Aims. Although low-intensity pulsed ultrasound (LIPUS) combined with disinfectants has been shown to effectively eliminate portions of biofilm in vitro, its efficacy in vivo remains uncertain. Our objective was to assess the antibiofilm potential and safety of LIPUS combined with 0.35% povidone-iodine (PI) in a rat debridement, antibiotics, and implant retention (DAIR) model of periprosthetic joint infection (PJI). Methods. A total of 56 male Sprague-Dawley rats were established in acute PJI models by intra-articular injection of bacteria. The rats were divided into four groups: a Control group, a 0.35% PI group, a LIPUS and saline group, and a LIPUS and 0.35% PI group. All rats underwent DAIR, except for Control, which underwent a sham procedure. General status, serum biochemical markers, weightbearing analysis, radiographs, micro-CT analysis, scanning electron microscopy of the prostheses, microbiological analysis, macroscope, and histopathology evaluation were performed 14 days after DAIR. Results. The group with LIPUS and 0.35% PI exhibited decreased levels of serum biochemical markers, improved weightbearing scores, reduced reactive bone changes, absence of viable bacteria, and decreased inflammation compared to the Control group. Despite the greater antibiofilm activity observed in the PI group compared to the LIPUS and saline group, none of the monotherapies were successful in preventing reactive bone changes or eliminating the infection. Conclusion. In the rat model of PJI treated with DAIR, LIPUS combined with 0.35% PI demonstrated stronger antibiofilm potential than monotherapy, without impairing any local soft-tissue. Cite this article: Bone Joint Res 2024;13(7):332–341

Aim. To investigate the effect of intraoperative wound irrigation with povidone-iodine on surgical site infection. Methods. Data were collected prospectively for all cases of instrumented thoracic and lumbar spine surgery undertaken by the senior author (DB) from 01/10/2008 to 1/10/2010. Variables recorded included patient factors (age, co-morbidities, drug history) and operative factors (type of operation, duration of operation, elective/emergency, in hours/out of hours, consultant/junior, perioperative antibiotic administration). Routine povidone-iodine application commenced on 1/06/2009. Surgical site infection was defined as wound infection confirmed on wound swab or blood cultures. Comparison was made between patients receiving povidone-iodine intraoperative wound irrigation and those who did not using Fisher's exact test. Results. Data from 91 consecutive patients who had undergone instrumented thoracic or lumbar fusions under the care of the senior author were analysed. Mean age was 58.0±16.9 years. There was no difference in age (Mean±SD) between those receiving povidone-iodine (59.1 ±16.9y) and those without povidone-iodine administration (55.3 ±16.9) (p=0.33). The number of wound infections was significantly reduced from 19% (5/26) in those without povidone-iodine to 0% (0/65) in those with application of povidone-iodine (p=0.001, Fisher's exact). Conclusion. Intraoperative povidone-iodine irrigation appears to be an effective method of reducing SSIs in instrumented spinal fixation surgery

Purpose: Biomaterial-related infections continue to hamper the success of reconstructive and arthroplasty procedures in orthopaedic surgery. Staphylococci are the most common etiologic agents, with biofilm formation representing a major virulence factor. Environmental stress factors and sub-inhibitory concentration of some antibiotics have been identified to trigger staphylococcal biofilm formation through increased icaADBC expression. In staphylococci, production of polysaccharide intercellular adhesin (PIA) by the enzyme products of the icaADBC operon is the best understood mechanism of biofilm development, making the ica genes a potential target for biofilm inhibitors. Aims of the current study were. Determine the minimum inhibitory concentration (MIC) of Povidone-iodine. Investigate the effect of Povidone-iodine on icaADBC operon encoded staphylococcal biofilm formation. Investigate wether any observed changes on biofilm by Povidone-iodine is mediated through a change in icaADBC operon. Method: MIC of povidone – iodine for both reference strains and strains isolated from infected orthopaedic implants was determined. Biofilm assay was performed at different Povidone-iodine concentrations using 96-well polystyrene plates. Total RNA for cDNA synthesis was isolated from bacteria at different twofold dilutions of Povidone-iodine concentrations. Real time polymerase chain reaction was used to quantify effects of Povidone-iodine on gene expression pattern of the icaADBC operon using the constitutively expressed gyrB gene as internal control. Results: The MIC of povidone-iodine was 1.4% for all bacterial strains. Clinical in-use doses of povidone-iodine prevented biofilm formation. A step-wise reduction of biofilm was observed at increasing sub-inhibitory doses of povidone-iodine (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 povidone-iodine 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. These data reveal an additional therapeutic benefit of povidone-iodine and suggest that studies to evaluate the suitability of povidone-iodine as biomaterial coating agent to reduce device-related infection rates are merited

Aim. Polypropylene (PPE) synthetic mesh is increasingly used in knee arthroplasty surgery to salvage a disrupted extensor mechanism. Despite its clinical success, it is associated with a high rate of periprosthetic joint infection (PJI), which is hypothesized to be caused by bacterial biofilm. The purpose of the current study is to describe the progression of PPE-based biofilm formation over time and to determine if intraoperative antiseptic solutions could be used to effectively remove biofilm when treating PJI. Method. Commercially available knotted monofilament PPE mesh. 1. was cut into 10mm circular shape, immersed in tryptic soy broth (TSB) with methicillin-sensitive staphylococcus aureus and cultured individually in 48-well plates for 10 days to elucidate the biofilm grown on mesh over time. At every 24 hours, a triplicate of samples was retrieved and biofilm on the mesh was dislodged by sonicating at 52 kHz for 15 minutes and quantified by counting colony-forming units (CFUs) after overnight growth. The biofilm growth was also verified using scanning electron microscopy. The effect of saline and antiseptic solutions was verified by exposing 1) 0.05% chlorohexidine gluconate. 2. , 2) acetic acid-based mixture. 3. , 3) diluted povidone-iodine (0.35%), 4) undiluted povidone-iodine (10%). 4. , and 5) 1:1 combination of 10% povidone-iodine & 3% hydrogen peroxide on immature and mature biofilms for 3 minutes, created by culturing with bacteria for 24 hours and 72 hours respectively. All experiments were performed in quintuples and repeated. Antiseptic treatments that produced a three-log reduction in CFU counts compared to controls were considered clinically significant. Results. PPE-mesh produced reliable CFU counts at 24 hours and reached peak growth at 72 hours. For immature biofilm, all formulations of povidone-iodine produced significant reductions in CFU counts compared to controls. Although not meeting the established threshold, saline irrigation removed 86.5% of CFUs, while formulation based on chlorohexidine and acetic acid removed 99.2% and 99.7% respectively. For mature biofilm, formulations based on povidone-iodine and acetic acid produced significant reductions in CFU counts. Conclusions. Our findings suggest biofilm may form on mesh as early as 24 hours after bacterial exposure. Povidone-iodine formulations were consistently the most effective in removing biofilm on mesh surfaces. We recommend that surgeons consider using an antiseptic solution, preferably povidone-iodine-based, in addition to regular saline lavage when attempting to salvage a PPE mesh in the setting of PJI. 1. Marlex mesh (CR Bard, Davol Inc, Warwick, RI), . 2. Irrisept (Irrimax Corp, Gainesville, FL), . 3. Bactisure (Zimmer-Biomet, Warsaw, IN), . 4. Aplicare (Inc, Meriden, CT)

Aims. Periprosthetic joint infections (PJIs) are among the most devastating complications after joint arthroplasty. There is limited evidence on the efficacy of different antiseptic solutions on reducing biofilm burden. The purpose of the present study was to test the efficacy of different antiseptic solutions against clinically relevant microorganisms in biofilm. Methods. We conducted an in vitro study examining the efficacy of several antiseptic solutions against clinically relevant microorganisms. We tested antiseptic irrigants against nascent (four-hour) and mature (three-day) single-species biofilm created in vitro using a drip-flow reactor model. Results. With regard to irrigant efficacy against biofilms, Povidone-iodine treatment resulted in greater reductions in nascent MRSA biofilms (logarithmic reduction (LR) = 3.12; p < 0.001) compared to other solutions. Bactisure treatment had the greatest reduction of mature Pseudomonas aeruginosa biofilms (LR = 1.94; p = 0.032) and a larger reduction than Vashe or Irrisept for mature Staphylococcus epidermidis biofilms (LR = 2.12; p = 0.025). Pooled data for all biofilms tested resulted in Bactisure and Povidone-iodine with significantly greater reductions compared to Vashe, Prontosan, and Irrisept solutions (p < 0.001). Conclusion. Treatment failure in PJI is often due to failure to clear the biofilm; antiseptics are often used as an adjunct to biofilm clearance. We tested irrigants against clinically relevant microorganisms in biofilm in vitro and showed significant differences in efficacy among the different solutions. Further clinical outcome data is necessary to determine whether these solutions can impact PJI outcome in vivo. Cite this article: Bone Joint J 2021;103-B(5):908–915

Summary. A meta-analysis was performed to compare rate of SSI after application of chlorhexidine vs. iodine in total joint arthroplasty. Chlorhexidine had significantly lower odds of SSI. Introduction. Surgical site infections (SSI) are a significant source of morbidity and mortality. The optimal preoperative skin preparation in lower extremity total joint arthroplasty (TJA) remains debatable between chlorhexidine and iodine-containing solutions. This meta-analysis sought compare SSI rates between chlorhexidine cloth application the night before surgery plus povidone-iodine-alcohol (povidone-iodine) solution at surgery or only povidone-iodine at surgery. Methods. A structured literature search was performed using Web of Science, PubMed, and EMBASE databases for randomized clinical trials (RCTs) and comparative studies that evaluated preoperative chlorhexidine-gluconate versus iodine-alcohol exclusively in TJA patients. Databases were searched from database inception to January 2, 2018, and studies were included if they had specific aims and 1) compared preoperative chlorhexidine-gluconate cloths to povidone-iodine at surgery, or 2) if they compared preoperative chlorhexidine-gluconate cloths and povidone-iodine at surgery, to solely povidone-iodine at surgery. The main outcome was deep or superficial SSI at or before 1 year postoperatively. If multiple studies reported the same patient cohort, the more recent study was used. To compare the chlorhexidine versus povidone-iodine groups, pooled odds ratios (OR) and 95% confidence intervals (95% CI) were used to calculate odds of SSI. Results. Four studies involving 2,997 TJA patients were included in this meta-analysis. Three were retrospective cohort studies, and one was a RCT. One retrospective cohort study assessed chlorhexidine to povidone-iodine using a historical control. One RCT compared chlorhexidine to povidone-iodine. The remaining two studies compared chlorhexidine in addition to povidone-iodine, to only povidone-iodine. Bias analysis showed low-to-moderate quality cohort studies and one moderate-quality RCT. Chlorhexidine had significantly lower odds of SSI compared to povidone iodine (OR=0.28; 95%CI: 0.15–0.51; p<0.0001). Conclusion. Preoperative chlorhexidine-gluconate was superior at reducing SSI risk in patients who underwent lower extremity TJA, compared to povidone-iodine. This can potentially lead to decreased morbidity and lower surgical revision rates for infections. For any figures or tables, please contact authors directly

Aim. The efficacy of various irrigation solutions in removing microbial contamination of a surgical wound and reducing the rate of subsequent surgical site infection (SSI), has been demonstrated extensively. However, it is not known if irrigation solutions have any activity against established biofilm. This issue is pertinent as successful management of patients with periprosthetic joint infection (PJI) includes the ability to remove biofilm established on the surface of implants and necrotic tissues. The purpose of this study was to evaluate the efficacy of various irrigation solutions in eradicating established biofilm, as opposed to planktonic bacteria, in a validated in vitro model. Method. Established biofilms of Staphylococcus aureus and Escherichia coli were exposed to different irrigation solutions that included Polymyxin 500,000U/L plus bacitracin 50,000U/L, Vancomycin 1g/L, Gentamicin 80mg/L, Normal saline 0.9%, off-the-shelf Betadine 0.3%, Chlorhexidine 0.05%, Benzalkonium 1.3g/L, Sodium hypochlorite 0.125%, and Povidone-iodine 0.5%. Each experiment was conducted in a 96-well microtiter plate with a peg lid and standardized per the MBEC assay manufacturer's protocol. Following 2 minutes of solution exposure to the irrigation solution, residual biofilms were recovered by sonication. Outcome measures for antibiofilm efficacy were residual colony forming units (CFU) and optical density (690nm). Experiments were conducted in 24 replicates and the observations recorded by two blinded observers. Statistical analysis involved t-tests with Bonferonni adjustment. Results. Povidone-iodine 0.5%, Betadine 0.3%, Benzalkonium 1.3g/L, and Sodium hypochlorite 0.125% were significantly more efficacious against S.aureus biofilm versus all other solutions (p<0.001). Against E.coli biofilm, Povidone-iodine-0.5%, Benzalkonium-1.3g/L and Sodium hypochlorite-0.125% were also most effective compared to other irrigation solutions (p<0.001). Polymyxin-bacitracin, Gentamicin, Vancomycin, and Saline solutions had minimal activity against both E.coli and S.aureus biofilms (p<0.001). Similar trends were observed using both experimental endpoints (CFU and Turbidity) and both investigators (interrater reliability; r=0.99). Conclusion. This in vitro study observed that topical antibiotic solutions do not have any activity against established biofilms. Irrigations solutions containing adequate amount of povidone-iodine, betadine, sodium hypochlorite, and benzalkonium appear to have activity against established biofilm by gram positive and gram negative organisms. The use of these irrigation solutions may need to be considered in patients with established PJI

Aims. Despite recent literature questioning their use, vancomycin and clindamycin often substitute cefazolin as the preoperative antibiotic prophylaxis in primary total knee arthroplasty (TKA), especially in the setting of documented allergy to penicillin. Topical povidone-iodine lavage and vancomycin powder (VIP) are adjuncts that may further broaden antimicrobial coverage, and have shown some promise in recent investigations. The purpose of this study, therefore, is to compare the risk of acute periprosthetic joint infection (PJI) in primary TKA patients who received cefazolin and VIP to those who received a non-cephalosporin alternative and VIP. Methods. This was a retrospective cohort study of 11,550 primary TKAs performed at an orthopaedic hospital between 2013 and 2019. The primary outcome was PJI occurring within 90 days of surgery. Patients were stratified into two groups (cefazolin vs non-cephalosporin) based on their preoperative antibiotic. All patients also received the VIP protocol at wound closure. Bivariate and multiple logistic regression analyses were performed to control for potential confounders and identify the odds ratio of PJI. Results. In all, 10,484 knees (90.8%) received cefazolin, while 1,066 knees (9.2%) received a non-cephalosporin agent (either vancomycin or clindamycin) as preoperative prophylaxis. The rate of PJI in the cefazolin group (0.5%; 48/10,484) was significantly lower than the rate of PJI in the non-cephalosporin group (1.0%; 11/1,066) (p = 0.012). After controlling for confounding variables, the odds ratio (OR) of developing a PJI was increased in the non-cephalosporin cohort compared to the cefazolin cohort (OR 2.389; 1.2 to 4.6); p = 0.01). Conclusion. Despite the use of topical irrigant solutions and addition of local antimicrobial agents, the use of a non-cephalosporin perioperative antibiotic continues to be associated with a greater risk of TKA PJI compared to cefazolin. Strategies that increase the proportion of patients receiving cefazolin rather than non-cephalosporin alternatives must be emphasized. Cite this article: Bone Jt Open 2022;3(1):35–41

Introduction. The use of irrigation solution during surgical procedures is a common and effective practice in reduction of bioburden and the risk of subsequent infection. The optimal irrigation solution to accomplish this feat remains unknown. Many surgeons commonly add topical antibiotics to irrigation solutions assuming this has topical effect and eliminates bacteria. The latter reasoning has never been proven. In fact a few prior studies suggest addition of antibiotics to irrigation solution confers no added benefit. Furthermore, this practice adds to cost, has the potential for anaphylactic reactions, and may also contribute to the emergence of antimicrobial resistance. We therefore sought to compare the antimicrobial efficacy and cytotoxicity of irrigation solution containing polymyxin-bacitracin versus other commonly used irrigation solutions. Methods. Using two in vitro breakpoint assays of Staphylococcus aureus (ATCC#25923) and Escherichia coli (ATCC#25922), we examined the efficacy of a panel of irrigation solutions containing topical antibiotics (500,000U/L Polymyxin-Bacitracin 50,000U/L; Vancomycin 1g/L; Gentamicin 80mg/L), as well as commonly used irrigation solutions (Normal saline 0.9%; Povidone-iodine 0.3%; Chlorhexidine 0.05%; Castile soap 0.45%; and Sodium hypochlorite 0.125%) following 1 minute and 3 minutes of exposure. Surviving bacteria were counted in triplicate experiments. Failure to eradicate all bacteria was considered to be “not effective” for that respective solution and exposure time. Cytotoxicity analysis in human fibroblast, osteoblast, and chrondrocyte cells exposed to each of the respective irrigation solutions was performed by visualization of cell structure, lactate dehydrogenase (LDH) activity and evaluation of vital cells. Toxicity was quantified by determination of LDH release (ELISA % absorbance; with higher percentage considered a surrogate for cytotoxicity). Descriptive statistics were used to present means and standard deviation of triplicate experimental runs. Results. Polymyxin-Bacitracin, Saline and Castile soap irrigation at both exposure times were not effective at eradicating S aureus or E coli (Figure 1). In contrast, Povidone-iodine, Chlorhexidine, and Sodium hypochlorite irrigation were effective at eradicating both S aureus and E coli. Vancomycin irrigation was effective at S aureus eradication but not against E coli, whereas Gentamicin irrigation showed partial efficacy against E coli eradication but none against S aureus. The greatest cytotoxicity was seen with Chlorhexidine (49.4% ± 1.9). This was followed by Castile soap (33.2% ±3.9), Vancomycin (9.01% ±5.1), Polymyxin-Bacitracin (8.45% ±1.5), and Gentamicin irrigation (4.72% ±2.3) (Figure 2 and Figure 3 microscopy images). Povidone-iodine and Sodium hypochlorite showed least cytotoxicity (0.05% ±0.08 and 0.11%±0.19, respectively). Similar trends were seen at both exposure times and across fibroblasts, osteoblasts and chondrocytes. Discussion. This in vitro study suggests that addition of polymyxin-bacitracin to saline irrigation solution is a futile exercise. Taken within the context of its associated expense, risk of hypersensitivity and impact upon antimicrobial resistance, our findings bring its widespread clinical usage into question. Povidone-iodine may be a more effective option, with a more favorable cytotoxicity profile than the other commonly used irrigation solutions. Clinical outcomes should be studied to determine the most effective agent, concentration, and exposure time for intraoperative irrigation

Prosthetic joint infection (PJI) is a serious complication following joint replacement. Antiseptic solutions are often used for intraoperative wound irrigation particularly in cases of revision for PJI. Antiseptic irrigation is intended to eradicate residual bacteria which may be either free floating or in residual biofilm although there is no clear clinical efficacy for its use. Also, reviewing the scientific literature there is discordance in in vitro results where some studies questions antiseptic efficacy whilst others suggest that even at low concentration antiseptic agents are effective at eradicating bacterial biofilms. The aim of this in vitro study was to establish the efficacy of undiluted antiseptic agents at eradication of a typical PJI forming biofilm and determine the importance of an antiseptic neutralisation step in this assessment. Mature Staphylococcus epidermidis biofilms grown on TiAl6V4 discs were submerged in chlorohexidine (CHL) gluconate 4%, povidone-iodine (PI) 10% or phosphate-buffered saline (PBS) control solution. The discs were then rinsed, the biofilm bacteria suspended in solution using sonication and vortexing, and the viable count (CFU/ml) of the bacterial suspensions determined. The rinse/suspension solution was either (a) PBS or (b) Dey-Engley neutralization broth (NB). When PBS was used to rinse/suspend the biofilm a highly significant, 7.5 and 4.1, mean log reduction in biofilm vitality was observed from the control, for CHL 4% and PI 10%, respectively. However, when NB was the rinse/suspension solution the apparent antiseptic biofilm eradication efficacy was replaced with a statistically significant but clinically irrelevant less the one log-reduction in biofilm vitality. Clinical antiseptic agents are ineffective at eradicating S. epidermidis biofilm in an in vitro PJI model and absence of a neutralisation step gives the false impression of efficacy. Antiseptics alone are an ineffective treatment for biofilm related PJI and no substitute for meticulous debridement

Aim. Irrigation and debridement with an irrigation solution are essential components of the surgical management of acute and chronic periprosthetic joint infection (PJI). Nevertheless, there is a lack of agreement regarding the most effective solution to use. The aim of the study was to perform a systematic review and meta-analysis of the current literature concerning the efficacy of different irrigation solutions over bacterial biofilm. Method. This study was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis extension for Network meta-analysis (PRISMA-NMA) checklist for systematic reviews and meta-analyses. A comprehensive literature search of PubMed, Cochrane Library, Web of Science and Scopus databases from inception to September 1, 2023. We combined terms related to PJI, biofilm and irrigation solutions studied in vitro. We performed a network meta-analysis to analyze which irrigation solution achieved a higher reduction of colony forming units (CFU) after specific exposure times, always with a maximum of five minutes, replicating intraoperative conditions. Effect-size was summarized with logarithmic response ratio (logRR) and 95% confidence intervals (95% CI). The rank probability for each treatment was calculated using the p-scores. Results. We screened 233 potential sources. Following deduplication, screening and full-text review, four studies with ten irrigation solutions for different duration of exposures were included, always less than five minutes, replicating intraoperative conditions. Solutions were studied over mature biofilms of most frequent bacteria grown over metal, bone cement or polyethylene surfaces. The highest effect was achieved with povidone iodine 10% during 5 minutes (logRR: −12.02; 95% CI: −14.04, −9.99). The best ranked solutions were povidone iodine 10% during five, three and one minute (respective p-scores: 0.977, 0.932, 0.887) and its combination with hydrogen peroxide for 3 minutes (p-score: 0.836). Povidone iodine 0.3% acting for 5 minutes completed the top 5 best ranked solutions in this study (p-score: 0.761). We assumed that there were no inconsistencies in our network because after examining both scenarios, with and without inconsistencies, the results were not significantly different. Conclusions. Our results show that 10% povidone-iodine is the best antiseptic solution when studied in vitro in the context of prosthetic joint infection. However, the included studies did not evaluate the possible cytotoxic effects of these solutions. This should also be taken into account before choosing the most appropriate antiseptic solution

Periprosthetic joint infection (PJI) occurs in 0.2-2% of primary hip and knee arthroplasty and is a leading cause of revision surgery, impaired function, and increased morbidity and mortality. Topical, intrawound vancomycin administration allows for high local drug concentrations at the surgical site and has demonstrated good results in prevention of surgical site infection after spinal surgery. It is a promising treatment to prevent infection following hip and knee arthroplasty. Prior studies have been limited by small sample sizes and the low incidence of PJI. This systematic review and meta-analysis was performed to determine the effectiveness of topical vancomycin for the primary prevention of PJI in hip and knee arthroplasty. A search of Embase, MEDLINE, and PubMed databases as of June 2020 was performed according to PRISMA guidelines. Studies comparing topical vancomycin to standard perioperative intravenous antibiotics in primary THA and TKA with a minimum of three months follow-up were identified. The results from applicable studies were meta-analysed to determine the impact of topical vancomycin on PJI rates as well as wound-related and overall complications. Results were expressed as odds ratios (ORs) and 95% confidence intervals. Nine comparative observational studies were eligible for inclusion. 3371 patients treated with 0.5-2g of topical vancomycin were compared to 2884 patients treated with standard care. Only one of nine studies found a significantly lower rate of PJI after primary THA or TKA (OR 0.09-1.97, p=0.04 for one study, p>0.05 for eight of nine studies), though meta-analysis showed a significant benefit, with vancomycin lowering PJI rates from 1.6% in controls to 0.7% in the experimental group (OR 0.47, p=0.02, Figure 1). Individually, only one of five studies showed a significant benefit to topical vancomycin in THA, while none of seven studies investigating PJI after TKA showed a benefit to topical vancomycin. In meta-analysis of our subgroups, there was a significant reduction in PJI with vancomycin in THA (OR 0.34, p=0.04), but there was no significant difference in PJI after TKA (OR 0.60, p = 0.13). In six studies which reported complication rates other than PJI, there were no significant differences in overall complication rates with vancomycin administration for any study individually (OR 0.48-0.94, p>0.05 for all studies), but meta-analysis found a significant difference in complications, with a 6.7% overall complication rate in controls compared to 4.8% after topical vancomycin, largely driven by a lower PJI incidence (OR 0.76, p=0.04). Topical vancomycin is protective against PJI after hip and knee arthroplasty. No increase in wound-related or overall complication rates was found with topical vancomycin. This meta-analysis is the largest to date and includes multiple recent comparative studies while excluding other confounding interventions (such as povidone-iodine irrigation). However, included studies were predominantly retrospective and no randomized-controlled trials have been published. The limited evidence summarized here indicates topical vancomycin may be a promising modality to decrease PJI, but there is insufficient evidence to conclusively show a decrease in PJI or to demonstrate safety. A prospective, randomized-controlled trial is ongoing to better answer this question. For any figures or tables, please contact the authors directly

Aim: To assess the effectiveness of povidone-iodine alcoholic tincture and the alcoholic chlorhexidine gluconate solution in the eradication of bacteria in forefoot surgery, and to assess any added benefits with the use of surgical bristles. Methods: Fifty consecutive patients were prospectively enrolled into the study and randomised to receive one of two surgical skin preparations. Results: The use of povidone-iodine with prior surgical scrubbing had a better eradication rate compared to povidone-iodine alone in the interdigital web-spaces. Prior surgical scrubbing with both solutions had a better eradication rate for the skin over the 1st metatarso-phalangeal joints. But neither solution with or without the use of surgical scrubbing was superior at eradicating organisms from the medial hallucal fold. However none of these results were statistically significant. None of the patients developed any post-operative wound infection. Conclusions: Our results did not show any statistically significant advantage with either solution nor was there any apparent advantage with the use of the surgical scrub prior to the skin preparation. The authors believe that eradication of bacteria in forefoot surgery is dependant on a meticulous and methodical skin preparation technique and less so on the solution used and method of application

Aims. We studied the impact of direct anterior (DA) versus non-anterior (NA) surgical approaches on prosthetic joint infection (PJI), and examined the impact of new perioperative protocols on PJI rates following all surgical approaches at a single institution. Patients and Methods. A total of 6086 consecutive patients undergoing primary total hip arthroplasty (THA) at a single institution between 2013 and 2016 were retrospectively evaluated. Data obtained from electronic patient medical records included age, sex, body mass index (BMI), medical comorbidities, surgical approach, and presence of deep PJI. There were 3053 male patients (50.1%) and 3033 female patients (49.9%). The mean age and BMI of the entire cohort was 62.7 years (18 to 102, . sd. 12.3) and 28.8 kg/m. 2. (13.3 to 57.6, . sd. 6.1), respectively. Infection rates were calculated yearly for the DA and NA approach groups. Covariates were assessed and used in multivariate analysis to calculate adjusted odds ratios (ORs) for risk of development of PJI with DA compared with NA approaches. In order to determine the effect of adopting a set of infection prevention protocols on PJI, we calculated ORs for PJI comparing patients undergoing THA for two distinct time periods: 2013 to 2014 and 2015 to 2016. These periods corresponded to before and after we implemented a set of perioperative infection protocols. Results. There were 1985 patients in the DA group and 4101 patients in the NA group. The overall rate of PJI at our institution during the study period was 0.82% (50/6086) and decreased from 0.96% (12/1245) in 2013 to 0.53% (10/1870) in 2016. There were 24 deep PJIs in the DA group (1.22%) and 26 deep PJIs in the NA group (0.63%; p = 0.023). After multivariate analysis, the DA approach was 2.2 times more likely to result in PJI than the NA approach (OR 2.2 (95% confidence interval 1.1 to 3.9); p = 0.006) for the overall study period. Conclusion. We found a higher rate of PJI in DA versus NA approaches. Infection prevention protocols such as use of aspirin, dilute povidone-iodine lavage, vancomycin powder, and Gram-negative coverage may have been positively associated with diminished PJI rates observed for all approaches over time. Cite this article: Bone Joint J 2019;101-B(6 Supple B):2–8

We modelled a 'clean' surgical wound lightly contaminated with airborne bacteria, using agar, ovine muscle and ovine adipose tissue. This was used to assess the effect on bacteria of ultraviolet C light (UVC) 1200 mu W/cm2, hydrogen peroxide 3%, povidone-iodine 1% and 10%, chlorhexidine 0.05%, pulsed jet lavage with UVC and syringe and needle lavage with chlorhexidine 0.05%. All the agents were effective on agar, but mixing with blood or plasma neutralised hydrogen peroxide and povidone-iodine 1%. All the agents were less effective on tissue specimens than on agar, but were more effective on adipose tissue than on muscle. All the antiseptics except chlorhexidine were less effective when blood or plasma was added to muscle specimens before disinfection. UVC after pulsed jet lavage had an additive effect. Syringe and needle lavage with chlorhexidine 0.05% was the most effective method tested; it reduced colony counts by 99.8% and warrants clinical investigation

Aim. Periprosthetic joint infections (PJI) are increasing due to our elderly population with the need of a joint prosthesis. These infections are difficult to treat, because bacteria form biofilms within one day on the orthopedic implant surface. Notably, most of the current available antibiotics do not penetrate the biofilm or are not active against the sessile forms of bacteria. Therefore, prevention is key. In the current paradigm, bacteria from the skin surface or dermis - such as Staphylococcus aureus, coagulase-negative staphylococci, or Cutibacterium sp. – contaminate the periimplant tissue during surgery. Cutibacterium avidum, which has increasingly been reported in hip PJIs, colonizes the skin in the groin area in 32.3%. We were wondering if standard skin antisepsis before hip arthroplasty is effective to eliminate C. avidum colonization in the surgical field. Method. In a single-center, prospective study, we preoperatively screened all patients undergoing a hip arthroplasty through a direct anterior approach for different skin bacteria in the groin area. Only in patients colonized with C. avidum, we intraoperatively searched for persistent bacterial growth during and after triple skin antisepsis with povidone-iodine/alcohol. For that, we collected skin scrapings after first and third antisepsis and biopsies from the dermis at the surgical incision and evaluated bacterial growth and species. In addition, thin sections of the dermis biopsies were submitted to Fluorescence in situ Hybridization (FISH) using pan-bacteria probe EUB338. Results. From October 2018 until March 2019, 53 patients (47.2% female) were screened. Patients were mainly colonized with coagulase-negative staphylococci (41, 77.4%; 41), C. avidum (12, 22.6%), and Cutibacterium acnes (8, 15.1%). Intraoperative skin antisepsis of patients colonized with C. avidum was ineffective to eliminate any bacteria in 75% (5 out of 7) after the first and 28.6% (2 out of 7) after the third antisepsis. Focusing on C. avidum, antisepsis was ineffective in 43% (3 out of 7) and 14% (1 out of 7), respectively. Dermis biopsies were all culture negative, but FISH showed positive ribosome-rich bacteria in 50%. Conclusions. We show in our ongoing study that the commensal C. avidum resists the standard skin antisepsis and bacteria visually persist in the dermis as demonstrated by FISH technique. Standard skin antisepsis is of limited effectiveness, resulting in a risk for intraoperatively acquired PJIs. Thus, new and more effective techniques to improve skin antisepsis are urgently needed

We report a systematic review and meta-analysis of published randomised and quasi-randomised trials evaluating the efficacy of pre-operative skin antisepsis and cleansing techniques in reducing foot and ankle skin flora. The post-preparation culture number (Post-PCN) was the primary outcome. The data were evaluated using a modified version of the Cochrane Collaboration’s tool. We identified eight trials (560 participants, 716 feet) that met the inclusion criteria. There was a significant difference in the proportions of Post-PCN between hallux nailfold (HNF) and toe web spaces (TWS) sites: 0.47 vs 0.22, respectively (95% confidence interval (CI) 0.182937 to 0.304097; p < 0.0001). Meta-analyses showed that alcoholic chlorhexidine had better efficacy than alcoholic povidone-iodine (PI) at HNF sites (risk difference 0.19 (95% CI 0.08 to 0.30); p = 0.0005); a two-step intervention using PI scrub and paint (S& P) followed by alcohol showed significantly better efficacy over PI (S& P) alone at TWS sites (risk difference 0.13 (95% CI 0.02 to 0.24); p = 0.0169); and a two-step intervention using chlorhexidine scrub followed by alcohol showed significantly better efficacy over PI (S& P) alone at the combined (HNF with TWS) sites (risk difference 0.27 (95% CI 0.13 to 0.40); p < 0.0001). No significant difference was found between cleansing techniques. Cite this article: Bone Joint J 2013;95-B:498–503