Aim. Periprosthetic joint infections follow 1-3% of arthroplasty surgeries, with the biofilm nature of these infections presenting a significant treatment challenge. 1. Prevention strategies include antibiotic-loaded bone cement; however, increases in cementless procedures means there is an urgent need for alternative local antimicrobial delivery methods. 2. A novel, ultrathin, silica-based sol-gel technology is evaluated in this research as an anti-infective coating for orthopaedic prosthetic devices, providing local antibiotic release following surgery. Method. Reduction in clinically relevant microbial activity and biofilm reduction by antimicrobial sol-gel coatings, containing a selection of antibiotics, were assessed via disc diffusion and microdilution culture assays using the Calgary biofilm device. 3. Proliferation, morphology, collagen, and calcium production by primary bovine osteoblasts cultured upon antibiotic sol-gel surfaces were examined, and cytotoxicity evaluated using Alamar blue staining and lactate dehydrogenase assays. Concentrations of silica, calcium and phosphorus compounds within the cell layer cultured on sol-gel coatings and concentrations eluted into media, were quantified using ICP-OES. Furthermore, cellular phenotype was assessed using alkaline phosphatase activity with time in culture. Results. Low antibiotic concentrations within sol-gel had an inhibitory effect on clinically relevant biofilm growth, for example 0.8 mg ml. -1. tobramycin inhibited clinically isolated S. aureus (MRSA) growth with an 8-log reduction in viable colony forming units. There was no significant difference in metabolic activity between untreated and sol-gel exposed primary bovine osteoblasts in elution-based assays. Reduction (2-fold) in metabolic activity in direct contact assays after 48 hours exposure was likely to be due to increased osteoinduction, whereas no impact upon cell proliferation were observed (p=0.92 at 14 days culture). The morphology of primary osteoblasts was unaffected by culture on sol-gel coatings and collagen production was maintained. Calcium containing nodule production within bovine osteoblastic cells was increased 16-fold after 14 days culture upon sol-gel. Conclusions. The ultrathin sol-gel coating showed low cytotoxicity, strong biofilm reducing activity and antimicrobial activity, which was comparable to antibiotics alone, demonstrating that sol-gel delivery of antibiotics could provide local antimicrobial effects to inhibit PJI growth without the need for bone cement. Future work will develop and evaluate sol-gel performance in an ex vivo explant bone infection model which will reduce the need for animal experimentation

Orthopedic Device-Related Infections (ODRIs) are a major medical challenge, particularly due to the involvement of biofilm-encased and multidrug-resistant bacteria. Current treatments, based on antibiotic administration, have proven to be ineffective. Consequently, there is a need for antibiotic-free alternatives. Antimicrobial peptides (AMPs) are a promising solution due to their broad-spectrum of activity, high efficacy at very low concentrations, and low propensity to induce resistance. We aim to develop a new AMP-based chitosan nanogel to be injected during orthopedic device implantation to prevent ODRIs. Chitosan was functionalized with norbornenes (NorChit) through the reaction with carbic anhydride and then, a cysteine-modified AMP, Dhvar5, a peptide with potent antibacterial activity, even against methicillin-resistant Staphylococcus aureus (MRSA), was covalently conjugated to NorChit (NorChit- Dhvar5), through a thiol-norbornene photoclick chemistry (UV= 365 nm). For NorChit-Dhvar5 nanogels production, the NorChit-Dhvar5 solution (0.15% w/v) and Milli-Q water were injected separately into microfluidic system. The nanogels were characterized regarding size, concentration, and shape, using Transmission Electron Microscopy (TEM), Nanoparticle Tracking Analysis (NTA) and Dynamic light scattering (DLS). The nanogels antibacterial properties were assessed in Phosphate Buffer (PBS) for 6 h, against four relevant microorganisms (Pseudomonas aeruginosa, S. aureus and MRSA, and in Muller- Hinton Broth (MHB), 50% (v/v) in PBS, supplemented with human plasma (1% (v/v)), for 6 and 24 h against MRSA. The obtained NorChit-Dhvar5 nanogels, presented a round-shaped and ∼100 nm. NorChit- Dhvar5 nanogels in a concentration of 10. 10. nanogels/mL in PBS were capable of reducing the initial inoculum of P. aeruginosa by 99%, S. aureus by 99%, and MRSA by 90%. These results were corroborated by a 99% MRSA reduction, after 24 h in medium. Furthermore, NorChit-Dhvar5 nanogels do not demonstrate signs of cytotoxicity against MC3T3-E1 cells (a pre-osteoblast cell line) after 14 days, having high potential to prevent antibiotic-resistant infection in the context of ODRIs

AM specifically allows for cost-efficient production of patient-specific Orthopaedic medical devices with unusual designs and properties. A porous design allows to adjust the stiffness of metallic implants to that of the host bone. Beyond traditional metals, like titanium alloys, this talk will review the present state-of-the-art of directly printed absorbable metal families. Physicochemical, mechanical and biological properties of standardized design prototypes from all currently available metal families will be compared and their clinical application potential discussed. The impact of in vitro test environments on comparative corrosion behavior, post manufacturing aspects, and the recent status quo in biocompatibility testing and present knowledge gaps will be addressed

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The aim of this study was to perform the first population-based description of the epidemiological and health economic burden of fracture-related infection (FRI).

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Revision total knee arthroplasty (rTKA) is a technically challenging and costly procedure. It is well-documented that primary TKA (pTKA) have better survivorship than rTKA; however, we were unable to identify any studies explicitly investigating previous rTKA as a risk factor for failure following rTKA. The purpose of this study is to compare the outcomes following rTKA between patients undergoing index rTKA and those who had been previously revised.

The importance of registries has been brought into focus by recent UK national reports focusing on implant (Cumberlege) and surgeon (Paterson) performance. National arthroplasty registries provide real-time, real-world information about implant, hospital, and surgeon performance and allow case identification in the event of product recall or adverse surgical outcomes. They are a valuable resource for research and service improvement given the volume of data recorded and the longitunidal nature of data collection. This review discusses the current value of registry data as it relates to both clinical practice and research.

Cite this article: Bone Joint J 2023;105-B(4):356–360.

Local antimicrobial therapy is an integral aspect of treating orthopaedic device related infection (ODRI), which is conventionally administered via polymethylmethacrylate (PMMA) bone cement. PMMA, however, is limited by a suboptimal antibiotic release profile and a lack of biodegradability. In this study, we compare the efficacy of PMMA versus an antibioticloaded hydrogel in a single- stage revision for chronic methicillin-resistant Staphylococcus aureus (MRSA) ODRI in. sheep. Antibiofilm activity of the antibiotic combination (gentamicin and vancomycin) was determined in vitro. Swiss alpine sheep underwent a single-stage revision of a tibial intramedullary nail with MRSA infection. Local gentamicin and vancomycin therapy was delivered via hydrogel or PMMA (n = 5 per group), in conjunction with systemic antibiotic therapy. In vivo observations included: local antibiotic tissue concentration, renal and liver function tests, and quantitative microbiology on tissues and hardware post-mortem. There was a nonsignificant reduction in biofilm with an increasing antibiotic concentration in vitro (p = 0.12), confirming the antibiotic tolerance of the MRSA biofilm. In the in vivo study, four out of five sheep from each treatment group were culture negative. Antibiotic delivery via hydrogel resulted in 10–100 times greater local concentrations for the first 2–3 days compared with PMMA and were comparable thereafter. Systemic concentrations of gentamicin were minimal or undetectable in both groups, while renal and liver function tests were within normal limits. This study shows that a single-stage revision with hydrogel or PMMA is equally effective, although the hydrogel offers certain practical benefits over PMMA, which make it an attractive proposition for clinical use

While surgeon-industry relationships in orthopaedics have a critical role in advancing techniques and patient outcomes, they also present the potential for conflict of interest (COI) and increased risk of bias in surgical education. Consequently, robust processes of disclosure and mitigation of potential COI have been adopted across educational institutions, professional societies, and specialty journals. The past years have seen marked growth in the use of online video-based surgical education platforms that are commonly used by both trainees and practicing surgeons. However, it is unclear to what extent the same COI disclosure and mitigation principles are adhered to on these platforms. Thus, the purpose of the present study was to evaluate the frequency and adequacy of potential COI disclosure on orthopaedic online video-based educational platforms. We retrospectively reviewed videos from a single, publicly-accessible online peer-to-peer orthopaedic educational video platform (VuMedi) that is used as an educational resource by a large number of orthopaedic trainees across North America. The 25 highest-viewed videos were identified for each of 6 subspecialty areas (hip reconstruction, knee reconstruction, shoulder/elbow, foot and ankle, spine and sports). A standardized case report form was developed based on the COI disclosure guidelines of the American Academy of Orthopaedic Surgery (AAOS) and the Journal of Bone and Joint Surgery. Two reviewers watched and assessed each video for presentation of any identifiable commercial products or brand names, disclosure of funding source for video, and presenter's potential conflict of interest. Additionally, presenter disclosures were cross-referenced against commercial relationships reported in the AAOS disclosure database to determine adequacy of disclosure. Any discrepancies between reviewers were resolved by consensus wherever possible, or with adjudication by a third reviewer when necessary. Out of 150 reviewed videos, only 37 (25%) included a disclosure statement of any kind. Sixty-nine (46%) videos involved the presentation of a readily identifiable commercial orthopaedic device, implant or brand. Despite this, only 13 of these (19%) included a disclosure of any kind, and only 8 were considered adequate when compared to the presenter's disclosures in the AAOS database. In contrast, 83% of the presenters of the videos included in this study reported one or more commercial relationships in the AAOS disclosure database. Videos of presentations given at conferences and/or academic meetings had significantly greater rates of disclosure as compared to those that were not (41% vs 14%; p=0.004). Similarly, disclosures associated with conference/meeting presentations had significantly greater rates of adequacy (21% vs 7%; p=0.018). Even so, less than half of the educational videos originating from a conference or meeting included a disclosure of any kind, and only about half of these were deemed adequate. No differences were seen in the rate of disclosures between orthopaedic subspecialties (p=0.791). Online orthopaedic educational videos commonly involve presentation of specific, identifiable commercial products and brands, and the large majority of presenters have existing financial relationships with potential for conflict of interest. Despite this, the overall rate of disclosure of potential conflict of interest in these educational videos is low, and many of these disclosures are incomplete or inadequate. Further work is needed to better understand the impact of this low rate of disclosure on orthopaedic education both in-training and in practice

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There is a considerable challenge in treating bone infections and orthopaedic device-associated infection (ODAI), partly due to impaired penetration of systemically administrated antibiotics at the site of infection. This may be circumvented by local drug administration. Knowledge of the release kinetics from any carrier material is essential for proper application. Ceftriaxone shows a particular constant release from calcium sulphate (CaSO₄) in vitro, and is particularly effective against streptococci and a large portion of Gram-negative bacteria. We present the clinical release kinetics of ceftriaxone-loaded CaSO₄ applied locally to treat ODAI.

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Our objective was describing an algorithm to identify and prevent vascular injury in patients with intrapelvic components.

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In the UK, the NHS generates an estimated 25 megatonnes of carbon dioxide equivalents (4% to 5% of the nation’s total carbon emissions) and produces over 500,000 tonnes of waste annually. There is limited evidence demonstrating the principles of sustainability and its benefits within orthopaedic surgery. The primary aim of this study was to analyze the environmental impact of orthopaedic surgery and the environmentally sustainable initiatives undertaken to address this. The secondary aim of this study was to describe the barriers to making sustainable changes within orthopaedic surgery.

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Periprosthetic joint infections (PJIs) and fracture-related infections (FRIs) are associated with a significant risk of adverse events. However, there is a paucity of data on cardiac complications following revision surgery for PJI and FRI and how they impact overall mortality. Therefore, this study aimed to investigate the risk of perioperative myocardial injury (PMI) and mortality in this patient cohort.

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This study compared the cobalt and chromium serum ion concentration of patients treated with two different metal-on-metal (MoM) hinged total knee arthroplasty (TKA) systems, as well as a titanium nitride (TiN)-coated variant.

Abstract. Objectives. Additive manufacturing has led to numerous innovations in orthopaedic surgery: surgical guides; surface coatings/textures; and custom implants. Most contemporary implants are made from titanium alloy (Ti-6Al-4V). Despite being widely available industrially and clinically, there is little published information on the performance of this 3D printed material for orthopaedic devices with respect to regulatory approval. The aim of this study was to document the mechanical, chemical and biological properties of selective laser sintering (SLS) manufactured specimens following medical device (TOKA®, 3D Metal Printing LTD, UK) submission and review by the UK Medicines and Healthcare Products Regulatory Agency (MHRA). Methods. All specimens were additively manufactured in Ti-6Al-4V ELI (Renishaw plc, UK). Mechanical tests were performed according to ISO6892-1, ISO9585 and ISO12107 for tensile (n=10), bending (n=3) and fatigue (n=16) respectively (University of Bath, UK). Appropriate chemical characterisation and biological tests were selected according to recommendations in ISO10993 and conducted by external laboratories (Wickham Labs, UK; Lucideon, UK; Edwards Analytical, UK) in adherence with Good Lab Practise guidelines. A toxicological review was conducted on the findings (Bibra, UK). Results. The mechanical tests demonstrated that the material performed to the specification for conventionally manufactured titanium alloy of this type (ISO5832-3). The toxicology review concluded that there were no significant concerns for the health of the patients identified in this evaluation and implantation of the TOKA® device would not result in a significant health risk to patients. Conclusions. Reflecting on our MHRA experience, additive manufacture of orthopaedic devices is still considered to be a ‘novel’ process by regulatory bodies, requiring additional safety evidence. Despite this, our findings demonstrate that there is no difference, mechanically or chemically, to the traditionally manufactured alloy material. We hope to support the widening use of 3D printed titanium alloy orthopaedic devices by publishing our route to regulatory approval. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Abstract. INTRODUCTION. Polyetheretherketone (PEEK) is a high-performance thermoplastic polymer which has found increasing application in orthopaedic implant devices and has a lot of promise for ‘made-to-measure’ implants produced through additive manufacturing [1]. However, a key limitation of PEEK is that it is bioinert and there is a requirement to functionalise its surface to make the material osteoconductive to ensure a more rapid, improved and stable fixation, in vivo. One approach to solving this issue is to modify PEEK with bioactive materials, such as hydroxyapatite (HA). OBJECTIVE. To 3D PEEK/HA composite materials using a Fused Filament Fabrication (FFF) approach to enhance the properties of the PEEK matrix. METHODS. PEEK/HA composites (0–30% w/w HA/PEEK) were 3D printed using a modified Ultimaker 2+ 3D printer. The mechanical, thermal, physical, chemical and in vitro properties of the 3D printed samples were all studied as part of this work. RESULTS. The CT images of both the filament and the 3D printed samples showed that the HA material was evenly dispersed throughout the bulk all the samples. SEM/EDX measurements highlighted that HA was homogenously distributed across the surface. As the HA content of the samples increases, so does the tensile modulus, ranging from 4.2 GPa (PEEK) to 6.1 GPa (30% HA/PEEK) and are significantly higher than datasheet information of injected molded PEEK samples. All materials supported the growth of osteoblast cells on their surface. CONCLUSIONS. The results clearly show that we can successfully and easily 3D print HA/PEEK composite materials up to 30% w/w HA/PEEK. The samples produced have a homogeneous distribution of HA in both the bulk and surface of all the samples, and their mechanical performance of the PEEK is enhanced by the addition of HA

Aims

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