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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_19 | Pages 68 - 68
22 Nov 2024
Mannala G Labat B Ladam G Pascal T Walter N Szymski D Riool M Alt V Rupp M
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Aim

Orthopedic implants play a tremendous role in fixing bone damages due to aging as well as fractures. However, these implants tend to get colonized by bacteria on the surface, leading to infections and subsequently prevention of healing and osteointegration. Recently, Roupie et al. showed that a nisin layer-by-layer based coating applied on biomaterials has both osteogenic and antibacterial properties. The Galleria mellonella larva is a well-known insect infection model that has been used to test the virulence of bacterial and fungal strains as well as for the high throughput screening of antimicrobial compounds against infections. Recently, we have developed an insect infection model with G. mellonella larvae to study implant-associated biofilm infections using Kirschner (K)-wires as implant material. Here, we would like to test the antibacterial capacity of nisin layer-by-layer based coatings on K-wires against Staphylococcus aureus in the G. mellonella larva implant infection model.

Method

Prior to the implantation procedure, G. mellonella larvae are maintained at room temperature on wheat germ in an incubator. The larvae received bare titanium K-wires (uncoated), or either control-coated or nisin-coated K-wires. After one hour, the larvae were injected with 5×105S. aureus bacteria per larva (i.e., hematogenous implant infection model). Next, the larvae were incubated at 37oC in an incubator and the survival of the larvae was monitored for five days. Moreover, the number of bacteria on the implant surface and in the surrounding tissue was determined after 24h of incubation. Further, scanning electron microscopy (SEM) analyses were performed to study the effect of nisin on biofilm formation.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 52 - 52
24 Nov 2023
Szymski D Walter N Hierl K Rupp M Alt V
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Aim

The number of periprosthetic joint infections (PJI) is increasing due to ageing population and increasing numbers of arthroplasty procedures and treatment is costly. Aim of the study was to analyze the direct healthcare costs of PJI in Europe for total hip arthroplasties (THA) and total knee arthroplasties (TKA).

Method

A systematic review in PubMed with search of direct costs of PJI in European countries was performed. Thereby the term cost* AND (infection OR PJI) AND (prosthesis OR knee OR hip OR “TKA” OR “THA” OR arthroplast*) was combined with each European country to detect relevant publications. Publications with definition of performed procedure and joint localization were included into further analysis. The mean value of direct healthcare cost was calculated for the respective joint and the respective operation performed.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 5 - 5
24 Nov 2023
Szymski D Walter N Krull P Melsheimer O Grimberg A Alt V Steinbrück A Rupp M
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Aim

The aim of this investigation was to compare risk of infection in both cemented and cementless hemiarthroplasty (HA) as well as total hip arthroplasty (THA) following femoral neck fracture.

Methods

Data collection was performed using the German Arthroplasty Registry (EPRD) In HA and THA following femoral neck fracture fixation method was divided into cemented and cementless protheses and paired according to age, sex, body mass index (BMI), and the Elixhauser score using Mahalanobis distance matching.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 84 - 84
24 Nov 2023
Bärtl S Lovasz D Li J Alt V Rupp M
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Aim

Sepsis is a life-threatening complication of periprosthetic joint infections (PJI) that requires early and effective therapy. This study aims to investigate the epidemiology, associated risk factors, and outcome of sepsis in the context of periprosthetic joint infections (PJI).

Method

This single-center retrospective cohort study included patients treated for PJI from 2017 to 2020. Patients were classified based on the criteria of the European Bone and Joint Infection Society. The presence of sepsis was determined using the SOFA score and SIRS criteria. The cohort with PJI and sepsis (sepsis) was compared to patients with PJI without sepsis (non-sepsis). Risk factors considered were patient characteristics, affected joints, surgical therapy, microbiological findings, preexisting medical conditions, clinical symptoms, and symptom duration. Outcome parameters were mortality, length of hospital stay, and length of stay in the intensive care unit.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 65 - 65
24 Nov 2023
Schindler M Walter N Sigmund IK Maderbacher G Alt V Rupp M
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Background

The identification of novel biomarker which is highly specific and sensitive for periprosthetic joint (PJI) have the potential to improve diagnostic accuracy and ultimately improve patient outcomes. Thus, the aim of this systemic review is to identify and evaluate novel biomarkers for the preoperative diagnostics of PJI.

Methods

MEDLINE, EMBASE, PubMed and Cochrane Library databases identified from 1st of January 2018 to 30th of September. 2022. We used “periprosthetic joint infection” OR “prosthetic joint infection” OR “periprosthetic infection” as the diagnosis of interest and the target index applied AND “marker”. To focus on novel biomarkers already used biomarkers of the established PJI diagnostic criteria of MSIS, ICM and EBJIS were not included in the analysis. These three criteria were considered the reference standard during quality assessment.


Aim

The aim of the present work was (i) to survey the situation of healthcare regarding the use of antibiotics in orthopaedics and trauma surgery in Germany, (ii) to determine which empiric antibiotic regimens are preferred in the treatment of periprosthethic joint infections (PJI) and (iii) to evaluate the hypothetical antibiotic adequacy of the applied empirical antibiotic therapy regimens based on a patient collective of a German university hospital.

Method

A survey on empirical and prophylactic antibiotic therapy was conducted at German university and occupational health clinics (BG clinics), each in the specialties of orthopedics and trauma surgery. A total of 71 clinics were contacted by email. The questionnaire sent included open-ended questions on systemic antibiotic prophylaxis in primary hip arthroplasty; a distinction was made between hip arthroplasty due to femoral fractures and elective hip arthroplasty. In addition, the empirical antibiotic therapy used in PJIs was surveyed. To determine the success rate of prophylaxis and therapy according to sensitivity to the antibiotics applied, the survey results were compared with previously published data on antimicrobial treatment in n=81 PJI patients treated in our department between 2017 and 2020.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_10 | Pages 85 - 85
1 Oct 2022
Mannala G Rupp M Alt V
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Aim

Fungal periprosthetic joint infections are difficult to treat and often associated with a limited outcome for patients. Candida species account for approximately 90% of all fungal infections. In vivo biofilm models play major role to study biofilm development, morphology, and regulatory molecules for bacteria. However, in vivo modeling of biofilm-associated fungi models are very rare. Furthermore, due to ethical restrictions, mammalian models are replaced with other alternative models in basic research. Recently, we have developed insect infection model G. mellonella larvae to study implant associated biofilm infections with bacteria. This model organism was not used for fungi biofilm infection yet. Thus, we aimed to establish G. mellonella as in vivo model to study fungal implant infections using Candida albicans as model organism and to test anti-fungal medication.

Method

Titanium and Stainless steel K-wires were cut into small pieces with size of 4mm. For the infection process, implants were pre-incubated in specified fungal growth culture Candida albicans at 1×107 CFU/ml for 30 min at 150 rpm shaking conditions. Later, these implants were washed with 10ml PBS and implanted in the larvae as mentioned. To analyze the susceptibility of the implant-associated fungal infections towards anti fungal compounds, the larvae were treated with amphotericin B, fluconazole and voriconazole after 24h of implantation. The effect of anti-fungal compounds was measured in terms of survival observation for 5 days and fungal load in larvae on 2nd day. To reveal the fungal biofilm formation on implant, the implants were removed on day 3 and processed for SEM analysis.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_10 | Pages 63 - 63
1 Oct 2022
Mendelsohn DH Walter N Niedermair T Alt V Brochhausen C Rupp M
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Aim

Osteomyelitis is a difficult-to-treat disease with high chronification rates. The surgical amputation of the afflicted limb sometimes remains as the patients’ last resort. Several studies suggest an increase in mitochondrial fission as a possible contributor to the accumulation of intracellular reactive oxygen species and thereby to cell death of infectious bone cells. The aim of this study is to analyze the ultrastructural impact of bacterial infection and its accompanying microenvironmental tissue hypoxia on osteocytic and osteoblastic mitochondria.

Method

19 Human bone tissue samples from patients with osteomyelitis were visualized via light microscopy and transmission electron microscopy. Osteoblasts, osteocytes and their respective mitochondria were histomorphometrically analyzed. The results were compared to the control group of 5 non-infectious human bone tissue samples.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_10 | Pages 28 - 28
1 Oct 2022
Mannala G Rupp M Alt V
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Aim

Galleria mellonella larvae is a well-known insect infection model that has been used to test the virulence of bacterial and fungal strains as well as for the high throughput screening of antimicrobial compounds against infections. Recently, we have developed insect infection model G. mellonella larvae to study implant associated biofilm infections using small K-wire as implant material. Here, we aimed to further expand the use of G. mellonella to test other materials such as bone cement with combination of gentamicin to treat implant-associated infections.

Method

The poly methyl methacrylate (PMMA) with and without gentamicin and liquid methyl methacrylate (MMA) were kindly provided by Heraeus Medical GmbH, Wehrheim. To make the bone cement implants as cubes, Teflon plate (Karl Lettenbauer, Erlangen) with specified well size was used. The Radiopaque polymer and monomer were mixed well in a bowl, applied over on to the Teflon plate and pressed with spatula to form fine and uniform cubes. After polymerization, the bone cement implants were taken out of the Teflon well plate with the help of pin. For the infection process, bone cement cubes were pre-incubated with S. aureus EDCC 5055 culture at 5×106 CFU/ml for 30 min at 150 rpm shaking conditions. Later, these implants were washed with 10ml PBS and implanted in the larvae as mentioned. Survival of the larvae were observed at 37°C in an incubator. To analyze the susceptibility of the bacterial infections towards gentamicin, survival of the larvae compared with control group implanted only with bone cement. The effect of gentamicin was also measured in terms of S. aureus load in larvae on 2nd day. SEM analysis was performed to see the effect of gentamicin on biofilm formation on bone cement.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 5 - 5
1 Dec 2021
Alagboso F Mannala G Steinmann S Docheva D Rupp M Brochhausen C Alt V
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Aim

Bone regeneration following the treatment of Staphylococcal bone infection or osteomyelitis is challenging due to the ability of Staphylococcus aureus to invade and persist within bone cells, which could possibly lead to antimicrobial tolerance and incessant bone destruction.

Here, we investigated the influence of Staphylococcal bone infection on osteoblasts metabolism and function, with the underlying goal of determining whether Staphylococcus aureus-infected osteoblasts retain their ability to produce extracellular mineralized organic matrix after antibiotic treatment.

Method

Using our in vitro infection model, human osteoblasts-like Saos-2 cells were infected with high-grade Staphylococcus aureus EDCC 5055 strain, and then treated with 8 µg/ml rifampicin and osteogenic stimulators up to 21-days.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 76 - 76
1 Dec 2021
Mannala G Rupp M Alagboso F Docheva D Alt V
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Aim

In vivo biofilm models play major role to study biofilm development, morphology, and regulatory molecules involve in biofilm. Due to ethical restrictions, the use mammalian models are replaced with other alternative models in basic research. Recently, we have developed insect infection model G. mellonella larvae to study implant associated biofilm infections. This model organism is easy to handle, cheap and ethical restriction free and could be used for the high through put screening of antimicrobial compounds to treat biofilm. To promote the use of this model in basic research we aimed to validate this based on the typical biofilm features such as less susceptible to the antibiotics, complexity of the biofilm structure and gene expression profile of biofilms.

Method

G. mellonella larvae are maintained at 30oC on artificial diet in an incubator. Titanium and Stainless steel K-wires were cut into small pieces with size of 4mm. After sterilization with 100% alcohol, these K-wires were pre-incubated in S. aureus bacterial suspension (5×106 CFU/ml) for 30 min, washed in PBS and implanted inside the larva after with help of scalpel. The larvae were incubated at 37oC for two day for the survival analysis. To analyze the less susceptibility of the biofilms towards antibiotics, the larvae were treated with gentamicin and compared survival with planktonic infection in G. mellonella. To reveal the complex structure of biofilm, the implants were removed and processed for the MALDI analysis. Whole genome-based transcriptome of biofilm was performed to explore the changes in transcriptional landscapes.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 12 - 12
1 Dec 2021
Rupp M Henssler L Brochhausen C Zustin J Geis S Pfeifer C Alt V Kerschbaum M
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Aim

Adequate debridement of necrotic bone is of paramount importance for eradication of infection in chronic osteomyelitis. Currently, no tools are available to detect the exact amount of necrotic bone in order to optimize surgical resection. The aim of the present study was to evaluate the feasibility of an intraoperative illumination method (VELscope®) and the correlation between intraoperative and pathohistological findings in surgically treated chronic fracture related infection patients.

Method

Ten consecutive patients with chronic fracture related infections of the lower extremity were included into this prospectively performed case series. All patients had to be treated surgically for fracture related infections requiring bony debridement. An intraoperative illumination method (VELscope®) was used to intraoperatively differentiate between viable and necrotic bone. Tissue samples from the identified viable and necrotic bone areas were histopathologically examined and compared to intraoperative findings.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 25 - 25
1 Dec 2021
Walter N Bärtl S Brunotte M Engelstädter U Ehrenschwender M Hitzenbichler F Alt V Rupp M
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Aim

Fracture-related infection (FRI) is a challenging complication. This study aims to investigate (1) microbial patterns in fracture-related infection (FRI), (2) the comparison of isolated pathogens in FRI patients with early, delayed, and late onset of infection and (3) antibiotic susceptibility profiles to identify effective empiric antibiotic therapy for FRI.

Method

Patients treated for FRI from 2013 to 2020 were grouped into early (< 2 weeks), delayed (2– 10 weeks) and late (> 10 weeks) onset of infection. Pathogens detected during treatment were evaluated for pathogens. Antibiotic susceptibility profiles were examined with respect to broadly used antibiotics and antibiotic combinations.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 67 - 67
1 Dec 2021
Walter N Rupp M Hierl K Koch M Kerschbaum M Worlicek M Alt V
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Aim

We aimed to evaluate the impact of knee periprosthetic joint infection (PJI) by assessing the patients’ long-term quality of life and explicitly their psychological wellbeing after successful treatment.

Method

Thirty-six patients with achieved eradication of infection after knee PJI were included. Quality of life was evaluated with the EQ-5D and SF-36 outcome instruments as well as with an ICD-10 based symptom rating (ISR) and compared to normative data.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 26 - 26
1 Dec 2021
Lang S Loibl M Gläsner J Simon M Rupp M Grad S Neumann C Alt V Gessner A Hanses F
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Aim

Vertebral osteomyelitis (VO) is an infection of the spine mostly caused by bacterial pathogens. The pathogenesis leading to destruction of intervertebral discs (IVD) and adjacent vertebral bodies (VB) is poorly described. We aimed to investigate the connection between infection, bone- and disc-metabolism in VO patients.

Method

Fourteen patients with VO (infection group) and 14 patients with incomplete burst fractures of the spine (fracture group as controls) were included prospectively. Demographic data, treatment details, laboratory infection markers, and patient-reported outcome were assessed. Tissue biopsies from affected IVDs and adjacent VBs were analyzed for mRNA-expression levels of 18 target genes including chemokines, adipokines and genes involved in bone-metabolism by RT-qPCR.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 51 - 51
1 Dec 2021
Lang S Frömming A Ehrenschwender M Neumann C Walter N Loibl M Alt V Rupp M
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Aim

Empiric antibiotic therapy for suspected pyogenic spondylodiscitis (SD) should be initiated immediately with severely ill patients and may also be necessary for culture-negative SD. The aim of this study was to infer an appropriate empiric antibiotic regimen by analyzing the antimicrobial susceptibility of isolated pathogens from microbiologically proven pyogenic spondylodiscitis.

Method

We performed a retrospective review of adult patients with clinically proven SD treated at our level 1 trauma center between 2013 and 2020. Demographic data, radiologic findings, and treatment modalities were evaluated. The appropriateness of empiric antibiotic regimens was assessed based on the antibiograms of the isolated pathogens. Anamneses were used to distinguish between community-acquired (CA) and healthcare-associated (HA) pathogens, which included cases that had a hospital stay or invasive intervention in the past 6 months.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 87 - 87
1 Dec 2021
Mannala G Rupp M Walter N Brunotte M Alagboso F Docheva D Brochhausen C Alt V
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Aim

Here, we are aimed to evaluate bacteriophage (191219) to treat S. aureus implant-associated bone infections by means of testing against S. aureus during its planktonic, biofilm and intracellular growth phases and finally assessing antimicrobial effect on in vivo biofilm formed on metal K-wire in an alternative insect model Galleria mellonella.

Method

The bacteriophages (191219) were provided from D&D Pharma GmbH. These bacteriophages were tested against S. aureus EDCC 5055 (MSSA) and S. aureus DSM 21979 (MRSA) strains. To assess the activity of bacteriophages against planktonic growth phase, bacteriophages, and S. aureus EDCC 5055(1×107 CFU/ml) were co-cultured in LB media as multiplicity of infection (MOI) of 10, 1, 0.1, and 0.01 for 24 hours at 37oC and finally plated out on the LB agar plates to estimate the bacterial growth. The antimicrobial activity of bacteriophages on biofilms in vitro was measured by analysing the incubating the several fold dilutions of bacteriophages in LB media with biofilms formed on 96-well plate. The eradication of biofilm was analysed with crystal violet as well as CFU analysis methods. Later, the effect of bacteriophages on intracellular growth of S. aureus in side osteoblast was tested by treating the S. aureus infected osteoblasts at 2h, 4h and 24h time points of post treatment. In addition, we have analysed synergistic effect with gentamicin and rifampicin antibiotics to clear intracellular S. aureus. Finally, experiments are performed to prove the effect of bacteriophages to clear in vivo biofilm using alternative insect model G. mellonella as well as to detect the presence of bacteriophages inside the osteoblasts through transmission electron microscopy (TEM) analysis.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_14 | Pages 62 - 62
1 Dec 2019
Rupp M Kern S Biehl C Knapp G Khassawna TE Heiß C Alt V
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Introduction

Polymicrobial infections are expected to complicate the treatment of bone and joint infections. Septic nonunions often occur after initial open fractures, which prophylactically receive broad-spectrum antibiotics. However, no data that describes frequencies of polymicrobial infections and pathogens evident in course of the treatment of septic nonunions is published. Therefore, this study aims at investigating the frequency and pathogen types in polymicrobial infections.

Methods

Surgically treated Patients with long bone septic nonunion admitted between January 2010 and March 2018 were included in the study. Following parameters were examined: age, gender, American Society of Anesthesiologists (ASA) score, body mass index (BMI), and anatomical location of the infected nonunion. Microbiological culture data, polymerase-chain-reaction results of tissue samples, sonication, and joint fluid of the initial and follow-up revision surgeries were assessed. No exclusion criteria were determined.