Voriconazole is delivered from antifungal-loaded bone cement

Impact of Anti-Mycotic Drugs on the Osteogenic Response of Bone Marrow Mesenchymal Stem Cells In Vitro

The treatment of fungal bone infections and infected non-unions is a huge challenge in modern trauma and orthopedics, which normally contain the local and systemic administration of anti-fungal drugs. Although frequently used, little is known about the impact of systemic and locally administered fungicides on the osteogenic regenerative capabilities of infected bone tissue, especially upon the osteogenesis of human bone marrow mesenchymal stem cells (BM-hMSCs). This study evaluates the effects of the three most common fungicides for the systemic treatment of bone infections, Voriconazole (VOR), liposomal Amphotericin B (LAMB), and Fluconazole (FLU), as well as the effects of VOR and LAMB-loaded Polymethylmethacrylate (PMMA) cement chips in different concentrations upon the osteogenic response of BM-hMSCs in vitro. Within this study, we compared the ability of BM-hMSC to differentiate into osteoblast-like cells and synthesize hydroxyapatite as assessed by radioactive 99mTechnetium-Hydroxydiphosphonate (99mTc-HDP) labeling, cell proliferation, and analyses of supernatants upon various osteogenic parameters. Our results revealed that VOR added to the cell culture medium affects the osteogenic potential of BM-hMSC negatively, while there were no detectable effects of LAMB and FLU. Moreover, we showed dose-dependent negative effects of high- and extended-dose fungicide-loaded PMMA cement due to cytotoxicity, with a higher cytotoxic potential of VOR than LAMB, while low-dose fungicide-loaded PMMA had no significant effect on the osteogenic potential of BM-hMSC in vitro.

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.

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.

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.

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.

Poly(DL-lactic acid) scaffolds as a bone targeting platform for the co-delivery of antimicrobial agents against S. aureus-C. albicans mixed biofilms

New strategies for the treatment of polymicrobial bone infections are required. In this study, the co-delivery of two antimicrobials by poly(D,L-lactic acid) (PDLLA) scaffolds was investigated in a polymicrobial biofilm model. PDLLA scaffolds were prepared by solvent casting/particulate leaching methodology, incorporating minocycline and voriconazole as clinically relevant antimicrobial agents. The scaffolds presented a sponge-like appearance, suitable to support cell proliferation and drug release. Single- and dual-species biofilm models of Staphylococcus aureus and Candida albicans were developed and characterized. S. aureus presented a higher ability to form single-species biofilms, compared to C. albicans. Minocycline and voriconazole-loaded PDLLA scaffolds showed activity against S. aureus and C. albicans single- and dual-biofilms. Ultimately, the cytocompatibility/functional activity of PDLLA scaffolds observed in human MG-63 osteosarcoma cells unveil their potential as a next-generation co-delivery system for antimicrobial therapy in bone infections.

Conventional Antifungals for Invasive Infections Delivered by Unconventional Methods; Aerosols, Irrigants, Directed Injections and Impregnated Cement

The administration of approved antifungals via unapproved formulations or administration routes (such as aerosol, direct injection, irrigation, topical formulation and antifungal-impregnated orthopedic beads or cement) may be resorted to in an attempt to optimize drug exposure while minimizing toxicities and/or drug interactions associated with conventional (systemic) administrations. Existing data regarding such administrations are mostly restricted to uncontrolled case reports of patients with diseases refractory to conventional therapies. Attribution of efficacy and tolerability is most often problematic. This review updates prior published summaries, reflecting the most recent data and its application by available prevention and treatment guidelines for invasive fungal infections. Of the various dosage forms and antifungals, perhaps none is more widely reported than the application of amphotericin B-containing aerosols for the prevention of invasive mold infections (notably Aspergillus spp.).

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.

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.

Eradication of Lomentospora prolificans Osteomyelitis of the Wrist with Combination Antifungal Therapy, Voriconazole Bone Cement, and Surgical Debridement

Lomentospora prolificans is an emerging pathogen that is difficult to treat due to its intrinsic resistance to currently available antifungal agents. Current evidence demonstrates synergy between Azoles and Terbinafine against L. prolificans infections, while adjunct use of antifungal agent-loaded bone cement has also shown favourable outcomes. We report a case of an immunosuppressed adult with rheumatoid arthritis who developed L. prolificans osteomyelitis in his right wrist following trauma and subsequent exposure to commercially available fertiliser. The infection was successfully eradicated via a combination of aggressive, staged surgical source control, antifungal therapy using voriconazole and Terbinafine, and insertion of voriconazole-loaded bone cement into the wrist and carpus. The utility of this approach supports the synergistic effects of voriconazole and Terbinafine and, more broadly, the clinical benefits of antifungal-loaded bone cement, as demonstrated in previous case reports and in vitro studies. As such, combination antifungal therapy and voriconazole-loaded bone cement should be considered the therapy of choice in cases of osteomyelitis where L. prolificans is proven to be the causative organism.

Voriconazole-natural latex dressings for treating infected Candida spp. skin ulcers

Aim: This work aimed to develop a membrane based on voriconazole (VCZ)-loaded natural rubber latex (NRL) for treating infected ulcers with Candida spp. and study their interaction, drug release, antifungal activity against Candida parapsilosis and biological characterization. Materials & methods: VCZ-loaded NRL membrane was produced by casting method. Results: Infrared spectrum showed that the incorporation of VCZ into the NRL membrane maintained its characteristics. Its mechanical properties were considered suitable for dermal application. The VCZ was able to release from NRL membrane, maintaining its antifungal activity against C. parapsilosis, besides did not present hemolytic effects. Conclusion: The VCZ-NRL membrane showed good results in mechanical, antifungal and biological assays, representing an interesting alternative to treatment of infected wound with Candida spp.

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.

Management of osteoarticular fungal infections in the setting of immunodeficiency

Introduction: Osteoarticular fungal infections (OAFIs) complicate the clinical course of high-risk patients, including immunosuppressed individuals. Their management, however, despite being intricate, is governed by evidence arising from sub-optimal quality research, such as case series. Guidelines are scarce and when present result in recommendations based on low quality evidence. Furthermore, the differences between the management of immunocompromised and immunocompetent patients are not distinct. This is a narrative review after a literature search in PubMed, up to November 2019.Areas covered: The major fungal groups causing osteomyelitis and/or arthritis are Candida spp., Aspergillus spp., non-Aspergillus filamentous fungi, non-Candida yeasts and endemic dimorphic fungi. Their epidemiology is briefly analyzed with emphasis on immunodeficiency and other risk factors. Management of OAFIs includes appropriate antifungal drug therapy (liposomal amphotericin B, triazoles or echinocandins), local surgery and immunotherapy for primary immunodeficiencies. Cessation of immunosuppressive drugs is also mandated.Expert opinion: Management of OAFIs includes affordable and available options and approaches. However, research on therapeutic practices is urgently required to be further improved, due to the rarity of affected patients. Evolution is expected to translate into novel antifungal drugs, less invasive and precise surgical approaches and targeted enhancement of immunoregulatory pathways in defense of challenging fungal pathogens.

Fungal prosthetic joint infection in total hip or knee arthroplasty

Aims

Fungal prosthetic joint infections (PJIs) are rare and account for about 1% of total PJIs. Our aim was to present clinical and microbiological results in treating these patients with a two-stage approach and antifungal spacers.

Patients and Methods

We retrospectively reviewed our institutional database and identified 26 patients with positive fungal cultures and positive Musculoskeletal Infection Society (MSIS) criteria for PJI who were treated between 2009 and 2017. We identified 18 patients with total hip arthroplasty (THA) and eight patients with total knee arthroplasty (TKA). The surgical and antifungal treatment, clinical and demographic patient data, complications, relapses, and survival were recorded and analyzed.

Results

The median follow-up was 33 months. The success rate was 38.5% (10/26). Fluconazole resistance was found in 15%. Bacterial co-infection was common in 44% of patients for THA and 66% of patients with TKA. Mortality, reoperations, and treatment failure were common complications.

Conclusion

Treatment with a two-stage exchange is a possible option for treatment, although fungal infections have a high failure rate. Therapeutic factors for treatment success remain unclear. Cite this article: Bone Joint J 2019;101-B:589–595.

Candida glabrata-Induced Refractory Infectious Arthritis: A Case Report and Literature Review

The incidence of deep fungal infection due to non-albicans Candida species (especially Candida glabrata) has significantly increased in recent decades. Candida glabrata is an opportunistic pathogen of low virulence which mainly invades the gastrointestinal, genitourinary, and respiratory tracts, but has rarely been reported as complication of articular surgery in the literature. We present a case of knee fungal arthritis caused by C. glabrata after a minimally invasive arthroscopic surgery. In this case, the patient's knee got infected after arthroscopic treatment for a recurrent popliteal cyst, and she was unable to be cured by either debridement or antifungal drugs. Mycological and molecular identification of the necrotic tissues isolate revealed C. glabrata as etiologic agent. We originally planned to conduct a debridement once again, but it was found that the articular cartilage was extensively damaged during the operation. Besides, the magnetic resonance imaging of the affected knee also showed that the infection had invaded the subchondral bone. So we treated this case with a two-stage primary total knee arthroplasty with an antibiotic-laden cement spacer block. After a 10-month follow-up, the patient had completely recovered and has not experienced any recurrence to date. In addition, we review 21 cases of C. glabrata-induced infectious arthritis described to date in the literature.

Successful Release of Voriconazole and Flavonoids from MAPLE Deposited Bioactive Surfaces

We explored the potential of biomimetic thin films fabricated by means of matrix-assisted pulsed laser evaporation (MAPLE) for releasing combinations of active substances represented by flavonoids (quercetin dihydrate and resveratrol) and antifungal compounds (amphotericin B and voriconazole) embedded in a polyvinylpyrrolidone biopolymer; the antifungal activity of the film components was evaluated using in vitro microbiological assays. Thin films were deposited using a pulsed KrF* excimer laser source which were structurally characterized using atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR). High-quality thin films with chemical structures similar to dropcast ones were created using an optimum laser fluence of ~80 mJ/cm2. Bioactive substances were included within the polymer thin films using the MAPLE technique. The results of the in vitro microbiology assay, which utilized a modified disk diffusion approach and were performed using two fungal strains (Candida albicans American Type Culture Collection (ATCC) 90028 and Candida parapsilosis American Type Culture Collection (ATCC) 22019), revealed that voriconazole was released in an active form from the polyvinylpyrrolidone matrix. The results of this study show that the MAPLE-deposited bioactive thin films have a promising potential for use in designing combination devices, such as drug delivery devices, and medical device surfaces with antifungal activity.

Two-Stage Exchange Arthroplasty Is a Favorable Treatment Option Upon Diagnosis of a Fungal Periprosthetic Joint Infection

BACKGROUND

This study investigated the prevalence of medical comorbidities, risk factors, and treatment outcomes in patients with fungal periprosthetic joint infection (PJI).

METHODS

All patients with fungal PJI treated from 1999 to 2014 were retrospectively identified at a single institution. Demographic data, comorbidity, and surgical variables were obtained from medical records. Patients were followed up for at least 2 years. PJI was diagnosed using the Musculoskeletal Infection Society criteria. Treatment success was defined using the Delphi consensus criteria. Kaplan-Meier survivorship curves with 95% confidence interval were used for analysis.

RESULTS

Overall, fungal PJIs accounted for 2.4% of the PJI treated at our institution. Twenty-seven patients (93.1%) had 2 or more underlying systemic illnesses. Age and revision surgery were significant risk factors for development of fungal PJI after adjusting for confounding variables. Overall treatment success was 55.2% at 1 year and 40.5% at 5 years. When stratified by initial surgical management, treatment success was 57.1% at 1 year and 28.6% at 5 years following irrigation and debridement; 33.3% at 1 year and 5 years following 1-stage revision; and 57.9% at 1 year and 46.3% at 5 years for 2-stage exchange arthroplasty.

CONCLUSION

Patients with fungal PJI have a high prevalence of systemic illness and poor outcome after surgical management. Irrigation and debridement and single-stage revision demonstrate poor longterm outcomes and may have no place as treatment choices for fungal PJI. Moving forward, our efforts should concentrate on optimizing the systemic status of these patients prior to 2-stage exchange arthroplasty.

Candida albicans Sacral Osteomyelitis Causing Necrosis of a Sacral Nerve Root: A Case Report

CASE

A 31-year-old immunocompetent woman presented with a large sacral mass on the left side, concerning for a neoplastic process. A biopsy specimen demonstrated fungal osteomyelitis. Intraoperatively, the left S1 sacral nerve root was found to be necrotic, consistent with the symptoms of numbness and weakness. The infection was resolved with aggressive surgical debridement and long-term therapy with antifungal medication.

CONCLUSION

Fungal osteomyelitis of the sacrum is rare, especially in an immunocompetent patient, and untreated infections can cause nerve root necrosis. We recommend aggressive surgical and antifungal management to avoid neurologic compromise.

Efficacy of antifungal-impregnated cement spacer against chronic fungal periprosthetic joint infections after total knee arthroplasty

BACKGROUND

Although two-stage exchange arthroplasty is considered a treatment of choice for chronic features of fungal PJI (periprosthetic joint infection), there is no consensus for local use of antifungal agent. The purpose of this study was to evaluate the efficacy of antifungal-impregnated cement spacer (AICS).

METHODS

Nine patients who were diagnosed and treated for chronic fungal PJI after TKA in a single center from January 2001 to December 2016 were enrolled. Two-stage exchange arthroplasty was performed. During the 1st stage resection arthroplasty, AICS was inserted for all patients. Systemic antifungal medication was used during the interval between the two stage operations.

RESULTS

The average duration from the initial symptom to fungal PJI diagnosis was 20 months (range, five to 72 months). Average erythrocyte sedimentation rate and C-reactive protein level at diagnosis were 56 mm/h (range, 30 to 89 mm/h) and 2.25 mg/dl (range, 0.11 to 3.97 mg/dl), respectively. Fungal PJI was confirmed by open debridement tissue culture in three cases (33%). The average number of operations before final exchange arthroplasty was 2.7 times (range, one to five times). Average duration of antifungal agent use confirmed by sensitivity test was seven months (range, four to 15 months). Mean interval between the two stage operations was six months (range, 1.5 to 15 months). After two-stage exchange arthroplasty, no patient had recurrent fungal infection during a mean follow-up of 66 months (range, 24 to 144 months).

CONCLUSION

Two-stage exchange arthroplasty with AICS is a very effective strategy with excellent outcomes.

LEVEL OF EVIDENCE

Case series, IV.

Fungal Musculoskeletal Infections

Fungi are rare but important causes of osteoarticular infections, and can be caused by a wide array of yeasts and molds. Symptoms are often subacute and mimic those of other more common causes of osteoarticular infection, which can lead to substantial delays in treatment. A high index of suspicion is required to establish the diagnosis. The severity of infection depends on the inherent pathogenicity of the fungi, the immune status of the host, the anatomic location of the infection, and whether the infection involves a foreign body. Treatment often involves a combination of surgical debridement and prolonged antifungal therapy.

Single-Stage Revision for Chronic Fungal Periprosthetic Joint Infection: An Average of 5 Years of Follow-Up

BACKGROUND

Periprosthetic infections caused by fungal pathogens are a rare entity, and there exist no definite guidelines according to which these infections can be successfully managed. In these situations, we wondered whether patients could be treated successfully for their fungal infections with single-stage revision.

METHODS

A retrospective analysis between January 2004 and October 2014 included 11 patients (4 hips and 7 knees) with chronic fungal periprosthetic joint infection who underwent single-stage revision, including aggressive soft-tissue debridement, thorough removal of infected components and cement, pouring powdered vancomycin into the medullary cavity and direct intra-articular injection of fungus-sensitive antibiotics, and a reasonable combination of antifungal agents and antibacterial medications. Recurrence of infection and clinical outcomes were evaluated. The average follow-up was 5 years (range, 2-10 years).

RESULTS

There were 3 failures during the study period; 1 patient died during the perioperative period because of acute heart failure on the eighth postoperative day. Of the 11 patients, 7 patients had satisfactory outcomes and required no additional surgical or medical treatment for recurrence of infection. The mean postoperative Harris hip score and Hospital for Special Surgery knee score was 77 points (67-88 points; P < .05) and 78 points (73-84 points; P < .05), respectively, at the most recent assessment.

CONCLUSION

Treatment of chronic fungal periprosthetic joint infection with single-stage revision can be fairly effective for achieving acceptable functional outcomes, which indicated that this may be a feasible alternative strategy in selected patients.

Periprosthetic fungal infection of a hip caused by Trichosporon inkin

An immunocompromised patient with a history of multiple hip implant revisions extended courses of empiric antibiotic treatment, and a retained metallic rod in the femoral medullary canal was transferred for diagnostic studies and treatment. A high suspicion of fungal infection and utilization of extended and specific fungal cultures were the diagnostic keys for infection with Trichosporon inkin. The treatment consisted in a debridement surgery with the use of a functional spacer with cement supplemented with voriconazole and vancomycin plus a 6-month systemic treatment with voriconazole. After 2 years of follow-up, the patient is free of symptoms.

Staged Reimplantation of a Total Hip Prosthesis After Co-infection with Candida tropicalis and Staphylococcus haemolyticus: A Case Report

Fungal prosthetic joint infection is a rare complication in total joint arthroplasty. There are no established guidelines for management of these infections. We present a case of a 53-year-old male with a hip joint prosthesis co-infected with Candida tropicalis and Staphylococcus haemolyticus. A two-stage exchange arthroplasty was performed. The patient underwent implant removal, debridement, irrigation with saline solution and application of cement spacer impregnated with vancomycin followed by aggressive antimicrobial treatment in first stage. Complete eradication of infection was demonstrated by negative culture of sonicated cement spacer fluid and negative 16S rRNA and 18S rRNA gene PCR of sonicate fluid, synovial fluid and periprosthetic tissue samples. He underwent second-stage revision hip arthroplasty after 9 months of the first stage. At the latest follow-up, there was no evidence of recurrence of infection. This case illustrates the utility of sonication of biomaterials and molecular techniques for microbiological confirmation of absence of infection in staged surgeries which is required for a successful outcome.

Management of Resistant, Atypical and Culture-negative Periprosthetic Joint Infections after Hip and Knee Arthroplasty

BACKGROUND

Periprosthetic joint infection (PJI) is a devastating complication following lower extremity total joint arthroplasty (TJA). It is a leading cause of morbidity and revision following TJA. As such, PJI is a significant driver of healthcare costs. The prevalence of PJI related to resistant and atypical organisms is increasing, and approximately 10-30% of PJIs are culture-negative. The purpose of this review is to summarize the current epidemiology, diagnostics, and management of PJI associated with resistant and atypical pathogens and of culture-negative PJIs.

METHODS

The published literature related to the epidemiology, diagnosis, and management of atypical, drug-resistant, and culture-negative PJI is reviewed.

RESULTS

The clinical diagnosis of PJI is often challenging, particularly when pathogens are fastidious or when antibiotics have been administered empirically. Molecular diagnostic studies, such as synovial α-defensin, may provide rapid, accurate identification of PJI, even in the setting of concurrent antibiotics administration or systemic inflammatory disease. Once PJI is diagnosed, two-stage exchange arthroplasty remains the gold standard for treating PJI with resistant microorganisms, since there is a high rate of treatment failure with irrigation and debridement and with one-stage exchange arthroplasty.

CONCLUSION

Additional research is needed to define the optimal treatment of PJIs associated with rare pathogens, such as fungi and mycobacteria. There is a need for inexpensive, reliable tests that rapidly detect specific microbial species and antimicrobial susceptibilities. Additional research is also required to define the specific organisms, clinical scenarios, surgical techniques, and antimicrobial regimens that allow for reproducible treatment success with prosthetic retention strategies.

Risk factors and the clinical and surgical features of fungal prosthetic joint infections: A retrospective analysis of eight cases

Fungal prosthetic joint infections (PJI) and reports of their clinical investigation are rare. In addition, there has been little evidence regarding the outcome of the two-stage exchange protocol for the treatment of fungal PJI. In order to investigate the risk factors and clinical, microbiological and pathological features of fungal PJIs, as well as the effects of the two-stage exchange protocol on their outcome, the present study analyzed eight retrospective fungal PJI cases, involving four cases affecting the hips and four affecting the knees, between May 2000 and March 2012. In all cases, a cemented spacer saturated with antimicrobials was used during the two-stage exchange protocol, and systematic antifungal agents were administrated during the interim period. The average follow-up duration was 4.4 years. Of the eight cases, six had undergone additional surgery on the infected joint prior to infection with the fungus. Following histological analyses, it was determined that the average number of polymorphonuclear cells in the three patients infected with a fungus was only <5/high power field (HPF; magnification, ×400), and that of the five patients with a hybrid infection was >5/HPF. The average Harris Hip scores or Hospital for Special Surgery knee scores were 43.6 preoperatively and 86 at the last follow-up. The two-stage exchange protocol was performed eight times in seven cases, with a failure rate of 12.5%. The remaining case was successfully treated by resection arthroplasty. The average duration of antifungal agent administration during the interim period in five of the eight cases was 1.5 months. For three of the patients, the duration of antifungal agent administration was prolonged until the c-reactive protein levels were decreased to normal. The average duration of spacer implantation into the joint was 4.3 months. The results of the present study suggested that undergoing surgery on a prosthetic joint may be a potential risk factor for the development of fungal PJI. In addition, infiltration of polymorphonuclear leukocytes into the site of the infection may not occur at the same rate as bacterial PJI. Therefore, a two-stage exchange protocol with implantation of a cement spacer saturated with antimicrobials may be considered an effective therapeutic strategy for the treatment of fungal PJI.

Liposomal Formulation Decreases Toxicity of Amphotericin B In Vitro and In Vivo

BACKGROUND

Liposomal amphotericin B is locally delivered to treat fungal orthopaedic infections but little is known about local tissue toxicity, if any, that might be associated with local delivery.

QUESTIONS/PURPOSES

(1) Is liposomal amphotericin B cytotoxic in vitro? (2) Is locally delivered liposomal amphotericin B toxic to tissue in vivo?

METHODS

Mouse fibroblasts (BA LB/3T3 A31) and osteoblasts (MC3T3) were exposed to two formulations of amphotericin B (liposomal and deoxycholate) at concentrations of 0, 1, 5, 10, 100, 500, and 1000 μg/mL. Cell viability was determined by MTT assay after 1, 3, and 5 hours of exposure and a proliferation assay after 1, 4, and 7 days of exposure and then after 3 recovery days without drug. Tissue exposure occurred by local delivery of liposomal amphotericin B, 200 or 800 mg/batch antifungal-loaded bone cement (ALBC), or amphotericin B deoxycholate, 800 mg/batch ALBC in rat paraspinal muscles. White blood cell count (WBC) and serum amphotericin B levels were obtained on Days 1 and 3. Rats were euthanized at 2 and 4 weeks and semiqualitative histopathology was performed.

RESULTS

Liposomal amphotericin B is cytotoxic in vitro but not toxic to tissues in vivo. All cells survived concentrations up to 1000 μg/mL for 5 hours, 100% ± 0%, but none survived ≥ 100 μg/mL for 7 days, 0% ± 0%. Fibrosis was seen adjacent to ALBC without inflammation or necrosis, indistinguishable from controls for both liposomal amphotericin B doses. Amphotericin B serum levels were all less than 1 µg/mL and WBC counts were all normal.

CONCLUSIONS

In vitro cytotoxicity to liposomal amphotericin B occurred but no adverse tissue reaction was seen in vivo.

CLINICAL RELEVANCE

Local delivery of liposomal amphotericin B in ALBC was well tolerated by mouse tissue; however, clinical studies are needed to confirm this finding in humans.

Fungal periprosthetic joint infection of the hip: a systematic review

Periprosthetic joint infection (PJI) is a severe complication of total joint arthroplasty with an incidence of approximately 1%. Due to the high risk of persisting infection, successful treatment of fungal PJI is challenging. The purpose of this study was to gain insight into the current management of fungal PJI of the hip and, by systematically reviewing the cases published so far, to further improve the medical treatment of this serious complication of total hip arthroplasty. Thus, we conducted a systematic review of the available literature concerning fungal PJI in total hip arthroplasty, including 45 cases of fungal PJI. At the moment a two-stage revision procedure is favorable and there is an ongoing discussion on the therapeutic effect of antifungal drug loaded cement spacers on fungal periprosthetic infections of the hip. Due to the fact that there is rare experience with it, there is urgent need to establish guidelines for the treatment of fungal infections of total hip arthroplasty.

Successful treatment of Candida osteoarticular infections with limited duration of antifungal therapy and orthopedic surgical intervention

BACKGROUND

Current guidelines for treatment of Candida osteoarticular infections (COAIs) recommend a prolonged course of antifungal therapy (AFT) of 6-12 months. Based upon strategies developed at the Hospital for Special Surgery (HSS), we hypothesized that the duration of antifungal therapy may be substantially reduced for management of COAI.

METHODS

This was a retrospective chart review of cases of COAI treated at the HSS for the past 14 years. COAI was documented by open biopsy and direct culture in all cases. The mean (95% confidence interval, CI) duration of documented follow-up was 39 (16-61) months.

RESULTS

Among the 23 cases of COAI, the median age was 62 years (range 22-83 years) with 61% having no underlying condition. Orthopedic appliances, including joint prostheses and fracture hardware, were present in 74% of cases. All patients had COAI as the first proven site of candidiasis. Candida albicans and Candida parapsilosis were the most common species. Hip, knee, foot, and ankle were the most common sites. All patients received aggressive surgical intervention followed by AFT administered for a mean (95% CI) duration of 45 (38-83) days. Systemic AFT consisted principally of fluconazole alone (65%) or in combination with other agents (26%). Adjunctive intraoperative amphotericin B irrigation was used in 35%. Among eight cases of CAOI that required placement of a new prosthetic joint, all were successfully treated. There were no microbiologic failures.

CONCLUSIONS

Candida osteoarticular infections may be successfully treated with substantially limited durations of AFT when combined with a thorough surgical approach.

Failed Reverse Total Shoulder Arthroplasty Caused by Recurrent Candida glabrata Infection with Prior Serratia marcescens Coinfection

This report describes a 58-year-old insulin-dependent diabetic male patient who initially sustained a proximal humerus fracture from a fall. The fracture fixation failed and then was converted to a humeral hemiarthroplasty, which became infected with Candida glabrata and Serratia marcescens. After these infections were believed to be cured with antibacterial and antifungal treatments and two-stage irrigation and debridement, he underwent conversion to a reverse total shoulder arthroplasty. Unfortunately, the C. glabrata infection recurred and, nearly 1.5 years after implantation of the reverse total shoulder, he had a resection arthroplasty (removal of all implants and cement). His surgical and pharmacologic treatment concluded with (1) placement of a tobramycin-impregnated cement spacer also loaded with amphotericin B, with no plan for revision arthroplasty (i.e., the spacer was chronically retained), and (2) chronic use of daily oral fluconazole. We located only three reported cases of Candida species causing infection in shoulder arthroplasties (two C. albicans, one C. parapsilosis). To our knowledge, a total shoulder arthroplasty infected with C. glabrata has not been reported, nor has a case of a C. glabrata and S. marcescens periprosthetic coinfection in any joint. In addition, it is well known that S. marcescens infections are uncommon in periprosthetic joint infections.

Single-stage revision for fungal peri-prosthetic joint infection: a single-centre experience

Fungal peri-prosthetic infections of the knee and hip are rare but likely to result in devastating complications. In this study we evaluated the results of their management using a single-stage exchange technique. Between 2001 and 2011, 14 patients (ten hips, four knees) were treated for a peri-prosthetic fungal infection. One patient was excluded because revision surgery was not possible owing to a large acetabular defect. One patient developed a further infection two months post-operatively and was excluded from the analysis. Two patients died of unrelated causes. After a mean of seven years (3 to 11) a total of ten patients were available for follow-up. One patient, undergoing revision replacement of the hip, had a post-operative dislocation. Another patient, undergoing revision replacement of the knee, developed a wound infection and required revision 29 months post-operatively following a peri-prosthetic femoral fracture. The mean Harris hip score increased to 74 points (63 to 84; p < 0.02) in those undergoing revision replacement of the hip, and the mean Hospital for Special Surgery knee score increased to 75 points (70 to 80; p < 0.01) in those undergoing revision replacement of the knee. A single-stage revision following fungal peri-prosthetic infection is feasible, with an acceptable rate of a satisfactory outcome.

Periprosthetic joint infections: clinical and bench research

Prosthetic joint infection is a devastating complication with high morbidity and substantial cost. The incidence is low but probably underestimated. Despite a significant basic and clinical research in this field, many questions concerning the definition of prosthetic infection as well the diagnosis and the management of these infections remained unanswered. We review the current literature about the new diagnostic methods, the management and the prevention of prosthetic joint infections.

Voriconazole is cytotoxic at locally delivered concentrations: a pilot study

BACKGROUND

Fungal infections are rare but major problems when they involve orthopaedic implants. Preferred treatment in North America is two-staged: resection and then delayed reconstruction, with local delivery of an antifungal between stages. The effect of voriconazole, a hydrophobic antifungal, on local tissues and wound healing is unclear.

QUESTIONS/PURPOSES

We asked: (1) Is voriconazole cytotoxic to fibroblasts or osteoblasts at target concentrations for local delivery? And (2) if cytotoxic, can fibroblasts or osteoblasts resume proliferation after voriconazole is removed?

METHODS

We exposed 5000 fibroblasts or osteoblasts/well to voriconazole concentrations of 0, 1, 5, 10, 25, 100, 500, 1000, 5000, 10,000, and 20,000 μg/mL (n=4 wells/concentration) in 24-well plates. At 3 and 7 days, cell growth was assessed with alamarBlue® and light microscopy. After Day 7, exposure to voriconazole was stopped and incubation continued for 4 days in medium with no voriconazole. On Day 11, cell growth (recovery) was assessed with alamarBlue® and light microscopy.

RESULTS

Increasing voriconazole concentration to more than 100 μg/mL decreased osteoblast and fibroblast growth. Cell growth recovered after 7 days' exposure to 1000 μg/mL or less.

CONCLUSIONS

Voriconazole is cytotoxic to osteoblasts and fibroblasts, but cell growth recovers over 4 days after exposure to 1000 μg/mL or less.

CLINICAL RELEVANCE

Cytotoxicity seen from voriconazole to mouse osteoblasts and fibroblasts occurs at concentrations achievable clinically from local delivery. It may be prudent to limit the dose of voriconazole in antibiotic-loaded bone cement.