Complication Of Orthopedic Surgery Research Articles

Assessment of Bacteriophage Pharmacokinetic Parameters After Intra-Articular Delivery in a Rat Prosthetic Joint Infection Model.

Prosthetic joint infections (PJIs) are a serious complication of orthopedic surgery. Bacteriophage (phage) therapy shows promise as an adjunctive treatment but requires further study, particularly in its pharmacokinetics. Consequently, we performed a pharmacokinetic assessment of phage therapy for PJIs using a Staphylococcus epidermidis Kirschner wire-based prosthesis rat model. We used 52 male Sprague-Dawley rats in four groups: negative controls (no phage, sterile implant), PJI controls (bacteria, no phage), sterile phage (phages given, sterile implant), and PJI (bacteria, phages given). The PJI groups were inoculated with ~106 CFU of S. epidermidis. The groups receiving phage were intra-articularly injected with ~108 PFU of vB_SepM_Alex five days post-implantation. The rats were euthanized between 30 min and 48 h post-injection. The measured phage concentrations between the PJI rats and the sterile controls in periarticular tissues were not significantly different. In a noncompartmental pharmacokinetic analysis, the estimated phage half-lives were under 6 h (combined: 3.73 [IQR, 1.45, 10.07]). The maximum phage concentrations were reached within 2 h after administration (combined: 0.75 [0.50, 1.75]). The estimated phage mean residence time was approximately three hours (combined: 3.04 [1.44, 4.19]). Our study provides a preliminary set of pharmacokinetic parameters that can inform future phage dosing studies and animal models of phage therapy for PJIs.

Novel biocompatible magnetron-sputtered silver coating for enhanced antibacterial properties and osteogenesis in vitro

Peri-implant infection is a serious complication in orthopedic surgery. This study aimed to reduce the incidence of peri-implant infection by developing a durable and safe antibacterial silver coating. We compared the antibacterial properties and process controllability of various coating techniques to identify the most effective method for silver coating. We refined substrate treatment techniques and coating thicknesses through antibacterial and scratch tests. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to analyze the coating’s morphology and composition. Micron-sized magnetron sputtering silver coating samples underwent in vitro antibacterial testing, cytotoxicity testing, silver ion release testing, and osteogenic testing using membrane contact culture, CCK-8 assay, inductively coupled plasma (ICP) detection, and alkaline phosphatase (ALP) activity/osteogenic gene PCR. Magnetron sputtering demonstrated superior antibacterial properties, uniformity, and process controllability compared to alternative techniques. The optimal adhesion strength was achieved with a 0.5 μm coating thickness and a 400 mesh sandpaper pretreatment process, without compromising antibacterial efficacy. The coating showed near-perfect antiseptic results in antibacterial and anti-biofilm tests. Fibroblasts cultured in silver ion precipitation medium exhibited growth rates of 89% on day 30 and 88% on day 90, compared to 95% in the control group. The osteogenic test indicated that the magnetron sputtering silver coating promotes osteogenesis effectively. Our study demonstrated that micron-sized magnetron sputtering silver coating has potential for clinical use to prevent peri-implant infections in the future.

Regenerative Medicine in Orthopedic Surgery: Expanding Our Toolbox.

Regenerative medicine leverages the body's inherent regenerative capabilities to repair damaged tissues and address organ dysfunction. In orthopedics, this approach includes a variety of treatments collectively known as orthoregeneration, encompassing modalities such as prolotherapy, extracorporeal shockwave therapy, pulsed electromagnetic field therapy, therapeutic ultrasound, and photobiomodulation therapy, and orthobiologics like platelet-rich plasma and cell-based therapies. These minimally invasive techniques are becoming prominent due to their potential for fewer complications in orthopedic surgery. As regenerative medicine continues to advance, surgeons must stay informed about these developments. This paper highlights the current state of regenerative medicine in orthopedics and advocates for further clinical research to validate and expand these treatments to enhance patient outcomes.

Do preoperative glucose levels predict risk of complications in orthopaedic surgery?

Post-operative hyperglycemia is a known risk factor for post-surgical complications. The predictive value of pre-operative blood glucose levels, however, is less understood. This study aimed to determine if pre-operative screening blood glucose levels affect the rate of post-operative infection or wound complications. We also investigated if case urgency or anatomic location alters this relationship. A single-institution retrospective chart review was performed to evaluate patients treated between 2018 and 2021. Subjects ≥ 18years with closed, non-infected orthopaedic diagnoses requiring surgery were included. Case urgency, demographics, comorbidities, blood glucose level within twelve h prior to surgery, and hemoglobin A1c level within 3months of surgery, were collected. Infections and wound complications were recorded as outcomes. A total of 775 subjects with a mean age of 61 (range 18-96) were identified, including 543 elective and 232 trauma patients, with a mean pre-operative fasting glucose value of 127.7mg/dL (range, 49-388mg/dL) and average HbA1c of 6.9%. The odds of infectious complications were increased by a factor of 1.01 for every 1-point increase in blood glucose (95% CI 1.01-1.02; p < 0.01). Pre-operative blood glucose levels greater than 137mg/dL were associated with an increase in wound complications, but not deep infections. Infection rates stratified by anatomic site and case urgency were not impacted by pre-operative glucose levels. The increased risk of poor wound healing in patients with pre-operative hyperglycemia demonstrates that day of surgery point-of-care blood glucose screening can be a useful risk stratification tool.

Combating multidrug-resistant bacteria: Encapsulated gallic acid@capped titanium dioxide on graphene oxide/carboxymethylated chitosan

Periprosthetic joint infection (PJI) caused by methicillin-resistant Staphylococcus aureus (MRSA) is a significant complication in orthopedic surgery. Developing effective strategies to combat bacterial colonization and inhibit biofilm formation is crucial. This study focused on enhancing the antibacterial efficacy of titanium dioxide nanoparticles (TiO2 NPs) without relying on ultraviolet (UV) light activation, which has limitations in clinical applications. By encapsulating TiO2 NPs with gallic acid (GA@TiO2) and incorporating graphene oxide/carboxymethylated chitosan (GO/CMCh) to prevent aggregation, remarkable antibacterial activity against MRSA was observed. Surprisingly, even in the absence of UV irradiation, TiO2, GA@TiO2, and GA@TiO2/GO/CMCh exhibited substantial bactericidal effects, with inhibition zones of 14, 12, and 12 mm, respectively. Furthermore, these materials demonstrated enhanced antibiofilm formation. Importantly, they displayed favorable biocompatibility, supporting their potential for clinical applications in reducing the morbidity and mortality associated with MRSA-PJI. Our findings highlight the significant antibacterial properties of GA@TiO2/GO/CMCh as a promising strategy for combating MRSA, independent of UV light exposure, and emphasize the need for further in vivo investigations to assess its potential in addressing MRSA-PJI.

Modern Microbiological Methods to Detect Biofilm Formation in Orthopedy and Suggestions for Antibiotic Therapy, with Particular Emphasis on Prosthetic Joint Infection (PJI).

Biofilm formation is a serious problem that relatively often causes complications in orthopedic surgery. Biofilm-forming pathogens invade implanted foreign bodies and surrounding tissues. Such a condition, if not limited at the appropriate time, often requires reoperation. This can be partially prevented by selecting an appropriate prosthesis material that prevents the development of biofilm. There are many modern techniques available to detect the formed biofilm. By applying them we can identify and visualize biofilm-forming microorganisms. The most common etiological factors associated with biofilms in orthopedics are: Staphylococcus aureus, coagulase-negative Staphylococci (CoNS), and Enterococcus spp., whereas Gram-negative bacilli and Candida spp. also deserve attention. It seems crucial, for therapeutic success, to eradicate the microorganisms able to form biofilm after the implantation of endoprostheses. Planning the effective targeted antimicrobial treatment of postoperative infections requires accurate identification of the microorganism responsible for the complications of the procedure. The modern microbiological testing techniques described in this article show the diagnostic options that can be followed to enable the implementation of effective treatment.

NSQIP data collection up to 30 postoperative days is sufficient to capture some complications in orthopedic surgeries

PurposeThe primary aim of this study is to determine if the 30-day follow-up period used by the National Surgical Quality Improvement Program (NSIQP) is an appropriate timeframe to capture complications after orthopedic surgeries.MethodsThe 2019 NSQIP data were used. The independent variables were complication type. The dependent variable was days to complication. A Shapiro–Wilk test was used to determine if the data were normally distributed.Results271,397 orthopedic cases were included. Myocardial infarction, pneumonia, ventilator over 48 h, progressive renal insufficiency, acute renal failure, stroke, and cardiac arrest had positive skewness and positive kurtosis. Deep incisional surgical site infection (SSI), organ/space SSI, wound disruption, unplanned reoperation one, unplanned reoperation two, readmission two, and readmission three had negative kurtosis and negative skewness. Complications with positive kurtosis and positive skewness are more likely to be confined to the 30-day postoperative period, whereas complications with negative skewness and negative kurtosis may be underreported within the 30-day follow-up.ConclusionsThese findings are useful in their ability to inform future orthopedic research using NSQIP which continues to generate new data for surgeons to consider for their postoperative care and complication management.

Long stem revision versus short stem revision with plate osteosynthesis for Vancouver type B2 periprosthetic femoral fracture: a comparative study of eighty five cases

PurposePeriprosthetic femoral fractures (PPFs) around the hip are challenging complications in orthopaedic surgery, particularly Vancouver type B2 (VTB2) fractures. The surgical management of these fractures is crucial and depends on various factors. Cementless short taper stem with plate osteosynthesis is an alternative surgical technique. This study aims to compare the outcomes of this surgical technique with revision arthroplasty (RA) with long stem in the treatment of VTB2 PPFs.MethodsThis retrospective study was conducted in a single medical institute from February 2010 to May 2019. Patients who had received either total hip arthroplasty or bipolar hemiarthroplasty and subsequently developed a VTB2 PPF were included; patients who sustained intra-operative fractures or received a cemented stem previously were excluded from the analysis. The patients were divided into two groups: group I received RA with cementless long stem, while group II underwent RA with cementless short taper stem with plate osteosynthesis. Demographic data, radiographic and functional outcomes, and complications were analyzed between the two groups.ResultsA total of 85 patients diagnosed with VTB2 PPFs were included in the study. There were no significant differences between the two groups in terms of demographic data, including age, gender, mean follow-up times, estimated blood loss, and operative times. The radiographic results showed that there was no significant difference in the incidence of subsidence and implant stability between the two groups. However, group II tended to have less subsidence and periprosthetic osteolysis. Patients in group II had significantly better functional scores (mean Harris hip score: post-operative: 60.2 in group I and 66.7 in group ii; last follow-up: 77.4 in group 1 and 83.2 in group II (both p < 0.05)). There were no significant differences in the overall complication rate, including infection, dislocation, re-fracture, and revision surgery, between the two groups.ConclusionsBoth surgical techniques, cementless long stem and cementless short taper stem with plate osteosynthesis, are effective in the treatment of Vancouver B2 PPFs, with no significant differences in outcomes or complications. However, patients in cementless short taper stem with plate osteosynthesis had better functional scores at both post-operative and the last follow-up.

Debridement, Antibiotic Pearls, and Retention of the Implant (DAPRI) in the Treatment of Early Periprosthetic Knee Joint Infections: A Literature Review.

(1) Background: Periprosthetic joint infections (PJIs) are severe and frightening complications in orthopaedic surgery, and they are generally divided into three categories: early infections (those occurring within the first 4-6 weeks), delayed infections (those occurring between 3 and 24 months), and late infections (those occurring more than 2 years after surgery). PJI treatment comprises "debridement, antibiotics, and implant retention" (DAIR), single-stage revision, and double-stage revision. Nowadays, to improve the chances of retaining an infected implant and to improve the traditional DAIR method, a modified surgical technique has been developed, named DAPRI (debridement, antibiotic pearls, and retention of the implant). Our study aims to present an up-to-date concept evaluation of the DAPRI technique and its success rate. (2) Methods: Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards were followed, applying a protocol defined by the authors: a total of 765 articles were identified, and at the end of the screening process only 7 studies were included. (3) Results: Currently, the DAPRI procedure can be performed only on patients who have had PJI symptoms for less than 4 weeks, and in order to achieve the highest success rate, indications are quite strict: it is appropriate in patients with acute, superficial infections without sinus tract presence, and well-fixed implants with known sensitive bacteria. The DAPRI surgical method follows a step-by-step process consisting of a first phase of biofilm identification with intra-articular injection of methylene blue, followed by biofilm removal (thermic, mechanical, and chemical aggression), and a last step consisting of prevention of PJI recurrence by using calcium sulphate antibiotic-added beads. (4) Conclusions: The DAPRI approach improves the traditional DAIR technique. It is a correct treatment for acute and early haematogenous PJI, and improves the DAIR success rate.

Nanomaterials for Anti-Infection in Orthopedic Implants: A Review

Postoperative implant infection is a severe complication in orthopedic surgery, often leading to implant failure. Current treatment strategies mainly rely on systemic antibiotic therapies, despite contributing to increasing bacterial resistance. In recent years, nanomaterials have gained attention for their potential in anti-infection methods. They exhibit more substantial bactericidal effects and lower drug resistance than conventional antimicrobial agents. Nanomaterials also possess multiple bactericidal mechanisms, such as physico-mechanical interactions. Additionally, they can serve as carriers for localized antimicrobial delivery. This review explores recent applications of nanomaterials with different morphologies in post-orthopedic surgery infections and categorizes their bactericidal mechanisms.

[Artículo traducido] Utilidad del índice de fragilidad modificado de 5 items para predecir complicaciones y reoperaciones después de la cirugía percutánea de hallux valgus

IntroductionThe modified 5-item frailty index (mFI-5) has been recently proposed as a useful tool for predicting postoperative complications in orthopedic surgery. We aimed to analyze the utility of this score in predicting complications and reoperations after hallux valgus (HV) deformity surgery. Methods551 patients undergoing percutaneous HV corrective surgery were retrospectively reviewed. The mFI-5 was calculated based and patients were categorized in three groups: 1) non-frail: patients without any of the 5 comorbidities, 2) pre-frail: patients with one comorbidity and 3) frail: patients with two or more comorbidities. Complications and surgical reoperations were recorded. ResultsIn the study period 772 percutaneous surgeries were performed to correct HV deformity, 551 patients were included with a median age of 60 (IQR 48-70). Three hundred eighty-nine patients were non-frail (70.6%), 132 were pre-frail (23.9%) and 30 were frail (5.4%). 75 patients suffered complications (13.6%). Even though the rate of complications was higher in frailty patients (23.3%) compared with pre-frail (13.6%) and non frail (12.8%), no significant differences were observed among groups. 48 patients required reoperation (8.7%) but the rate of reoperations among frailty groups was not significantly different (P=.11). Frailty patients had worse AOFAS scores at final follow up (P=.011). ConclusionThe mFI-5 was not useful to predict postoperative complications and reoperations after hallux valgus corrective surgery. Therefore, other factors should be considered when analyzing the risk of complications after HV corrective surgery.

Nanoadjuvant-triggered STING activation evokes systemic immunotherapy for repetitive implant-related infections

Repetitive implant-related infections (IRIs) are devastating complications in orthopedic surgery, threatening implant survival and even the life of the host. Biofilms conceal bacterial-associated antigens (BAAs) and result in a "cold tumor"-like immune silent microenvironment, allowing the persistence of IRIs. To address this challenge, an iron-based covalent organic framed nanoadjuvant doped with curcumin and platinum (CFCP) was designed in the present study to achieve efficient treatment of IRIs by inducing a systemic immune response. Specifically, enhanced sonodynamic therapy (SDT) from CFCP combined with iron ion metabolic interference increased the release of bacterial-associated double-stranded DNA (dsDNA). Immunogenic dsDNA promoted dendritic cell (DC) maturation through activation of the stimulator of interferon gene (STING) and amplified the immune stimulation of neutrophils via interferon-β (IFN-β). At the same time, enhanced BAA presentation aroused humoral immunity in B and T cells, creating long-term resistance to repetitive infections. Encouragingly, CFCP served as neoadjuvant immunotherapy for sustained antibacterial protection on implants and was expected to guide clinical IRI treatment and relapse prevention.

Utility of the modified 5-item frail index to predict complications and reoperations after hallux valgus surgery

IntroductionThe modified 5-item frailty index (mFI-5) has been recently proposed as a useful tool for predicting postoperative complications in orthopedic surgery. We aimed to analyze the utility of this score in predicting complications and reoperations after hallux valgus (HV) deformity surgery. Methods551 patients undergoing percutaneous HV corrective surgery were retrospectively reviewed. The mFI-5 was calculated based and patients were categorized in three groups: (1) non-frail: patients without any of the 5 comorbidities, (2) pre-frail: patients with one comorbidity and (3) frail: patients with two or more comorbidities. Complications and surgical reoperations were recorded. ResultsIn the study period 772 percutaneous surgeries were performed to correct hallux valgus deformity, 551 patients were included with a median age of 60 (IQR 48–70). 389 patients were non-frail (70.6%), 132 were pre-frail (23.9%) and 30 were frail (5.4%). 75 patients suffered complications (13.6%). Even though the rate of complications was higher in frailty patients (23.3%) compared with pre-frail (13.6%) and non frail (12.8%), no significant differences were observed among groups. 48 patients required reoperation (8.7%) but the rate of reoperations among frailty groups was not significantly different (p=0.11). Frailty patients had worse AOFAS scores at final follow up (p=0.011). ConclusionThe mFI-5 was not useful to predict postoperative complications and reoperations after hallux valgus corrective surgery. Therefore, other factors should be considered when analyzing the risk of complications after HV corrective surgery.

Risk Factors Associated With Postoperative Cardiac Events Following Total Hip and Knee Arthroplasty

BackgroundThis study investigated the prevalence of adverse cardiac events following a total joint arthroplasty and subsequently analyzed risk factors that may increase the likelihood of these events. MethodsData for this study were extracted from a large national database. Chi-squared analyses and multivariate modelings were performed to determine the risk factors associated with 30-day perioperative troponin elevation, myocardial infarction (MI), and heart failure. We identified 80,544 total hip arthroplasty (THA) patients and 112,531 total knee arthroplasty (TKA) patients and analyzed the following cardiac risk factors: diabetes, renal insufficiency, prior MI, hypertension, and cerebrovascular disease. ResultsThere were 34% of THA patients and 52% of TKA patients who had at least one of the studied risk factors. At-risk THA patients had 2.2, 5.9, and 5.3 times the odds of troponin elevation, MI, and postoperative heart failure, respectively, within 1 month compared to the control group (P < .0001). The TKA group had 2.9, 5.3, and 5.9 times the odds of troponin elevation, MI, and postoperative heart failure within 1 month compared to the control group (P < .0001). For both procedures, prior MI had the highest odds of resulting in perioperative troponin elevation and MI. Renal insufficiency had the highest odds of resulting in perioperative heart failure. ConclusionsRisk stratification for postoperative complications in orthopedic surgery is important to minimize adverse outcomes. This study highlights the need for consideration of risk factors prior to joint arthroplasty surgery. Level of EvidenceLevel III, Prognostic.

Host bone microstructure for enhanced resistance to bacterial infections

Postoperative bacterial infection is a serious complication of orthopedic surgery. Not only infections that develop in the first few weeks after surgery but also late infections that develop years after surgery are serious problems. However, the relationship between host bone and infection activation has not yet been explored. Here, we report a novel association between host bone collagen/apatite microstructure and bacterial infection. The bone-mimetic-oriented micro-organized matrix structure was obtained by prolonged controlled cell alignment using a grooved-structured biomedical titanium alloy. Surprisingly, we have discovered that highly aligned osteoblasts have a potent inhibitory effect on Escherichia coli adhesion. Additionally, the oriented collagen/apatite micro-organization of the bone matrix showed excellent antibacterial resistance against Escherichia coli. The proposed mechanism for realizing the antimicrobial activity of the micro-organized bone matrix is by the controlled secretion of the antimicrobial peptides, including β-defensin 2 and β-defensin 3, from the highly aligned osteoblasts. Our findings contribute to the development of anti-infective strategies for orthopedic surgeries. The recovery of the intrinsically ordered bone matrix organization provides superior antibacterial resistance after surgery.

Anti-Staphylococcal Activity of Ligilactobacillus animalis SWLA-1 and Its Supernatant against Multidrug-Resistant Staphylococcus pseudintermedius in Novel Rat Model of Acute Osteomyelitis.

Osteomyelitis caused by staphylococcal infection is a serious complication of orthopedic surgery. Staphylococcus pseudintermedius is the main causative agent of osteomyelitis in veterinary medicine. Methicillin-resistant S. pseudintermedius (MRSP) has been reported in companion animals, especially dogs. Multidrug-resistant S. pseudintermedius is an emerging pathogen and has acquired antibiotic resistance against various commercial antimicrobial agents. New antimicrobial compounds are urgently needed to address antibiotic resistance, and the development of novel agents has become an international research hotspot in recent decades. Antimicrobial compounds derived from probiotics, such as bacteriocins, are promising alternatives to classical antibiotics. In this study, the antibacterial activities of Ligilactobacillus animalis SWLA-1 and its concentrated cell-free supernatant (CCFS) were evaluated in vitro and in vivo. The CCFS of this bacterium showed no toxicity against osteoblast and myoblast cells in vitro, while significantly inhibiting the multidrug-resistant S. pseudintermedius KUVM1701GC strain in a newly established rat model. The CCFS significantly inhibited multidrug-resistant staphylococci both in vitro and in vivo. This suggests that CCFS derived from L. animalis SWLA-1 has potential as an alternative to classic antibiotics for staphylococcal infections in dogs.

Staphylococcus aureus planktonic but not biofilm environment induces an IFN-β macrophage immune response via the STING/IRF3 pathway

ABSTRACT Chronic implant-related bone infections are a severe complication in orthopaedic surgery. Biofilm formation on the implant impairs the immune response, leading to bacterial persistence. In a previous study, we found that Staphylococcus aureus (SA) induced interferon regulatory factor 3 (IRF3) activation and Ifnb expression only in its planktonic form but not in the biofilm. The aim of this study was to clarify the role of the stimulator of interferon genes (STING) in this process. We treated RAW 264.7 macrophages with conditioned media (CM) generated from planktonic or biofilm cultured SA in combination with agonists or inhibitors of the cyclic GMP-AMP synthase (cGAS)/STING pathway. We further evaluated bacterial gene expression of planktonic and biofilm SA to identify potential mediators. STING inhibition resulted in the loss of IRF3 activation and Ifnb induction in SA planktonic CM, whereas STING activation induced an IRF3 dependent IFN-β response in SA biofilm CM. The expression levels of virulence-associated genes decreased during biofilm formation, but genes associated with cyclic dinucleotide (CDN) synthesis did not correlate with Ifnb induction. We further observed that cGAS contributed to Ifnb induction by SA planktonic CM, although cGAS activation was not sufficient to induce Ifnb expression in SA biofilm CM. Our data indicate that the different degrees of virulence associated with SA planktonic and biofilm environments result in an altered induction of the IRF3 mediated IFN-β response via the STING pathway. This finding suggests that the STING/IRF3/IFN-β axis is a potential candidate as an immunotherapeutic target for implant-related bone infections.

Comparative analysis of venous thromboembolic complications in diverse groups of orthopaedic patients.

Venous thromboembolism (VTE) is one of the most important and life-threatening complications in orthopaedic surgery. According to current scientific reports, there are several variables that can affect the severity of CVD, including the site of the pathology or the type of treatment implemented. The aim of the study was to analyze the risk of VTE depending on the location of the pathology, as well as to evaluate the impact of surgical treatment compared to conservative management. Analysis of laboratory results and clinical picture of 276 patients hospitalized for orthopaedic reasons, admitted between January 2008 - December 2019, with suspected pulmonary embolism (PE). Among patients diagnosed with PE, the most common location of the disease was in the lower limb 59/116 (50.9%), followed by the pelvis location - 22/116 (19.0%), the spine - 19/116 (16.4%), disseminated lesions in oncological patients - 12/116 (10.3%), and a group of pathologies in the upper limb - 4/116 (3.5%). Significant statistical differences were found between the incidence of PE and the diagnosis of pathology in the lower limb and the pelvis. In the group of patients, there was no statistically significant relationship between the incidence of PE associated with surgical treatment, compared to conservative management. The group with the highest risk of VTE were lower limb and pelvic pathologies. The results are largely consistent with numerous reports treating the risk of CVD among orthopaedic patient populations.

Hydrogel delivery of DNase I and liposomal vancomycin to eradicate fracture-related methicillin-resistant staphylococcus aureus infection and support osteoporotic fracture healing.

Fracture-related infection (FRI) is a devastating complication in orthopedic surgery. A recent study showed that FRI causes more severe infection and further delays healing in osteoporotic bone. Moreover, bacterial biofilm formed on implants cannot be eradicated by systemic antibiotics, warranting novel treatments.Here, we developed a DNase I and Vancomycin hydrogel delivery vehicle to eradicate Methicillin-resistant Staphylococcus aureus (MRSA) infection in vivo. Vancomycin was encapsulated in liposomes, and DNase I and Vancomycin/liposomal-Vancomycin was loaded on thermosensitive hydrogel. In vitro drug release test showed a burst release of DNase I (77.2%) within 72h and sustained release of Vancomycin (82.6%) up to day 14. The in vivo efficacy was evaluated in a clinically relevant ovariectomy (OVX) induced osteoporotic metaphyseal fracture model with MRSA infection, and a total of 120 Sprague Dawley rats were used. In the OVX with infection group, biofilm development caused a drastic inflammatory response, trabecular bone destruction, and non-union. In the DNase I and Vancomycin co-delivery hydrogel group (OVX-Inf-DVG), bacteria on bone and implant were eradicated. X-ray and micro-CT showed preservation of trabecular bone and bone union. HE staining showed the absence of inflammatory necrosis, and fracture healing was restored. The local elevation of TNF-α and IL-6 and increased number of osteoclasts were prevented in the OVX-Inf-DVG group. Our findings suggest that dual release of DNase I and Vancomycin initially followed by Vancomycin only later up to 14 days effectively eliminates MRSA infection, prevents biofilm development and provides a sterile environment to promote fracture healing in osteoporotic bone with FRI. STATEMENT OF SIGNIFICANCE: The biofilm on implants are difficult to eradicate, causing recurrent infection and non-union in fracture-related infection (FRI). Here we developed a hydrogel therapy with high in vivo efficacy to eliminate MRSA biofilm infection in a clinically-relevant FRI model in osteoporotic bone. By loading DNase I and vancomycin/liposomal-vancomycin on thermosensitive poly-(DL-lactic acidco-glycolic acid) (PLGA)-polyethylene glycol (PEG)-PLGA hydrogel, a dual release of DNase I and Vancomycin was achieved whilst preserving enzyme activity. In this model, the progressive development of infection caused a drastic inflammatory response, osteoclastogenesis, trabecular bone destruction, and non-union of fracture. These pathological changes were successfully prevented by the dual delivery of DNase I and vancomycin. Our findings provide a promising strategy for FRI in osteoporotic bone.

Are self-reported anthropometric data reliable enough to meet antibiotic prophylaxis guidelines in orthopedic surgery?

BackgroundSurgical site infection is a serious complication in orthopedic surgery. The use of antibiotic prophylaxis (AP) combined with other prevention strategies has been shown to reduce this risk to 1% for hip arthroplasty and 2% for knee arthroplasty. The French Society of Anesthesia and Intensive Care Medicine (SFAR) recommends doubling the dose when the patient's weight is greater than or equal to 100 kg, and the body mass index (BMI) is greater than or equal to 35 kg/m2. Similarly, patients with a BMIgreater than40 kg/m2 orlesser than18 kg/m2 are ineligible for surgery in our hospital. Self-reported anthropometric measurements are commonly used in clinical practice to calculate BMI, but their validity has not been assessed in the orthopedic literature. Therefore, we conducted a study comparing self-reported with systematically measured values and observed the impact these differences may have on perioperative AP regimens and contra-indications to surgery. HypothesisThe hypothesis of our study was that self-reported anthropometric values differed from those measured during preoperative orthopedic consultations. Materials and methodsThis single-center retrospective study with prospective data collection was conducted between October and November 2018. The patient-reported anthropometric data were first collected and then directly measured by an orthopedic nurse. Weight was measured with a precision of 500 g and height was measured with a precision of 1 cm. ResultsA total of 370 patients (259 women and 111 men) with a median age of 67 years (17–90) were enrolled. The data analysis found significant differences between the self-reported and measured height [166 cm (147–191) vs. 164 cm (141–191) (p<0.0001)], weight [72.9 kg (38–149) vs. 73.1 kg (36–140) (p<0.0005)] and BMI [26.3 (16.2–46.4) vs. 27 (16–48.2) (p<0.0001)]. Of these patients, 119 (32%) reported an accurate height, 137 (37%) an accurate weight, and 54 (15%) an accurate BMI. None of the patients had two accurate measurements. The maximum underestimation was 18 kg for weight, 9 cm for height, and 6.15 kg/m2 for BMI. The maximum overestimation was 28 kg for weight, 10 cm for height, and 7.2 kg/m2 for BMI. The verification of the anthropometric measurements identified another 17 patients who had contra-indications to surgery (12 with a BMI>40 kg/m2 and 5 with a BMI<18 kg/m2) and who would not have been detected based on the self-reported values. ConclusionsAlthough patients underestimated their weight and overestimated their height in our study, these had no impact on the perioperative AP regimens. However, this misreporting failed to detect potential contraindications to surgery. Level of evidenceIV; retrospective study with prospective data collection and no control group.