Abstract. Introduction. Neck of femur (NOF) fracture patients are at risk of developing venous thromboembolisms (VTE). VTE risks could be reduced by adhering to the National Institute for Health and Care Excellence (NICE) recommendation for 1 month of prophylaxis with low molecular weight heparin. This audit aimed to assess and improve local compliance to national guidelines on VTE prophylaxis in NOF fracture patients following discharge. Methods. A retrospective consecutive case series of all NOF fractures treated at our institution from May – July 2021 was conducted. Those not eligible for outpatient VTE prophylaxis were excluded (anticoagulated for other indications, completed prophylactic course in hospital, inpatient death, pharmacological prophylaxis contraindicated). The agent and duration of VTE prophylaxis, and the occurrence of clinically significant VTE or bleeds were recorded. A re-audit was conducted in March 2022. Results. From May – July 2021, only 1/65 (1.5%) patient was discharged on a VTE prophylaxis regime consistent with NICE guidelines (1 enoxaparin, 56 rivaroxaban, 6 apixaban; 58 35-day course, 5 28-day course). A quick-guide document summarising the standard inpatient and outpatient VTE prophylaxis regimes for various orthopaedic indications was designed and widely disseminated. In March 2022, 30/34 (88.2%) patients were discharged with enoxaparin and 24/34 (70.6%) received a 28-day course. There were no cases of clinically significant VTE or bleeds in both cycles. Conclusion. Local compliance to national guidelines improved significantly with the implementation of a standardised VTE prophylaxis protocol. Our quick-guide document is a reproducible way of communicating consensus and ensuring consistency within a department

Aim. In 10% of the presumed aseptic hip or knee revisions, a low-grade infection is unexpectedly diagnosed based on the tissue samples taken during revision. Extended antimicrobial prophylaxis can possibly reduce the failure rate in cases of unexpected PJI, because the prophylaxis can be considered as early empiric treatment. In this randomized controlled study we analysed whether extended antimicrobial prophylaxis compared to a single dose is beneficial to improve the outcome of treatment in unexpected PJI in revision arthroplasty. Method. This study was nested in a randomized clinical trial comparing single-dose cefazolin with prolonged prophylaxis (15 doses of cefazolin over 5 days) for revision arthroplasty of the hip or knee. For this analysis, patients were included if an unsuspected PJI (defined as ≥2 positive intraoperative tissue samples with the same microorganism) was diagnosed. PJI treatment consisted of 12 weeks of a rifampicin-based regimen in Staphylococcal PJI, without removal of the prosthesis. We examined Infection characteristics and success of treatment after one year, defined as the absence of signs or treatment for PJI during follow-up. Results. After randomization of 662 patients, 68 unexpected PJI were diagnosed. In 5 cases no antimicrobial treatment was started. The success rate after one year follow-up for those who received PJI treatment was 96% (28/29) in the single dose group and 91% (31/34) in the extended prophylaxis group (p=1.00). The most frequently identified pathogens in unexpected PJI were Cutibacterium acnes (n=50) and Staphylococcus epidermidis (n=14). The causatives were susceptible for the cefazolin prophylaxis in 61 of the 63 cases. The interval between the stopped prophylaxis and the re-start of antimicrobial treatment was on average 10 days (SD 4) for the single dose and 5 days (SD 4) for the extended group. The mean duration of antimicrobial treatment was 83 days (SD 12) and did not differ between both groups (p=0.16). Conclusions. This is the first randomized controlled trial in which extended prophylaxis showed no benefit on the prosthesis survival for patients with an unexpected PJI after assumed aseptic revision of the hip or knee prosthesis. The results imply that extended prophylaxis should not be given as part of early empiric therapy

Despite the routine use of systemic antibiotic prophylaxis, postoperative infection following fracture surgery remains a persistent issue with substantial morbidity. The use of additional local antibiotic prophylaxis may have a protective effect and some orthopaedic surgeons have adopted their use in recent years, despite limited evidence of its beneficial effect. The purpose of this systematic review and meta-analysis was to evaluate the current literature regarding the effect of prophylactic local antibiotics on the rate of infection in fracture surgery in both open and closed fractures. A comprehensive search of Medline, EMBASE, and PubMed was performed. Cohort studies were eligible if they investigated the effect on infection rate of additional local antibiotic prophylaxis compared with systemic prophylaxis alone following fracture surgery. The data were pooled in a meta-analysis. In total, four randomized controlled trials and 11 retrospective cohort studies with a total of 6161 fractures from various anatomical locations were eligible for inclusion. The majority of the included studies were Level 3 evidence and had a moderate risk of bias. When all fractures were pooled, the risk of infection was significantly reduced when local antibiotics were applied compared with the control group receiving systemic prophylaxis only (OR = 0.39; 95%CI: 0.26 to 0.53, P < 0.001). In particular, there was a significant reduction in deep infections (OR = 0.59; 95%CI: 0.38 to 0.91, P = 0.017). The beneficial effect of local antibiotics for preventing total infection was seen in both open fractures (OR = 0.35; 95%CI: 0.23 to 0.53, P < 0.001) and closed fractures (OR = 0.58; 95%CI: 0.35 to 0.95, P = 0.029) when analyzed separately. This meta-analysis suggests a significant risk reduction for postoperative infection following fracture surgery when local antibiotics were added to standard systemic prophylaxis, with a protective effect present in both open and closed fractures

The incidence of PJI in knee replacements is 2.8% and slightly lower with hip replacement surgery. PJI make up 15% (or even more) of knee revisions. To combat PJI, antibiotic laden bone cement has been used for many decades, but antibiotic stewardship dictates more prudent management of antimicrobials. Projected increase in infection rate, due to increased surgery and latent infection to be almost 5-fold up to 2035. Biofilm is a complex structure of bacteria and polysaccharide matrix and, is recognised as a major component in PJI and other orthopaedic infections. Biofilm is responsible for high incidence of resistance to antimicrobials and ineffective host immune response. Method. Stabilized hypochlorous acid has been reported to have a rapid kill rate on all pathogens, including MDR pathogens associated with chronic and acute wound infections. It destroys biofilm on contact, is not cytotoxic, reduces inflammation and stimulates wound healing. 0,038% of Hypochlorous acid was used as prophylaxis against infection and to treat PJI. We report on our experience with hypochlorous acid as a wound irrigation as prophylaxis against infection (more than 600 cases) and for PJI. We also report on a University study where a head to head analysis was done on the anti-biofilm efficacy between hypochlorous acid 0,038% (Trifectiv Surgical Wound Irrigation) and Product X (an industry-standard product for the prevention and treatment of biofilm infection. Hypochlorous acid offers a valuable addition to the armamentarium of wound antiseptics, with added anti-inflammatory value. An in vitro study demonstrated superior efficacy against biofilm when compared to Product X

Aim. Periprosthetic joint infection (PJI) is a severe complication after total joint arthroplasty. To prevent PJI, strict infection prevention measures are followed in combination with surgical antibiotic prophylaxis (SAP). To date, scientific reports concerning the optimal duration of SAP in revision arthroplasty are scarce. The aim of this multicenter open-label, randomized controlled trial in the Netherlands, is to investigate the superiority of 5 days (extended) versus a single dose of cefazolin to prevent PJI within the first year after revision arthroplasty of the hip and knee. Method. Included patients with an assumed aseptic hip or knee revision procedure received a single dose of 2 or 3 gram cefazolin preoperatively. Patients were randomly assigned in a 1:1 ratio to receive extended prophylaxis of cefazolin during 5 days postoperatively versus no prophylaxis after wound closure. Patients were excluded if evidence of PJI at revision. The primary endpoint was the incidence of PJI within one year after revision arthroplasty. PJI was defined according to the 2018 Philadelphia consensus criteria. With a sample size of 746 patients, an alpha of 5% and a power of 80%, superiority of the extended regimen would be shown if the lower boundary of the 95% confidence interval (CI) of the absolute between-group difference of the percentage of PJI is below −4%. Results. In total 751 patients were included for analysis: 379 in the single dose cefazolin group and 372 in the extended group. Within one year, PJI occurred in 2.6% (10/379) in the single dose group and 2.4% (9/372) in the extended group (risk difference, −0.2 percentage points; 95% CI, −2.5 to 2.0%), thus superiority was not shown. Adverse drug events were seen in 20 cases with extended and 7 cases with a single dose prophylaxis. Conclusions. Extended prophylaxis is not significantly superior to a single dose of cefazolin to prevent PJI within the first year after revision arthroplasty of the hip or knee. This is the first randomized controlled trail in which the duration of SAP in the selected group of patients undergoing revision arthroplasty was studied. Extending SAP after closure of the wound could increase the selection or induction of antimicrobial resistance, has an increased risk for adverse drug events, and is therefore not in line with the primary goal of antimicrobial stewardship, comprising optimizing clinical outcomes and ensuring cost-effective therapy while minimizing unintended consequences of antimicrobial use

Gram-negative organisms are increasingly seen as causative pathogens in orthopaedic fracture surgery, which might necessitate a change in antibiotic prophylaxis protocols. A single-centre retrospective review of antibiogram results from all patients treated for fracture-related infection (FRI) was conducted. Subgroup analysis was undertaken to identify any host, injury or treatment variables predisposed to Gram-negative infection. The bacteriological results of 267 patients who underwent surgical treatment for FRI were analysed. Pathogens were isolated in 216 cases (81%), of which 118 (55%) were Gram-negative infections. Fractures involving the tibia and femur (p=0.007), the presence of soft tissue defect (p=0.003) and bone defects (p=0.001) were associated with an increased risk of developing a Gram- negative FRI. Gram-negative fracture-related infections were associated with injuries experiencing bone loss and those requiring soft tissue reconstruction. It is, therefore, prudent to consider extended Gram-negative directed antimicrobial prophylaxis in these cases to prevent the development of fracture-related infection

Thromboembolic disease (TED) remains as a major concern for orthopaedic surgeons and is a well-known complication of lower extremity joint replacement procedures. While there is voluminous literature on the topic, it is difficult for the average orthopaedic surgeon to keep up with all the advancements in this area as well as the newer pharmacological options for prophylaxis. To address this, the American Academy of Orthopaedic Surgeons (AAOS) has developed a clinical practice guideline (CPG) in this area to provide treatment recommendations based on the best available evidence. Historically, guidelines for TED prophylaxis have been based largely on randomised controlled trials whose outcome measure was venographically documented deep vein thrombosis (DVT). However, many venographically documented DVTs, particularly those distal to the popliteal vein, are of no clinical consequence. Therefore, in the AAOS CPG the systematic review of the literature was focused on those outcomes that have the most clinical relevance: all-cause mortality, symptomatic or fatal pulmonary embolism (PE), proximal DVT, major bleeding and symptomatic DVT rates. Using these as the clinically important endpoints, it is evident that the extant literature is insufficient to provide definitive guidance in this area and to make specific recommendations about optimal pharmacological prophylaxis. Nonetheless, one strong recommendation has emerged from this systematic review: the guideline recommended against routine post-operative duplex ultrasonography screening of patients who undergo elective hip or knee arthroplasty. Only one risk factor – previous history of TED – had evidence demonstrating a higher risk beyond the risk from elective hip or knee arthroplasty itself (weak recommendation). There was not sufficient evidence that other potential risk factors increase the risk of TED, likely because of the relatively high background risk of elective hip or knee arthroplasty. In addition, there is very little evidence defining populations at increased risk for bleeding and bleeding-associated complications associated with pharmacological prophylaxis. However, the panel did come to a consensus that patients with known bleeding disorders or active liver disease are at an increased risk for post-operative bleeding. In these circumstances, it is recommended that mechanical compressive devices be the primary modality of prophylaxis as pharmacologic prophylaxis may increase the risk of bleeding. There was a moderate strength recommendation for the superiority of neuraxial anesthesia to limit blood loss even though there is no demonstrable effect on the incidence of TED. Finally, there was a moderate grade recommendation that pharmacologic agents (including aspirin) and/or mechanical compression devices be utilised for the prevention of VTE in patients that are undergoing elective hip or knee arthroplasty who are not at elevated risk beyond that of the surgery itself for VTE or bleeding. Clearly there is great need for better evidence with appropriately powered studies that examine the most clinically relevant outcomes in TED prophylaxis

Aim. The aim of the present work was (i) to survey the situation of healthcare regarding the use of antibiotics in orthopaedics and trauma surgery in Germany, (ii) to determine which empiric antibiotic regimens are preferred in the treatment of periprosthethic joint infections (PJI) and (iii) to evaluate the hypothetical antibiotic adequacy of the applied empirical antibiotic therapy regimens based on a patient collective of a German university hospital. Method. A survey on empirical and prophylactic antibiotic therapy was conducted at German university and occupational health clinics (BG clinics), each in the specialties of orthopedics and trauma surgery. A total of 71 clinics were contacted by email. The questionnaire sent included open-ended questions on systemic antibiotic prophylaxis in primary hip arthroplasty; a distinction was made between hip arthroplasty due to femoral fractures and elective hip arthroplasty. In addition, the empirical antibiotic therapy used in PJIs was surveyed. To determine the success rate of prophylaxis and therapy according to sensitivity to the antibiotics applied, the survey results were compared with previously published data on antimicrobial treatment in n=81 PJI patients treated in our department between 2017 and 2020. Results. In 93.2% (elective) and 88.6% (fracture care) of the hospitals, 1st- and 2nd-generation cephalosporins are administered perioperatively for infection prophylaxis in primary hip arthroplasty. In contrast, empiric antibiotic treatment for PJI showed a clearly inhomogeneous therapeutic picture. Monotherapy with an aminopenicillin/betalactamase inhibitor is most frequently used (38.7%); 1st- and 2nd-generation cephalosporins are second most frequently used as monotherapy (18.2%). In addition, dual combination therapies have become established, mostly aminopenicillin/betalactamase inhibitor or 1st- and 2nd-generation cephalosporins, whose administration is supplemented with another antibiotic. The most common combination in PJI is aminopenicillin/betalactamase inhibitor + vancomycin (11.4%). The most widely used therapy (monotherapy with aminopenicillin/betalactamase inhibitor) would have covered 69.0% of PJI patients. Monotherapy with 1st- and 2nd-generation cephalosporins would have been susceptible to 57.8% of PJI patients. In contrast, a combination of vancomycin + 1st- and 2nd-generation cephalosporins would have been most effective, with an efficacy of 91.5% according to the resistograms, but this was used by only two hospitals. Conclusions. Empirical antibiotic therapy for the treatment of PJI is applied in more than half of the clinics with a single broad-spectrum beta-lactamase inhibitor antibiotic. This discrepancy between the everyday care in the clinics and the administration of clearly more effective combination therapies underlines the need for recommendation guidelines

The selection of a prophylaxis agent is a balance between efficacy and safety. Total knee arthroplasty patients receive DVT prophylaxis because orthopaedic surgeons are concerned about the morbidity and mortality associated with pulmonary embolism. However, at the same time there is great concern about excessive bleeding. The goal is to provide the appropriate anticoagulation to prevent symptomatic pulmonary embolism (PE) and DVT but at the same time avoid over anticoagulation which can be associated with bleeding and other wound problems. Therefore, risk stratification is necessary. Although risk stratification is the ideal way to determine the appropriate prophylaxis agent to use for a specific patient, there is no validated risk stratification strategy available today. There is general agreement at this time that patients who have had a prior PE or symptomatic DVT are at higher risk for development of a pulmonary embolism. In addition, there is a general belief that patients who have coagulation abnormalities (i.e. Factor V Leiden, Protein C and S deficiency) have an increased risk of developing a pulmonary embolism. Other factors that have been mentioned as associated with PE after total hip arthroplasty include age, female gender, and higher body mass index. The selection of a prophylaxis regimen should be influenced by the ability to mobilise the patient after surgery

Aim. Deep infection following endoprosthetic replacement (EPR) of long bones is a devastating complication occurring in 15% of musculoskeletal tumour patients. The recently published PARITY Trial demonstrated that extending antibiotic prophylaxis from 24 hours to 5 days does not reduce infection rates. However, questions remain about the optimal antibiotic choice and dose. Method. A 23-question multiple-choice questionnaire was designed and piloted through an iterative feedback process until the final version was agreed by all authors. Open and closed-ended questions were used to gather information on practice and Likert-type scale responses were used to grade responses to ascertain surgeon perceptions and preferences. The online survey was sent to all surgeon delegates of the 34th Annual Meeting of the European Musculo-Skeletal Oncology Society in London in October 2022. Results. Amongst 61 respondents, 43 were based in Europe and 18 outside of Europe. The majority (48/61) had been in clinical practice over 11 years. Antibiotic choice. 1st or 2nd generation cephalosporins were the first line choice practiced among 49 (80.3%) of respondents. Of these, 39 responded had a 2nd line protocol for beta-lactam allergy which was most commonly clindamycin (18), vancomycin (11) or a combination of a glycopeptide or clindamycin plus gentamicin (4). Respondents changed their first line regimen for radiotherapy in 6/61, chemotherapy in 8/61 and tumour site in 20/61. Re-dosing. Intraoperative re-dosing intervals of 1st and 2nd generation cephalosporins ranged from 2 to 8 hourly. Re-dosing for blood loss ranged from never to when 2 litres was lost. Of the 47 respondents, 24 said intraoperative re-dosing is always reliably administered. Duration. Six (10%) of 61 respondent routinely cover the intraoperative period only, whereas 30 (49%) give 24 hours, 16 (give 48 hours or longer and 8 continue until surgical drains are removed. 31 of 61 change duration depending on clinical situation. The most common reasons for changing were patient risk factors, soft tissue status and previous radiotherapy. 57/61 surgeons were aware of the PARITY Trial. When these respondents were asked whether they had changed practice based on PARITY, 12 said yes, 24 said no and 21 said they always give 24 hours anyway. Conclusions. Amongst an international cohort of orthopaedic oncology surgeons there was a wide variation in practice. Further research should focus on the optimum choice and re-dosing strategy, which have not been defined

Aim. Megaprosthesis have become a standard option in limb preserving surgery after bone resection in musculoskeletal tumors. Recently they have also been used in complex revision arthroplasty in cases with massive bone loss. The aim of this study was to analyze the incidence of periprosthetic joint infection (PJI) both in primary oncology cases and aseptic revision cases and analyze which are the significant risk factors for PJI with a special interest on the use of prophylactic antibiotic loaded calcium sulfate beads. Method. All patients undergoing surgery with the use of megaprosthesis in our institution between January/2012 and December/2022 were retrospectively reviewed. Data was collected from electronic medical records. We identified 108 procedures involving megaprosthesis in 90 patients with an average follow-up of 37 months. Indications were 79 primary musculoskeletal tumors and 29 aseptic complex revision arthroplasty. Results. Table 1 shows relevant clinical information. No significant risk factor was found either in uni or multivariate analysis. PJI rate was 15% (12/79) for primary musculoskeletal surgery and 31% (9/29) for complex revision surgery. The use of antibiotic loaded calcium sulfate beads did not show an advantage – 22% (9/41) with vs. 18% (12/67) without. Conclusions. In this relatively small series it was not possible to show a significal association between PJI and certain known risk factors such as gender, ASA score, site of surgery (knee) and revision surgery. The use of antibiotic loaded calcium sulfate beads as prophylaxis was not beneficial in reducing PJI rates in our cohort. We acknowledge the limitations of our study: a small sample group, in a single institution with heterogeneity in terms of diagnosis and surgical site. We recognize the need for a multicentric study with a larger cohort to validate these findings. For any tables or figures, please contact the authors directly

The selection of venous thromboembolism (VTE) prophylaxis after total joint arthroplasty (TJA) has been controversial. Although the aspirin controversy is presumably resolved, there is no medical evidence for the “optimal” VTE prophylaxis regime for individual patients. A risk-stratified multi-modal VTE prophylaxis protocol was developed and adopted by consensus. VTE risk factors and bleeding risk factors were categorised into six VTE/bleeding risk levels: (1) pre-operative vitamin K antagonists (VKA) use, (2) bleeding risk factors, (3) hypercoagulable state, (4) pre-operative anti-platelet therapy [clopidogrel use], (5) VTE risk factors, (6) no VTE or bleeding risk factors. The pharmacologic agents used for each risk level were: (1) resume VKA with low molecular weight heparin (LMWH) bridge, (2) pharmacologic agents contra-indicated and mechanical prophylaxis only, (3) VKA for 90 days with LMWH bridge, (4) resume anti-platelet therapy, (5) LMWH in hospital and discharge on aspirin for 90 days, (6) aspirin for 90 days (starting in hospital). In addition to pharmacologic treatment, all patients received multi-modal prophylaxis including early mobilisation, mechanical foot pumps, and neuraxial anesthesia when not contra-indicated. Prior to surgery, a VTE/bleeding risk factor checklist was completed determining the risk level. The intervention cohort included all TJA patients from January 1, 2010 to December 31, 2012. The comparison cohort included all TJA patients from the year prior to implementation of the protocol at the same community hospital. Thirty day all-cause non-elective re-admissions, 30 day same-site re-operations, 90 day VTE events, and protocol compliance were abstracted from the electronic medical record. The intervention group consisted of 2679 patients (1075 hip arthroplasty patients and 1604 knee arthroplasty patients). The comparison group consisted of 1118 patients (323 hip arthroplasty patients and 795 knee arthroplasty patients). The 30 day all cause non-elective re-admission rate was 2.72% (73/2679) in the intervention group and 4.29% (48/1118) in the comparison group (p=0.0148). The 30 day same-site re-operation rate was 1.38% (37/2679) in the intervention group and 1.25% (14/1118) in the comparison group (p=0.8773). The 90 day VTE event rate was 1.57% (42/2679) in the intervention group and 3.40% (38/1118) in the comparison group (p=0.0007). The VTE rate was higher for knee arthroplasty patients 2.00% (32/1604) than for hip arthroplasty patients 0.93% (10/1075) (p=0.0379). The rate of VTE events was higher for patients that deviated from the VTE protocol 5.03% (10/199) than for all risk groups treated per the protocol 1.29% (32/2481) (p=0.0007). The risk-stratified multi-modal VTE prophylaxis protocol simultaneously reduced 30 day all-cause non-elective re-admissions and 90 day VTE events. The possible causes for reducing 30 day re-admissions and reducing 90 day VTE events are: (1) reducing bleeding events by using aspirin for VTE prophylaxis in more than 80% of patients, (2) extending VTE prophylaxis to 90 days, and (3) using multi-modal prophylaxis. The risk-stratified multi-modal VTE prophylaxis protocol for total joint arthroplasty is consistent with 9 of the 10 recommendations in the AAOS Clinical Practice Guideline. The risk-stratification checklist provides a standardised tool to assess risks, discuss risks, and make shared decision with patients. Patient treatment that deviated from the protocol had a significantly higher VTE rate (5.03%). Protocol compliance increased each year from 91.1% in 2010 to 94.2% in 2012

Aim. Alongside debridement and irrigation, soft tissue coverage and osseous stabilization, systemic antibiotic prophylaxis is considered the gold standard in the management of open fractures and considerably reduces the risk of subsequent fracture-related Infections (FRI). The direct application of antibiotics into the surgical field (local antibiotics) has been used for decades as additional prophylaxis in open fractures, although definitive evidence confirming a beneficial effect is scarce. The purpose of the present study was to review the clinical evidence regarding the effect of prophylactic application of local antibiotics in open limb fractures. Method. A comprehensive literature search was performed in PubMed, Web-of- Science and Embase. Cohort studies investigating the effect of additional local antibiotic prophylaxis compared to systemic prophylaxis alone in the management of open fractures were included and the data were pooled in a meta-analysis. Results. Eight studies, with a total of 2738 patients were eligible for quantitative synthesis. Six of these studies investigated the effect of antibiotic loaded PMMA beads and two studies evaluated the effect of local antibiotics applied without a carrier. Meta-analysis showed a significantly lower infection rate when local antibiotics were applied (4.7%;94/1996) than in the control group receiving standard systemic prophylaxis alone (16.2%;129/797) (p-value < 0.001) (OR 0.30; 95%CI 0.22–0.40). Conclusions. This meta-analysis suggests a clear risk reduction in FRI if additional local antibiotics are given prophylactically for open limb fractures. However, due to limited quality, heterogeneity and considerable risk of bias, the pooling of data from primary studies has to be interpreted with caution

Venous thromboembolic events (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), remain one of the most common complications following total joint arthroplasty. Reported rates of symptomatic VTE following THA and TKA range from 0.83% to 15% and 2% to 10%, respectively. Thus, VTE prophylaxis should be routinely administered following total joint arthroplasty. However, while orthopaedic surgeons have considerable flexibility regarding their VTE prophylaxis regimen, it remains unclear which is optimal. Patients at low risk of VTE may receive excessive anticoagulation and unnecessarily risk further perioperative morbidity (wound complications, bleeding) following total joint arthroplasty. With an evolving health care landscape, emphasis on complications and readmissions, and shorter inpatient hospitalizations, it is imperative that a VTE prophylaxis regimen is simple, effective, easy to monitor, and has high patient compliance. Mobile pneumatic compression devices (MCDs) have been used with greater frequency following total joint arthroplasty, with multiple reports demonstrating their effectiveness in VTE prevention with or without the addition of aspirin for chemical prophylaxis. The use of MCDs allows the avoidance of more aggressive anticoagulation in the majority of patients undergoing total joint arthroplasty, decreases the incidence of wound complications, and achieves a low overall incidence of symptomatic VTE. Future investigations are necessary to determine the necessity and impact of the addition of aspirin to the use of MCDs for VTE prophylaxis

Purpose. Antibiotic prophylaxis plays an important role in minimizing surgical site infections as well as other nosocomial peri-operative infections in orthopaedic trauma patients. Pre-operative prophylaxis has been shown to be efficacious, but the role and duration of post-operative prophylaxis remains controversial. The goal of this study was to assess whether patients receive their antibiotic prophylaxis as prescribed. What dose and duration of antibiotics are typically ordered, what patients actually receive, and factors causing the ordered antibiotic regime to be altered were also investigated. This study did not investigate infection rates or the efficacy of various antibiotic prophylactic regimes. Method. This study presents data collected through a retrospective chart review of 205 patients treated surgically for a closed fracture at one institution. A national survey was also distributed to all surgeon members of the Canadian Orthopaedic Trauma Society (COTS) concerning antibiotic prophylaxis in the setting of surgical treatment for closed fractures. Results. Ninety three percent (179/193) of patients received an appropriate pre-operative dose, while less than 32% (58/181) of patients received their post-operative antibiotics as ordered. The most common stated reason for patients not receiving their post-operative antibiotics as ordered was patients being discharged before completing three post-op doses. There was a 70% (39/56) response rate to the survey sent to COTS surgeons. A single dose of a first-generation cephalosporin pre-operatively followed by three doses post-operatively is the most common practice amongst orthopaedic trauma surgeons across Canada, but several surgeons use only pre-operative prophylaxis. Conclusion. Adherence to multi-dose post-operative antibiotic regimens is poor. Meta-analyses have failed to demonstrate the superiority of multi-dose regimens over single-dose prophylaxis. Single-dose pre-operative antibiotic prophylaxis may be a reasonable choice for most orthopedic trauma patients with closed fractures

Aim. Prosthetic joint infection (PJI) is a devastating and costly complication of total joint arthroplasty (TJA). Use of extended oral antibiotic prophylaxis (EOAP) has become increasingly popular in the United States following a highly publicized study (Inabathula et al) from a single center demonstrating a significant protective effect (81% reduction) against PJI in ‘high-risk’ patients. However, these results have not been reproduced elsewhere and EOAP use directly conflicts with current antibiotic stewardship efforts. In order to study the role of EOAP in PJI prevention, consensus is needed for what defines ‘high-risk’ patients. The revision TJA (rTJA) population is an appropriate group to study due to having a higher incidence of PJI. The purpose of the current study was to rigorously determine which preoperative conditions described by Inabathula et al. (referred to as Inabathula criteria (IBC)) confer a higher rate of PJI in patients undergoing aseptic rTJA. Method. 2,256 patients that underwent aseptic rTJA at a single high-volume institution between 2016–2022 were retrospectively reviewed. Patient demographics and comorbidities were recorded to determine if they had 1 or more ‘IBC’, a long list of preoperative conditions including autoimmune diseases, active smoking, body mass index (BMI)>35, diabetes mellitus, and chronic kidney disease (CKD). Reoperation for PJI at 90-days and 1-year was recorded. Chi-squared or Fischer's exact tests were calculated to determine the association between preoperative presence/absence of IBC and PJI. Multivariable logistic regressions were conducted to determine if specific comorbidities within the IBC individually conferred an increased PJI risk. Results. 1223 patients (54.2%) had at least one IBC condition. IBC-positive patients were more likely to be female, have an increased ASA score, and higher BMI. IBC-positive patients had a significant increase in PJI risk at both 90-days (relative risk (RR)=2.32, p<0.0001) and 1-year (RR=2.14, p=0.002) versus IBC-negative patients. Within IBC-positive patients, every additional IBC condition conferred a 1.8× odds increase for 90-day PJI (p<0.0001), and 1.76× odds increase in 1-year PJI (p<0.0001). Multivariable logistic regression identified active smoking, BMI>35, CKD, and diabetes mellitus as being independently associated with PJI development (p<0.05). Conclusions. Over half of rTJA patients meet IBC and could be eligible to receive EOAP in the United States. However, the specific presence of active smoking, BMI>35, CKD, and diabetes mellitus appear to be responsible for the increased risk of PJI. Prospective studies investigating EOAP use for patients with these specific conditions are urgently needed to prevent unnecessary antibiotic use

Culture negative prosthetic joint infections (PJI) still remain an issue even the advantages in PJI diagnosis. This is the reason why some orthopedic surgeons fear to use preoperative antibiotic prophylaxis when a PJI is suspected. The purpose of the present study was to evaluate the influence of preoperative antibiotic prophylaxis in intraoperative cultures. An enhanced diagnostic protocol for PJI (Zimmerli criteria) was used for the inclusion criteria in order to collect all PJI accounted in a University Hospital. Patients were prospectively randomized in two groups. The control group received the classical preoperative antibiotic prophylaxis. The study group did not receive prophylaxis prior to surgery. There were 14 patients in each group. They correspond to 13 infections of total hip arthroplasty (THA), 12 infections of total knee arthroplasty (TKA) and 3 reverse shoulder prosthesis (RSA) infections. There were 10 patients in the study group and 10 patients in the control group with at least one positive microbiological criterion. There were 8 patients in each group with culture negative PJI (p>0.05). Preoperative antibiotic prophylaxis does not affect intraoperative cultures in suspected or confirmed PJI. Therefore it is essential to deliver antibiotic prophylaxis in any patient in which prosthesis is to be implanted in order to protect the prosthesis from infection

Aim. Prosthetic joint infections (PJI) are a common reason for revisions in patients that underwent total arthroplasty of the hip (THA) or knee (TKA). Extensive antibiotic treatment follows while a clear understanding of target site concentrations is lacking. The aim is to investigate the target site concentrations, like bone and synovial tissue concentrations, which consequently may lead to an optimisation of the dosing regiments of cefuroxime of PJI patients suffering from pain and immobility. Dosing optimisation may lead to a reduced risk of (re-)infection and adverse effects like renal-insufficiency and therefore lower health-care costs. Method. Patients (n=26) with PJI of hip or knee undergoing a one- or two-stage revision treated with cefuroxime were included as part of the ASTERICS study. During implant removal two samples were collected 15-30 and 60-120 minutes after IV infusion of plasma, bone tissue and synovial tissue and one synovial fluid sample. Samples were analysed using a UltraPerformance Convergence Chromotography – quadruple mass spectrometry system (UPC. 2. -MS/MS). Bone tissue and synovial tissue were pulverized before analysis acquiring for bone tissue a homogenate of cortical and cancellous bone. Using nonlinear mixed effect modelling (NONMEM) a base model was developed to analyse the bone to plasma ratio of cefuroxime in osteomyelitis patients. Results. Mean bone concentrations (mg/L) of cefuroxime at 30-60 min after IV administration in the knee and hip are 21.29 (SD:11.86) and 19.06 (SD: 11.79) respectively and 8.23 (SD:4.90) and 9.67 (SD:9.75) respectively at 90-120 min after IV administration. The penetration of cefuroxime described by the bone:plasma ratio into knee and hip affected by osteomyelitis is 0.3 and 0.4 respectively within 1 hour and 0.1 for both joints within 2 hours. The results mentioned here were collected during knee operations without blood void conditions. Concentration data was used to develop a base pharmacokinetic model using NONMEM and was best described by a two-compartment model. Conclusions. Cefuroxime penetrates osteomyelitis affected bone tissue within the hour proving the usefulness of cefuroxime as prophylaxis of orthopaedic surgery and as treatment option for PJI. However, PK modelling and further simulations need to prove whether repeated cefuroxime dosing in this population is required to reach minimal inhibitory concentrations in target tissue

Aim. The current recommendation in Norway is to use four doses of a first-generation cephalosporin (cefazolin or cephalotin) as systemic antibiotic prophylaxis (SAP) the day of surgery in primary joint arthroplasty. Due to shortage of supply, scientific development, changed courses of treatment and improved antibiotic stewardship, this recommendation has been disputed. We therefore wanted to assess if one dose of SAP was non-inferior to four doses in preventing periprosthetic joint infection (PJI) in primary joint arthroplasty. Method. We included patients with primary hip- and knee arthroplasties from the Norwegian Arthroplasty Register and the Norwegian Hip Fracture Register for the period 2005-2023. We included the most used SAPs (cephalotin, cefazolin, cefuroxime, cloxacillin and clindamycin), administered as the only SAP in 1-4 doses, starting preoperatively. Risk of revision (Hazard rate ratio; HRR) for PJI was estimated by Cox regression analyses with adjustment for sex, age, ASA class, duration of surgery, reason for- and type of arthroplasty, and year of primary arthroplasty. The outcome was 1-year reoperation or revision for PJI. Non-inferiority margins were calculated for 1, 2 and 3 doses versus reference of 4 doses of SAP at the day of surgery, against a predetermined limit of 15% increased risk of PJI. Results. In total 274,188 primary arthroplasties (total hip 133,985, hemi hip 51,442, and total knee 88,761) were included. Of these primary arthroplasties, 2,996 (1.1%) had subsequent revisions for PJI during the first postoperative year. One dose of SAP was given in 9,603 arthroplasties, two doses in 10,068, three doses in 18,351, and four doses in 236,166 arthroplasties. With the recommended four doses as reference, the HRR (95% CI) for 1-year revision for infection was 0.9 (0.7-1.1) for one dose, 1.0 (0.8-1.2) for two doses, and 0.9 (0.8-1.1) for three doses. The corresponding adjusted 1-year revision incidences for PJI was 0.9 (0.7-1.1), 1.0 (0.8-1.2), 0.9 (0. 8-1.1) and 1.0 (1.0-1.1) for one, two, three and four doses respectively, and less than four doses was found to be non-inferior. Conclusions. One preoperative dose of SAP in primary joint arthroplasty surgery seems to be non-inferior to the current recommendation of four doses of a first-generation cephalosporin as PJI-prophylaxis. This finding may simplify the course of treatment for arthroplasty patients, save costs, and improve antibiotic stewardship

Aim. Tourniquet is widely used in extremity surgery. In order to prevent surgical site infection, correct timing of antimicrobial prophylaxis and tourniquet inflation is important. We aimed to evaluate the time for which the free drug concentration of cefuroxime is maintained above the minimal inhibitory concentration (T>MIC) in subcutaneous tissue and calcaneal cancellous bone during three clinically relevant tourniquet application scenarios. Method. Twenty-four female pigs were included. Microdialysis catheters were placed for sampling of cefuroxime concentrations bilaterally in calcaneal cancellous bone and subcutaneous tissue, and a tourniquet cuff was applied on a randomly picked leg of each pig. Subsequently, the pigs were randomized into three groups to receive 1.5 g of cefuroxime by intravenous injection 15 min prior to tourniquet inflation (Group A), 45 min prior to tourniquet inflation (Group B), and at the tourniquet release (Group C). The tourniquet duration was 90 min in all groups. Dialysates and venous blood samples were collected eight-hours postcefuroxime administration. Results. Cefuroxime concentrations were maintained above the clinical breakpoint MIC for Staphylococcus aureus (4 µg/mL) in calcaneal cancellous bone and subcutaneous tissue throughout the 90 min tourniquet duration in Group A and B. Cefuroxime administration at tourniquet release (Group C) resulted in concentrations above 4 µg/mL for a minimum of 3.5 hours in the tissues on the tourniquet side. There were no significant differences in the T>MIC (4 µg/mL) in subcutaneous tissue or calcaneal cancellous bone between the three groups. However, Group A tended toward shorter T>MIC in tourniquet calcaneal cancellous bone compared to Group C (p=0.08). Conclusions. Administration of cefuroxime (1.5 g) in the 15–45 min window prior to tourniquet inflation resulted in sufficient calcaneal cancellous bone and subcutaneous tissue concentrations throughout the 90 min tourniquet application. If the target is to maintain postoperative cefuroxime concentrations above relevant MIC values, our results suggest that a second dose of cefuroxime should be administered at tourniquet release