Fungal Prosthetic Joint Infection Research Articles

Fungal Prosthetic Joint Infection: A Case Series and Review of the Literature.

Fungal prosthetic joint infections comprise less than 1% of prosthetic joint infections. Thus, little is known regarding optimal management. This study aims to characterize the microbiology, surgical and medical management, and outcomes for these complex infections. The objectives of this study were to assess the impact of surgical approach, antifungal treatment, fungal species, and time to onset of infection from initial surgery on patient outcomes. A retrospective record review over 12years was performed in two health systems that included patients with a deep culture positive for a fungal isolate and the presence of a prosthetic joint. A literature review was performed using the same inclusion criteria. A total of 289 cases were identified and analyzed. Candida was the most common isolate, and a two-stage revision was the most commonly employed surgical modality. The type of surgical intervention had a statistically significant relationship with outcome (P = 0.022). Two-stage revision with extended antifungal therapy is preferred in these infections due to higher rates of positive outcomes.

Fungal Prosthetic Joint Infection

Fungal Prosthetic Joint Infection

Dual Organism Periprosthetic Joint Infection Following Total Knee Arthroplasty: A Case Report and One Year Follow-Up

Abstract Periprosthetic joint infections (PJI) of the knee are mostly due to a single organism, very rarely, it is due to dual organisms, and even rarer are dual Gram-negative bacilli and fungal infections. Most fungal infections are caused by Candida albicans; however, very few case reports are available for nonalbicans Candida in immunocompetent patients. We report an unusual case of nonalbicans Candida infection with Gram-negative bacilli in the knee joint with no predisposing risk factors. A 59-year-old man reported following mild pain, swelling, and restricted knee movements in a case of a primary total knee arthroplasty. The patient had minimal symptoms but had gross lysis around implants on imaging. His inflammatory markers were significantly high and knee aspiration was turbid, with raised polymorphs without any conclusive staining result. The culture reports revealed a fungal and Gram-negative organism infection. The patient was managed by debridement, prosthesis removal and antibiotic-loaded cement spacer insertion, and culture-specific antibiotics, followed by revision TKA and oral fluconazole therapy. The patient had a good clinical performance at 3 months and 1-year follow-up visits, with a painless range of motion of 10°–90° and there was no evidence of recurrence of infection. Dual Gram-negative and fungal prosthetic joint infection is a rare but serious complication. In the presence of mild clinical symptoms, but extensive lysis around the implant, fungal pathology should be considered irrespective of the immune status of the patient.

1309. Fungal Prosthetic Joint Infection - Case Series and Review of the Literature

Abstract Background The most effective treatment for fungal prosthetic joint infections remains unclear. Most cases are treated with two-stage revisions combined with systemic antifungal medications. To date, the largest studies of total hip arthroplasty and total knee arthroplasty fungal infections have included 37 and 45 patients, respectively. Methods A retrospective record review of patients admitted in two health systems between January 1, 2007 and December 31, 2018 with prosthetic joints and a deep culture of the joint positive for fungal organisms was performed as well as a review of the literature. A Pubmed and Embase search of the English-language literature from Jan 1, 1980 to Jan 1, 2023 was performed with review of the pertinent references for cases meeting the following case definition: individual with prosthetic joint and positive deep tissue culture for fungus. Results 159 patients fit criteria. 73 patients had knee replacements, 62 patients had hip replacements, and 5 had other joint involvement. 52% were female. 137 patients had yeast involvement, with Candida species being predominant, while 11 had mold and 11 with dimorphic infections. 55 patients were treated with two-stage revisions, 44 received one-stage revisions, 32 received debridement only or Girdlestone procedure, and 1 required amputation. 141 reported details on antifungal therapy. After performing multivariate analysis, polyene treatment was found to be associated with higher rate of recovery, p=0.042. However, there was a trend towards recurrence requiring surgical intervention in patients treated with polyenes, p=0.067. 22.6% had a poor outcome, including recurrence, amputation, or death. Conclusion Surprisingly, polyenes did not underperform when compared to other antifungal therapy. Prospective research assessing optimal surgical treatment modality and antifungal therapy is needed as this infection is associated with high morbidity and mortality. Disclosures All Authors: No reported disclosures

1312. Incidence and Microbiology of Prosthetic Joint Infection According to Time Following Total Knee Arthroplasty: A Retrospective Cohort Study Among US Veterans

Abstract Background Despite the frequency of total knee arthroplasty (TKA) and clinical impact of prosthetic joint infections (PJIs), the incidence and microbiology of these infections in the United States remains unclear. Our objective was to determine the incidence of PJI occurring ≤ 3 months (early), between > 3 and ≤ 12 months (delayed), and > 12 months (late) after primary TKA and to identify the organisms isolated from microbiologic cultures during each of these periods. Methods We conducted a retrospective study of patients in the Veterans Aging Cohort Study- National Cohort who underwent elective primary TKA in the VA between October 1, 1999 to September 30, 2019. The primary outcome was incident hospitalization with PJI. We estimated incidence rates (events/10,000 person-months) with 95% confidence intervals (CIs) of early, delayed, and late PJI. Poisson regression was used to estimate the incidence rate ratio (IRR) with 95% CI of early and delayed PJI compared to late PJI. The Kaplan-Meier method was used to demonstrate the cumulative incidence of PJI at 3, 12 and 24 months. We measured the frequency of Gram-positive, Gram-negative, fungal, polymicrobial, and culture-negative PJI occurring within each of the three time periods and compared frequencies of interest using Pearson’s chi-squared tests. Results Among 82,401 VHA patients who underwent primary TKA, a total of 1,605 incident PJIs (1.9%) were identified. The incidence rate of PJI was higher in the first 12 months after primary TKA surgery, with an IRR of 20.4 (95% CI, 18.2-222.8) for early and 4.2 (95% CI, 3.7-4.8) for delayed periods when compared to late. The cumulative incidence of PJI at 3 months was 0.77% (95% CI, 0.71-0.83%), at 12 months was 1.25% (95% CI 1.17-1.33%), and at 24 months was 1.56% (95% CI 1.48-1.65%) (Figure 1). Staphylococcus aureus was the most common organism isolated (33.2%) across the periods. Gram-negative bacteria were isolated in 11.1% of all infections, and 15.1% of early PJIs (Table 1). Kaplan Meier failure curves for prosthetic joint infection for the overall study period (upper panel) as well as the first 24 months (lower panel) following primary total knee arthroplasty. Abbreviations: PJI, prosthetic joint infection; CI, confidence interval.Table 1.Organisms isolated from synovial fluid or operative tissue cultures of early, delayed and late prosthetic joint infections after primary total knee arthroplasty. aAmong the 1,605 PJIs in the Overall Cohort, the microbiology data for 103 were missing and 1,502 PJIs with available microbiology data were included in these results. bPolymicrobial defined by multiple genera of organisms identified cIncludes: Micrococcus species, diphtheroids dIncludes: Salmonella, Pasteurella, Citrobacter, Morganella, Acinetobacter, Pasteurella, Burkholderia species, and Gram-negative organisms not otherwise specified eAll fungal infections were identified as Candida species fNumbers may not sum to group totals or percentages as polymicrobial infections with more than one organism were possible Abbreviations: PJI, prosthetic joint infection. Conclusion Incidence rates of early and delayed PJI were significantly higher than late PJI following primary TKA. Gram-negative organisms were more prevalent in early compared to delayed or late PJI. Empiric Gram-negative antibiotic therapy should be considered with a suspected PJI within 3 months after elective primary TKA. Disclosures Alisa Stephens-Shields, PhD, Gilead Sciences: Advisor/Consultant Charles Nelson, MD, Stryker: Advisor/Consultant|Zimmer-Biomet: Advisor/Consultant|Zimmer-Biomet: Grant/Research Support

High Rates of Treatment Failure and Amputation in Modular Endoprosthesis Prosthetic Joint Infections Caused by Fungal Infections With Candida.

Fungal prosthetic joint infections (PJIs) are rare yet severe events associated with high rates of recurrent infection. Although bacterial PJIs associated with megaprostheses are known to be associated with higher rates of recurrence and amputation, little is known about fungal PJIs near megaprostheses. In patients with fungal megaprosthesis PJIs from one institutional registry, We asked: (1) what were the most common microorganisms isolated? (2) What were the reoperation-, revision-, and amputation-free survival rates 1 and 2 years after surgery? We conducted a retrospective analysis of megaprostheses in our institutional database. Between 2000 and 2022, 86 patients with a diagnosis of PJI after megaprosthesis implantation were surgically treated at our institution. We considered patients with microbiological cultures that were positive for fungal organisms and who had a minimum follow-up of 2 years from the initial treatment for PJI. Ten patients with fungal megaprosthesis PJIs were included. Although four patients had a follow-up shorter than 2 years, all reached one of the study endpoints at that earlier interval, and therefore were included. All included patients were treated between 2016 and 2022, and the diagnosis of PJI was made in accordance with the 2011 Musculoskeletal Infection Society criteria. Patients were treated with either debridement, antibiotics, and implant retention (DAIR), DAIR-plus (debridement, antibiotics, modular implant component exchange, and stem retention), or one-stage or two-stage revision. In general, DAIR was used for acute PJIs, while DAIR-plus was performed in patients with chronic PJIs who were deemed medically unfit to endure the high morbidity associated with removal of the stems. In cases of prior unsuccessful DAIR-plus or patients with fewer comorbidities, one-stage or two-stage revision was the main treatment approach. The median age at diagnosis was 67 years (range 32 to 84 years), 5 of 10 patients were female, and the median BMI was 31 kg/m2 (range 20 to 43 kg/m2). The median follow-up was 26 months (range 1 to 54 months). A Kaplan-Meier survival analysis was performed to calculate reoperation-, revision-, and amputation-free survival at 1 and 2 years from the index surgery for PJI. The two most common organisms were Candida albicans (5 of 10 patients) and C.parapsilosis (3 of 10). Six of 10 patients had coinfection with a bacterial organism. One-year reoperation-free and revision-free survival were 35% (95% CI 9% to 64%) and 42% (95% CI 11% to 71%), respectively. Two-year reoperation-free and revision-free survival were 12% (95% CI 1% to 40%) and 14% (95% CI 1% to 46%), respectively. Amputation-free survival was 74% (95% CI 30% to 93%) at the 1-year interval and 40% at the 2-year interval (95% CI 7% to 73%). At the final follow-up interval, four patients had undergone amputations and four were being administered chronic antifungal suppression. Megaprosthesis fungal PJIs are rare but devastating. Arthroplasty surgeons should consider treatment efficacy, which appears to be low across surgical strategies, and the patient's capacity to withstand it. A lower decision threshold for performing amputation may be considered in patients who require rapid infection control to initiate immunosuppressive treatments. Future studies should aim to compare the surgical and clinical outcomes of fungal PJIs with those of other etiologies while controlling for potential variables. Efforts should be made to establish multi-institutional collaborations to achieve larger study samples. Level IV, therapeutic study.

Prosthetic joint infection in the hip and knee

Prosthetic joint infection (PJI) is one of the worst complications of joint arthroplasty with an incidence of around 1% following primary arthroplasty, 3% following aseptic revision, and 20% following septic revision. It can occur following direct inoculation, haematogenous or contiguous spread. The majority of PJIs are secondary to bacterial infection although fungal PJI may be seen in multiply operated or immune compromised patients. Risk factors for PJI include patient, pathology and procedure-related factors which, where possible, should be optimized prior to surgery. The diagnosis of PJI remains a challenge and is based on patient history, clinical examination, laboratory tests, and imaging studies. No diagnostic assessment is 100% accurate with various diagnostic criteria used clinically. Investigation and treatment of PJI should be guided by a multi-disciplinary team. Surgical treatment remains the gold standard with the aim of eradicating infection. During surgery the causative organism is sought through a rigorous standardized tissue sampling technique. Surgical approaches including debridement, antibiotics and implant retention (DAIR), single-stage revision, two-stage revision, excision arthroplasty, arthrodesis and amputation. The approach used is tailored to the individual patient with the optimum surgical strategy being one that successfully eradicates the infection, but at the same time minimizes morbidity to the patient.

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.

A Case of Prosthetic Infection with Candida Growth in the Knee Joınt

Introduction: Fungal prosthetic joint infections, constitute a small portion of all prosthetic infection cases and candida species are the causative agent in the majority of these cases. Most fungal prosthetic joint infections occur after revision arthroplasty. Case: A 72-year-old male patient, underwent total knee prosthesis operation for the right knee due to gonarthrosis. About 5 months later, he was hospitalized and treated due to bacterial prosthesis infection. 8 days after discharge, he applied again with the complaints of swelling, pain, temperature increase and redness in the right knee. He was hospitalized again due to prosthesis infection. Antifungal treatment was started for the patient due to the growth of Candida albicans in the knee joint. A total of 2.5 months of antifungal therapy was given. The patient, who recovered without any problems, continues to follow up in the outpatient clinic. Discussion: In this case report, we wanted to emphasize that in the presence of risk factors in prosthesis infection, we should not forget that the cause may also be fungus, that culture should be taken during the operation and that effective and long-term antifungal treatment should be given in fungal-related prosthesis infections.

Epidemiology of Fungal Periprosthetic Joint Infection: A Systematic Review of the Literature.

Fungal prosthetic joint infection (fPJI) is a rare complication; nonetheless, it represents a significant diagnostic and therapeutic challenge. There are no official guidelines on the most effective approach to identify and treat fPJIs. This systematic review aims to review the current literature on fPJI management and provide a comprehensive overview of this topic, especially from an epidemiologic point of view. Studies eligible for this systematic review were identified through an electronic systematic search of PubMed, Scopus, and Web of Science until 30 September 2022. Further references were obtained by cross-referencing. Sixty-three studies met the inclusion criteria, reporting on 372 cases of fPJI; such cases were described mostly in case reports and small case series with only a few larger cohort studies. Diagnosis of fPJI is challenging because of its chronic and indolent clinical course; it is further complicated by the technical difficulty of harvesting fungal cultures. A two-stage revision was the primary procedure in 239 (64.2%) patients whereas DAIR and one-stage approaches were reported in 30 (8.0%) and 18 (4.8 %) cases. In conclusion, our study highlights the heterogeneity of the reported treatments of fPJI, particularly in terms of medical management. With concern to a surgical approach, a two-stage revision arthroplasty is generally suggested, considering fPJI a delayed or late infection. The need for multicenter, prospective studies to provide standardized protocols and improve the treatment of fungal PJI clearly emerges.

Prosthetic Knee Joint Infection Due to Candida lusitaniae: A Diagnostic and Therapeutic Odyssey: A Case Study

Prosthetic joint infections (PJIs) caused by fungi, although relatively rare, represent a major surgery-related complication. An extremely rare fungal PJI, following revised total knee replacement (TKR) caused by Candida lusitaniae, is reported, and a meticulous review of similar cases is provided. A 74-year-old female, who underwent primary total knee arthroplasty 10 years ago and a revision surgery three weeks ago, presented with signs and symptoms of PJI. C. lusitaniae was eventually isolated from the periprosthetic tissue using the MALDI-TOF VitekMS-bioMérieux technique. Multiple strategies for managing this fungal PJI were performed, and finally, the patient was treated successfully with an intramedullary arthrodesis system and proper antifungal treatment, including fluconazole. A multidisciplinary approach is essential for the diagnosis and treatment of such severe infections. In persistent cases and in cases where revision surgery is extremely difficult to perform, arthrodesis seems to be an effective solution for the elimination of the infection. The efficacy of the therapeutic management of fungal PJIs remains unclear. Therefore, more research should be reported, focusing on proper treatment so that the optimal strategy in treating these severe infections may be established.

Fungal Periprosthetic Hip Joint Infections.

Introduction: Fungal hip prosthetic joint infections (PJIs) are rare but severe infections. Their incidence has increased in the last decades due to the aging population, as well as due to the increased number of immunosuppressed hosts. The present review of all published fungal PJIs in hip arthroplasties aims to present as much data as possible for both medical and surgical treatment options, so that the best applicable management may be concluded. Methods: A meticulous review of all published fungal hip PJIs was conducted. Information regarding demographics, causative fungus, antifungal treatment (AFT), surgical management as well as the infection outcome was recorded. Results: A total of 89 patients suffering fungal hip PJI were identified. The patients’ mean age was 66.9 years. The mean time from initial arthroplasty to onset of symptoms was 69.3 months, while 40.4% of the patients were immunocompromised. The most common imaging method indicating diagnosis was plain X-ray or CT scan (20.2%), while definite diagnosis had become possible through cultures in most cases (98.9%), and/or histology (44.9%). The most frequently isolated fungus was C. albicans (49.4%), followed by C. parapsilosis (18%) and C. glabrata (12.4%), while bacterial co-infection was present in 32 cases (36%). Two-stage revision arthroplasty (TSRA) was the most commonly performed procedure (52.8%), with mean time between the two stages = 7.9 months. Regarding antifungal treatment (AFT), fluconazole was the preferred agent (62.9%), followed by amphotericin B (36%), while the mean duration of AFT was 5.1 months. Outcome was successful in 68 cases (76.4%). Conclusions: Both diagnosis and management of fungal PJIs in patients having undergone total hip arthroplasty are quite demanding. A multidisciplinary approach is of utmost importance, since the combination of AFT and TSRA appears to be the proper treatment method.

257. Outcomes in Fungal Prosthetic Joint Infection

Abstract Background There is a paucity of data in the literature regarding the most effective treatment and related outcomes of fungal prosthetic joint infection. The majority of reported cases are treated using a two stage revision method in which the initial prosthesis is removed and the patient is treated with systemic antifungal medications and potentially irrigation of the joint cavity with antifungal and antibacterial agents. Alternately, others have suggested a one-stage revision in order to prevent a period of significant functional impairment and potentially improved functional outcomes and lower overall costs. Cases of radical removal of the prosthesis without replacement have been reported. To date, the largest studies of total hip arthroplasty and total knee arthroplasty have included 37 and 45 patients, respectively. Methods A retrospective record review of patients admitted within two health systems between January 1, 2007 and December 31, 2018 with prosthetic joints and a deep culture of the joint positive for fungal organisms was performed. Results Eighteen patients fit criteria. Nine patients had knee replacements and nine patients had hip replacements. The average age at time of infection was 61. Ten patients were female. Average BMI was 32.1. Twelve presented with a painful joint, eight presented with drainage, and one with dehiscence. Average WBC count was 9.3, average ESR was 47, and average CRP was 11.8. All patients were noted with Candida species. Eight patients were treated with two stage revisions, three received one stage revisions as destination therapy. One required amputation. All but one patient was associated with concurrent bacterial infection. Of the twelve patients that had known outcomes, six were noted with cure and six were noted with relapse. All patients that were cured received two stage exchange or girdlestone procedure. Conclusion In our study, fungal prosthetic joint infection was associated with poor outcomes. All of the patients in our study were noted with Candida species, which is in concordance with the known literature. Two stage exchange was associated with better outcomes. Disclosures All Authors: No reported disclosures

Non-Candida Fungal Prosthetic Joint Infections.

Background: Fungal prosthetic joint infections (PJIs) are rare, especially those caused by non-Candida species. Treatment has not been fully elucidated, since a plethora of antifungal and surgical interventions have been proposed. Τhis study represents an effort to clarify the optimal management of non-Candida fungal PJIs, by reviewing all relevant published cases. Methods: A thorough review of all existing non-Candida fungal PJIs in the literature was conducted. Data regarding demographics, responsible organisms, antifungal treatment (AFT), surgical intervention, time between initial arthroplasty and onset of symptoms, and time between onset of symptoms and firm diagnosis, as well as the infection’s outcome, were evaluated. Results: Forty-two PJIs, in patients with mean age of 66.2 years, were found and reviewed. Aspergillus spp. were isolated in most cases (10; 23.8%), followed by Coccidioides spp. (7; 16.7%) and Pichia anomala (5; 11.9%). Fluconazole was the preferred antifungal regimen (20 cases; 47.6%), followed by amphotericin B (18 cases; 42.9%), while the mean AFT duration was 9.4 months (SD = 7.06). Two-stage revision arthroplasty (TSRA) was performed in 22 cases (52.4%), with the mean time between stages being 5.2 months (SD = 2.9). The mean time between initial joint implantation and onset of symptoms was 42.1 months (SD = 50.7), while the mean time between onset of symptoms and diagnosis was 5.8 months (SD = 14.3). Conclusions: Non-Candida fungal PJIs pose a clinical challenge, demanding a multidisciplinary approach. The present review has shown that combination of TSRA separated by a 3–6-month interval and prolonged AFT has been the standard of care in the studied cases.

Risk Factors for Fungal Prosthetic Joint Infection.

Background: Fungal prosthetic joint infections (PJIs) are rare and often associated with poor outcome; however, risk factors are not well described.Methods: This was a retrospective case control study among all patients with PJIs from 2006-2016 at two major academic centers. Each fungal PJI case was matched 1:1 with a bacterial PJI control by joint (hip, knee, shoulder) and year of diagnosis. We compared demographics, comorbidities, and clinical characteristics between cases and controls using chi square/Fisher's exact or Wilcoxon rank sum test. Independent risk factors were identified with multivariable logistic regression.Results: Forty-one fungal PJIs occurred over the study and 61% were due to Candida albicans. The hip was involved in 51.2% of cases, followed by the knee (46.3%). Compared to bacterial PJI, fungal PJI cases were more likely to have received antibiotics within the previous 3 months (70.7% vs 34%, P=.001), wound drainage lasting >5 days (48% vs 9%, P=.0002), had a lower median CRP (2.95 mg/dl vs 5.99, P=.013) and synovial fluid white blood cell count (13,953 cells/mm3 vs 33,198, P=.007), and a higher proportion of prior two-stage exchanges (82.9% vs 53.6%, P=.008). After controlling for center, prolonged wound drainage (OR, 7.3; 95% CI, 2.02-26.95) and recent antibiotics (OR, 3.4; 95% CI, 1.2-9.3) were significantly associated with fungal PJI.Conclusion: In our study, Candida albicans was the most common species in fungal PJIs and prolonged wound drainage and recent antibiotics were independent risk factors. These clinical characteristics may help providers anticipate fungal PJI and adjust management strategies.

Release of different amphotericin B formulations from PMMA bone cements and their activity against Candida biofilm

Amphotericin B is used for local delivery from polymethylmethacrylate to treat fungal prosthetic joint infections. The optimal amphotericin B formulation and the influence of different poragens in the bone cements are unknown. To investigate the necessary amount of amphotericin B in the bone cement to prevent Candida biofilm several amphotericin B formulations were studied: non-liposomal and liposomal with or without poragen gentamicin. For the non-liposomal formulation, standard bile salt, the sodium deoxycholate, was used and additionally N-methyl-D-glucamine/palmitate was applied. The activity of the released amphotericin B was tested against C. albicans, C. glabrata, C. parapsilosis and C. krusei biofilms with application of the isothermal calorimeter and standard microbiological methods. Compressive strength was measured before and after antifungal elution from the cements. There is less aggregated N-methyl-D-glucamine/palmitate amphotericin B released but its antifungal activity is equivalent with the deoxycholate amphotericin B. The minimum quantity of antifungal preventing the Candida biofilm formation is 12.5 mg in gram of polymer powder for both non-liposomal formulations. The addition of gentamicin reduced the release of sodium deoxycholate amphotericin B. Gentamicin can be added to N-methyl-D-glucamine/palmitate amphotericin B in order to boost the antifungal release. When using liposomal amphotericin B more drug is released. All amphotericin B formulations were active against Candida biofilms. Although compressive strength slightly decreased, the obtained values were above the level of strength recommended for the implant fixation. The finding of this work might be beneficial for the treatment of the prosthetic joint infections caused by Candida spp.

Prosthetic fungal infections: poor prognosis with bacterial co-infection.

The aims of this study were to report the efficacy of revision surgery for patients with co-infective bacterial and fungal prosthetic joint infections (PJIs) presenting to a single institution, and to identify prognostic factors that would guide management. A total of 1189 patients with a PJI were managed in our bone infection service between 2006 and 2015; 22 (1.85%) with co-infective bacterial and fungal PJI were included in the study. There were nine women and 13 men, with a mean age at the time of diagnosis of 64.5 years (47 to 83). Their mean BMI was 30.9 kg/m2 (24 to 42). We retrospectively reviewed the outcomes of these PJIs, after eight total hip arthroplasties and 14 total knee arthroplasties. The mean clinical follow-up was 4.1 years (1.4 to 8.8). The median number of risk factors for PJI was 5.5 (interquartile range (IQR) 3.25 to 7.25). All seven patients who initially underwent debridement and implant retention (DAIR) had a recurrent infection that led to a staged revision. All 22 patients underwent the first of a two-stage revision. None of the nine patients with negative tissue cultures at the second stage had a recurrent infection. The rate of recurrent infection was significantly higher in the presence of multidrug-resistant bacteria (p = 0.007), a higher C-reactive protein (CRP) at the time of presentation (p = 0.032), and a higher number of co-infective bacterial organisms (p = 0.041). The overall rate of eradication of infection after two and five years was 50% (95% confidence interval (CI) 32.9 to 75.9) and 38.9% (95% CI 22.6 to 67), respectively. The risk of failure to eradicate infection with the requirement of amputation associated with this diagnosis is much higher than in patients with PJI without bacterial and fungal co-infection, and this risk is heightened when the fungal organism is joined by polymicrobial and multidrug-resistant bacterial organisms. Cite this article: Bone Joint J 2019;101-B:582-588.

Fungal prosthetic joint infection in total hip or knee arthroplasty: a retrospective single-centre study of 26 cases.

Fungal prosthetic joint infections (PJIs) are rare and account for about 1% of total PJIs. Our aim was to present clinical and microbiological results in treating these patients with a two-stage approach and antifungal spacers. We retrospectively reviewed our institutional database and identified 26 patients with positive fungal cultures and positive Musculoskeletal Infection Society (MSIS) criteria for PJI who were treated between 2009 and 2017. We identified 18 patients with total hip arthroplasty (THA) and eight patients with total knee arthroplasty (TKA). The surgical and antifungal treatment, clinical and demographic patient data, complications, relapses, and survival were recorded and analyzed. The median follow-up was 33 months. The success rate was 38.5% (10/26). Fluconazole resistance was found in 15%. Bacterial co-infection was common in 44% of patients for THA and 66% of patients with TKA. Mortality, reoperations, and treatment failure were common complications. Treatment with a two-stage exchange is a possible option for treatment, although fungal infections have a high failure rate. Therapeutic factors for treatment success remain unclear. Cite this article: Bone Joint J 2019;101-B:589-595.

Different microbiological profiles between hip and knee prosthetic joint infections.

The study aims to analyze the demographics and microbiological profiles of hip and knee prosthetic joint infection (PJI) and to compare the microbiological differences between hip and knee PJI. We performed a retrospective study of all PJI cases between January 2006 and December 2014 at a referral medical center in Taiwan. A total of 294 PJI cases were collected: 159 were identified as hip PJI and 135 as knee PJI. The most common causative pathogen was Staphylococcus aureus (78 cases, 27%), followed by coagulase-negative staphylococci (CoNS, 42 cases, 14%). Methicillin-resistant staphylococci (MRS) accounted for 21% of all PJI cases. Fungus and mycobacterium were only involved in 12 cases (4.1%) of all PJI cases. Polymicrobial pathogens, anaerobes, and enteric gram-negative bacilli (GNB) were more likely to occur in hip joint prostheses than in knee joint prostheses (22 vs. 6 cases, p = 0.006; 11 vs. 0 cases; p = 0.002; 20 vs. 6 cases; p = 0.014, respectively). The prevalence of polymicrobial pathogens, anaerobes, and enteric GNB was higher in the prosthetic hip infection than in the prosthetic knee infection. The high prevalence of MRS, including Methicillin-resistant (MR) S. aureus and MR-CoNS in PJI, may warrant the need for empiric antibiotic therapy with broader coverage while pending the culture result of PJI. Although fungal and mycobacterial PJI cases are rare, the incidence of these infections is relatively high in Taiwan. Fungus and mycobacterium should also be taken into consideration whenever a persistent PJI case is encountered.

Low Yield of Routine Fungal Culture from Periprosthetic Joint Specimens

BackgroundProsthetic joints may fail for a variety of reasons, including infection, which are estimated to occur in 1–2 percent of joint replacements. Bacterial and fungal cultures are commonly ordered on the same specimens, despite the rarity of fungal prosthetic joint infections. To evaluate the yield of fungal cultures from specimens collected from prosthetic joint revision procedures, we performed a retrospective analysis of culture positivity for orthopedic surgical specimens submitted for culture at our institution.MethodsMicrobiology culture results for all orthopedic surgical specimens collected from January 2016 through February 2017 were obtained from a laboratory information system. Bacterial and fungal culture results for each patient were matched by MRN, date of specimen collection and accession number. Culture positivity was defined as growth of any microorganism on any piece of media used for bacterial or fungal media per each specimen submitted for culture.ResultsOver a 14-month period, 888 cultures from 189 unique surgical events (unique date/MRN) were submitted for bacterial culture. On average, 5 specimens were submitted per patient (range 1–11). Of these, 352 specimens (40%) were positive for bacterial growth. Ninety-seven percent of specimens submitted for bacterial culture had a corresponding fungal culture ordered. Only 1 of the 861 fungal cultures ordered was positive for fungal growth (0.1%). One specimen from a shoulder revision grew Aureobasidium pullulans, a ubiquitous fungus that is a rare human pathogen. Direct exam of the specimen revealed no PMNs or organisms. No A. pullulans was isolated from eight other cultures from the same procedure. This organism was likely viewed as a contaminant as no anti-fungal therapy was initiated.ConclusionOver a recent 14-month period at our institution, the yield of fungal culture of orthopedic surgical specimens was exceedingly low (0.1% positivity). Importantly, yeasts such as Candida species, can readily grow on bacterial culture media, especially if incubation times are extended. Therefore, fungal culture from periprosthetic joint specimens should be limited unless there is a strong clinical suspicion of fungal infection.Disclosures All authors: No reported disclosures.