug resistance from previous cultures. Our results do not support the routine use of empirical antifungals.

A rare first case of prosthetic knee joint infection by Citrobacter koseri

Citrobacter generally colonizes the gastrointestinal and urogenital tracts of humans, but musculoskeletal infection by Citrobacter in the elderly is extremely rare. To our knowledge, less than 15 cases of causing musculoskeletal infection have been reported in the literature. In the last few years, there has been a considerable increase in the incidence of prosthetic knee joint infection in the United States, with a higher risk of infection in the first two years following surgery. Although gram-positive bacteria like Staphylococcus and Streptococci are more common cause of PJI, gram-negative bacteria can also be found in infected joints. We report the first case of PJI in the left knee due to in an 82-year-old adult two years after bilateral knee arthroplasty. This case report intends to educate and raise awareness for causing PJI as a long term post-op complication even in healthy individuals. We searched articles on Pubmed and Medline for PJI and citrobacter infection. We report clinically and microbiologically confirmed in a synovial fluid sample of the left knee joint. should be considered as a possible pathogen for PJI in long term setting even in an otherwise healthy individual.

Short-term outcomes of articular cement spacer in the treatment of prosthetic knee joint infections: a retrospective case series.

Short-term outcomes of articular cement spacer in the treatment of prosthetic knee joint infections: a retrospective case series.

Functional Outcomes of Knee Arthrodesis for Infected Total Knee Arthroplasty.

As the occurrence of total knee arthroplasties (TKAs) is forecasted to continue rising, so too will the frequency of prosthetic joint infections (PJIs) and revision TKAs. Multiple revisions can result in an unreconstructible knee. In such instances, the knee may be salvaged through arthrodesis. We evaluated whether height, BMI, and age impacted patient-reported outcome measures (PROMs) in patients who underwent knee arthrodesis after revision TKA due to PJI. We conducted a retrospective review of patients undergoing arthrodesis for an infected TKA at a dedicated orthopedic infection service from 2014 to 2022. Patient demographics and PROMs from 36-Item Short Form Survey (SF-36) and Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaires were collected. Correlation analysis was performed to determine if any association between height, BMI, and age was present with the various PROMsand sub-scores. Forty-four patients (19 males, 25 females) were included, with a mean follow-up of 48 months. Increases in height (>166 cm), BMI (>30), and age (>62 years) had a statistically significant negative impact on three SF-36 components: health changes (P = 0.016), physical functioning ability (P = 0.0096), and general health components (P = 0.0075). Our results suggest that a knee arthrodesis is an acceptable option in patients with a persistent knee PJI with good functional PROMs and ambulatory status. Patients with shorter height, lower BMI, and younger age showed overall better outcomes. Knee arthrodesis can be an alternative option for amputationin patients with an infected TKA and provide good functional outcomes in selected patients.

Role of α-Defensin and the Microbiome in Prosthetic Joint Infection: A Prospective Cohort Study in Korea.

The utility of α-defensin (AD), leukocyte esterase (LE) levels, and metagenomics sequencing as diagnostic tools for prosthetic joint infection (PJI) has been suggested, but there are few studies among the Asian population. This study aimed to evaluate the diagnostic performance of various biomarkers for PJI and the role of the microbiome in the synovial fluid of patients with prostheses. Patients with suspected knee PJI were enrolled, and their blood and synovial fluid were collected. The cases were classified into the PJI and non-PJI groups. Significant differences between the two groups were observed in the levels of AD (4698 µg/L vs. 296 µg/L, p < 0.001) and positivity for LE (62.5% vs. 21.1%, p = 0.01). AD had 94.4% sensitivity and 89.5% specificity for diagnosing PJI, whereas LE had 37.5% sensitivity and 100% specificity. Microbiome taxonomic profiling showed high sensitivity. The number of operational taxonomic units and the richness of the microbiome in the synovial fluid were higher in the non-PJI than in the PJI group. AD has shown encouraging results in the Asian population as a diagnostic biomarker for PJI, and LE can be used as a diagnostic adjunct. The bacterial richness of the synovial fluid is likely associated with infections.

Outcome of debridement, antibiotics and implant retention for streptococcal hip and knee prosthetic joint infections: A systematic review and meta-analysis

Outcome of debridement, antibiotics and implant retention for streptococcal hip and knee prosthetic joint infections: A systematic review and meta-analysis

Systemic Inflammatory Response Syndrome and Prosthetic Joint Infection

BackgroundThe development of systemic inflammatory response syndrome (SIRS) criteria leads to increased mortality. Little is known about development of SIRS in patients who have prosthetic joint infection (PJI). We aimed to determine the incidence, risk factors, clinical outcomes, and causative organisms in patients who develop SIRS with PJI. MethodsWe retrospectively identified 655 patients (321 men, 334 women; 382 total hip, 273 total knee) who have hip or knee PJI at 1 institution between July 1, 2015 and December 31, 2020. We formed 2 groups: patients who have SIRS alert (PJI + SIRS) and patients who do not have SIRS alert (PJI). We analyzed clinical outcomes, comorbidities, and operating room culture results. ResultsOf 655 patients, 63 developed SIRS with PJI (9.6%). Intensive care unit (ICU) admission rates (27.0 versus. 6.9%, P < .001) and length of stay (7.7 versus. 5.6 days, P = .003) were greater in PJI + SIRS. At 2 years, reoperation (36.5 versus. 22.3%, P = .01) and mortality rates (17.5 versus. 8.8%, P = .03) were greater in PJI + SIRS. Risk factors included deficiency anemia (P = .001), blood loss anemia (P = .013), uncomplicated diabetes (P = .006), diabetes with complication (P = .001), electrolyte disorder (P < .00001), neurological disorder (P = .0001), paralysis (P = .026), renal failure (P = .005), and peptic ulcer disease (P = .004). Staphylococcus aureus more commonly speciated on tissue cultures in PJI + SIRS (P = .002). ConclusionThe incidence of SIRS is 10% among patients who have PJI. Development of PJI + SIRS is associated with increased lengths of stay, ICU admissions, and 2-year reoperation and mortality rates. Identifying certain comorbidities can stratify patients' risk of developing PJI + SIRS.

Prosthetic knee joint infection caused by α-hemolytic Streptococcus species: a case report

BackgroundKnee arthroplasty is an orthopedic surgical procedure in which a damaged joint is replaced with an artificial one. It is estimated that 1–2% of knee arthroplasties will encounter infection over their lifetime. Although α-hemolytic Streptococcus species play an important role in prosthetic joint infection, they are less common than staphylococcal species.Case presentationIn this report, a 50-year-old Iranian woman was diagnosed with prosthetic knee joint infection based on clinical, radiological, and laboratory findings. She was diabetic and had undergone a left total knee arthroplasty, which, 18 months after the surgery, presented pain, erythema, and edema in that knee. The primary culture of knee aspirate was positive for α-hemolytic Streptococcus species, but following antibiotic medication, culture was negative. The primary antibiotic regime was vancomycin and meropenem, which was changed to cefepime for the management of the infection based on the results of antimicrobial susceptibility testing.ConclusionsThis report indicated the clinical presentation and management of the patient with prosthetic joint infection in which the patient recovered without any severe complications or surgical intervention.

The Utility of Flap Coverage for Limb Salvage in Patients With Severe Prosthetic Joint Infections of the Knee Requiring Implant Exchange.

Prosthetic joint infection (PJI) is a challenging complication of knee arthroplasty, which can require amputation in severe cases. This study analyzes the utility of flap reconstruction in PJIs requiring hardware removal and extensive soft tissue debridement. This was a retrospective analysis of patients who were treated according to a multistage extremity salvage protocol between 2018 and 2022. The protocol involved at least 3 planned surgeries including (1) hardware removal with antibiotic spacer placement and soft tissue debridement, (2) spacer exchange with flap coverage, and (3) hardware reimplantation with simultaneous or delayed extensor mechanism reconstruction. All patients had large periprosthetic tissue defects that would necessitate an amputation if not reconstructed. Primary outcomes were extremity salvage and successful defect coverage. Fifty-two patients (25 female) underwent 62 reconstructions (52 primary, 10 salvage). Flap techniques included pedicled muscular (n = 32), fasciocutaneous (n = 4), combined muscular and fasciocutaneous (n = 2), and free flaps (n = 24). Overall rate of successful defect coverage was 95% (98% in primary and 80% in salvage reconstructions). At a median follow-up of 11 months, 41 patients completed the treatment protocol with a 68% (n = 28) extremity salvage rate (reimplantation arthroplasty, n = 15; permanent knee fusion, n = 13). On the multivariate model including demographic factors, defect size, and flap type, no single factor independently predicted limb salvage. Alongside intensive orthopedic surgical treatment, flap coverage may aid in extremity salvage in severe knee PJIs by reestablishing healthy soft tissue coverage and allowing reimplantation arthroplasty. We recommend a multispecialty approach including plastic surgeons for this challenging condition.

Dalbavancin as suppressive antibiotic therapy in patients with prosthetic infections: efficacy and safety.

Suppressive antibiotic therapy (SAT) is a strategy to alleviate symptoms and/or to reduce the progression of an infection when other treatment options cannot be used. Dalbavancin, due to its prolonged half-life, enables (bi) weekly dosing. Here, we report our multicenter real-life clinical experience with dalbavancin used as SAT in patients with prosthetic joint or vascular infections. Medical records of all adult patients with documented vascular or orthopedic chronic prosthetic infections, who received dalbavancin as SAT between 2016 and 2018 from four Spanish hospitals were reviewed for inclusion. Descriptive analysis of demographic characteristics, Charlson Comorbidity index, Barthel index, isolated pathogens and indication, concomitant antibiotic use, adverse events, and clinical outcome of SAT were performed. Eight patients were eligible for inclusion, where six patients had prosthetic vascular infections (aortic valve) and two patients had knee prosthetic joint infections. The most common pathogens were methicillin-susceptible Staphylococcus aureus and Enterococcus faecium. All patients had a history of prior antibiotic treatment for the prosthetic infection [median duration of antibiotic days 125days (IQR, 28-203days)]. The median number of dalbavancin doses was 29 (IQR, 9-61) and concomitant antibiotic use (n = 5, 62.5%). Clinical success was reported in 75% (n = 6) of patients. Adverse events were reported in two patients (mild renal and hepatic impairment). The median estimated cost savings due to the avoided hospital days was €60185 (IQR, 19,916-94984) per patient. Despite the limitations of our study, this preliminary data provides valuable insight to support further evaluation of dalbavancin for SAT in patients with prosthetic infections in the outpatient setting when alternative treatments are not feasible.

Hematogenous prosthetic knee joint infection with Klebsiella pneumoniae caused by asymptomatic gallbladder abscess: a case report and literature review

Abstract Klebsiella pneumoniae has the ability to form biofilm; therefore, the treatment of prosthetic joint infection involving K. pneumoniae is often challenging. This report describes the first case of acute hematogenous prosthetic knee joint infection with K. pneumoniae that occurred as a result of an asymptomatic gallbladder abscess. The patient was a 78-year-old man who underwent bilateral total knee arthroplasty 6 years ago. He had pain and swelling in his right knee. The synovial fluid culture of the right knee revealed K. pneumoniae and prosthetic joint infection was diagnosed. Computed tomography revealed a gallbladder abscess in the absence of right upper abdominal pain. The patient underwent simultaneous debridement of the knee and open cholecystectomy. The treatment was successful and the prosthesis was retained. In cases of hematogenous prosthetic joint infection with K. pneumoniae, other sources of infection should be suspected and investigated regardless of whether they are symptomatic.

Treatment and Outcomes of Fungal Prosthetic Joint Infections: A Systematic Review of 225 Cases

BackgroundFungal prosthetic joint infections (PJIs) after a total joint arthroplasty are a rare, yet severe, occurrence not often reported in the literature. Unlike in bacterial PJIs, no clear consensus exists on fungal PJI optimal management. MethodsA systematic review was performed using the PubMed and Embase databases. Manuscripts were assessed for inclusion and exclusion criteria. The Strengthening the Reporting of Observational Studies in Epidemiology checklist was applied for quality assessment. Individual demographic, clinical, and treatment information was retrieved from included manuscripts. ResultsSeventy one patients who had a PJI of the hip and 126 of the knee were included. Infection recurrence occurred in 29.6% and 18.3% of patients with hip or knee PJI, respectively. Patients who had knee PJIs recurrence had a significantly higher Charlson Comorbidity Index (CCI). For knee PJIs, infection recurrence was more common in patients with Candida albicans (CA) PJIs (P = .022). Two-stage exchange arthroplasty was the most common procedure in both joints. Multivariate analysis found that CCI ≥ 3 was associated with an 18.5-fold increase in the risk of knee PJI recurrence (Odds ratio [OR] = 18.57). Additional risk factors for recurrence in the knee included CA etiology (OR = 3.56) and C-reactive protein at presentation ≥ 6 (OR = 6.54). Compared to debridement, antibiotics, and implant retention, 2-stage procedure was a protective factor for PJI recurrence in the knee (OR = 0.18). No risk factors were found in patients who had hip PJIs. ConclusionTreatment of fungal PJIs varies widely, but 2-stage revision is the most common. Risk factors for knee fungal PJI recurrence include elevated CCI, infection by CA, and high C-reactive protein at presentation.

Success of Debridement, Antibiotics, and Implant Retention in Prosthetic Joint Infection Following Primary Total Knee Arthroplasty: Results From a Prospective Multicenter Study of 189 Cases

BackgroundThis study aimed to identify the success rate of debridement, antibiotics, and implant retention (DAIR) for prosthetic joint infection (PJI) in a large prospective cohort of patients undergoing total knee arthroplasty (TKA). The ability for different PJI classification systems to predict success was assessed. MethodsProspective data recorded in the Prosthetic Joint Infection in Australia and New Zealand Observational study were analyzed. One hundred eighty-nine newly diagnosed knee PJIs were managed with DAIR between July 2014 and December 2017. Patients were prospectively followed up for 2 years. A strict definition of success was used, requiring the patient being alive with documented absence of infection, no ongoing antibiotics and the index prosthesis in place. Success was compared against the Coventry (early PJI ≤1 month), International Consensus Meeting (early ≤90 days), Auckland (early <1 year), and Tsukayama (early ≤1 month, hematogenous >1 month with <7 days symptoms, chronic >1 month with >7 days symptoms) classifications. ResultsDAIR success was 45% (85/189) and was highest in early PJIs defined according to the Coventry (adjusted odds ratio [aOR] = 3.9, P = .01), the International Consensus Meeting (aOR = 3.1, P = .01), and the Auckland classifications (aOR = 2.6, P = .01). Success was lower in both hematogenous (aOR = 0.4, P = .03) and chronic infections (aOR = 0.1, P = .003). ConclusionTime since primary TKA is an important predictor of DAIR success. Success was highest in infections occurring <1 month of the primary TKA and progressively decreased as time since the primary TKA increased.

Ultrasonography performed by an infectiologist in hip and knee prosthetic joint and native joint infections

IntroductionClinical ultrasonography (US) by infectiologists has only recently been developing, and as now there is little literature on the subject. Our study focuses on the conditions and diagnostic performance of clinical ultrasound imaging by infectiologists in cases of hip and knee prosthetic and native joint infection. MethodsA retrospective study carried out between June 1st 2019 and March 31st 2021 in the University Hospital of Bordeaux, South-Western France. We measured US sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV), combined or not with the analysis of articular fluid, compared to the MusculoSketetal Infection Society (MSIS) score in prosthetic joints, or to expert diagnosis in native joints. ResultsFifty-four patients underwent US by an infectiologist in an infectious disease ward, including 11 (20.4%) for native joint and 43 (79.6%) for prosthetic joint. Joint effusion and/or periarticular collection were highlighted in 47 (87%) patients, and US led to 44 punctures. In all patients (n = 54), Se, Sp, PPV and NPV of US alone were 91%, 19%, 64% and 57%, respectively. When US was combined with fluid analysis, Se, Sp, PPV, NPV were 68%, 100%, 100%, 64% in all patients (n = 54), 86%, 100%, 100%, 60% in acute arthritis (n = 17) and 50%, 100%, 100% and 65% respectively in non-acute arthritis (n = 37). ConclusionThese results suggest that US by infectiologists effectively diagnoses osteoarticular infections (OAIs). This approach has many applications in infectiology routines. Consequently, it would be interesting to define the contents of a first level of infectiologist competence in US clinical practice.

THE PROFILE OF CAUSAL PATHOGEN OF HIP/ KNEE PROSTHETIC JOINT INFECTION (PJI): A SINGLE CENTER STUDY

Introduction: One of the most challenging and serious complications associated with total joint arthroplasty is prosthetic joint infection (PJI). Advancements in prevention, diagnosis, and treatment of PJI seem promising. Accurate identification of the causal pathogen is a key factor for successful treatment and also for choosing antibiotic treatment. This study was aimed to evaluate the prevalence of PJI and distribution of causative pathogen using microbiological culture and pathological examination. Methods: A retrospective descriptive study was conducted by collecting data from our center registry from 2018 to 2020. The inclusion criteria of this study were patients diagnosed with hip or knee PJI based on the diagnostic criteria for PJI. The exclusion criteria were incomplete microbiology data which were either refusal to participate or loss of contact. The data extracted from medical records are demographic data such as age, sex, and microbiology and pathological examination data. Results: A total of 1359 total hip/ knee arthroplasty surgeries were performed during the years 2018–2020. Among them, 1031 were total knee arthroplasty (TKA) and 321 were total hip arthroplasties (THA). During the same period, a total of 52 patients with PJI were treated at our center. There were 31 knee PJI cases (59.61%) and 21 were hip PJI cases (40.38%). Microbiology culture and pathologic anatomy results showed gram positive Staphylococcus sp bacteria, which was the common causal pathogen of PJI. Negative culture results were found in 10/52 (19.23%) of cases. Conclusions: Staphylococcus sp was the most common causal pathogen of Hip/ Knee PJI in our center. Relatively high rate of culture-negative PJI was observed in this study, further strategies are needed to increase the rate of causal pathogen isolation in hip/ knee PJI cases in our center.