Diagnosis and Management of Fungal Periprosthetic Joint Infections

Graphene Oxide-Silver-Coated Sulfonated Polyetheretherketone (Ag/GO-SPEEK): A Broad-Spectrum Antibacterial Artificial Bone Implants

Polyetheretherketone (PEEK), particularly its sulfonated form (SPEEK), has emerged as a promising synthetic biomaterial for artificial bone implants, providing an alternative to conventional titanium metal. However, postoperative infections pose a critical challenge, driven by diverse and antibiotic-resistant bacteria. To address this issue, we propose the modification of the SPEEK surface using a thin graphene oxide (GO) film containing silver (Ag) ions. The resulting coating exhibits substantial antibacterial effects against various pathogens, including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans. Experimental assessments elucidate the coating's impact on bacterial adhesion, biofilm formation, and morphology. The results suggest that hindered bacterial growth stems from reduced biofilm production and the controlled release of Ag ions facilitated by the GO coating. The Ag/GO-SPEEK material holds promise as a bioactive implant, addressing the challenges associated with bacterial targeting in bone tissue engineering applications.

Surgical procedures for the treatment of fungal periprosthetic infection following hip arthroplasty: a systematic scoping review

Background

There has been limited literature synthesizing the therapeutic effects of surgical procedures for fungal periprosthetic joint infection (PJI) following hip arthroplasty. The authors' current study aims to comprehensively review and analyze those relevant literature, and carefully make recommendations for future clinical practices.

Methods

Our current study was carried out in accordance with the PRISMA 2020 statement. Studies regarding the surgical management of fungal PJI following hip arthroplasty were collected via a thorough search of PubMed, Embase and Google scholar databases. The search was lastly performed in March 2023. Non-English language, reviews, articles with duplicated data, and articles without clear information about the type of fungal pathogens and treatment options were excluded. The authors evaluated their systematic review compliance by using AMSTAR 2 criteria and fell in moderate quality. Clinical outcomes of different surgical procedures were evaluated, and a binary logistic regression model was used to identify the risks associated with treatment failure. Data analyses were performed using the SPSS version 19.0.

Results

A total of 33 articles encompassing 80 patients with fungal PJI following hip arthroplasty were identified. Candida albicans was the most frequently isolated fungus (56.3%, 45/80). The overall treatment success was achieved in 71.1% (54/76) of the reported cases. Univariate analysis showed that the differences of success rate were not significant between publication periods, genders, ages, specimen collection methods, and fungal pathogens. Treatment success rate was 47.4% (9/19) in fungal PJI cases with bacterial co-infection, significantly lower than those without [vs. 79.0% (45/57), P=0.017]. The pooled success rate for surgical debridement, spacer implantation, resection arthroplasty, one-stage revision, and two-stage revision was 50.0% (4/8), 42.9% (3/7), 55.0% (11/20), 86.7% (13/15), and 88.5% (23/26), respectively, with significant differences between them (P=0.009). A binary logistic regression model showed that bacterial co-infection and surgical option were the two significant risk factors associated with treatment failure for fungal PJI following hip arthroplasty.

Discussion

Regarding the surgical treatment of fungal PJI following hip arthroplasty, patients with bacterial co-infection, and those treated with surgical procedures such as debridement, spacer implantation, and resection arthroplasty should be aware of the higher risks of failure. Nonetheless, future multiple-centre cohort studies are required to establish the optimal treatment.

Diagnostic value of procalcitonin in patients with periprosthetic joint infection: a diagnostic meta-analysis

Background

The success rate of periprosthetic joint infection (PJI) treatment is still low. Early diagnosis is the key to successful treatment. Therefore, it is necessary to find a biomarker with high sensitivity and specificity. The diagnostic value of serum procalcitonin (PCT) for PJI was systematically evaluated to provide the theoretical basis for clinical diagnosis and treatment in this study.

Methods

We searched the Web of Science, Embase, Cochrane Library, and PubMed for studies that evaluated the diagnostic value of serum PCT for PJI (from the inception of each database until September 2020). Two authors independently screened the literature according to the inclusion and exclusion criteria. The quality of each selected literature was evaluated by using the Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2) tool. RevMan 5.3 software was used for the quality evaluation. The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were merged by using Meta-DiSc 1.4 software. The area under the curve (AUC) and Q index were calculated after the summary receiver operating characteristic (SROC) was generated. We also performed subgroup analysis.

Results

A total of 621 patients were enrolled in the nine studies. The pooled sensitivity of serum PCT for PJI diagnosis was 0.441 [95% confidence interval (CI), 0.384-0.500], the pooled specificity was 0.852 (95% CI, 0.811-0.888), the pooled PLR was 2.271 (95% CI, 1.808-2.853), the pooled NLR was 0.713 (95% CI, 0.646-0.786), and the pooled DOR was 5.756 (95% CI, 3.673-9.026). The area under SROC (the pooled AUC) was 0.76 (0.72-0.79). Q index was 0.6948.

Conclusion

This study showed that PCT detection of PJI had poor diagnostic accuracy. Hence, the serum PCT is not suitable as a serum marker for PJI diagnosis.

Two-Stage Treatment Protocol of Fungal Periprosthetic Hip and Knee Joint Infections: the Clinical Experience from a Single Center Experience

PURPOSE OF THE STUDY

To evaluate the clinical results and safety of fungal periprosthetic joint Infections (fPJIs) using two-stage treatment protocol.

MATERIAL AND METHODS

8 patients with fPJIs (3 hips and 5 knees) using two-stage revision were reviewed retrospectively and followed up at least 2 years. The preoperative demographic data, two-stage treatment protocol, results of microbiology and histologic workup and postoperative follow-up results (reimplantation success rate and infection free time) were recorded.

RESULTS

7 patients got successful reimplantation, with a 75% reimplantation success rate. Two patients got knee arthrodesis eventually. All patients were infection free with a median follow-up of 4.0 ± 2.0 years (range, 2-7 years). Of them, Candida species were found in 7 patients, while non-Candida specimen was only isolated in 1 patient with Aspergillus. Only 2 patients had coexisting bacterial infection (Methicillin-resistant coagulase-negative Staphylococci and Proteus mirabilis respectively). The average interval between the initial surgery and diagnosis of fPJIs was 21.50±34.79 months (range, 4-104 months). The mean time of spacer implantation was 7.75±2.77 months (range, 6-14 months). None serious complication or above knee amputation was found.

DISCUSSION

fPJIs are very rare and considerable challenge after total hip or knee arthroplasty. The goal of therapy is to eradicate local infection and maintain function. Candida species were the most common pathogen. The duration between spacer placement and staged reimplantation was highly variable, and generally dependent upon the results of joint aspirates and infl ammatory markers. The current study shows that the two-stage treatment protocol is recommended for fungal periprosthetic hip and knee joint infections.

CONCLUSIONS

The two-stage treatment protocol is recommended for fungal periprosthetic hip and knee joint infections. The safety and effi cacy of biantibiotical impregnated (antifungal + antibiotics) cement spacer is confi rmed. Further evidence-based work is needed to determine the optimal drug dose and reimplantation time.

KEY WORDS

two-stage treatment protocol, fungal periprosthetic infections, hip spacer, knee spacer.

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.

Value of Acid-Fast Bacilli and Fungal Cultures in Foot and Ankle Surgery in a US Hospital System

BACKGROUND

Acid-fast bacilli(AFB) and fungi are generally slow-growing, difficult to culture, and rarely the cause of infection. The goal of this study was to evaluate the value of routinely obtaining AFB and fungal cultures in foot and ankle surgery at a US hospital.

METHODS

A retrospective review was conducted to determine the number of positive AFB and fungal cultures out of the total number of foot and ankle samples tested. Between 2014 and 2019, patients who underwent surgery for a foot and ankle infection for soft tissue infection, septic arthritis, infectious postoperative complications were identified. Charts were reviewed to identify the results of the microbiological tests performed. To determine the value of running AFB and fungal cultures, the costs of each were provided by the microbiology lab at our institution.

RESULTS

Of the 322 patient charts reviewed, there were 434 AFB and 525 fungal cultures performed. None of these cultures were indicated to be positive for AFB (0%), and 22 (4.19%) were positive for fungi. The total labor and material costs were calculated to be $38 767. The AFB cultures cost $23 967, the positive fungal cultures cost $2371, and the negative fungal cultures cost $36 395.36.

CONCLUSION

This 322-case series of surgically managed foot and ankle infections showed 0% and 4.1% positivity rates of AFB and fungal cultures, respectively. Additionally, only 20% of cases with positive cultures were identified as pathologic requiring antifungal treatment. Further analysis is needed to determine best practices for obtaining vs declining to culture for AFB or fungal species, including assessing patient outcomes in the series of culture-positive(fungal-only) cases. Our results suggest that in our clinical setting of a US hospital system, routine fungal and AFB cultures may not be necessary but should be considered for chronic/recalcitrant infections, immunocompromised patients, and those with high surgeon suspicion.

LEVEL OF EVIDENCE

Level IV, case series.

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.

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.

1.5-Stage Versus 2-Stage Exchange Total Hip Arthroplasty for Chronic Periprosthetic Joint Infections: A Comparison of Survivorships, Reinfections, and Patient-Reported Outcomes

BACKGROUND

Management of periprosthetic joint infection after total hip arthroplasty (THA) has traditionally consisted of a 2-stage approach. However, 1.5-stage exchange has garnered recent interest. We compared 1.5-stage to 2-stage exchange recipients. Specifically, we assessed (1) infection-free survivorship and risk factors for reinfection; (2) 2-year surgical/medical outcomes (eg, reoperations, readmissions); (3) Hip Disability and Osteoarthritis Outcome Scores for Joint Replacement (HOOS-JR); and (4) radiographic outcomes (ie, progressive radiolucent lines, subsidences, and failures).

METHODS

We reviewed a consecutive series of 1.5-stage or planned 2-stage THAs. A total of 123 hips were included (1.5-stage: n = 54; 2-stage: n = 69) with mean clinical follow-up of 2.5 years (up to 8 years). Bivariate analyses assessed incidences of medical and surgical outcomes. Additionally, HOOS-JR scores and radiographs were evaluated.

RESULTS

The 1.5-stage exchange had 11% greater infection-free survivorship at final follow-up compared to 2 stages (94% versus 83%, P = .048). Morbid obesity was the only independent risk factor demonstrating increased reinfection among both cohorts. No differences in surgical/medical outcomes were observed between groups (P = .730). HOOS-JR scores improved markedly for both cohorts (1.5-stage difference = 44.3, 2-stage difference = 32.5; P < .001). A total of 82% of 1.5-stage patients did not demonstrate progressive femoral or acetabular radiolucencies, while 94% of 2-stage recipients did not have femoral radiolucencies and 90% did not have acetabular radiolucencies.

CONCLUSION

The 1.5-stage exchange appeared to be an acceptable treatment alternative for periprosthetic joint infections after THAs with noninferior infection eradication. Therefore, this procedure should be considered by joint surgeons for treatment of periprosthetic hip infections.

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.

The Impact of a Dedicated Multidisciplinary Team Approach for Prosthetic Joint Infections of the Lower Limb

Introduction

Prosthetic joint infections (PJI) of the hip and knee have significant morbidity and mortality, and present with varying local, host and microbiological factors. Given the broad presentation and complexity of PJI’s, we developed a dedicated multidisciplinary team (MDT) to manage this complex patient cohort, and report on our early outcomes.

Methods

This was a retrospective observational study of all patients diagnosed with a prosthetic joint infection of the hip or knee (n = 71) at our institution during a 4.5-year period. Patients treated after development of the MDT (post-MDT) (n = 44), were compared to a control group prior establishment of the MDT (pre-MDT) (n = 27).

Results

85.2% of individuals in the pre-MDT, and 85.7% of individuals in the post-MDT group were considered cured at a minimum 2 years post-operatively according to the Delphi-based definition. The total number of admissions to hospital (2.44 vs. 1.84) and total number of antibiotics used (3.37 vs. 2.75) decreased in the post-MDT group; however, differences were not considered statistically significant.

Discussion

Implementation of a dedicated MDT in the management of individuals with PJI’s of the lower limb at our hospital has allowed early and effective collaboration between healthcare personnel, with early promising results. Given the broad nature of PJI, future studies are ongoing to determine modifiable risk factors to reduce the incidence and improve outcomes of individuals with PJI’s where systems can then be implemented into already established MDTs to achieve the best clinical outcome for our patients.

Profiling the Immune Response to Periprosthetic Joint Infection and Non-Infectious Arthroplasty Failure

Arthroplasty failure is a major complication of joint replacement surgery. It can be caused by periprosthetic joint infection (PJI) or non-infectious etiologies, and often requires surgical intervention and (in select scenarios) resection and reimplantation of implanted devices. Fast and accurate diagnosis of PJI and non-infectious arthroplasty failure (NIAF) is critical to direct medical and surgical treatment; differentiation of PJI from NIAF may, however, be unclear in some cases. Traditional culture, nucleic acid amplification tests, metagenomic, and metatranscriptomic techniques for microbial detection have had success in differentiating the two entities, although microbiologically negative apparent PJI remains a challenge. Single host biomarkers or, alternatively, more advanced immune response profiling-based approaches may be applied to differentiate PJI from NIAF, overcoming limitations of microbial-based detection methods and possibly, especially with newer approaches, augmenting them. In this review, current approaches to arthroplasty failure diagnosis are briefly overviewed, followed by a review of host-based approaches for differentiation of PJI from NIAF, including exciting futuristic combinational multi-omics methodologies that may both detect pathogens and assess biological responses, illuminating causes of arthroplasty failure.

Synovial fluid neutrophil extracellular traps could improve the diagnosis of periprosthetic joint infection

AIMS

This study aimed to explore the diagnostic value of synovial fluid neutrophil extracellular traps (SF-NETs) in periprosthetic joint infection (PJI) diagnosis, and compare it with that of microbial culture, serum ESR and CRP, synovial white blood cell (WBC) count, and polymorphonuclear neutrophil percentage (PMN%).

METHODS

In a single health centre, patients with suspected PJI were enrolled from January 2013 to December 2021. The inclusion criteria were: 1) patients who were suspected to have PJI; 2) patients with complete medical records; and 3) patients from whom sufficient synovial fluid was obtained for microbial culture and NET test. Patients who received revision surgeries due to aseptic failure (AF) were selected as controls. Synovial fluid was collected for microbial culture and SF-WBC, SF-PNM%, and SF-NET detection. The receiver operating characteristic curve (ROC) of synovial NET, WBC, PMN%, and area under the curve (AUC) were obtained; the diagnostic efficacies of these diagnostic indexes were calculated and compared.

RESULTS

The levels of SF-NETs in the PJI group were significantly higher than those of the AF group. The AUC of SF-NET was 0.971 (95% confidence interval (CI) 0.903 to 0.996), the sensitivity was 93.48% (95% CI 82.10% to 98.63%), the specificity was 96.43% (95% CI 81.65% to 99.91%), the accuracy was 94.60% (95% CI 86.73% to 98.50%), the positive predictive value was 97.73%, and the negative predictive value was 90%. Further analysis showed that SF-NET could improve the diagnosis of culture-negative PJI, patients with PJI who received antibiotic treatment preoperatively, and fungal PJI.

CONCLUSION

SF-NET is a novel and ideal synovial fluid biomarker for PJI diagnosis, which could improve PJI diagnosis greatly.Cite this article: Bone Joint Res 2023;12(2):113-120.

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.

One and a Half-Stage Revision With Prosthetic Articulating Spacer for Definitive Management of Knee Periprosthetic Joint Infection

This paper is a comprehensive review that describes indications, contraindications, clinical outcomes, and pearls and pitfalls of 1.5-stage revision total knee arthroplasty (TKA) utilizing a primary TKA femoral component, all-polyethylene tibial component, and hand-crafted antibiotic cement for the management of chronic periprosthetic joint infection. The 1.5-stage exchange TKA details placement of an articulating spacer for an indefinite period, prolonging revision until reinfection, deterioration of functional status, or construct failure. A 1.5-stage revision TKA technique is a viable option for treatment of chronic periprosthetic knee infections. The inherent advantages of decreased health-care costs, decreased morbidity and mortality, and improved emotional ease from having a single procedure is attractive, especially if reinfection rates are determined to be equivocal to 2-stage revision.

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.

Serum and Synovial Markers in Patients with Rheumatoid Arthritis and Periprosthetic Joint Infection

Current diagnostic standards for PJI rely on inflammatory markers that are typically elevated in autoimmune diseases, thus making the diagnosis of PJI in patients with rheumatoid arthritis and joint replacement particularly complicated. There is a paucity of data on differentiating PJI from rheumatoid arthritis in patients with previous arthroplasty. In this study, we retrospectively analyzed the cases of 17 patients with rheumatoid arthritis and 121 patients without rheumatoid disease who underwent surgical intervention due to microbiology-positive PJI of the hip or knee joint. We assessed clinical patient characteristics, laboratory parameters, and prosthesis survival rates in patients with and without rheumatoid arthritis and acute or chronic PJI. ROC analysis was conducted for the analyzed parameters. In patients with chronic PJI, peripheral blood CRP (p = 0.05, AUC = 0.71), synovial WBC count (p = 0.02, AUC = 0.78), synovial monocyte cell count (p = 0.04, AUC = 0.75), and synovial PMN cell count (p = 0.02, AUC = 0.80) were significantly elevated in patients with rheumatoid arthritis showing acceptable to excellent discrimination. All analyzed parameters showed no significant differences and poor discrimination for patients with acute PJI. Median prosthesis survival time was significantly shorter in patients with rheumatoid arthritis (p = 0.05). In conclusion, routinely used laboratory markers have limited utility in distinguishing acute PJI in rheumatoid patients. In cases with suspected chronic PJI but low levels of serum CRP and synovial cell markers, physicians should consider the possibility of activated autoimmune arthritis.

Hydrolytic Enzymes as Potentiators of Antimicrobials against an Inter-Kingdom Biofilm Model

Biofilms are recalcitrant to antimicrobials, partly due to the barrier effect of their matrix. The use of hydrolytic enzymes capable to degrade matrix constituents has been proposed as an alternative strategy against biofilm-related infections. This study aimed to determine whether hydrolytic enzymes could potentiate the activity of antimicrobials against hard-to-treat interkingdom biofilms comprising two bacteria and one fungus. We studied the activity of a series of enzymes alone or in combination, followed or not by antimicrobial treatment, against single-, dual- or three-species biofilms of Staphylococcus aureus, Escherichia coli, and Candida albicans, by measuring their residual biomass or culturable cells. Two hydrolytic enzymes, subtilisin A and lyticase, were identified as the most effective to reduce the biomass of C. albicans biofilm. When targeting interkingdom biofilms, subtilisin A alone was the most effective enzyme to reduce biomass of all biofilms, followed by lyticase combined with an enzymatic cocktail composed of cellulase, denarase, and dispersin B that proved previously active against bacterial biofilms. The subsequent incubation with antimicrobials further reduced the biomass. Enzymes alone did not reduce culturable cells in most cases and did not interfere with the cidal effects of antimicrobials. Therefore, this work highlights the potential interest of pre-exposing interkingdom biofilms to hydrolytic enzymes to reduce their biomass besides the number of culturable cells, which was not achieved when using antimicrobials alone. IMPORTANCE Biofilms are recalcitrant to antimicrobial treatments. This problem is even more critical when dealing with polymicrobial, interkingdom biofilms, including both bacteria and fungi, as these microorganisms cooperate to strengthen the biofilm and produce a complex matrix. Here, we demonstrate that the protease subtilisin A used alone, or a cocktail containing lyticase, cellulase, denarase, and dispersin B markedly reduce the biomass of interkingdom biofilms and cooperate with antimicrobials to act upon these recalcitrant forms of infection. This work may open perspectives for the development of novel adjuvant therapies against biofilm-related infections.

Pharmacodynamics of Moxifloxacin, Meropenem, Caspofungin and their Combinations Against In Vitro Polymicrobial Inter-kingdom Biofilms

Biofilms colonize medical devices and are often recalcitrant to antibiotics. Inter-kingdom biofilms, when at least a bacterium and a fungus are co-isolated, increase the likelihood of therapeutic failures. In this work, a three-species in vitro biofilm model including S. aureus, E. coli and C. albicans was used to study the activity of the antibiotics moxifloxacin and meropenem, the antifungal caspofungin, and combinations of them against inter-kingdom biofilms. The culturable cells and total biomass were evaluated to determine the pharmacodynamic parameters of the drug response for the incubation with the drugs alone. The synergic or antagonistic effects (increased/decreased effects) of the combination of drugs were analysed with the highest single agent method. Biofilms were imaged in confocal microscopy after live/dead staining. The drugs had limited activity when used alone against single-, dual- or three-species biofilms. When used in combination, additive effects were observed against single- or dual-species biofilms, and increased effects (synergy) against biomass of three-species biofilms. In addition, the two antibiotics showed different patterns, moxifloxacin being more active when targeting S. aureus and meropenem when targeting E. coli. All these observations were confirmed by confocal microscopy images. Our findings highlight the interest in combining caspofungin with antibiotics against inter-kingdom biofilms.

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.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00264-021-05214-y.

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.

Does the Organism Profile of Periprosthetic Joint Infections Change With a Topical Vancomycin Powder and Dilute Povidone-Iodine Lavage Protocol?

BACKGROUND

While vancomycin powder and dilute povidone-iodine (VIP) is associated with fewer total joint arthroplasty (TJA) periprosthetic joint infections (PJI), its effect on PJI organism profiles is unclear. This study evaluates primary TJA PJI organism profiles before and after the implementation of a VIP protocol.

METHODS

In total, 18,299 primary TJAs performed at a university-affiliated, not-for-profit orthopedic hospital from before (1/2012-12/2013) and after (1/2016-12/2019) a VIP protocol was initiated were reviewed to identify deep PJIs that occurred within 90 days of the index arthroplasty as defined by the Musculoskeletal Infection Society guidelines. Demographics, overall organism incidence (n/TJAs), and relative organism incidence (n/PJIs) from the two cohorts were compared.

RESULTS

In total, 103 TJA PJIs were identified (pre-VIP: 32/3982; VIP: 71/14,317). Following the introduction of VIP, the overall and relative incidence of coagulase-negative staphylococcal TJA PJIs significantly decreased (overall: 0.20% to 0.04%, P = .004; relative: 25.00% to 8.45%, P = .031). In response, the relative incidence of MSSA TJA PJIs significantly increased (18.75% to 40.85%, P = .042). Broken down by arthroplasty type, VIP was associated with a significantly lower overall incidence of coagulase-negative staphylococcal total knee arthroplasty (TKA) PJIs (0.27% to 0.06%, P = .015), a significantly lower overall incidence of MRSA TKA PJIs (0.18% to 0.03%, P = .031), and a nonsignificant decrease in the overall incidence of gram-negative TKA PJIs (0.18% to 0.04%, P = .059). No organism profile changes were found in total hip arthroplasty PJIs.

CONCLUSION

VIP is not associated with more difficult to treat primary TJA PJIs. While promising, these findings require a prospective randomized controlled trial for confirmation.

LEVEL OF EVIDENCE

Level III, Retrospective cohort study.

A spacer infection by Candida albicans secondary to a Staphylococcus capitis prosthetic joint infection: a case report

BACKGROUND

Prosthetic joint infection (PJI) is one of the most feared complications following total arthroplasty surgeries. Gram-positive bacteria are the most common microorganisms implicated in PJIs, while infections mediated by fungi only account for 1% of cases. When dealing with PJIs, a two-stage revision arthroplasty is widely used. Briefly, a spacer is introduced until re-implantation of the definitive prosthesis to provide skeleton stabilization while delivering antibiotics in the site of the infection. Sometimes, antimicrobial therapy may fail, but the isolation of a second microorganism from the spacer is uncommon and even less frequent that of a yeast.

CASE PRESENTATION

Here is described a case of a 75-year-old woman who underwent two-stage revision surgery of the left hip prosthesis secondary to a Staphylococcus capitis infection, whose spacer was found to be infected by Candida albicans at a later time. Briefly, the patient underwent revision surgery of the hip prosthesis for a suspected PJI. After the debridement of the infected tissue, an antibiotic-loaded spacer was implanted. The microbiological analysis of the periprosthetic tissues and the implant depicted a S. capitis infection that was treated according to the antimicrobial susceptibility profile of the clinical isolate. Three months later, the patient was admitted to the emergency room due to local inflammatory signs. Synovial fluid was sent to the laboratory for culture. No evidence of S. capitis was detected, however, a yeast was identified as Candida albicans. Fifteen days later, the patient was hospitalized for the removal of the infected spacer. Microbiological cultures confirmed the results of the synovial fluid analysis. According to the susceptibility profile, the patient was treated with fluconazole (400 mg/day) for 6 months. Seven months later, the patient underwent second-stage surgery. The microbiological tests on the spacer were all negative. After 12 months of follow-up, the patient has fully recovered and no radiological signs of infection have been detected.

CONCLUSIONS

Given the exceptionality of this complication, it is important to report these events to better understand the clinical outcomes after the selected therapeutic options to prevent and forestall the development of either bacterial or fungal spacer infections.

Facing multidrug-resistant pathogens in periprosthetic joint infections with self-administered outpatient parenteral antimicrobial therapy-A prospective cohort study

A key factor in the successful management of periprosthetic joint infection (PJI) besides the surgical regime is a consistent antimicrobial therapy. Recently, oral versus intravenous (IV) antibiotics for bone and joint infection trial demonstrated the noninferiority of oral antimicrobial therapy compared to IV, implying that an early transition to oral administration is reasonable. It is likely that the international consensus meeting of musculoskeletal Infections and the European Bone and Joint Infection Society will consider these findings. However, rising levels of antimicrobial resistance are challenging and recommendations for dealing with multidrug-resistant (MDR) pathogens resistant to oral antibiotics are lacking. This study focuses on establishing guidance towards their management in PJI. From December 2015 to June 2019, patients with MDR pathogens were included in a single-center prospective cohort study and treated with self-administered outpatient parenteral antimicrobial therapy (S-OPAT) based on a two-stage revision strategy. Demographics, pathogens, antimicrobial agents, and outcomes were recorded. A total of 1738 outpatient days in 26 patients were analyzed. The incidence of pathogens resistant to oral antibiotics in PJI was 4%, most frequently encountered were staphylococcus epidermidis. The Kaplan-Meier-estimated infection-free survival after 3 years was 90% (95% confidence interval, 84.6%-95.5%). We recorded adverse events in 6 of 54 (11%) S-OPAT episodes (3.45/1000 S-OPAT days). (i) S-OPAT in two-stage revision arthroplasty to counter increasing numbers of MDR pathogens resistant to oral agents can achieve a high infection eradication rate and (ii) should therefore be taken into account at the next society's consensus treatment updates.

Conversion From Knee Arthrodesis Back to Arthroplasty: A Particular Challenge in Combination With Fungal Periprosthetic Joint Infection

A 58-year-old female treated at an outside facility with knee arthrodesis due to persistent periprosthetic joint infection fulfilled all prerequisites for a conversion back to arthroplasty, as part of a 2-stage revision. Owing to the detection of Candida parapsilosis, the treatment concept was converted to a three-stage procedure. A scheduled spacer exchange with additional amphotericin B-loaded polymethylmethacrylate was conducted as an intermediate revision before reimplantation. Conversion in the setting of fungal periprosthetic joint infection presents a challenge, and successful treatment hinges on the use of proper antifungal and antimicrobial protocols, advanced surgical techniques, and a multidisciplinary team approach. At the 3-year follow-up, successful infection eradication as measured by the Delphi-based consensus definition was achieved with a range of motion of 0°-100°.

Candidal periprosthetic joint infection after primary total knee arthroplasty combined with ipsilateral intertrochanteric fracture: A case report

BACKGROUND

Candidal periprosthetic joint infection is a rare and difficult to diagnose complication of total knee arthroplasty. The treatment of such complications is inconclusive and may include prosthesis removal, debridement, arthrodesis, and extensive antifungal therapy to control the infection.

CASE SUMMARY

A 62-year-old male with a history of total knee arthroplasty (TKA) in his left knee presented with ipsilateral knee pain and a sinus discharge 20 mo after TKA. The patient was previously evaluated for left knee pain, swelling, and a transient fever one month postoperatively. Prothesis removal and insertion of a cement spacer were performed in a local hospital six months prior to the current presentation. Medical therapy included rifampicin and amphotericin which were administered for 4 wk following prosthesis removal. A second debridement was performed in our hospital and Candida parapsilosis was detected in the knee joint. Fourteen weeks following the latter debridement, the patient suffered a left intertrochanteric fracture and received closed reduction and internal fixation with proximal femoral nail anterotation. Two weeks after fracture surgery, a knee arthrodesis with autograft was performed using a double-plate fixation. The patient recovered adequately and was subsequently discharged. At the two-year follow-up, the patient has a stable gait with a pain-free, fused knee.

CONCLUSION

Fungal periprosthetic joint infection following TKA may be successfully and safely treated with prosthesis removal, exhaustive debridement, and arthrodesis after effective antifungal therapy. Ipsilateral intertrochanteric fractures of the affected knee can be safely fixated with internal fixation if the existing infection is clinically excluded and aided by the investigation of serum inflammatory markers.

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.

Prosthetic Joint Infection of a Revision Knee Arthroplasty with Candida parapsilosis

We report a case of an infected total knee arthroplasty with Candida parapsilosis. The patient was successfully treated with a two-stage exchange arthroplasty, local antifungal treatment, and systemic antifungal treatment. This specific combination therapy to treat C. parapsilosis joint infection has not been previously reported.