Objectives. Infection of implants is a major problem in elective and trauma surgery. Heating is an effective way to reduce the bacterial load in food preparation, and studies on hyperthermia treatment for cancer have shown that it is possible to heat metal objects with pulsed electromagnetic fields selectively (PEMF), also known as induction heating. We therefore set out to answer the following research question: is non-contact induction heating of metallic implants effective in reducing bacterial load in vitro?. Methods. Titanium alloy cylinders (Ti6Al4V) were exposed to PEMF from an induction heater with maximum 2000 watts at 27 kHz after being contaminated with five different types of micro-organisms: Staphylococcus epidermidis; Staphylococcus aureus; Pseudomonas aeruginosa; spore-forming Bacillus cereus; and yeast Candida albicans. The cylinders were exposed to incremental target temperatures (35°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C) for up to 3.5 minutes. Results. There was an average linear heating rate of 0.39°C per second up to the target temperature, and thereafter the target temperature was maintained until the end of the experiment. At 60°C and higher (duration 3.5 minutes), there was a 6-log reduction or higher for every micro-organism tested. At 60°C, we found that the shortest duration of effective induction heating was 1.5 minutes. This resulted in a 5-log reduction or higher for every micro-organism tested. Conclusion. Non-contact induction heating of a titanium disk is effective in reducing bacterial load in vitro. These promising results can be further explored as a new treatment modality for infections of metal orthopaedic implants. Cite this article: B. G. Pijls, I. M. J. G. Sanders, E. J. Kuijper, R. G. H. H. Nelissen. Non-contact electromagnetic induction heating for eradicating bacteria and yeasts on biomaterials and possible relevance to orthopaedic implant infections: In vitro findings. Bone Joint Res 2017;6:323–330. DOI: 10.1302/2046-3758.65.BJR-2016-0308.R1

We have designed a prospective study to evaluate the usefulness of prolonged incubation of cultures from sonicated orthopaedic implants. During the study period 124 implants from 113 patients were processed (22 osteosynthetic implants, 46 hip prostheses, 54 knee prostheses, and two shoulder prostheses). Of these, 70 patients had clinical infection; 32 had received antibiotics at least seven days before removal of the implant. A total of 54 patients had sonicated samples that produced positive cultures (including four patients without infection). All of them were positive in the first seven days of incubation. No differences were found regarding previous antibiotic treatment when analysing colony counts or days of incubation in the case of a positive result. In our experience, extending incubation of the samples to 14 days does not add more positive results for sonicated orthopaedic implants (hip and knee prosthesis and osteosynthesis implants) compared with a conventional seven-day incubation period. Cite this article: Bone Joint J 2013;95-B:1001–6

To determine risk factors of infection in total knee arthroplasty. This descriptive study was conducted in the Department of Orthopedics for a duration of three years from January 2016 to January 2019. All patients undergoing primary total knee replacement were included in the study. Exclusion criteria were all patients operated in another hospital and revision total knee replacement. All patients were followed up at 2, 4, 8, 12 and 24 weeks post-operatively. Signs of inflammation and inflammatory markers such as total leukocyte count (TLC), C-reactive protein (CRP) and ESR were measured. Risk factors like age, body mass index (BMI), ASA, co-morbid conditions were also noted. A total of 78 patients underwent primary unilateral Total Knee Replacement (TKR) during the study period. Of these, 30 (34.09%) were male and 48 (61.54%) female patients. Mean age of patients was 68.32 ± 8.54 years. Average BMI 25.89 Kg/m2 .Osteoarthritis was the pre-dominant cause of total knee replacement (94.87%). Among co-morbid factors 33.33% were diabetic, 28.20% having ischemic heart disease and 12.82% with chronic lung disease. Upon anaesthesia fitness pre-operatively, 91.02% patients had an American society of anaesthesiologist score (ASA) between 0–2 while 07 (8.97%) between 3- 5. Average duration of surgery was 85.62± 4.11 minutes. 6.41% cases got infected. In majority of the infected cases (60%), Staphylococcus aureus was the infective organism. Diabetes Mellitus (p=0.01) and Obesity (p=0.02) had a significant relation to post-operative infection. Pre-operative risk evaluation and prevention strategies along with early recognition of infection and control can greatly reduce the risk of joint infection post-TKR which will not only improve the mobility of patient but also its morbidity and mortality as well. Key Words:. C-reactive protein (CRP), Erythrocyte Sedimentation Rate (ESR), Staphylococcus aureus, Total Knee Arthroplasty (TKA)

There is no consensus on how to evaluate and grade pin site infection. A precise, objective and reliable pin site infectious score is warranted. The literature was reviewed for pin site infection classification systems, The Modified Gordon Score (MGS) grade 0-6 was used. The aim was to test the reliability of The Modified Gordon Infection Score. The observed agreement and inter-rater reliability were investigated between nurse and doctors. MGS was performed in the outpatient clinic at Aalborg University Hospital, Denmark on 1472 pin sites in 119 patients by one nurse and one of three orthopaedic surgeons blinded to each other's judgement. The data was stored in a Red Cap Database for further statistical analysis. The observed agreement between the nurse and the 3 orthopaedic surgeons was evaluated with a one-way random-effect model with interclass correlation with absolute agreement. Furthermore the observed agreement for each of the 3 surgeons with the nurse was calculated. The distribution of MGS infection grade in the 1472 pin sites was: Grade 0; n=1372, Grade 1; n=32, Grade 2; n=39, Grade 3; n=24, Grade 4; n=5, Grade 5; n=0, Grade 6; n=0. The observed agreement between the nurse and the surgeons was calculated as 98%. The ICC estimated between nurse and the surgeons was 0,8943 (ICC >0,85 = reliable). The grading was done by three different doctors with an agreement with the nurse as follows. Rater1 (n=416) =99,5 %, Rater2 (n=1440) =97,4%, Rater3 (n=1440) =96,6%. A limitation to this study is that the dataset represents mostly clean pin sites with MGS 0. Only 100 pin sites had signs of superficial infection MGS 1-4 none above 4. We found that the MGS infection score is highly reliable for low grade infections but we cannot conclude on reliability in severe infections

Open tibial fractures can be difficult to manage, with a range of factors that could affect treatment and outcome. We present a large cohort of patients, and analyse which factors have significant associations with infection outcome. Elucidation will allow clinicians to strive for treatment optimisation, and patients to be advised on likely complications. Open tibia fractures treated at a major trauma centre between 2015-2021 were included. Mean age at injury was 55.4 (range 13-102). Infection status was categorized into no infection, superficial infection, and osteomyelitis. Age, mode of injury, polytrauma, fibula status, Gustilo-Anderson (GA) classification, wound contamination, time from injury to: first procedure/definitive plastics procedure/definitive fixation, type of definitive fixation, smoking and diabetic status, and BMI, were collected. Multicollinearity was calculated, with highly correlated factors removed. Multinomial logistic regression was performed. Chi Squared testing, with Post Hoc Bonferroni correction was performed for complex categorical factors. Two hundred forty-four patients with open tibial fractures were included. Forty-five developed superficial infection (18.4%), and thirty-nine developed osteomyelitis (16.0%). Polytrauma, fibula status, and type of definitive fixation were excluded from the multivariate model due to strong multicollinearity with other variables. With reference to the non-infected outcome; superficial infection patients had higher BMI (p<0.01), higher GA grade (p<0.01), osteomyelitis patients had longer time to definitive fixation (p=0.049) and time to definitive plastics procedure (p=0.013), higher GA grade (p<0.01), and positive wound contamination(p=0.015). Poc hoc analysis showed “no infection” was positively associated with GA-I (p=0.029) and GA-II (p<0.01), and negatively associated with GA-IIIC (p<0.01). Osteomyelitis was positively associated with GA-IIIc (p<0.01). This study investigated the associations between the injury and presentation factors that may affect infection outcome. The variables highlighted are the factors clinicians should give extra consideration to when treating cases, and take preventative measures to optimize treatment and mitigate infection risk

Introduction. Despite the implementation of numerous preventive measures in recent years, the persistent challenge of periprosthetic infections remains. Among the various strategies, metallic modification of implants, particularly with silver, has emerged as a promising avenue. Silver's antimicrobial properties, coupled with its low human toxicity, render it an appealing option. However, ongoing debate surrounds its comparative efficacy in infection prevention when contrasted with titanium-coated prostheses. Methods. The PubMed database was systematically searched up to March 2024. Studies in English that met predetermined inclusion/exclusion criteria and utilized “Megaprosthesis AND infection” and “ silver-coated AND infection “ as key terms were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA) statement guided the article selection process. Results. From a pool of 1892 potential papers after literature screening, 11 studies with a total of 1419 patients were meticulously selected for analysis. Among these patients, 638 were treated with silver-coated implants, while 781 received titanium-coated implants, resulting in 166 recorded cases of infection. Remarkably, the infection rate stood at 9.2% for the silver-coated group, contrasting with 13.4% for the titanium-coated group. The subsequent analysis unveiled a notable discrepancy in proportions (P difference = -0.0473, 95%CI: -0.088 to -0.006), signaling a statistically significant decrease in infections within the silver-coated cohort. Furthermore, the I2 statistic, denoting heterogeneity in effect sizes, stood at 21.8% (95%CI: 0.0-66.9), indicating a modest degree of variability among the studies. Conclusion. In conclusion, our systematic review and meta-analysis shed light on the potential of silver-coated implants in mitigating periprosthetic infections. Despite the persistent challenge posed by such infections, our findings suggest a statistically significant decrease in infection rates among patients treated with silver-coated implants compared to those with titanium-coated ones

Introduction. Bone and joint infection (BJI) is often characterized by severe inflammation and progressive bone destruction. Osteocytes are the most numerous and long-lived bone cell type, and therefore represent a potentially important long-term reservoir of bacterial infection. Staphylococcus aureus is known to establish stable intracellular osteocytic infections, however, little is known about the less virulent yet second most prevalent BJI pathogen, S. epidermidis, associated with late-diagnosed, chronic BJI. Thus, this study sought to establish an in vitro model to study the infection characteristics of S. epidermidis in human osteocyte-like cells. Methods. SaOS2 cells (1 ×10. 4. cells/cm. 2. ) were grown to confluence either without differentiation, representing an osteoblast-like (OB) state (SaOS2-OB) or differentiated to an osteocyte-like stage (SaOS2-OY), using established methods. Four S. epidermidis strains used (ATCC-12228, ATCC-14990, ATCC-35984 and a clinical osteomyelitis strain RAH-SE1) were tested to be Lysostaphin-resistant, necessitating antibiotic (Levofloxacin) control of extracellular bacteria. Infection of host cells (OB or OY) was tested at three multiplicities of infection (MOI: 10, 100 and 1000). Extracellular bacteria were controlled by overnight incubation at a 10X minimum inhibitory concentration (MIC) of Levofloxacin and thereafter at 1XMIC. At each time point (days 1, 3, 5) viable intra- and extracellular bacteria were quantified. Result. All strains displayed similar intracellular infection and persistence capabilities in SaOS2-OB and SaOS2-OY. Independent of MOI, intracellular bacteria in SaOS2-OB decreased over time, becoming non-culturable by day 5. In contrast, SaOs2-OY displayed enhanced intracellular bacterial persistence at each time point. In the presence of increased Levofloxacin concentration (10XMIC), S. epidermidis could persist intracellularly for at least 14 days. Conclusion. This study showed for the first time that S. epidermidis can infect human osteocytes and persist intracellularly. Additionally, even a 10xMIC antibiotic concentration failed to eradicate intracellular bacteria, suggesting that persistence within osteocytes could contribute to treatment failure and establishment of chronic BJI

To detect early signs of infection infrared thermography has been suggested to provide quantitative information. Our vision is to invent a pin site infection thermographic surveillance tool for patients at home. A preliminary step to this goal is the aim of this study, to automate the process of locating the pin and detecting the pin sites in thermal images efficiently, exactly, and reliably for extracting pin site temperatures. A total of 1708 pin sites was investigated with Thermography and augmented by 9 different methods in to totally 10.409 images. The dataset was divided into a training set (n=8325), a validation set (n=1040), and a test set (n=1044) of images. The Pin Detection Model (PDM) was developed as follows: A You Only Look Once (YOLOv5) based object detection model with a Complete Detection Intersection over Union (CDIoU), it was pre-trained and finetuned by the through transfer learning. The basic performance of the YOLOv5 with CDIoU model was compared with other conventional models (FCOS and YOLOv4) for deep and transition learning to improve performance and precision. Maximum Temperature Extraction (MTE) Based on Region of Interest (ROI) for all pin sites was generated by the model. Inference of MTE using PDM with infected and un-infected datasets was investigated. An automatic tool that can identify and annotate pin sites on conventional images using bounding boxes was established. The bounding box was transferred to the infrared image. The PMD algorithm was built on YOLOv5 with CDIoU and has a precision of 0.976. The model offers the pin site detection in 1.8 milliseconds. The thermal data from ROI at the pin site was automatically extracted. These results enable automatic pin site annotation on thermography. The model tracks the correlation between temperature and infection from the detected pin sites and demonstrates it is a promising tool for automatic pin site detection and maximum temperature extraction for further infection studies. Our work for automatic pin site annotation on thermography paves the way for future research on infection assessment using thermography

Irrigation with antiseptic agents, antibiotics, and surfactants are used for treatment and prevention of infections. Despite desirable microbicidal actions, studies have demonstrated cytotoxic effects on host tissue that may impair healing. This study investigated the extent of tissue damage caused by commonly used irrigation solutions in the presence or absence of infection. Air pouches created in 60 balb/c mice were divided into two groups (n=30): infected with Staphylococcus aureus and control. One week later the infected group was subdivided into 5 subgroups (n=6) based on irrigation solutions and by day 0 (immediately) and day7 after irrigation (n=3). Solutions included Saline, Bacitracin, Clorpactin, Irrisept and Bactisure. In infected group wash fluid was collected for quantitative analysis of bacterial growth. At the specified times mice were sacrificed, pouch tissue sent for histology, and sections analyzed for inflammation, necrosis, and edema. Inflammation decreased in infected vs sterile pouches for all solutions except Bacitracin day 0 and for all solutions day 7 with significance in all except Bacitracin (p<0.05). On day 0, necrosis increased in infected vs sterile pouches in Bacitracin (p=0.006), Irrisept (p=0.18), or Bactisure (p=0.07); however, on day 7, necrosis significantly decreased in infected pouches for all solutions (p<0.05) except for Clorpactin (p=0.18). Edema decreased in infected vs sterile pouches on day 0 for all solutions with significance in saline, Irrisept, and Bacitracin (p<0.05). On day 7, infected pouches had decreased edema in saline, Bacitracin, and Bactisure (p<0.05) and increased in Irrisept (p<0.05) and Clorpactin (p=0.069) compared to sterile pouches. Bacterial culture of washouts demonstrated that Clorpactin, Irrisept and Bactisure controlled the infection, whereas saline and Bacitracin showed bacterial multiplication 3.9 × 10^7 CFU/ml and 6.7 × 10^7 CFU/ml respectively. Bacitracin wash showed significantly more bacteria growth compared to Clorpactin (p=0.024), Irrisept (p=0.025) and Bactisure (p=0.025). Tissue damage varied with irrigation solutions and the presence or absence of infection. Presence of bacteria appeared to lead to less tissue inflammation and edema. Tissue necrosis varied over time with different solutions. Surgeons must weigh risks and benefits when selecting solutions and determining when to irrigate

Determine the infection risk of nonoperative versus operative repair of extraperitoneal bladder ruptures in patients with pelvic ring injuries. Pelvic ring injuries with extraperitoneal bladder ruptures were identified from a prospective trauma registry at two level 1 trauma centers from 2014 to 2020. Patients, injuries, treatments, and complications were reviewed. Using Fisher's exact test with significance at P value < 0.05, associations between injury treatment and outcomes were determined. Of the 1127 patients with pelvic ring injuries, 68 (6%) had a concomitant extraperitoneal bladder rupture. All patients received IV antibiotics for an average of 2.5 days. A suprapubic catheter was placed in 4 patients. Bladder repairs were performed in 55 (81%) patients, 28 of those simultaneous with ORIF anterior pelvic ring. The other 27 bladder repair patients underwent initial ex-lap with bladder repair and on average had pelvic fixation 2.2 days later. Nonoperative management of bladder rupture with prolonged Foley catheterization was used in 13 patients. Improved fracture reduction was noted in the ORIF cohort compared to the closed reduction external fixation cohort (P = 0.04). There were 5 (7%) deep infections. Deep infection was associated with nonoperative management of bladder rupture (P = 0.003) and use of a suprapubic catheter (P = 0.02). Not repairing the bladder increased odds of infection 17-fold compared to repair (OR 16.9, 95% CI 1.75 – 164, P = 0.01). Operative repair of extraperitoneal bladder ruptures substantially decreases risk of infection in patients with pelvic ring injuries. ORIF of anterior pelvic ring does not increase risk of infection and results in better reductions compared to closed reduction. Suprapubic catheters should be avoided if possible due to increased infection risk later. Treatment algorithms for pelvic ring injuries with extraperitoneal bladder ruptures should recommend early bladder repair and emphasize anterior pelvic ORIF

C. Difficile infections in elderly patients with hip fractures is associated with high morbidity and mortality. Antibiotic regimens with penicillin and its derivatives is a leading cause. Antibiotic prophylactic preferences vary across different hospitals within NHS. We compared two antibiotic prophylactic regimens - Cefuroxime only prophylaxis and Teicoplanin with Gentamicin prophylaxis in fracture neck of femur surgery, and evaluated the incidence of C. Difficile diarrhea and Surgical Site Infection (SSI). To assess the Surgical Site Infection and C. Difficile infection rate associated with different regimens of antibiotics prophylaxis in fracture neck of femur surgery. Data was analyzed retrospectively. Neck of femur fracture patients treated surgically from 2009 in our unit were included. Age, gender, co morbidities, type of fracture, operation, ASA grade was collected. 1242 patients received Cefuroxime only prophylaxis between January 2009 and December 2012 (Group 1) and 486 patients received Teicoplanin with Gentamicin between October 2015 and March 2017 (Group 2). There were 353 males and 889 female patients in Group 1 and 138 males and 348 female patients in Group 2. The co morbidities in both groups were comparable. Incidence of C. Difficile diarrhea and Surgical Site Infection (SSI) was noted. Statistical analysis with chi square test was performed to determine the ‘p’ value. C. Diff diarrhea rate in Group 2 was 0.41 % as compared to 1.29 % in Group 1. The Surgical Site Infection (SSI) rate in Group 2 was 0.41 % as compared to 3.06 % in Group 1. The comparative results were statistically significant (p = 0.0009). Prophylactic antibiotic regimen of Teicoplanin with Gentamicin showed significant reduction in C. Difficile diarrhea & Surgical Site Infection in fracture neck of femur patients undergoing surgery

Orthopedic device-related infection (ODRI) preclinical models are widely used in translational research. Most models require induction of general anesthesia, which frequently results in hypothermia in rodents. This study aimed to evaluate the impact of peri anesthetic hypothermia in rodents on outcomes in preclinical orthopedic device-related infection studies. A retrospective analysis of all rodents that underwent surgery under general anesthesia to induce an ODRI model with inoculation of Staphylococcus epidermidis between 2016 and 2020 was conducted. A one-way multivariate analysis of covariance was used to determine the fixed effect of peri anesthetic hypothermia (hypothermic defined as rectal temperature <35°C) on the combined harvested tissue and implant colonies forming unit counts, and having controlled for the study groups including treatments received duration of surgery and anesthesia and study period. All animal experiments were approved by relevant ethical committee. A total of 127 rodents (102 rats and 25 mice) were enrolled in an ODRI and met the inclusion criteria. The mean lowest peri-anesthetic temperature was 35.3 ± 1.5 °C. The overall incidence of peri-anesthetic hypothermia was 41% and was less frequently reported in rats (34% in rats versus 68% in mice). Statistical analysis showed a significant effect of peri anesthetic hypothermia on the post-mortem combined colonies forming unit counts from the harvested tissue and implant(s) (p=0.01) when comparing normo- versus hypothermic rodents. Using Wilks’ Λ as a criterion to determine the contribution of independent variables to the model, peri-anesthetic hypothermia was the most significant, though still a weak predictor, of increased harvested colonies forming unit counts. Altogether, the data corroborate the concept that bacterial colonization is affected by abnormal body temperature during general anesthesia at the time of bacterial inoculation in rodents, which needs to be taken into consideration to decrease infection data variability and improve experimental reproducibility

Infection of implanted medical devices (biomaterials), like titanium orthopaedic implants, can have disastrous consequences, including removal of the device. These so-called biomaterial-associated infections (BAI) are mainly caused by Staphylococcus aureus and Staphylococcus epidermidis. To prevent biofilm formation using a non-antibiotic based strategy, we aimed to develop a novel permanently fixed antimicrobial coating for titanium devices based on stable immobilized quaternary ammonium compounds (QACs). Medical grade titanium implants were dip-coated in subsequent solutions of hyperbranched polymer, polyethyleneimine and 10 mM sodium iodide, and ethanol. The QAC-coating was characterized using water contact angle measurements, scanning electron microscopy, FTIR, AFM and XPS. The antimicrobial activity of the coating was evaluated against S. aureus strain JAR060131 and S. epidermidis strain ATCC 12228 using the JIS Z 2801:2000 surface microbicidal assay. Lastly, we assessed the in vivo antimicrobial activity in a mouse subcutaneous implant infection model with S. aureus administered locally on the QAC-coated implants prior to implantation to mimic contamination during surgery. Detailed material characterization of the titanium samples showed the presence of a homogenous and stable coating layer at the titanium surface. Moreover, the coating successfully killed S. aureus and S. epidermidis in vitro. The QAC-coating strongly reduced S. aureus colonization of the implant surface as well as of the surrounding tissue, with no apparent macroscopic signs of toxicity or inflammation in the peri-implant tissue at 1 and 4 days after implantation. An antimicrobial coating with stable quaternary ammonium compounds on titanium has been developed which holds promise to prevent BAI. Non-antibiotic-based antimicrobial coatings have great significance in guiding the design of novel antimicrobial coatings in the present, post-antibiotic era. Acknowledgements: This research was financially supported by the Health∼Holland/LSH-TKI call 2021–2022, project 25687, NACQAC: ‘Novel antimicrobial coatings with stable non-antibiotic Quaternary Ammonium Compounds and photosensitizer technology'

An increasing elderly population means joint replacement surgery numbers are projected to increase, with associated complications such as periprosthetic joint infections (PJI) also rising. PJI are particularly challenging due to antimicrobial resistant biofilm development on implant surfaces and surrounding tissues, with treatment typically involving invasive surgeries and systemic antibiotic delivery. Consequently, functionalisation of implant surfaces to prevent biofilm formation is a major research focus. This study characterises clinically relevant antimicrobials including gentamicin, clindamycin, daptomycin, vancomycin and caspofungin within a silica-based, biodegradable sol-gel coating for prosthetic devices. Antimicrobial activity of the coatings against clinically relevant microorganisms was assessed via disc diffusion assays, broth microdilution culture methods and the MBEC assay used to determine anti-biofilm activity. Human and bovine cells were cultured in presence of antimicrobial sol-gel to determine cytotoxicity using Alamar blue and antibiotic release was measured by LC-MS. Biodegradability in physiological conditions was assayed by FT-IR, ICP-MS and measuring mass change. Effect of degradation products on osteogenesis were studied by culturing mesenchymal stem cells in the presence of media in which sol-gel samples had been immersed. Antimicrobial-loaded coatings showed strong activity against a wide range of clinically relevant bacterial and fungal pathogens with no loss of activity from antibiotic alone. The sol-gel coating demonstrated controlled release of antimicrobials and initial sol-gel coatings showed no loss of viability on MSCs with gentamicin containing coatings. Current work is underway investigating cytotoxicity of sol-gel compositions against MG-63 cells and primary osteoblasts. This research forms part of an extended study into a promising antimicrobial delivery strategy to prevent PJI. The implant coating has potential to advance PJI infection prevention, reducing future burden upon healthcare costs and patient wellbeing

Orthopedic device-related bone infection is one of the most distressing complications of the surgical fixation of fractures. Despite best practice in medical and surgical interventions, the rate of infection remains stubbornly persistent, and current estimates indicate that treatment failure rates are also significant. As we approach the limit of the effectiveness of current anti-infective preventative and therapeutic strategies, novel approaches to infection management assume great importance. This presentation will describe our efforts to develop and test various hydrogels to serve as customized antibiotic delivery vehicles for infection prevention and treatment. Hydrogels offer solutions for many of the challenges faced by complex trauma wounds as they are not restricted spatially within a poorly defined surgical field, they often degrade rapidly with no compatibility issues, and releases 100% of the loaded antibiotic. The preliminary data set proving efficacy in preventing and treating infection in both rabbit and sheep studies will be described, including local antibiotic concentrations in the intramedullary canal over time, compared to that of the more conventional antibiotic loaded bone cement. These two technologies show potential for the prevention and treatment of infection in trauma patients, with a clear focus on optimized antibiotic delivery tailored for complex wounds

The aim of this study was to assess the impact of Covid-19 measures on the rate of surgical site infections (SSI) and subsequent readmissions in orthopaedic patients. Retrospective, observational study in a level 1 major trauma center comparing rates of SSI in orthopaedic patients who underwent surgery prior to the Covid-19 lockdown versus that of patients who underwent surgery during the lockdown period. A total of 1151 patients were identified using electronic clinical records over two different time periods; 3 months pre Covid-19 lockdown (n=680) and 3 months during the Covid-19 lockdown (n=470). Patients were followed up for 1 year following their initial procedure. Primary outcome was readmission for SSI. Secondary outcomes were treatment received and requirement for further surgeries. The most commonly performed procedures were arthroplasty and manipulation under anaesthesia with 119 in lockdown vs 101 non-lockdown (p=0.001). The readmission rate was higher in the lockdown group with 61 (13%) vs 44 (6.5%) in the non-lockdown group (p <0.001). However, the majority were due to other surgical complications such as dislocations. Interestingly, the SSI rates were very similar with 24 (5%) in lockdown vs 28 (4%) in non-lockdown (p=0.472). Twenty patients (4.2%) required a secondary procedure for their SSI in the lockdown group vs 24 (3.5%) in non-lockdown (p=0.381). Mortality rate was similar at 44 (9.3%) in lockdown vs 61 (9.0%; p=0.836). Whilst Covid-19 precautions were associated with higher readmission rates, there was no significant difference in rate of SSI between the two groups

Introduction. Hip prosthetic joint infection (PJI) is a debilitating complication following joint replacement surgery, with significant impact on patients and healthcare systems. The INFection ORthopaedic Management: Evidence into Practice (INFORM: EP) study, builds upon the 6-year INFORM programme by developing evidence-based guidelines for the identification and management of hip PJI. Methods. A panel of 21 expert stakeholders collaborated to develop best practice guidelines based on evidence from the previous INFORM research programme. An expert consensus process was used to refine guidelines using RAND/UCLA criteria. The guidelines were then implemented over a 12-month period through a Learning Collaborative of 24 healthcare professionals from 12 orthopaedic centres in England. Qualitative interviews were conducted with 17 members of the collaborative and findings used to inform the development of an implementation support toolkit. Patient and public involvement contextualised the implementation of the guidelines. The study is registered with the ISCRTN (34710385). Result. The INFORM guidelines, structured around the stages of PJI management, were largely supported by surgeons, although barriers included limited awareness among non-surgical team members, lack of job planning for multidisciplinary teams, and challenges in ensuring timely referrals from primary care. Psychological support for patients was identified as a critical gap. Advanced Nurse Practitioners and multidisciplinary team (MDT) coordinators were seen as potential bridges to address these knowledge gaps. The guidelines were also viewed as a useful tool for service development. Conclusions. This study presents the first evidence-based guidelines for hip PJI management, offering a comprehensive approach to prevention, treatment, and postoperative care. Effective implementation is crucial, involving wider dissemination amongst primary and community care, as well as non-specialist treatment centres. Further resources are needed to ensure job planning for MDTs and psychological support for patients. Overall, this study lays the foundation for improved PJI management, benefiting patients and healthcare systems

The efficacy of saline irrigation for the treatment of periprosthetic infection (PJI) is limited in the presence of infected implants. This study evaluated the efficacy of vancomycin/tobramycin-doped polyvinyl alcohol (PVA)/ceramic composites (PVA-VAN/TOB-P) after saline irrigation in a mouse pouch infection model. 3D printed porous titanium (Ti) cylinders (400, 700 and 100 µm in pore size) were implanted into mice pouches, then inoculated with S. aureus at the amounts of 1X10. 3. CFU and 1X10. 6. CFU per pouch, respectively. Mice were randomized into 4 groups (n=6 for each group): (1) no bacteria; (2) bacteria without saline wash; 3) saline wash only, and (4) saline wash+PVA-VAN/TOB-P. After seven days, pouches were washed out alone or with additional injection of 0.2 ml of PVA-VAN/TOB-P. Mice were sacrificed 14 days after pouch wash. Bacteria cultures of collected Ti cylinders and washout fluid and histology of pouch tissues were performed. The low-grade infection (1X10. 3. CFU) was more significant in 400 µm Ti cylinders than that in Ti cylinders with larger pore sizes (700 and 1000 µm (p<0.05). A similar pattern of high-grade infection (1X10. 6. CFU) was observed (p<0.05). For the end wash, the bacteria burden (0.49±0.02) in saline wash group was completely eradicated by the addition of PVA-VAN/TOB-P (0.005±0.001, p<0.05). We noticed that 400 µm Ti cylinders have the highest risk of implant infection. Our data supported that the effect of saline irrigation was very limited in the presence of contaminated porous Ti cylinders. PVA-VAN/TOB-P was biodegradable, biocompatible, and was effective in eradicating bacteria retention after saline irrigation in a mouse model of low grade and high-grade infection. We believe that PVA-VAN/TOB-P represents an alternative to reduce the risk of PJI by providing a sustained local delivery of antibiotics

An international Consensus Group has by a Delphi approach identified the topic of host factors affecting pin site infection to be one of the top 10 priorities in external fixator management. The aim of this study was to report the frequency of studies reporting on specific host factors as a significant association with pin site infection. Host factors to be assessed was: age, smoking, BMI and any comorbidity, diabetes, in particular. The intention was an ethological review, data was extracted if feasible, however no meta-analysis was performed. A systematic literature search was performed according to the PRISMA-guidelines. The protocol was registered before data extraction in PROSPERO. The search string was based on the PICO criterias. A logic grid with key concept and index terms was made. A search string was built assisted by a librarian. The literature search was executed in three electronic bibliographic databases, including Embase MEDLINE (1111 hits) and CINAHL (2066 hits) via Ovid and Cochrane Library CENTRAL (387 hits). Inclusion criteria: external fixation, >1 pin site infection, host factor of interest, peer-reviewed journal. Exclusion criteria: Not written in English, German, Danish, Swedish, or Norwegian, animal or cadaveric studies, location on head, neck, spine, cranium or thorax, editorials or conference abstract. The screening process was done using Covidence. A total of 3564 titles found. 3162 excluded by title and abstract screening. 140 assessed for full text eligibility. 11 studies included for data extraction. The included studies all had a retrospective design. Three identified as case-control studies. Generally the included studies was assessed to have a high risk of bias. A significant associations between pin site infection for following host factors: a) increased HbA1C level in diabetic patients; b) congestive heart failure in diabetic patients; c) less co-morbidity; d) preoperative osteomyelitis was found individually. This systematic literature search identified a surprisingly low number of studies examining for risk of pin site infection and host factors. Thus, this review most of all serves to demonstrate a gap of evidence about correlation between host factors and risk of pin site infection, and further studies are warranted

Introduction and Objective. Digital infra-red thermography may have the capability of identifying local inflammations. Nevertheless, the role of thermography in diagnosing pin site infection has not been explored yet and the reliability and validity of this method for pin site surveillance is in question. The purpose of this study was to explore the capability and intra-rater reliability of thermography in detecting pin site infection. Materials and Methods. This explorative proof of concept study follows GRRAS -guidelines for reporting reliability and agreement studies. After clinical assessment of pin sites by one examiner using Modified Gordon Pin Infection Classification (Grade 0 – 6), thermographic images of the pin sites were captured with a FLIR C3 camera and analyzed by the FLIR tools software package. The maximum skin temperature around the pin site and the maximum temperature for the whole thermographic picture was measured. Intra-rater agreement was established and test-retests were performed with different camera angles. Results. Thirteen (4 females) patients (age 9–72 years) were included. Indications for frames: 4 fracture, 2 deformity correction, 1 lengthening, 6 bone transport. Days from surgery to thermography ranged from 27 to 385 days. Overall, 231 pin sites were included. Eleven pin sites were diagnosed with early signs of infection: five grade 1, five grade 2, one grade 3. Mean pin site temperature was 33.9 °C (29.0–35.4). With 34 °C as cut-off value for infection, sensitivity was 73%, specificity 67%, positive predictive value 10% and negative predictive value 98%. Intra-rater reliability for thermography was ICC 0.85 (0.77–0.92). The temperature measured was influenced by the camera postioning in relation to pin site with a variance of 0.2. Conclusions. Measurements of pin sites using the handheld FLIR C3 infrared camera was a reliable method and the temperature was related to infection grading. This study demonstrates that digital thermography with a handheld camera might be used for monitoring the pin sites after operations to detect early infection, however, future larger prospective studies are necessary