Objectives. Implant-related infection is one of the most devastating complications in orthopaedic surgery. Many surface and/or material modifications have been developed in order to minimise this problem; however, most of the in vitro studies did not evaluate bacterial adhesion in the presence of eukaryotic cells, as stated by the ‘race for the surface’ theory. Moreover, the adherence of numerous clinical strains with different initial concentrations has not been studied. Methods. We describe a method for the study of bacterial adherence in the presence of preosteoblastic cells. For this purpose we mixed different concentrations of bacterial cells from collection and clinical strains of staphylococci isolated from implant-related infections with preosteoblastic cells, and analysed the minimal concentration of bacteria able to colonise the surface of the material with image analysis. Results. Our results show that clinical strains adhere to the material surface at lower concentrations than collection strains. A destructive effect of bacteria on preosteoblastic cells was also detected, especially with higher concentrations of bacteria. Conclusions. The method described herein can be used to evaluate the effect of surface modifications on bacterial adherence more accurately than conventional monoculture studies. Clinical strains behave differently than collection strains with respect to bacterial adherence. Cite this article: M. Martinez-Perez, C. Perez-Jorge, D. Lozano, S. Portal-Nuñez, R. Perez-Tanoira, A. Conde, M. A. Arenas, J. M. Hernandez-Lopez, J. J. de Damborenea, E. Gomez-Barrena, P. Esbrit, J. Esteban. Evaluation of bacterial adherence of clinical isolates of Staphylococcus sp. using a competitive model: An in vitro approach to the “race for the surface” theory. Bone Joint Res 2017;6:315–322. DOI: 10.1302/2046-3758.65.BJR-2016-0226.R2

The aim of this study was to evaluate whether coating titanium discs with selenium in the form of sodium selenite decreased bacterial adhesion of Staphylococcus aureus and Staph. epidermidis and impeded osteoblastic cell growth.

In order to evaluate bacterial adhesion, sterile titanium discs were coated with increasing concentrations of selenium and incubated with bacterial solutions of Staph. aureus (ATCC 29213) and Staph. epidermidis (DSM 3269) and stained with Safranin-O. The effect of selenium on osteoblastic cell growth was also observed. The adherence of MG-63 cells on the coated discs was detected by staining with Safranin-O. The proportion of covered area was calculated with imaging software.

The tested Staph. aureus strain showed a significantly reduced attachment on titanium discs with 0.5% (p = 0.011) and 0.2% (p = 0.02) selenium coating. Our test strain from Staph. epidermidis showed a highly significant reduction in bacterial adherence on discs coated with 0.5% (p = 0.0099) and 0.2% (p = 0.002) selenium solution. There was no inhibitory effect of the selenium coating on the osteoblastic cell growth.

Selenium coating is a promising method to reduce bacterial attachment on prosthetic material.

Cite this article: Bone Joint J 2013;95-B:678–82.

Bone-regenerative and biocompatible materials are indicated for the regeneration of bone lost in periodontology and maxillofacial surgery. Bio-Oss is a natural bone mineral for bone grafting of bovine origin and the most common used in this kind of interventions. 1. Sil-Oss is a new synthetic nanostructured monetite-based material that is reabsorbed at the same time that is replaced by new bone tissue . 2. Bacterial infection is one of the complications related to this kind of material. Streptococcus oralis is the most associated oral infecting pathogen to oral surgery. 3. and Staphylococcus aureus is the most common infecting pathogen to maxillofacial non-oral interventions. 4. Here we evaluated bacterial adherence of two of the most common infecting bacteria of this kind of biomaterial: S. oralis and S. aureus, on Bio-Oss and Sil-Oss. S. oralis ATCC 9811 and S. aureus 15981 strains were used. Bacterial adherence was evaluated using the modified previously described protocol of Kinnari et al. 5. that was adapted to our biomaterial. The quantification was performed by the drop plate method. 6. The statistical data were analyzed by pairwise comparisons using the nonparametric Mann-Whitney test with a level of statistical significance of p<0.05. Values are cited and represented as medians. Bacterial adherence decreased significantly on Sil-Oss compared to Bio-Oss. S. oralis ATCC 9811 adherence was between 11 and 13-fold less on Sil-Oss compared to Bio-oss. In the case of S. aureus15981, the adherence was between 4 and 6-fold less on Sil-Oss compared to Bio-Oss. Sil-Oss nanostructured monetite-based biomaterial could be considered as a promising biomaterial to be used for the regeneration of bone defects since the bacterial adherence on it is lower than on another currently used material

In the past decades, titanium-based biomaterials have been broadly used in maxillofacial and periodontology surgery. The main aetiological agents related to complications in this procedures are Porphyromonas gingivalis, a Gram-negative anaerobic bacteria that is also responsible for the development of chronic gingivitis, and Streptococcus oralis, a Gram positive facultative anaerobic bacteria. In previous studies, we have demonstrated that the fluorine doping of titanium-based alloys reduces bacterial adherence. The aim of this study is to evaluate the bacterial adherence on fluorine-doped titanium (TiF) probes compared to chemical polishing titanium (Ti) probes. The P. gingivalis ATCC 33277 and S. oralis ATCC 9811 adherence study was performed by introducing each probe in a well of 6-well plate with 5 ml containing 106 colony forming units (CFU/ml) in sterile 0.9% NaCl and was incubated 37°C 5% CO2 for 90 minutes, in anaerobiosis in the case of P. gingivalis. After incubation, samples were stained with LIVE/DEAD BacLight Bacterial Viability Kit. Proportion of live and dead bacteria was calculated and studied by using ImageJ software. The experiments were performed in triplicate. The statistical data were analyzed by nonparametric Wilcoxon test with a level of statistical significance of 0.05. Our results showed a significant (p<0.0053) 14.41% decrease of the adherence of P. gingivalis on TiF and an increase of 30% of dead cells. For S. oralis we did not get significant results. In conclusion, TiF can be considered a promising approach to prevent and treat infections related to maxillofacial and periodontology surgery

Aim. To evaluate bacterial adhesion and biofilm formation to metallic cerclage wire versus polymer cerclage system (SuperCable®). Methods. Experimental in vitro study to evaluate quantitative bacterial adherence to different cerclage wire materials. Two types of cerclage wires were compared: a metallic versus a polymer based wire (SuperCable®). A two-centimeter cerclage wire piece of each material was included in 2 mL of tryptic soy broth (TSB) culture media, inoculated with 10 microliters of a 0.5 McFarland of a Staphylococcus epidermidis strain and cultivated at 37°C during 2h for adhesion and 48h for biofilm formation. After this time, the cerclages were washed using a 1% phosphate buffered saline (PBS) and sonicated in new culture medium. After sonication, dilutions of each culture were spread in TSB agar and incubated 37°C during 24h. The number of colonies were counted and the cfu/cm2 was calculated. Results. There were no differences in the number of colonies counted at 2 hours. At 48 hours, the polymer cerclage system showed a clinically and statistically reduction of 95.2% in the biofilm formation of S. epidermidis. The highest bacterial counts were observed in metallic cerclages after 48h. Conclusion. In in vitro conditions, the polymer cerclage system may offer decreased biofilm formation compared with metallic cerclage wires. However, there are many other factors in in vivo conditions that could play a role in bacterial adhesion to cerclage wires. Further research is needed in order to recommend the use of polymer cerclage systems for septic revision surgery

Uncemented implants combining antimicrobial properties with osteoconductivity would be highly desirable in revision surgery due to periprosthetic joint infection (PJI). Silver coatings convey antibacterial properties, however, at the cost of toxicity towards osteoblasts. On the other hand, topological modifications such as increased surface roughness or porosity support osseointregation but simultaneously lead to enhanced bacterial colonization. In this study, we investigated the antibacterial and osteoconductive properties of silver-coated porous titanium (Ti) alloys manufactured by electron beam melting, rendering a macrostructure that mimics trabecular bone. Trabecular implants with silver coating (TR-Ag) or without coating (TR) were compared to grit-blasted Ti6Al4V (GB) and glass cover slips as internal controls. Physicochemical characterization was performed by X-ray diffraction (XRD) and energy dispersive X-rays (EDX) together with morphological characterization through electron scanning microscopy (SEM). Bacterial adherence after incubation of samples with Staphylococcus (S.) aureus and S. epidermidis strains harvested from PJI patients was quantitatively assessed by viable count after detachment of adherent bacteria by collagenase/dispase treatment. Primary human osteoblasts (hOB) were used to investigate the osteoconductive potential by lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) activity. Cell morphology was investigated by fluorescence microscopy after staining with carboxifluorescein diacetate succinimidyl ester (CFDA-SE) and 4′,6-diamidino-2-phenylindole (DAPI). The trabecular implants depicted a porosity of 70% with pore sizes of 600µm. The amount of silver analyzed by EDX accounted for 35%wt in TR-Ag but nil in TR. Silver-coated TR-Ag implants had 24% lower S. aureus viable counts compared to non-coated TR analogues, and 9% lower compared to GB controls. Despite trabecular implants, both with and without silver, had higher viable counts than GB, the viable count of S. epidermidis was 42% lower on TR-Ag compared to TR. The percentage of viable hOB, measured by LDH and normalized to controls and area at 1 day, was lower on both TR-Ag (18%) and on TR (13%) when compared with GB (89%). However, after 1 week, cell proliferation increased more markedly on trabecular implants, with a 5-fold increase on TR-Ag, a 3.4-fold increase on TR, and a 1.7-fold increase on GB. Furthermore, after 2 weeks of hOB culture, proliferation increased 20-fold on TR-Ag, 29-fold on TR, and 3.9-fold for GB, compared to 1 day. The osteoconductive potential measured by ALP illustrated slightly higher values for TR-Ag compared to TR at 1 day and 2 weeks, however below those of GB samples. Cell morphology assessed by microscopy showed abundant growth of osteoblast-like cells confined to the pores of TR-Ag and TR. Overall, our findings indicate that the silver coating of trabecular titanium exerts limited cytotoxic effects on osteoblasts and confers antimicrobial effects on two PJI-relevant bacterial strains. We conclude that improving material design by mimicking the porosity and architecture of cancellous bone can enhance osteoconductivity while the deposition of silver confers potent antimicrobial properties

With an ever-increasing aging population, total hip and knee arthroplasty is projected to increase by 137% and 601%, respectively, between the period; 2005–2030. Prosthetic Join Infection (PJI) occurs in approximately 2% of total joint replacements (TJRs) in the U.S. PJI is primarily caused by adherence of bacteria to the surface of the prosthesis, ultimately forming an irreversibly attached community of sessile bacteria, known as a biofilm, highly tolerant to antibiotic treatment. Often the only resolution if the ensuing chronic infection is surgical removal of the implant – at high cost for the patient (increased morbidity), and for healthcare resources. Strategies to prevent bacterial adherence have significant potential for medical impact. Laser surface treatment using an automated continuous wave (CW) fiber laser system has shown promise in producing anti-adherent and bactericidal surfaces. Work presented here aims to investigate the effect of this approach on orthopaedic metals as a proof of concept, specifically Ti-6Al-4V (kindly supplied by Stryker Orthopaedics, Limerick). A coupon was surface treated using a laser (MLS-4030; Micro Lasersystems BV, Driel). Samples were incubated in Müller Hinton Broth (MHB) inoculated with methicillin resistant Staphylococcus aureus (MRSA; ATCC 43300) for 24h before Live/Dead staining (BacLight™ solution; Molecular Probes) and inspection by fluorescence microscopy (GXM-L3201 LED; GX Optical). Images were analysed using ImageJ software (NIH) and a significant reduction (p > 0.05, n=24) in total biofilm coverage and Live/Dead ratio was observed between the laser treated and as received surfaces. This data demonstrates the anti-adherent, and indeed bactericidal, effect of Laser-surface treatment

Prosthetic joint infections (PJI) occur infrequently, but they represent the most devastating complication with high morbidity and substantial cost. Staphylococcus aureus and coagulase-negative S. epidermidis are the most commonly infecting agents associated with PJI. Nowadays, Gram-negative species like Escherichia coli and Pseudomonas aeruginosa are gaining relevance. The use of TiO2 conical nanotubular doped with fluorine and phosphorous (FP-cNT) surfaces is an interesting approach to prevent surface bacterial colonization during surgery and favouring the osseointegration. Despite of there are serum markers related with PJI, to date there is described no biomaterial-related marker that allows detecting PJI. Here we describe the adherence and the bactericidal effect of FP-cNT and its capacity of marking the non-fermenting bacteria that have been in contact with it by Al. This metal is delivered by FP-cNT in non-toxic concentrations (between 25 and 29 ng/mL). F-P-cNT layers on Ti6Al4V alloy were produced as described previously by our group. Ti6Al4V chemical polishing (CP) samples without nanostructure were used as control and produced as described previously. S. aureus 15981, S. epidermidis ATCC 35984, E. coli ATCC 25922, and P. aeruginosa ATCC 27853 strains adherence study was performed using the protocol described by Kinnari et al. in 0.9% NaCl sterile saline with a 120 min incubation. After incubation, the samples were stained with LIVE/DEAD BacLight Bacterial Viability Kit. Proportion of live and dead bacteria was calculated and studied by using ImageJ software. The experiments were performed in triplicate. The aluminum concentration was estimated in the supernatant after incubation and in the 0.22 µm filtered supernatant by atomic absorption in graphite furnace. The statistical data were analyzed by nonparametric Kruskal-Walis test and by pairwise comparisons using the nonparametric unilateral Wilcoxon test with a level of statistical significance of p<0.05. The values are cited as medians. Our results show that the bacterial adherence of all tested species significantly decreased on FP-cNT compared to CP except P. aeruginosa ATCC 27853: 19.8% for S. aureus 15981, 45.3% for S. epidermidis ATCC 35984 and 8.1% for E. coli ATCC 25922. The bacterial viability decreased 2-fold for S. aureus 15981, and 5-fold for S. epidemidis ATCC 35984, but increased 95% for P. aeruginosa ATCC 27853 and there no was variation for E. coli ATCC 25922 on FP-cNT compared to CP. Only supernatant P. aeruginosa ATCC 27853 shows significant Al detection after 120 min incubation (p<0.05). In summary, F-P cNT is a promising biomaterial that besides favoring osseointegration and potential usefulness as drug carrier, present bactericidal, non-stick ability (at least for staphylococci and E. coli) and is able to mark P. aeruginosa with Al, which could be potentially monitored in serum and urine in patients with PJI

The most common bacteria in orthopaedic prosthetic infections are Staphylococcus, namely Staphylococcus Epidermidis (SE) and Staphylococcus Aureus (SA). Infection causes implant failure due to biofilm production. Biofilms are produced by bacteria once they have adhered to a surface. Nanotopography has major effects on cell behaviour. Our research focuses on bacterial adhesion and biofilm formation on nanofabricated materials. Bacteria studied were clinically relevant from an orthopaedic perspective, SA and SE. We hypothesise that that nanosurfaces can modulate bacterial adherence and biofilm formation and may reduce orthopaedic implant infection rate. Isolated bacteria were grown and growth conditions optimised. Bacterial concentrations were calculated by using qPCR. Statistical analysis allowed identification of optimal biofilm growth conditions. These were refined on standard, non-nanopatterned surfaces, and then control and nanopatterned polystyrene (nanopits) and titanium plates (nanowires). Adhesion analysis was performed using fluorescence imaging and quantitative PCR. 4 bacterial strains were isolated and cultured. Growth kinetics based on 24hr cultures allowed isolation of optimal media for biofilm conditions (Dulbecco's Modified Eagle Medium with additional supplements). Highest bacterial concentrations were found following 2hrs incubation with Lysozyme during qPCR. Bacterial concentration significantly increased between 30, 60 and 90 minutes incubation. Differences in percentage coverage on different polysyrene nanosurfaces (nanopits) were noted varying. This was confirmed by qPCR extractions that showed different bacterial concentrations on different nanopatterns. Titanium nanowire surfaces significantly increased bacterial adhesion (P<0.05). Our study cultured and quantified bacterial biofilm and suggests that by altering nanotopography, bacterial adhesion and therefore biofilm formation can be affected. Specific nanopatterned surfaces may reduce implant infection associated morbidity and mortality. Clearly this is of significant benefit to the patient, the surgeon and the NHS, and may well extend far beyond the realms of orthopaedics

Implantation of antibiotic-loaded beads is accepted as an efficient option for local antibiotic therapy in orthopedic-related infections. However, recent reports have emphasized the bacteria growth persistence on antibiotic-impregnated bone cement. Hence, the aim of this study was to elaborate if bacterial adherence and growth could be determined on explanted gentamicin- and gentamicin-vancomycin-loaded beads after infection eradication. 18 chains of antibiotic-loaded beads (11 gentamicin-, 7 gentamicin-vancomycin-loaded) were examined. Indications for primary beads implantation included postoperative infections after total hip or knee arthroplasty, rotator cuff reconstruction, chronic foot osteomyelitis, anterior cruciate ligament reconstruction and dorsal spondylodesis. Among the isolated organisms, Staphylococcus epidermidis, Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) were the most frequent ones. In 4 cases (3 × S. epidermidis, 1 × MRSA) bacteria growth persistence could be determined on the beads. S. epidermidis-strains persisted only on gentamicin-loaded beads, MRSA could grow on gentamicin-vancomycin-impregnated cement. In one case, the emergence of a gentamicin-resistant S. epidermidis-strain could be observed despite preoperative susceptibility. Bacteria growth persistence on bone cement is a hazardous problem in the orthopedic surgery and should therefore be born in mind. Adherence to cement can lead to emergence of bacteria resistance despite preoperative antibiotic susceptibility and might result in clinical recurrence of infection

Summary Statement. A study to evaluate biofilm development on different coatings of UHMWPE was performed. We observed a species-specific effect, with S. aureus affected mainly by DLC-F and S. epidermidis by DLC. These data correlates with previous adherence studies. Introduction. Prosthetic joint infection is intimately related to bacterial biofilms on implant biomaterials. Recently, diamond-like carbon (DLC) coating has been suggested to improve the antibacterial performance of medical grade GUR1050 ultra high molecular weight polyethylene (UHMWPE) supplied by Orthoplastics bacup, UK versus collection and clinical staphylococcal strains. The aim of this study was to make an approximation towards the actual impact of such coatings in biofilm formation. Material and Methods. Biofilm formation by two collection laboratory strains (S. aureus 15981[4] and S. epidermidis ATCC 35984) was evaluated with raw UHMWPE and two UHMWPEs coated with DLC, and fluorine doped DLC (F-DLC). The coated surfaces were obtained by plasma enhanced chemical vapour deposition, as previously described. All the sterilised surfaces were exposed to ≈10. 8. colony forming units/mL during 48 hours at 35° C, with total medium exchange at 24 hours without shaking. Surfaces were carefully washed with PBS (X 3) and then stained with Backlight. ©. live/dead stain for 15 minutes. Confocal Laser Scanning Microscopy was used for sampling the surfaces and studying biofilm, for which eight random series of photographs (Named SERIES) and four predefined biofilm series (Named BIOFILM) were taken. Biofilm thickness (microns) and covered surface by live/dead bacteria (%) were determined for both SERIES and BIOFILM. Assays were made in triplicates. Photographs were analyzed by ImageJ software, and data, by a Mann-Withney test. Results. Biofilm thickness and bacterial coverage per surface type in SERIES as well as BIOFILM for S. aureus and S.epidermidis, respectively is shown. A diminution of these two variables was observed in the coated surfaces versus raw UHWMPE with statistically significant reductions (p≤0.0001). F-DLC was the most effective coated surface versus S. aureus, with the least biofilm thickness and the highest proportional percentage of dead bacteria, and so DLC was versus S. epidermidis. Of interest, the proportion of dead S. epidermidis was higher in raw UHMWPE. Discussion & Conclusions. Staphylococcal biofilm formation on UHMWPE surfaces is irregular. Both biofilm thicknesses as bacterial coverage were lower in DLC and F-DLC. These preliminary data correlate to our previous bacterial adherence findings and support the better anti-adherence performance of DLC coated UHMWPEs. Fluorine is suggested to exhibit a bacteria-dependant behavior, but at present its role is quite far to be known. Further studies using clinical strains of both species are needed to evaluate the accuracy of these results

Background: The success of the increasing number of arthroplasty, spinal instrumentation and other implanted orthopaedic devices is hampered by device-related infections. More than half of these infections are caused by staphylococcal biofilm mediated antibiotic resistance. The hope of preventing prosthetic joint infection by antibiotic loaded cement is threatened by emerging resistant organisms. No bacterial resistance to betadine has been reported. Current intervention strategy is focussed on prevention of initial device colonisation and inhibition of genes encoding biofilm formation. Aim:. Determine the minimum inhibitory concentration (MIC) of betadine. Investigate the effect of betadine on icaADBC operon encoded staphylococcal biofilm formation. Investigate wether betadine can prevent bacterial adherence and biofilm formation by inhibition of the encoding genes. Methods: MIC of betadine for both reference strains and strains isolated from infected orthopaedic implants was determined. Biofilm assay was performed at different betadine concentrations using 96-well polystyrene plates. Total RNA for cDNA synthesis was isolated from bacterial at different twofold dilutions of betadine concentrations. Real time polymerase chain reaction was used to quantify effects of betadine on gene expression pattern of the icaADBC operon using the constitutively expressed gyrB gene as internal control. Bacterial was cultivated on polystyrene plates coated with different sub-inhibitory and clinical in-use doses of betadine to assess surface adherence. Results: The MIC of betadine was 1.4% for all bacterial strains. Clinical in-use doses of betadine prevented biofilm formation. A step-wise reduction of biofilm was observed at increasing sub-inhibitory doses of betadine (p< 0.0001). IcaA expression correlated with biofilm formation in staphylococcal organisms. Decrease in icaA expression was strongly associated with an increase in expression in the biofilm repressor gene, icaR. The repressive effect of betadine on biofilm formation by Staphylococcal bacteria is by a separate mechanism from its bacteriostatic mechanism of action. Conclusion: This study shows that icaR is a potential therapeutic target through which the ability of Staphylococcal bacterial to form biofilm may be reduced. Sub-inhibitory dose of betadine inhibited biofilm formation. Prevention of bacterial surface attachment as demonstrated by this study is suggestive that these compounds could be developed as a surface coating agents for orthopaedic implants

Most infections in arthroplasty are caused by staphylococci, about half being due to S. aureus. One of the most worrying aspects of this organism, and particularly of MRSA, is increasing multiple drug resistance, so that antimicrobial prophylaxis is probably already compromised. Vaccination offers a novel approach to overcome this. Detailed consideration of the pathogenesis of prosthesis–related infection indicates that a) prosthetic material rapidly becomes coated after implantation with plasma–derived conditioning film, and b) attachment of the bacteria to the conditioning film, by means of specific bacterial surface binding proteins, is an essential primary event. We hypothesise that antibodies to these binding proteins will block bacterial adhesion to the prosthesis, so reducing the incidence of infection. The aim of this research was to determine the effect of specific antibodies to two binding proteins (fibronectin - and fibrinogen–binding proteins, Fnbp and Fgbp respectively) on bacterial adherence to orthopaedic biomaterials coated with plasma conditioning film. Antibodies to recombinant sequences of Fnbp and Fgbp were raised in rabbits. A strain of S. aureus bearing a genetically inserted fluorescent reporter (GFP) was used. Orthopaedic biomaterials (steel, titanium and PMMA) were coated with FFP–derived conditioning film, placed in a specially–designed flow cell and exposed to a flow of S. aureus for 3h. Images were captured every 15min and analysed for adherent bacteria using image analysis software. The experiment was repeated in the presence of the antibodies and the results compared. Each antibody reduced the number of bacteria binding to all three materials by greater than 50%. Combining the two antibodies gave similar results to those when they were used individually. These preliminary results suggest that while further research is required, vaccination aimed at blocking bacterial attachment to conditioning film on implanted prostheses might reduce the incidence of S. aureus infection in arthroplasty. If so, this would apply even to MRSA. Questions remaining to be addressed include the clinical relevance of a 50% reduction in attachment, and future research will attempt to link this to a reduction in infection

Introduction: It is noted that infections make up the most feared complications of prostheses’ surgery in orthopaedic implants after resection of primary or secondary cancer of limb bones. The causes must be attributed to the entity of the skeletal resection and of surrounding soft tissues sacrifice, to the duration of surgery and to the pre-operative cycle of chemotherapy or radiotherapy. Infections of prostheses in oncology are caused mainly by bacteria present either in isolated strains or in poly-microbic associations, and most recently fungus infections have begun to be found, in immunodepressed patients. Candidemia makes up an important cause of systemic infections in immuno-compromised oncological patients, who received high doses of chemotherapy; moreover candidemia represents a high risk of hospital sepsis. It is noted that the behaviour of the Candida is interpreted through the production of a biofilm and then the inhibition of the production of the biofilm itself is translated into a potential antifungal effect. From the analysis of the literature a protective role carried out by the silver coating of the tumoural prostheses towards the bacterial infections is deduced. It is noted, in fact, the antimicrobiotic effect of medical devices coated in silver; in particular in studies conducted in animals favourable results were demonstrated on bacterial adherence of titanium devices coated with silver. The aim of the study was to evaluate in vitro the inhibition of the production of biofilm by different strains of Candida in the presence of titanium and titanium coated with silver. Materials and Methods: Six strains of Candida were analyzed: 2 strains of C. albicans, 2 of C. tropicalis and 2 of C. parapsilosis. The fungal strains were stratified on discs of pure titanium, a material in which implants of tumoural prostheses are made, and furthermore on discs of titanium coated in silver, and the ability of the fungus to produce protective biofilm on different substratum was evaluated. All of the studies were conducted 3 times. The adherence to the biofilm was measured by semi-quantitative, colormetric and spettrophotometric methods according to standardized protocols. Results: The spettrophotometric analysis demonstrated a statistically significant reduction of the production of biofilm by fungus strains that came in contact with titanium coated in silver compared to pure titanium in all of the strains that were examined, attested by the fact that the silver creates a micro-environment unfavourable for fungus growth. Conclusion: The analysis of the results demonstrated that the Silver coating of the oncological prosthesis made an unfavourable micro-environment not only for bacteria, as has already been widely established, but also for fungus. For this reason we maintain that this coating constitutes a valid opportunity in oncological resections for those patients who, being treated with chemotherapy, radiotherapy and to long hospitalitations present an elevated risk of fungal infection in oncological resections. From the studies we conducted it appeared how fundamental the use of silver in tumoural prosthesis is in order to prevent contamination by fungal strains and how this use must be taken more and more into consideration to improve life expectancy of a particular and sensitive category of patients, especially oncological

Aims

The mean age of patients undergoing total knee arthroplasty (TKA) has reduced with time. Younger patients have increased expectations following TKA. Aseptic loosening of the tibial component is the most common cause of failure of TKA in the UK. Interest in cementless TKA has re-emerged due to its encouraging results in the younger patient population. We review a large series of tantalum trabecular metal cementless implants in patients who are at the highest risk of revision surgery.

Antibiotic resistance represents a threat to human health. It has been suggested that by 2050, antibiotic-resistant infections could cause ten million deaths each year. In orthopaedics, many patients undergoing surgery suffer from complications resulting from implant-associated infection. In these circumstances secondary surgery is usually required and chronic and/or relapsing disease may ensue. The development of effective treatments for antibiotic-resistant infections is needed. Recent evidence shows that bacteriophage (phages; viruses that infect bacteria) therapy may represent a viable and successful solution. In this review, a brief description of bone and joint infection and the nature of bacteriophages is presented, as well as a summary of our current knowledge on the use of bacteriophages in the treatment of bacterial infections. We present contemporary published in vitro and in vivo data as well as data from clinical trials, as they relate to bone and joint infections. We discuss the potential use of bacteriophage therapy in orthopaedic infections. This area of research is beginning to reveal successful results, but mostly in nonorthopaedic fields. We believe that bacteriophage therapy has potential therapeutic value for implant-associated infections in orthopaedics.

Cite this article: Bone Joint J 2021;103-B(2):234–244.

Aims

The use of vitamin E-infused highly crosslinked polyethylene (HXLPE) in total knee prostheses is controversial. In this paper we have compared the clinical and radiological results between conventional polyethylene and vitamin E-infused HXLPE inserts in total knee arthroplasty (TKA).

Objectives

The aim of this study was to analyze drain fluid, blood, and urine simultaneously to follow the long-term release of vancomycin from a biphasic ceramic carrier in major hip surgery. Our hypothesis was that there would be high local vancomycin concentrations during the first week with safe low systemic trough levels and a complete antibiotic release during the first month.

Aims

Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty (THA). Different bearing surface materials have different surface properties and it has been suggested that the choice of bearing surface may influence the risk of PJI after THA. The objective of this meta-analysis was to compare the rate of PJI between metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), and ceramic-on-ceramic (CoC) bearings.

The development and pre-clinical evaluation of nano-texturised, biomimetic, surfaces of titanium (Ti) implants treated with titanium dioxide (TiO₂) nanotube arrays is reviewed. In vitro and in vivo evaluations show that TiO₂ nanotubes on Ti surfaces positively affect the osseointegration, cell differentiation, mineralisation, and anti-microbial properties. This surface treatment can be superimposed onto existing macro and micro porous Ti implants creating a surface texture that also interacts with cells at the nano level. Histology and mechanical pull-out testing of specimens in rabbits indicate that TiO₂ nanotubes improves bone bonding nine-fold (p = 0.008). The rate of mineralisation associated with TiO₂ nanotube surfaces is about three times that of non-treated Ti surfaces. In addition to improved osseointegration properties, TiO₂ nanotubes reduce the initial adhesion and colonisation of Staphylococcus epidermidis. Collectively, the properties of Ti implant surfaces enhanced with TiO₂ nanotubes show great promise.

Cite this article: Bone Joint J 2018;100-B(1 Supple A):9–16.