2-stage revision recommended for treatment of fungal hip and knee prosthetic joint infections

Prosthetic Joint Infections due to Candida Species: A Multicenter International Study

BACKGROUND

Prosthetic joint infection (PJI) caused by Candida spp is a severe complication of arthroplasty. We investigated the outcomes of Candida PJI.

METHODS

This was a retrospective observational multinational study including patients diagnosed with Candida-related PJI between 2010 and 2021. Treatment outcome was assessed at 2-year follow-up.

RESULTS

A total of 269 patients were analyzed. Median age was 73.0 (interquartile range [IQR], 64.0-79.0) years; 46.5% of patients were male and 10.8% were immunosuppressed. Main infection sites were hip (53.0%) and knee (43.1%), and 33.8% patients had fistulas. Surgical procedures included debridement, antibiotics, and implant retention (DAIR) (35.7%), 1-stage exchange (28.3%), and 2-stage exchange (29.0%). Candida spp identified were Candida albicans (55.8%), Candida parapsilosis (29.4%), Candida glabrata (7.8%), and Candida tropicalis (5.6%). Coinfection with bacteria was found in 51.3% of cases. The primary antifungal agents prescribed were azoles (75.8%) and echinocandins (30.9%), administered for a median of 92.0 (IQR, 54.5-181.3) days. Cure was observed in 156 of 269 (58.0%) cases. Treatment failure was associated with age >70 years (OR, 1.811 [95% confidence interval {CI}: 1.079-3.072]), and the use of DAIR (OR, 1.946 [95% CI: 1.157-3.285]). Candida parapsilosis infection was associated with better outcome (OR, 0.546 [95% CI: .305-.958]). Cure rates were significantly different between DAIR versus 1-stage exchange (46.9% vs 67.1%, P = .008) and DAIR versus 2-stage exchange (46.9% vs 69.2%, P = .003), but there was no difference comparing 1- to 2-stage exchanges (P = .777).

CONCLUSIONS

Candida PJI prognosis seems poor, with high rate of failure, which does not appear to be linked to immunosuppression, use of azoles, or treatment duration.

The heavy burden and treatment challenges of fungal periprosthetic joint infection: a systematic review of 489 joints

BACKGROUND

Fungal periprosthetic joint infection (FPJI) is an infrequent but devastating complication that imposes a heavy burden on patients. At present, a consensus regarding the most optimal surgical option for patients with FPJI, the ideal duration of systemic antifungal treatment, and many other issues has not been reached.

METHODS

A comprehensive literature search was performed on the PubMed and Embase databases. The search criteria employed were as follows: (fungal OR candida OR mycotic) AND periprosthetic joint infection. Initially, the titles and abstracts were screened, and subsequently, studies deemed irrelevant or duplicative were eliminated. Following this, the complete texts of remaining articles were thoroughly examined. According to the inclusion and exclusion criteria, 489 joints in 24 articles were screened out. We further extracted the demographic characteristics (age, gender, body mass index, etc.), clinical presentation, fungal species, presence of bacterial coinfection, surgical methods, systemic and local antifungal therapy, and treatment outcomes. Subgroup data were analyzed according to fungal species and bacterial coinfection. Univariate logistic regression analysis was conducted to ascertain the risk factors associated with the infection recurrence.

RESULTS

A total of 506 fungi were identified within 489 joints. The most prevalent fungal species were Candida albicans (41.5%). Out of 247 joints (50.5%) presenting with concurrent fungal and bacterial infections. Among the initial surgical interventions, two-stage exchange was the most common (59.1%). The infection recurrence rates of DAIR, resection arthroplasty, two-stage, one-stage, and three-stage exchange were 81.4%, 53.1%, 47.7%, 35.0%, and 30%, respectively. The mean duration of systemic antifungal therapy was 12.8 weeks. The most common drugs used both in intravenous (55.9%) and oral therapy (84.0%) were fluconazole. The proportion of patients who used antifungal drugs after replantation (two-stage and three-stage) was 87.6%. 33.2% of cement spacer or fixed cement contained antifungal drugs, of which amphotericin B was the main choice (82.7%). FPJI caused by candida albicans (OR = 1.717, p = 0.041) and DAIR (OR = 8.433, p = 0.003) were risk factors for infection recurrence.

CONCLUSIONS

Two-stage exchange remains the most commonly used surgical approach. The reliability of one- and three-exchange needs further evaluation due to the small sample size. Antifungal-loaded cement spacers, and direct intra-articular injections of antimycotics after reimplatation should be strongly considered. Medication is not standardized but rather individualized according to microbiology and the status of patients.

Incidence and Risk Factors for Acid-fast Bacillus/Fungal Culture Positivity in Primary, Conversion, and Revision Hip and Knee Arthroplasty

INTRODUCTION

Previous literature has reported minimal incidences of positive fungal/AFB cultures, questioning the routine use of these tests. With growing concern for excessive use, predictive factors for patients at higher risk for intraoperative AFB/fungal infections would help surgeons limit unnecessary testing. This study evaluates the positivity rate and predictive factors of positive fungal and/or acid-fast bacillus (AFB) cultures after primary, conversion, or revision hip and knee arthroplasty.

METHOD

Two hundred thirty-eight knee and hip procedures were done between January 2007 and 2022 where intraoperative AFB/fungal cultures were obtained. Procedures included primary total knee arthroplasty, primary total hip arthroplasty, conversion, first of two-stage, second of two-stage, irrigation and débridement polyexchange, and aseptic revision. Positivity rates of intraoperative AFB/fungal cultures were calculated as binomial exact proportions with 95% confidence intervals and are displayed as percentages. Univariable generalized linear mixed models estimated the unadjusted effects of demographics, individual comorbid conditions, and procedural characteristics on the logit of positive AFB/fungal cultures.

RESULTS

Two hundred thirty-eight knee and hip procedures recorded an overall positivity rate of 5.8% for intraoperative AFB/fungal cultures. Aseptic revisions showed the lowest rates of positivity at 3.6%, while conversions showed the highest rates of positivity at 14.3%. The positivity rates are highest among patients who are male (9.0%), of Hispanic origin (12.0%), with body mass index <30 (6.4%), and a Charlson Comorbidity Index <5 (6.1%). History of a prior infection in the same surgical joint showed statistically significant influence of odds of culture positivity with an odds ratio of 3.47 ( P -value: 0.039). Other demographic factors that we investigated including age, sex, race, ethnicity, body mass index, and Charlson Comorbidity Index did not show any notable influence on AFB/fungal positivity rates.

CONCLUSION

These results suggest utility in obtaining routine intraoperative AFB/fungal cultures, given the relatively high positivity and poor predictive factors.

Articulating Spacers in Total Hip Arthroplasty: Surgical Technique and Outcomes

Although one-stage exchange arthroplasty is gaining popularity, two-stage exchange arthroplasty remains the gold standard for the treatment of periprosthetic joint infections. Use of an articulating spacer for this procedure offers an avenue for maintaining hip motion and controlled weight-bearing, allowing local antibiotic elution. However, there is no uniform consensus on the optimal surgical protocol for using articulating spacers. This review describes the surgical technique for undertaking a first-stage exchange arthroplasty using an articulating spacer and discusses the pertinent literature on key concepts relating to periprosthetic joint infections in total hip arthroplasty to guide effective surgical decision making in these patients.

Comparison of outcomes between fungal and non-fungal periprosthetic joint infections in total knee arthroplasty

Aims

Fungal periprosthetic joint infections (PJIs) are rare, but their diagnosis and treatment are highly challenging. The purpose of this study was to investigate the clinical outcomes of patients with fungal PJIs treated with two-stage exchange knee arthroplasty combined with prolonged antifungal therapy.

Methods

We reviewed our institutional joint arthroplasty database and identified 41 patients diagnosed with fungal PJIs and treated with two-stage exchange arthroplasty after primary total knee arthroplasty (TKA) between January 2001 and December 2020, and compared them with those who had non-fungal PJIs during the same period. After propensity score matching based on age, sex, BMI, American Society of Anesthesiologists grade, and Charlson Comorbidity Index, 40 patients in each group were successfully matched. The surgical and antimicrobial treatment, patient demographic and clinical characteristics, recurrent infections, survival rates, and relevant risk factors that affected joint survivorship were analyzed. We defined treatment success as a well-functioning arthroplasty without any signs of a PJI, and without antimicrobial suppression, at a minimum follow-up of two years from the time of reimplantation.

Results

The fungal PJI group demonstrated a significantly worse treatment success rate at the final follow-up than the non-fungal PJI group (65.0% (26/40) vs 85.0% (34/40); p < 0.001). The mean prosthesis-free interval was longer in the fungal PJI group than in the non-fungal PJI group (6.7 weeks (SD 5.8) vs 4.1 weeks (SD 2.5); p = 0.020). The rate of survivorship free from reinfection was worse in the fungal PJI group (83.4% (95% confidence interval (CI) 64.1 to 92.9) at one year and 76.4% (95% CI 52.4 to 89.4) at two years) than in the non-fungal PJI group (97.4% (95% CI 82.7 to 99.6) at one year and 90.3% (95% CI 72.2 to 96.9) at two years), but the differences were not significant (p = 0.270). Cox proportional hazard regression analysis identified the duration of the prosthesis-free interval as a potential risk factor for failure (hazard ratio 1.128 (95% CI 1.003 to 1.268); p = 0.043).

Conclusion

Fungal PJIs had a lower treatment success rate than non-fungal PJIs despite two-stage revision arthroplasty and appropriate antifungal treatment. Our findings highlight the need for further developments in treating fungal PJIs.

Novel Local Antifungal Treatment for Fungal Periprosthetic Joint Infection With Continuous Local Antibiotic Perfusion: A Surgical Technique

Fungal periprosthetic joint infections are one of the most intractable orthopedic disorders. Continuous local antibiotic perfusion allows direct administration of the antifungal agent micafungin into the local infection area at biofilm-disruptive concentrations, while controlling the dead space in addition to conventional treatment. Although the appropriate use of continuous local antibiotic perfusion requires familiarity with the characteristics of local antibiotic perfusion, it is a versatile treatment modality that can improve the clinical outcomes of fungal periprosthetic joint infection in combination with conventional treatment methods.

Efficacy of DAIR in managing Candida parapsilosis-infected total knee arthroplasty with five-year follow-up: A case report and review of literature

RATIONALE

Fungal periprosthetic joint infections (fPJIs) are relatively uncommon, accounting for approximately 1% of all PJIs. Revision surgery is typically recommended for fungal infections; however, the physical and financial impact on patients is significant. In this report, we present a case of fPJI successfully treated with debridement, antibiotics, and implant retention (DAIR) with a favorable outcome over a 5-year period.

PATIENT CONCERN

A 56-year-old male patient presented with a non-healing surgical incision 1 week after undergoing primary total knee arthroplasty on the right side.

DIAGNOSIS

Microbiological culture of the wound effusion identified Candida parapsilosis. Postoperatively, the patient exhibited a significant decrease in serum albumin levels and poor glycemic control. Both C-reactive protein and erythrocyte sedimentation rate were elevated.

INTERVENTIONS

A comprehensive DAIR procedure was performed, along with continuous closed irrigation using fluconazole for 1 week. The patient received intravenous voriconazole for 4 weeks, followed by oral fluconazole for an additional 3 months.

OUTCOMES

At 1- and 5-year follow-up appointments, the patient C-reactive protein and erythrocyte sedimentation rate levels were within normal limits, and there was no evidence of swelling, erythema, or tenderness in the right knee joint, indicating no signs of infection.

LESSONS

DAIR is an effective treatment for early fPJIs, and continuous closed irrigation may provide specific advantages. The patient nutritional status plays a crucial role in the management of periprosthetic infections.

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 67 years (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.

Treatment Outcomes of Fungal Periprosthetic Joint Infection

BACKGROUND

Periprosthetic joint infection (PJI) continues to challenge surgeons and patients. The burden of fungal organisms may represent approximately 1% of all PJI. Additionally, fungal PJI is difficult to treat. Most available case series are small and report poor success rates. Fungi are opportunistic pathogens and patients who have fungal PJI are believed to be immunocompromised. Additionally, fungal biofilms are more complex than those formed by other pathogens and confer additional drug resistance. Due to these factors, treatment failure is common.

METHODS

A retrospective review of our institutional registry was performed to identify patients treated for fungal PJI. There were 49 patients identified with 8 excluded for not having follow-up, which left 22 knees and 19 hips for analyses. Demographics, clinical characteristics, and surgical details were collected. The primary outcome was failure defined as reoperation for infection following the index surgery for fungal PJI within 1 year of the index surgery.

RESULTS

Failure occurred in 10 of 19 knees and 11 of the 22 hips. A higher proportion of patients who have extremity grade C failed treatment, and every patient who failed was host grade 2 or 3. The average number of prior surgeries and time from resection to reimplantation were similar between groups.

CONCLUSION

To our knowledge, this represents the largest cohort of fungal PJIs reported in the literature to date. This data supports other literature in that failure rates were high. More study is needed to further understand this entity and improve care for these patients.

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

BACKGROUND

Fungal 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.

METHODS

A 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.

RESULTS

Seventy 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.

CONCLUSION

Treatment 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.

The fate of fungal periprosthetic joint infection after total knee arthroplasty

PURPOSE

To demonstrate the clinical outcomes of patients with fungal periprosthetic joint infections (PJIs) after two-stage exchange arthroplasty combined with antifungal therapy.

METHODS

We retrospectively reviewed the outcomes of 41 patients with fungal PJIs after primary total knee arthroplasty (TKA) in a single centre from January 1999 to October 2017. During the first stage of resection arthroplasty, antifungal-impregnated cement spacers (AICSs) were implanted in all patients. After systemic antifungal treatment during the interval between the two surgeries, delayed reimplantation as part of a two-stage exchange protocol was performed when patients were clinically stable. We defined treatment success as a well-functioning arthroplasty without any signs of PJI after a minimum follow-up of two years without antimicrobial suppression. Successful treatment was confirmed by repeat negative cultures as well as a return of inflammatory markers to normal levels.

RESULTS

The treatment success rate was 63.4% at the final follow-up. Thirty-six of 41 patients (87.8%) met the criteria for second-stage revision after confirmation of complete infection control. The mean prosthesis-free interval was 6.6 months (range, 2.0-30.0 months). During follow-up after two-stage exchange arthroplasty, ten patients (27.7% of 36 patients) unfortunately experienced recurrence or relapse of infection after an average of 31.3 months (range, 2.7-135.6 months). The rate of survivorship free from reinfection was 94.4% at six months, 84.8% at one year, and 73.6% at two years. Cox proportional hazard regression analysis demonstrated that the prosthesis-free interval (HR = 1.016, p = 0.037) and mean length of antifungal treatment (HR = 0.226, p = 0.046) were potential risk factors for failure.

CONCLUSION

Fungal PJIs led to devastating clinical outcomes despite even two-stage revision arthroplasty with the use of AICSs and antifungal medications.

Identification of prosthetic joint infection by Candida using metagenomic shotgun sequencing

Background

Periprosthetic joint infection (PJI) is a serious complication after total knee arthroplasty. Fungal infections are prone to biofilm formation, which makes it hard to diagnose and clarify the pathogenic species.

Case Presentation

This case study provides evidence of a novel PJI pathogen that is otherwise difficult to detect using conventional methods. A patient was reviewed with persistent postoperative pain, swelling and eventually drainage around the left knee after undergoing a bilateral total knee arthroplasty 2 years previously for progressive osteoarthritis. By using metagenomic shotgun sequencing to analyse both bacterial and fungal agent sequences, we were able to identify fungal strains of Candida tropicalis, a rarely reported and difficult-to-culture PJI pathogen.

Conclusion

Metagenomic shotgun sequencing enables the detection of difficult-to-detect pathogens and the formulation of treatment recommendations for fungal infections with low positive rates based on gene content analysis.

Rare Bipolaris Species Fungal Periprosthetic Hip Infection in an Immunocompetent Host: A Case Report

CASE

We present a case report of a 64-year-old man who developed a rare Bipolaris species fungal periprosthetic joint infection (PJI) after revision arthroplasty for complications associated with a metal-on-metal total hip arthroplasty. The patient underwent a 2-stage debridement with antibiotic bead placement and implant retention, along with chronic antifungal suppression. At the 2-year follow-up, the patient remained asymptomatic.

CONCLUSION

Fungal PJI with filamentous fungi such as Bipolaris species is a rare clinical entity. This case report highlights the clinical presentation and management of this rare condition.

The Outcomes of Hip and Knee Fungal Periprosthetic Joint Infections: A Retrospective Cohort Study

BACKGROUND

Fungal infections are a rare cause of periprosthetic joint infection (PJI), identified in 1% of all of these cases. Outcomes are not well-established due to small cohort sizes in the published literature. The aims of this study were to establish the patient demographics and infection-free survival of patients presenting to 2 high-volume revision arthroplasty centers who had fungal infection of either a hip or knee arthroplasty. We sought to identify risk factors for poor outcomes.

METHODS

A retrospective analysis was performed of patients at 2 high-volume revision arthroplasty centers who had confirmed fungal PJI of the total hip arthroplasty (THA) and total knee arthroplasty (TKA). Consecutive patients treated between 2010 and 2019 were included. Patient outcomes were classified as infection eradication or persistence. A total of 67 patients who had 69 fungal PJI cases were identified. There were 47 cases involving the knee and 22 of the hip. Mean age at presentation was 68 years (THA mean 67, range 46 to 86) (TKA mean 69, range, 45 to 88). A history of sinus or open wound was present in 60 cases (89%) (THA 21 cases, TKA 39 cases). The median number of operations prior to the procedure at which fungal PJI was identified was 4 (range, 0 to 9), THA 5 (range, 3 to 9), and TKA 3 (range, 0 to 9).

RESULTS

At a mean follow-up 34 months (range, 2 to 121), remission rates were 11 of 24 (45%) and 22 of 45 (49%) for hip and knee, respectively. There were 7 TKA (16%) and 1 THA cases (4%) that failed treatment resulting in amputations. During the study period, 7 THA and 6 TKA patients had died. Two deaths were directly attributable to PJI. Patient outcome was not associated with the number of prior procedures, patient comorbidities, or organisms.

CONCLUSION

Eradication of fungal PJI is achieved in less than half of patients, and outcomes are comparable for TKA and THA. The majority of patients who have fungal PJI present with an open wound or sinus. No factors were identified that increase the risk of persistent infection. Patients who have fungal PJI should be informed of the poor outcomes.

Histoplasma capsulatum prosthetic joint infection

Immunocompromised patients are at risk of opportunistic infections. This is a 67-year-old woman with systemic sclerosis and knee osteoarthritis who underwent left total knee arthroplasty in 2009. In 2018 she underwent surgery for presumed aseptic loosening. Inflammation and purulent fluid were found; implant was removed and replaced with a static spacer. Three weeks later, H. capsulatum was isolated. She was successfully treated with itraconazole for 18 months; cultures on revision spacer replacement surgery were negative.

Voriconazole Admixed with PMMA-Impact on Mechanical Properties and Efficacy

BACKGROUND

There are currently no recommendations to direct the optimal diagnosis and treatment of fungal osteoarticular infections, including prosthetic joint infections and osteomyelitis. Active agents (fluconazole; amphotericin B) are regularly applied per os or intravenously. Other drugs such as voriconazole are used less frequently, especially locally. Voriconazole is less toxic and has promising results. Local antifungal medication during primary surgical treatment has been investigated by implanting an impregnated PMMA cement spacer using intra-articular powder or by daily intra-articular lavage. The admixed dosages are rarely based on characteristic values and microbiological and mechanical data. The purpose of this in vitro study is to investigate the mechanical stability and efficacy of antifungal-admixed PMMA with admixed voriconazole at low and high concentrations.

METHODS

Mechanical properties (ISO 5833 and DIN 53435) as well as efficacy with inhibition zone tests with two Candida spp. were investigated. We tested three separate cement bodies at each measuring time (n = 3) Results: Mixing high dosages of voriconazole causes white specks on inhomogeneous cement surfaces. ISO compression, ISO bending, and DIN impact were significantly reduced, and ISO bending modulus increased. There was a high efficacy against C. albicans with low and high voriconazole concentrations. Against C. glabrata, a high concentration of voriconazole was significantly more efficient than a dose at a low concentration.

CONCLUSIONS

Mixing voriconazole powder with PMMA (Polymethylmethacrylate) powder homogeneously is not easy because of the high amount of dry voriconazole in the powder formulation. Adding voriconazole (a powder for infusion solutions) has a high impact on its mechanical properties. Efficacy is already good at low concentrations.

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.

Candida albicans Prosthetic Joint Infection After Total Knee Arthroplasty: A Rare Case Report

In this article, a 75-year-old patient with pain in left knee and restricted range of motion following total knee arthroplasty (TKA) is presented. Serological evaluation and aspiration of knee joint suggested a fungal prosthetic joint infection. After the diagnosis was confirmed, treatment started with antifungal drugs, removing prosthesis, exhaustive debridement, and revision of TKA after efficient antifungal treatment. At one-year follow-up, she has a painless motion range of 10 to 90 degrees, and there was no recurrence of infection observed.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Metagenomic next-generation sequencing assists the diagnosis treatment of fungal osteoarticular infections

Background

Fungal osteoarticular infection (FOI) is not commonly seen in clinical practice but proposes a great challenge to orthopedic surgeons. In this study, we aimed to investigate the risk factors, the clinical features, and surgical outcomes of FOI in our institution. Specifically, we aimed to explore the role of metagenomic next-generation sequencing (mNGS) in the diagnosis and treatment of FOI.

Methods

All the patients who were diagnosed and managed with FOI in our institution from January 2007 to December 2020 were retrospectively reviewed, including primary fungal implant-related infection, primary fungal osteomyelitis or arthritis, and fungal infections secondary to bacterial osteomyelitis or implant-related bacterial infections. The potential risk factors and the clinical and surgical features were analyzed. The pathogen data were compared between culture and the mNGS test.

Results

A total of 25 patients were included, namely, 12 primary implant-related infections, 7 primary fungal osteomyelitis or arthritis, and 6 fungal infections secondary to bacterial osteomyelitis or implant-related bacterial infections. Most cases had undergone multiple surgeries or long-term antibiotic treatment. Diagnosis was mainly based on microbial culture and the mNGS test. Optimization of culture methods and the use of mNGS assisted the diagnosis. Specifically, mNGS was performed in 12 patients, 5 of whom were culture-negative. In the remaining seven cases, mNGS demonstrated the same results as culture. Management of FOI was complicated as most patients required multiple surgeries followed by long-term antifungal treatment. In selected cases, antifungal-impregnated cement spacer retention can be an optional choice. The overall success rate was 100% (25/25) for our cohort.

Conclusion

We concluded that patients with comorbidities and a history of multiple surgeries or long-term antibiotics are under higher risk for FOI. Use of mNGS assists the diagnosis and treatment of FOI. Surgery combined with long-term antifungal treatment achieved satisfactory outcomes. In selected cases, antifungal-impregnated cement spacer retention can be an optional treatment choice.

Periprosthetic Joint Infections Caused by Candida Species—A Single-Center Experience and Systematic Review of the Literature

Background: The aim of this study was to analyze the treatment results of fungal periprosthetic joint infections (PJI) caused by Candida species from a single orthopedic center and to compare them with reports from other institutions. Methods: Eight patients operated on from January 2014 to December 2021 met the inclusion criteria and were analyzed in terms of clinical outcomes. A systematic review of the literature identified 153 patients with Candida PJIs extracted from 12 studies according to the PRISMA (Preferred Reporting Item for Systematic Reviews and Meta-Analyses) guidelines. Results: The success rate of the treatment in the case series was 50%. The most frequent pathogens were Candida albicans (three cases; 37.5%) and Candida parapsilosis (three cases; 37.5%). In one patient (12.5%), bacterial co-infection was noted, and in five patients (62.5%) significant risk factors of PJI were confirmed. The overall success rate on the basis of data collected for systematic review was 65.5%. A sub-analysis of 127 patients revealed statistically significant differences (p = 0.02) with a higher success rate for the knees (77.6%) than for the hips (58%). In 10 studies the analysis of risk factors was performed and among 106 patients in 77 (72.6%) comorbidities predispose to fungal PJI were confirmed. Bacterial co-infection was noted in 84 patients (54.9%). In 93 patients (60.7%) Candida albicans was the culprit pathogen, and in 39 patients (25.5%) Candida parapsilosis was the culprit pathogen. Based on these two most frequent Candida species causing PJI, the success rate of the treatment was statistically different (p = 0.03), and was 60.3% and 83.3%, respectively. The two-stage strategy was more favorable for patients with Candida parapsilosis infections (94.4% success rate) than the one-stage protocol (50% success rate; p = 0.02); as well as in comparison to the two-stage treatment of Candida albicans (65% success rate; p = 0.04). Conclusions: The analysis of the literature showed no differences in the overall success rate between one- and two-stage surgical strategies for all Candida species, but differed significantly comparing the two most frequent strains and concerning PJI localization. The frequent presence of bacterial co-infections makes it necessary to consider the additional administration of antibiotics in the case of fungal PJI.

Microbiological Profiles of Patients with Periprosthetic Joint Infection of the Hip or Knee

Periprosthetic joint infections (PJI) are one of the most devastating consequences after total joint arthroplasty. We sought to analyze the causative pathogens of patients with PJI to get better insights and improve treatment. We performed a retrospective study of all patients with PJI of the hip and knee with microbiological detection of a causative pathogen at a tertiary endoprothetic referral center between January 2016 and March 2021. A total of 432 cases with PJI (hip: n = 250; knee: n = 182) were included. The most common causative pathogen were coagulase-negative staphylococci (n = 240; 44.2%), of which Staphylococcus epidermidis (n = 144; 26.7%) was the most frequently detected, followed by S. aureus (n = 77; 14.3%) and enterococci (n = 49; 9%). Gram-negative pathogens and fungi could be detected in 21% (n = 136) and 2.4% (n = 13) of all cases. Overall, 60% of all coagulase-negative staphylococci were oxacillin-resistant, while none of these displayed to be vancomycin-resistant. In summary, the majority of pathogens in cases of PJI could be identified as coagulase-negative staphylococci. For empirical therapy vancomycin might provide the highest antimicrobial coverage in case of an unknown pathogen.

Two-Stage Revision Total Knee Arthroplasty for Chronic Histoplasma Capsulatum Prosthetic Joint Infection: A Case Report

CASE

This report describes a histoplasma capsulatum total knee prosthetic joint infection (PJI) in an immunosuppressed patient treated with a 2-stage revision. The diagnosis of PJI was made based on minor criteria, and the causative organism was identified from cultures obtained at the time of explantation. The patient underwent induction with amphotericin B, followed by oral antifungal therapy and a successful 2-stage revision with a hinged prosthesis with an interval of ∼7 months between stage 1 and stage 2. At the most recent follow-up (18 months), she remained clear from infection with planned lifetime antifungal suppression.

CONCLUSION

This case report highlights the importance of consideration of atypical organisms when treating immunocompromised patients. Furthermore, this case report documents one of the few cases of histoplasma PJI and provides a successful treatment algorithm to potentially be applied to future cases.

Effective single-stage revision using intra-articular antibiotic infusion after multiple failed surgery for periprosthetic joint infection : a mean seven years' follow-up

AIMS

Periprosthetic joint infections (PJIs) with prior multiple failed surgery for reinfection represent a huge challenge for surgeons because of poor vascular supply and biofilm formation. This study aims to determine the results of single-stage revision using intra-articular antibiotic infusion in treating this condition.

METHODS

A retrospective analysis included 78 PJI patients (29 hips; 49 knees) who had undergone multiple prior surgical interventions. Our cohort was treated with single-stage revision using a supplementary intra-articular antibiotic infusion. Of these 78 patients, 59 had undergone more than two prior failed debridement and implant retentions, 12 patients had a failed arthroplasty resection, three hips had previously undergone failed two-stage revision, and four had a failed one-stage revision before their single-stage revision. Previous failure was defined as infection recurrence requiring surgical intervention. Besides intravenous pathogen-sensitive agents, an intra-articular infusion of vancomycin, imipenem, or voriconazole was performed postoperatively. The antibiotic solution was soaked into the joint for 24 hours for a mean of 16 days (12 to 21), then extracted before next injection. Recurrence of infection and clinical outcomes were evaluated.

RESULTS

A total of 68 patients (87.1%) were free of infection at a mean follow-up time of 85 months (24 to 133). The seven-year infection-free survival was 87.6% (95% confidence interval (CI) 79.4 to 95.8). No significant difference in infection-free survival was observed between hip and knee PJIs (91.5% (95% CI 79.9 to 100) vs 84.7% (95% CI 73.1 to 96.3); p = 0.648). The mean postoperative Harris Hip Score was 76.1 points (63.2 to 92.4) and Hospital for Special Surgery score was 78. 2 (63.2 to 92.4) at the most recent assessment. Polymicrobial and fungal infections accounted for 14.1% (11/78) and 9.0% (7/78) of all cases, respectively.

CONCLUSION

Single-stage revision with intra-articular antibiotic infusion can provide high antibiotic concentration in synovial fluid, thereby overcoming reduced vascular supply and biofilm formation. This supplementary route of administration may be a viable option in treating PJI after multiple failed prior surgeries for reinfection. Cite this article: Bone Joint J 2022;104-B(7):867-874.

Antifungal-Loaded Acrylic Bone Cement in the Treatment of Periprosthetic Hip and Knee Joint Infections: A Review

Little is known about the clinical use of antifungal-loaded acrylic bone cement in the treatment of periprosthetic hip and knee joint infections (PJIs). Hence, we performed a literature search using PubMed/MEDLINE from inception until December 2021. Search terms were “cement” in combination with 13 antifungal agents. A total of 10 published reports were identified, which described 11 patients and 12 joints in which antifungal-loaded cement was employed. All studies were case reports or case series, and no randomized controlled trials were identified. In 6 of 11 patients, predisposing comorbidities regarding the emergence of a fungal PJI were present. The majority of the studies reported on infections caused by Candida species. In six cases (seven joints), the cement was solely impregnated with an antifungal, but no antibiotic agent (amphotericin B, voriconazole, and fluconazole). In the other five joints, the cement was impregnated with both antibiotic(s) and antifungals. Great discrepancies were seen regarding the exact loading dose. Four studies investigated the local elution of antifungal agents in the early postoperative period and observed a local release of antifungals in vivo. We conclude that there is a paucity of data pertaining to the clinical use of antifungal-loaded bone cement, and no studies have assessed the clinical efficacy of such procedures. Future studies are urgently required to evaluate this use of antifungals in PJI.

Evaluation of a syndromic panel polymerase chain reaction (spPCR) assay for the diagnosis of device-associated bone and joint infections (BJI)

OBJECTIVE

Pathogen detection is crucial for diagnosis and targeted therapy in implant-associated bone and joint infections (BJI). Culture-based microbiology regularly fails to identify causative pathogens. This study evaluated the diagnostic accuracy and clinical usefulness of a syndromic panel polymerase chain reaction (spPCR) assay targeting common BJI pathogens in tissue specimens from patients with implant-associated BJI.

METHODS

Results obtained by spPCR assay and a 16S rDNA PCR were compared with results obtained from a standard of care (SOC) culture-based diagnostics, serving as a gold standard. In total, 126 specimens obtained from 73 patients were analyzed.

RESULTS

The spPCR assay correctly identified 33/40 culture-positive samples (82.5 %) and was positive in 9/86 (10.5 %) culture-negative samples, resulting in an overall sensitivity of 84.6 % (95% confidence interval [CI] 68.79-93.59%) and specificity of 89.35% (95% CI 80.6-94.81%). The spPCR was more sensitive compared with the 16S rDNA PCR (37.5%). The spPCR identified pathogens in 7/51 (13.7%) SOC-negative patients. Re-evaluation of spPCR results in clinical context suggested their clinical significance.

CONCLUSION

An spPCR assay targeting common pathogens causing implant-associated BJI may help to identify causative agents in culture-negative cases. As false-negative results are possible, spPCR assays appear as an add-on approach for pathogen detection in implant-associated BJI.

Candida periprosthetic joint infections - risk factors and outcome between albicans and non-albicans strains

BACKGROUND

Despite its scarcity, fungal periprosthetic joint infection (PJI) is of great clinical relevance as diagnosis and treatment are highly challenging. Previous analyses focused on the treatment rather than the role of the causative fungal agent on clinical outcome. This is the largest study of its kind to evaluate Candida strain-dependent differences in patients with fungal PJI.

METHODS

We retrospectively analyzed 29 patients who underwent surgical intervention due to Candida hip or knee PJI in our department from 2010 to 2018. PJI was defined according to IDSA, recurrent PJI according to modified Delphi consensus criteria. Statistical analysis was performed using t-test, chi-square test with Yates correction, and log rank test.

RESULTS

Besides age and affected joint, no significant differences were found between Candida albicans and non-albicans PJI patients (75.83 versus 64.11 years, p = 0.012; 12 hip versus two knee cases, p = 0.013). Most patients received two- (27.59%) or three-stage exchange surgery (41.38%). There was a statistical trend towards an increase in surgery needed in non-albicans Candida PJI (2.92 versus 2.12; p = 0.103). After initial Candida PJI treatment, functional prosthesis implantation was achieved in 72.41% of all patients. At last follow-up, infection-free survival was at 26.79% in Candida albicans versus 72.00% in non-albicans PJI (p = 0.046).

CONCLUSIONS

In this study, we found infection-free survival rates to be significantly decreased in patients with albicans compared to non-albicans Candida PJI. While age and affected joint might play a confounding role, we speculate the causative pathogen to play a decisive role in disease progression.

A case of candida parapsilosis periprosthetic joint infection: Case report and literature review

A 76 year old female, with a background history of eczema and iatrogenic Cushing syndrome, received a right total knee replacement for her knee osteoarthritis. In the early post-operative period, a small amount of discharge was noted from the surgical wound. The wound swab culture of the discharge yielded candida species. It was regarded as contamination initially. Half year later, she presented with a subcutaneous abscess around the right knee. Aspiration and culture confirmed infection of Candida parapsilosis. The patient was treated conservatively with fluconazole because she had initially refused operative treatment. The infection progressed to abscess formation afterward. A two-stage revision arthroplasty with cement spacer was performed subsequently. In addition, we have reviewed the literature regarding fungal periprosthetic joint infection.

Candida periprosthetic infection of the knee: a systematic review of surgical treatments and clinical outcomes

BACKGROUND

Candida periprosthetic joint infections (PJIs) are a rare cause of prosthesis revision with severe consequences and challenging treatment. This study aims to produce a systematic analysis of types of treatment and outcome of knee Candida PJIs and their correlation with specific pathogen species.

METHODS

During April 2021, a literature search was performed according to PRISMA (Preferred Reporting Item for Systematic Reviews and Meta-Analyses) guideline. Reviewers used the Oxford Level of Evidence (LoE) and Methodological index for non-randomized studies (MINORS) score. Modal value of surgical, pharmacological treatment and outcome along with the correlation between types of treatment and outcome was calculated through Chi-square or Fisher exact test.

RESULTS

In total, 115 cases were collected through 51 articles, identifying 116 pathogens. Candida albicans was the most frequent pathogen. Analysis of LoE reveals 40 LoE 5 and 11 LoE 4. Thirteen patients underwent one-stage revision, 46 patients two-stage revision, 6 patients resection arthroplasty and arthrodesis, 4 patients long-term antifungal therapy, and 3 patients debridement with prosthesis retention. Global rate of success was 85.14%. Modal distribution revealed a preference for two-stage revision and Fluconazole in medical therapy. No difference in terms of fungal eradication was found among Candida species (p = 0.503) and for treatments except for two-stage revision and resection arthroplasty (p  = 0.0125) or debridement with implant retention (p  = 0.0498), and the rest of procedures and resection arthroplasty (0.0192). MINORS score was poor.

CONCLUSIONS

Analysis of the literature did not highlight any difference between types of surgical treatment and pathogens in terms of relapse or infection eradication. However, two-stage replacement may be preferred, allowing healing of infection in most cases.

Risk Factors of DAIR Failure and Validation of the KLIC Score: A Multicenter Study of Four Hundred Fifty-Five Patients

Background: Debridement, antibiotic agents, and implant retention (DAIR) is a currently accepted approach for the treatment of early prosthetic joint infections (PJI). The success of a DAIR procedure has shown variable results throughout the published literature. Scoring systems such as the Kidney, Liver, Index surgery, Cemented prosthesis, and C-reactive protein value (KLIC) score for the selection of patients that are likely to benefit from DAIR have proved to be helpful in decision making. Our study aims to further validate the KLIC score using a large external multicentric cohort and to evaluate other risk factors for failure. Patients and Methods: A retrospective analysis of patients with an early acute PJI who were treated with DAIR and recorded in a database of eight Spanish university hospitals was performed. According to pre-operative variables of the KLIC study, patients were categorized into five groups: group A, ≤2 points; group B, 2.5-3.5 points; group C, 4-5 points; group D, 5.5-6.5 points; and group E, ≥7 points. Failure rates were compared between groups at 60 days and after 60 days of DAIR. Further variables for risk of failure were also analyzed. Results: A total of 455 patients with early acute PJI were included in the analyses. At 60 days, patients presenting with pre-operative elevated C-reactive protein serum levels, Staphylococcus aureus, and polymicrobial infections were associated with failure. Failure rates recorded were 12% for group A (n = 210), 18% for group B (n = 83), 26% for group C (n = 89), 24% for group D (n = 66), and 0% for group E (n = 7). Univariable analysis between consecutive groups of the KLIC score showed no differences for failure before 60 days of the DAIR procedure. Scheduled surgery and having the procedure performed by a specialized unit were also identified as important factors for DAIR success. Conclusions: Our results suggest the KLIC score was not useful for predicting failure in our cohort. Furthermore, our results indicate a specialized unit should conduct DAIR procedures.

Mixed bacterial-fungal infection following total hip arthroplasty: A case report

Prosthetic infection is one of the severe postoperative complications of arthroplasty. Mixed bacterial-fungal prosthetic infection is rare but can be disastrous. This case was a 76-year-old female suffered from prosthetic infection following total hip replacement due to femoral neck fracture and underwent multiple debridements. The culture of periprosthetic tissue was bacteriologically sterile following the first debridement, while the Staphylococcus hominis was identified in the second debridement in the previous hospitalization where fungal infection had not been considered. Thus the pathogen spectrum of anti-infection therapy failed to contain fungus. Ultimately, the culture result of our sampled periprosthetic tissue during the third debridement was Candida albicans without bacterium in our hospital. The fungal prosthetic infection was successfully treated by a two-stage revision with antifungal drugs. Accurate diagnosis and standardized treatment is the key to the therapy of infection after hip arthroplasty, especially for mixed bacterial-fungal prosthetic infection.

Prosthetic joint infections and legal disputes: a threat to the future of prosthetic orthopedics

Prosthetic joint infections (PJI) represent one of the major problems in orthopedic prosthetic surgery. The incidence of PJIs varies according to the site of intervention, and different published case studies report occurrence at 0.5 to 3.0% in the event of first implants, with a significant greater risk in the case of prosthesis revisions. The diagnosis of prosthetic infections is seldom simple, needing a multi-specialist approach, which includes the accurate collection of patient anamnesis, its clinical evaluation, the evaluation of inflammation biomarkers, and the use of imaging techniques. It is essential to identify the bacteria responsible for the infection not only for an accurate diagnosis, but also to select the correct antibiotic treatment. Failure to identify the bacteria involved makes it impossible to establish targeted systemic antibiotic therapy. In developed countries such as Italy, the right to health is guaranteed by the Constitution, where the institutions that provide health services must be staffed by a team of medical professionals that can guarantee the safest possible health pathways. Risk management represents the set of actions aimed at improving the quality of the care provided, the adherence to guidelines and good care practices with the final objective of guaranteeing patients' safety. All hospitals, including the ones where prosthetic orthopedic surgery is performed, must adopt clinical risk management procedures which, through prospective tools aimed at preventing errors and complications and by retrospective methods, permit the identification of critical points in the different phases of the process and propose actions for improvement. The constant increase in litigation for malpractice in Western countries, especially in Italy, calls for special attention to the problem of PJIs and the in-depth assessment of medico-legal problems, also considering the new legislative initiatives in the field of medical malpractice. Hospitals need to tackle the onset of PJIs in a transparent and linear fashion by constantly informing the patient on their progress.

Three-stage revision arthroplasty for the treatment of fungal periprosthetic joint infection: outcome analysis of a novel treatment algorithm : a prospective study

Aims

Fungal periprosthetic joint infections (fPJIs) are rare complications, constituting only 1% of all PJIs. Neither a uniform definition for fPJI has been established, nor a standardized treatment regimen. Compared to bacterial PJI, there is little evidence for fPJI in the literature with divergent results. Hence, we implemented a novel treatment algorithm based on three-stage revision arthroplasty, with local and systemic antifungal therapy to optimize treatment for fPJI.

Methods

From 2015 to 2018, a total of 18 patients with fPJI were included in a prospective, single-centre study (DKRS-ID 00020409). The diagnosis of PJI is based on the European Bone and Joint Infection Society definition of periprosthetic joint infections. The baseline parameters (age, sex, and BMI) and additional data (previous surgeries, pathogen spectrum, and Charlson Comorbidity Index) were recorded. A therapy protocol with three-stage revision, including a scheduled spacer exchange, was implemented. Systemic antifungal medication was administered throughout the entire treatment period and continued for six months after reimplantation. A minimum follow-up of 24 months was defined.

Results

Eradication of infection was achieved in 16 out of 18 patients (88.8%), with a mean follow-up of 35 months (25 to 54). Mixed bacterial and fungal infections were present in seven cases (39%). The interval period, defined as the period of time from explantation to reimplantation, was 119 days (55 to 202). In five patients, a salvage procedure was performed (three cementless modular knee arthrodesis, and two Girdlestone procedures).

Conclusion

Therapy for fPJI is complex, with low cure rates according to the literature. No uniform treatment recommendations presently exist for fPJI. Three-stage revision arthroplasty with prolonged systemic antifungal therapy showed promising results.

Cite this article: Bone Jt Open 2021;2(8):671–678.

Occurrence of Rare Pathogens at the Site of Periprosthetic Hip and Knee Joint Infections: A Retrospective, Single-Center Study

The frequency and clinical relevance of rare pathogens at the site of periprosthetic infections of the hip and knee joint and their antibiotic resistance profiles have not yet been assessed in-depth. We retrospectively analyzed all periprosthetic hip and knee joint infections that occurred between 2016 and 2020 in a single center in southwest Germany. Among 165 infections, 9.7% were caused by rare microorganisms such as Veilonella sp., Pasteurella sp., Pantoea sp., Citrobacter koseri, Serratia marcescens, Parvimonas micra, Clostridium difficile, Finegoldia magna, Morganella morganii, and yeasts. No resistance to piperacillin/tazobactam, carbapenemes, fluoroquinolones, or gentamicin was observed. Some bacteria displayed resistance to ampicillin, ampicillin/sulbactam, and cefuroxime. We present follow-up data of patients with infections due to rare pathogens and discuss the importance of close, interdisciplinary collaboration between orthopedic surgeons and clinical microbiologists to carefully select the most appropriate anti-infective treatment regimens for the increasing number of patients with such infections.

Periprosthetic Fungal Infections in Severe Endoprosthetic Infections of the Hip and Knee Joint-A Retrospective Analysis of a Certified Arthroplasty Centre of Excellence

The treatment of periprosthetic joint infections (PJI), and especially of re-infections, poses a highly complex problem in orthopaedic surgery. While fungal infections are rare, they present a special challenge. The therapy is often protracted and based on limited evidence. A total of 510 hip and knee revision surgeries were analysed for the occurrence of bacterial and fungal PJI. In patients with PJI, the duration of the hospital stay and the incidence of disarticulation of the infected joint were recorded. Out of the analysed revision arthroplasties, 43.5% were due to PJI. Monomicrobial infection occurred in 55.2%, dual microbial infection in 21.4%, and polymicrobial (≥3 different bacterial or fungal species) infection in 17.2% of the cases. Overall, Candida species were detected in 12.4% cases. Candida albicans was the main fungal pathogen. In 6.9% of cases, disarticulation of the joint was the only option to control PJI. The detection of polymicrobial infection more than doubled in follow-up revisions and there was a strong association between detection of Candida infection and disarticulation (OR 9.39). The majority of fungal infections were mixed infections of bacteria and Candida albicans. The choice of a biofilm penetrating antimycotic, e.g., caspofungin, together with a sufficient standard procedure for detection and surgical treatment can help to control the infection situation. Fungal infection often proves to be more difficult to treat than anticipated and is more frequent than expected.

Fungal Periprosthetic Joint Infection: A Review of Demographics and Management

BACKGROUND

Periprosthetic joint infection (PJI) is one of the most feared complications of total joint arthroplasty (TJA). Although commonly the result of colonization by Staphylococcal species, a growing number of cases of PJI with fungal pathogens have been reported within the last decade. Although standard treatment with two-stage exchange mirrors that of bacterial PJI, the variability in virulence between fungal species makes for an unpredictable and challenging treatment course.

METHODS

A review of Pubmed and Scopus from years 2009 to 2019 was conducted with the search terms fungal, infection, Candida, arthroplasty, periprosthetic, and prosthesis. Publications were reviewed and screened, yielding data for 286 patients with fungal PJI in the hip, knee, shoulder, and elbow prosthetics.

RESULTS

Patient comorbidities generally included conditions impairing wound healing and immune response such as diabetes mellitus. Candida species were the most common fungal pathogens identified (85%); 30% had a concomitant bacterial infection. A two-stage exchange was most utilized, with a mean success rate of 65%. Antifungal impregnated spacers were utilized in 82 cases, with a comparatively high success rate (81%). Attempts at debridement with implant retention had substantially lower cure rates (15%).

CONCLUSIONS

Two-stage exchange is the favored approach to treating fungal PJI. Debridement with implant retention does not appear adequate to control infection, and retrieval of implanted materials should be prioritized. The use of antifungal impregnated spacers is an important area of ongoing research, with uncertainty regarding the type and quantity of antifungal agent to incorporate, although recent reports support the use of these agents.

Candida Periprosthetic Joint Infection: Is It Curable?

Candida periprosthetic joint infection (CPJI) is a rare and very difficult to treat infection, and high-quality evidence regarding the best management is scarce. Candida spp. adhere to medical devices and grow forming biofilms, which contribute to the persistence and relapse of this infection. Typically, CPJI presents as a chronic infection in a patient with multiple previous surgeries and long courses of antibiotic therapy. In a retrospective series of cases, the surgical approach with higher rates of success consists of a two-stage exchange surgery, but the best antifungal treatment and duration of antifungal treatment are still unclear, and the efficacy of using an antifungal agent-loaded cement spacer is still controversial. Until more evidence is available, focusing on prevention and identifying patients at risk of CPJI seems more than reasonable.

Eradicating Fungal Periprosthetic TKA "Super-infection": Review of the Contemporary Literature and Consideration of Antibiotic-Impregnated Dissolving Calcium Sulfate Beads as a Novel PJI Treatment Adjunct

Fungal periprosthetic joint infections are an uncommon but potentially devastating complication of arthroplasty surgery. The concurrent presence of a coexistent bacterial pathogen—a so called “super-infection”—adds further complexity. With delays to definitive diagnosis and a large number of procedures before cure, the associated physical and psychological morbidity is considerable. Beyond this, the economic and resource burden can be substantial. This case report presents the successful rapid treatment of an atypical bacterial and fungal periprosthetic super-infection with two-stage revision surgery augmented with a commercially available dissolving calcium sulfate bead system permitting targeted local antifungal elution. While not the panacea for treatment, these beads provide another potentially useful tool in the atypical pathogen eradication armamentarium. Much research is still indicated to define the optimal care pathway for fungal periprosthetic super-infections.

Fluorescent-conjugated antibodies as rapid ex vivo markers for bacterial presence on orthopedic surgical explants and synovium: A pilot study

Surgical infection is one of the most pressing problems in the field of orthopedic surgery; however, current detection methods are plagued by high costs and long wait times. This study seeks to demonstrate the ability of a novel assay using fluorescently conjugated antibodies and confocal laser scanning microscopy (CLSM) to accurately detect bacterial presence on orthopedic surgical explants, tissue, and synovial fluid in 30 min. Explanted hardware, tissue, and synovial fluid samples suspected to be infected were collected from human subjects with institutional review board consent. Samples were prepared using a 30-min protocol, consisting of rinsing, nonspecific blocking and staining steps, and imaged using CLSM. Images were analyzed using ImageJ (National Institute of Health) to determine the percent area of Gram positive and Gram negative bacteria. Results of the assay were compared to the hospital's microbiological laboratory and Gram staining results. Ninety three samples were collected and tested using the 30-min testing protocol; 75 samples were synovial fluid and 18 were tissue and explants. Seventy four of 75 (98.6%) synovial fluid samples correlated with the hospital laboratory's microbiological findings. Of the 18 explant and tissue samples, our assay found bacterial presence in 14 of 18 samples, while the hospital microbiology laboratory found bacterial presence in 13 of 18 samples. This assay reliably stained and rapidly identified the presence of Gram negative and Gram positive bacteria on surgical explants, tissue and synovial fluid in 30 min. This methodology may serve as a point of service tool for the determination of bacterial presence during surgical procedures.

Methods and probability of success after early revision of prosthetic joint infections with debridement, antibiotics and implant retention

Prosthetic joint infection (PJI) is a rare-and dreaded-complication of arthroplasty requiring multidisciplinary care. Given the dual goal of treating the infection and maintaining satisfactory function, it is preferable to determine how and when the implanted components can be retained. Bacteria and fungi organize themselves into biofilms that shield them from antibiotics and the immune system. This biofilm is in place after 15 days of active infection. Some antibiotics have a better activity on biofilms. The following factors have a negative impact on the probability of a successful debridement, antibiotics and implant retention (DAIR) intervention: fracture or revision, use of cement, bacteremia, kidney and/or liver failure, immunosuppression and elevated CRP. Hematogenous infections have a worse prognosis than early postoperative infections. Using a decision algorithm increases the chances of DAIR being successful. The KLIC score applies to early postoperative infections (<4 weeks postoperative and<3 weeks from the first signs) while the CRIME-80 score applies to hematogenous infections (<3 weeks from the first signs). Arthroscopic treatments have no role here, whereas DAIR through an arthrotomy is well standardized. Wide spectrum antibiotic therapy, secondarily adapted to the causative microorganism, is indicated for a total of 3 months. The results against the infection are mixed, although following a decision algorithm resolves the infection in about 75% of cases. The functional outcomes and quality of life are close to those of patients who have undergone primary joint replacement. It is not recommended to carry out a second DAIR if the first one fails. It is logical to apply the principles set out for the hip and knee to other joint replacements, and to use the same algorithm. For the upper limb, and especially for reverse shoulder arthroplasty, one must be careful about Cutibacterium acnes infections as they are hard to diagnose. Surgeons should not hesitate to contact a referral center for any PJI, although it is preferable that early infections be treated at the facility that performed the implantation.

Microbiological pattern of prosthetic hip and knee infections: a high-volume, single-centre experience in China

Introduction. Prosthetic joint infection (PJI) is a serious complication after arthroplasty, which results in high morbidity, prolonged treatment and considerable healthcare expenses in the absence of accurate diagnosis. In China, microbiological data on PJIs are still scarce.Hypothesis/Gap Statement. The incidence of PJI is increasing year by year, and the proportion of drug-resistant bacteria infection is nicreasing, which brings severe challenges to the treatment of infection.Aim. This study aimed to identify the pathogens in PJIs, multi-drug resistance, and evaluate the effect of the treatment regimen in patients with PJI.Methodology. A total of 366 consecutive cases of PJI in the hip or knee joint were admitted at the Orthopedic Surgery Center in Zhengzhou, China from January 2012 to December 2018. Infections were confirmed in accordance with the Infectious Diseases Society of America and the Musculoskeletal Infection Society (MSIS) criteria. Concurrently, patient demographic data, incidence and antibiotic resistance were investigated. Statistical differences were analysed using Fisher's exact test or chi-square test.Results. Altogether, 318 PJI cases satisfying the inclusion criteria were enrolled in this study, including 148 with hip PJIs and 170 with knee PJIs. The average age of patients with hip PJIs was lesser than that of patients with knee PJIs (56.4 vs. 68.6 years). Meanwhile, coagulase-negative staphylococcus (CNS, n=81, 25.5 %) was the predominant causative pathogen, followed by Staphylococcus aureus (n=67, 21.1 %). Methicillin-resistant Staphylococcus (MRS) was identified in 28.9 % of PJI patients. In addition, fungus accounted for 4.8 % (n=15), non-tuberculosis mycobacterium accounted for 1.6 % (n=5), polymicrobial pathogens accounted for 21.7 % (n=69), and Gram-negative bacteria accounted for 7.9 % (n=25) of the total infections. The results of antibiotic susceptibility testing showed that gentamicin and clindamycin β-lactam antibiotics were poorly susceptible to Gram-positive isolates, but they were sensitive to rifampicin, linezolid and vancomycin. While antibiotics such as amikacin and imipenem were effective against Gram-negative bacteria, there was a high resistance rate of other pathogens to gentamicin, clindamycin and some quinolone antibacterial drugs. Empirical antibiotic treatment should combine vancomycin and cephalosporin, levofloxacin or clindamycin. When the pathogen is confirmed, the treatment should be individualized.Conclusions. The prevalence of culture-negative PJIs is still very high. Gram-positive bacteria are still the main type of pathogens that cause PJIs. Attention should be paid to the high incidence of MRS, such as MRSA and MR-CNS, among PJI patients. Empirical antibiotic treatment should cover Gram-positive isolates, especially Staphylococcus.

Cryptococcus magnus Periprosthetic Shoulder Infection: A Case Report

CASE

We present a 68-year-old diabetic man with a periprosthetic shoulder infection (PSI) by Cryptococcus magnus. The fungus was identified 4 weeks after a revision surgery for a chronic bacterial PSI. Treatment was successful with a 2-week course of intravenous liposomal amphotericin B (5 mg/kg) followed by 6 weeks of fluconazole (200 mg/d).

CONCLUSION

To the best of our knowledge, only 2 periprosthetic infections due to Cryptococcus neoformans have been previously reported. This is the first report of cryptococcal involvement of a prosthetic shoulder, and the first identified osteoarticular infection ever by C. magnus.

Fungal Periprosthetic Knee Joint Infection in a Patient with Metamizole-Induced Agranulocytosis

We present the case of a 55-year-old female patient with metamizole-induced agranulocytosis after total knee arthroplasty, leading to septic periprosthetic joint infections (PJIs). Owing to metamizole-induced agranulocytosis, the synovial leukocyte count was negative. Here, we discuss the diagnostic challenges evolving from sepsis and neutropenia in patients with suspected PJIs. We suggest an urgent surgical approach, mainly focusing on the clinical presentation preoperatively. Later, our patient developed candidemia and periprosthetic tissue samples were positive for Candida albicans. For fungal PJIs, long-term follow-up studies are lacking and therapeutic recommendations differ. Here, we present our therapeutic approach, including staged revision and 12 weeks of systemic antifungal therapy, and discuss recent findings regarding the therapy of fungal PJIs.

A Biodegradable Antifungal-Loaded Sol-Gel Coating for the Prevention and Local Treatment of Yeast Prosthetic-Joint Infections

Fungal prosthetic-joint infections are rare but devastating complications following arthroplasty. These infections are highly recurrent and expose the patient to the development of candidemia, which has high mortality rates. Patients with this condition are often immunocompromised and present several comorbidities, and thus pose a challenge for diagnosis and treatment. The most frequently isolated organisms in these infections are Candida albicans and Candida parapsilosis, pathogens that initiate the infection by developing a biofilm on the implant surface. In this study, a novel hybrid organo-inorganic sol-gel coating was developed from a mixture of organopolysiloxanes and organophosphite, to which different concentrations of fluconazole or anidulafungin were added. Then, the capacity of these coatings to prevent biofilm formation and treat mature biofilms produced by reference and clinical strains of C. albicans and C. Parapsilosis was evaluated. Anidulafungin-loaded sol-gel coatings were more effective in preventing C. albicans biofilm formation, while fluconazole-loaded sol-gel prevented C. parapsilosis biofilm formation more effectively. Treatment with unloaded sol-gel was sufficient to reduce C. albicans biofilms, and the sol-gels loaded with fluconazole or anidulafungin slightly enhanced this effect. In contrast, unloaded coatings stimulated C. parapsilosis biofilm formation, and loading with fluconazole reduced these biofilms by up to 99%. In conclusion, these coatings represent a novel therapeutic approach with potential clinical use to prevent and treat fungal prosthetic-joint infections.

Periprosthetic joint infection of a total hip arthroplasty with Candida parapsilosis

INTRODUCTION

Fungal periprosthetic joint infection (PJI) is a disruptive and complex complication of joint arthroplasty. We present a case of a fungal PJI with Candida parapsilosis after a total hip arthroplasty (THA).

PRESENTATION OF CASE

A 73-year-old woman with a history of ovarian cancer with peritoneal metastases, was treated with a THA, due to symptomatic arthritis of the right hip. One month after surgery, she had difficulties walking. Inflammatory parameters were mildly increased. Aspiration of a subcutaneous abscess diagnosed Candida parapsilosis. A two-stage revision arthroplasty without spacer was performed. During a six-week prosthesis-free interval, intravenous fluconazole 400 mg was given. After reimplantation, fluconazole was continued for two weeks intravenously and life-long perorally. Follow-up of the patient after six months showed no recurrence of infection.

DISCUSSION

This case revealed that when PJI is suspected, a low treshold for joint aspiration is important. Two-stage revision with systematic antifungal therapy is the preferred treatment of fungal PJI. Our case demonstrated a good result with a prosthesis-free interval. Fluconazole is the preferred antifungal treatment and it should be applied for at least six months or longer.

CONCLUSION

To our knowledge, this is the first case of a fungal PJI with Candida parapsilosis after a THA treated with a two-stage revision arthroplasty without spacer and a life-long fluconazole treatment.

Prosthetic joint infection due to Candida species: Case series and review of literature

INTRODUCTION

The increase in the number of patients with prosthetic joints will entail a rise in the absolute number of infections associated with these procedures. Although less frequent, infections by Candida species are also expected to increase, and the clinical and surgical management of these cases is based on case reports and opinion of specialists. The objective of the present study was to review the available literature and describe the cases of prosthetic joint infection caused by Candida species in patients of the Institute of Orthopedics and Trauma of the University of São Paulo Faculty of Medicine Clinics Hospital (IOT-HCFMUSP) between 2007 and 2014.

PATIENT CONCERNS

Eleven patients were diagnosed with prosthetic joint infection due to Candida with mean age of 65 years. The most frequent comorbidities were heart disease and diabetes mellitus, and the main personal antecedent was previous bacterial infection in the prosthetic joint. At least one risk factor for fungal infection was present in 73% of the patients. There was no difference between the prevalence of infections caused by Candida albicans and non-albicans Candida species, and there was bacterial co-infection in 55% of the cases.

DIAGNOSIS

For building up the case series, patients with cultures of bone and joint specimens that were positive for Candida species and had a clinical diagnosis of prosthetic joint infection were included in the case series.

INTERVENTIONS

Surgical debridement with removal of the prosthesis was the most frequently used surgical approach (45%). All patients were treated with monotherapy, and the most frequently used antifungal agent was fluconazole. The total duration of antifungal therapy was 6 months in 73% of the cases.

OUTCOMES

After the initial management, 73% of the patients achieved clinical remission.

CONCLUSION

The most indicated initial management was debridement with removal of the prosthesis, and the most used treatment regimen was fluconazole monotherapy. The most prevalent treatment duration was 6 months. The initial management led to a favorable outcome in 73% of the cases.

DESCRIPTORS

Prosthetic joint infection, Candida, treatment, and diagnosis.

Can metagenomic next-generation sequencing identify the pathogens responsible for culture-negative prosthetic joint infection?

BACKGROUND

The aims of this study were to (1) evaluate the efficacy and safety of targeted antibiotics for the treatment of culture-negative prosthetic joint infection based on metagenomic next-generation sequencing results and (2) verify the accuracy and reliability of metagenomic next-generation sequencing for identifying pathogens related to culture-negative prosthetic joint infection.

METHODS

Ninety-seven consecutive PJI patients, including 27 patients with culture-negative prosthetic joint infection, were treated surgically at our center. Thirteen of the 27 culture-negative prosthetic joint infection patients, who were admitted before June 2017 and treated with empirical antibiotics, comprised the empirical antibiotic group (EA group), and the other 14 patients, who were admitted after June 2017 and treated with targeted antibiotics according to their metagenomic next-generation sequencing results, were classified as the targeted antibiotic group (TA group). The short-term infection control rate, incidence of antibiotic-related complications and costs were compared between the two groups.

RESULTS

Two of the patients in the EA group experienced debridement and prolonged antimicrobial therapy due to wound infection after the initial revision surgery. No recurrent infections were observed in the TA group; however, no significant difference in the infection control rate was found between the two groups (83.33% vs 100%, P = 0.217). More cases of antibiotic-related complications were recorded in the EA group (6 cases) than in the TA group (1 case), but the difference was not statistically significant (P = 0.0697). The cost of antibiotics obtained for the EA group was 20,168.37 Yuan (3236.38-45,297.16), which was higher than that found for the TA group (10,164.16 Yuan, 2959.54-16,661.04, P = 0.04).

CONCLUSIONS

Targeted antibiotic treatment for culture-negative prosthetic joint infection based on metagenomic next-generation sequencing results is associated with a favorable outcome, and metagenomic next-generation sequencing is a reliable tool for identifying pathogens related to culture-negative prosthetic joint infection.