Obese patients have higher rates of polymicrobial and Gram-negative early periprosthetic joint infections of the hip than non-obese patients

Effect of weight-adjusted antimicrobial antibiotic prophylaxis on postoperative dosage and surgical site infection incidence in total joint arthroplasty

Surgical site infections (SSI) following total joint arthroplasty pose a significant concern for both providers and patients across the globe. Currently, administration of antimicrobial antibiotic prophylaxis is used throughout the world to reduce the incidence of SSI. However, the correct dosage and frequency of administration remains debatable. In this editorial, we emphasized the determination of the effect of administration of weight-adjusted antimicrobial antibiotic prophylaxis regime on the incidence of SSI and postoperative dosage reduction compared to the conventionally used regime during total joint arthroplasty. The results demonstrated similar efficacy between both regimes with respect to the incidence of SSI. In addition, weight-adjustment led to reduced postoperative dosage and has the potential to reduce chances of achieving lower therapeutic concentration, drug resistance, drug toxicity, and costs.

Decreased Risk of Periprosthetic Joint Infection with Concurrent Hardware Removal During Conversion Total Hip Arthroplasty Compared to Staged Removal: A Matched Cohort Analysis

INTRODUCTION

Hardware removal before conversion total hip arthroplasty (cTHA) is a challenging task for the orthopaedic surgeon, although there is little consensus on the timing of hardware removal to mitigate risk of surgery-related complication following cTHA.

METHODS

Using a national insurance database, we evaluated patients who underwent hardware removal either on the same day or within 1 year before cTHA, resulting in a total of 7,756 patients. After matching based on demographic factors and comorbidities, both staged and concurrent groups consisted of 2,752 patients. The 90-day and 1-year risk of revision surgery, periprosthetic joint infection (PJI), periprosthetic fracture, and aseptic loosening were calculated and compared. Demographic factors and comorbidities were further evaluated as risk factors for PJI.

RESULTS

The rates of infection were 1.85% and 3.05% at 90 days postoperatively and 2.94% and 4.14% at 1 year postoperatively for concurrent versus staged cohorts, respectively (P = 0.004 and P = 0.02). No difference was observed at 90 days or 1 year between the two cohorts in risk of fracture, revision surgery, or aseptic loosening. Diabetes (P = 0.002 and P < 0.001), tobacco use (P < 0.001 and P < 0.001), and obesity (P = 0.026 and P = 0.025) were identified as risk factors for PJI at both 90 days and 1 year postoperatively.

DISCUSSION

The timing of hardware removal is associated with an increased risk of PJI, although no difference was observed in revision surgery, fracture, or loosening among staged versus concurrent cohorts. These findings are important to consider when surgeons are evaluating patients with periarticular implants surrounding their hip.

Racial Disparities in Periprosthetic Joint Infections after Primary Total Joint Arthroplasty: A Retrospective Study

In the United States, racial disparities have been observed in complications following total joint arthroplasty (TJA), including readmissions and mortality. It is unclear whether such disparities also exist for periprosthetic joint infection (PJI). The clinical data registry of a large New England hospital system was used to identify patients who underwent TJA between January 2018 and December 2021. The comorbidities were evaluated using the Elixhauser Comorbidity Index (ECI). We used Poisson regression to assess the relationship between PJI and race by estimating cumulative incidence ratios (cIRs) and 95% confidence intervals (CIs). We adjusted for age and sex and examined whether ECI was a mediator using structural equation modeling. The final analytic dataset included 10,018 TJAs in 9681 individuals [mean age (SD) 69 (10)]. The majority (96.5%) of the TJAs were performed in non-Hispanic (NH) White individuals. The incidence of PJI was higher among NH Black individuals (3.1%) compared with NH White individuals (1.6%) [adjusted cIR = 2.12, 95%CI = 1.16-3.89; p = 0.015]. Comorbidities significantly mediated the association between race and PJI, accounting for 26% of the total effect of race on PJI incidence. Interventions that increase access to high-quality treatments for comorbidities before and after TJA may reduce racial disparities in PJI.

Change in organism between first- and second-stage revision for periprosthetic joint infection of knee arthroplasty independently associated with increased risk of failure

Aims

Achievement of accurate microbiological diagnosis prior to revision is key to reducing the high rates of persistent infection after revision knee surgery. The effect of change in the microorganism between the first- and second-stage revision of total knee arthroplasty for periprosthetic joint infection (PJI) on the success of management is not clear.

Methods

A two-centre retrospective cohort study was conducted to review the outcome of patients who have undergone two-stage revision for treatment of knee arthroplasty PJI, focusing specifically on isolated micro-organisms at both the first- and second-stage procedure. Patient demographics, medical, and orthopaedic history data, including postoperative outcomes and subsequent treatment, were obtained from the electronic records and medical notes.

Results

The study cohort consisted of 84 patients, of whom 59.5% (n = 50) had successful eradication of their infection at a mean follow-up of 4.7 years. For the 34 patients who had recurrence of infection, 58.8% (n = 20) had a change in isolated organism, compared to 18% (n = 9) in the infection eradication group (p < 0.001). When adjusting for confound, there was no association when the growth on the second stage was the same as the first (odd ratio (OR) 2.50, 95% confidence interval (CI) 0.49 to 12.50; p = 0.269); however, when a different organism was identified at the second stage, this was independently associated with failure of treatment (OR 8.40, 95% CI 2.91 to 24.39; p < 0.001). There were no other significant differences between the two cohorts with regard to patient demographics or type of organisms isolated.

Conclusion

Change in the identified microorganism between first- and second-stage revision for PJI was associated with failure of management. Identification of this change in the microorganism prior to commencement of the second stage may help target antibiotic management and could improve the success of surgery in these patients.

Visceral Fat as a Risk Factor for Periprosthetic Joint Infection After Total Hip and Knee Arthroplasty

BACKGROUND

Visceral obesity, a strong indicator of chronic inflammation and impaired metabolic health, has been shown to be associated with poor postoperative outcomes and complications. This study aimed to evaluate the relationship between visceral fat area (VFA) and periprosthetic joint infection (PJI) in total joint arthroplasty (TJA) patients.

METHODS

A retrospective study of 484 patients who had undergone a total hip or knee arthroplasty was performed. All patients had a computed tomography scan of the abdomen/pelvis within two years of their TJA. Body composition data (ie, VFA, subcutaneous fat area, and skeletal muscle area) were calculated at the Lumbar-3 vertebral level via two fully automated and externally validated machine learning algorithms. A multivariable logistic model was created to determine the relationship between VFA and PJI, while accounting for other PJI risk factors. Of the 484 patients, 31 (6.4%) had a PJI complication.

RESULTS

The rate of PJI among patients with VFA in the top quartile (> 264.1 cm2) versus bottom quartile (< 82.6 cm2) was 5.6% versus 10.6% and 18.8% versus 2.7% in the total hip arthroplasty and total knee arthroplasty cohorts, respectively. In the multivariate model, total knee arthroplasty patients with a VFA in the top quartile had a 30.5 times greater risk of PJI than those in the bottom quartile of VFA (P = .0154).

CONCLUSION

VFA may have a strong association with PJI in TJA patients. Using a standardized imaging modality like computed tomography scans to calculate VFA can be a valuable tool for surgeons when assessing risk of PJI.

The Impact of Sex on the Outcomes of Prosthetic Joint Infection Treatment with Debridement, Antibiotics and Implant Retention: A Systematic Review and Individual Patient Data Meta-analysis

BACKGROUND

The influence of sex on the failure of débridement antibiotics and implant retention (DAIR) for treating prosthetic joint infection (PJI) is important for decision-making, patient counseling, and equitable health care. However, very few studies in the orthopaedic literature conduct sex-specific analyses.

AIM

The primary aim was to determine whether sex influences treatment success after DAIR.

METHODS

A systematic review and individual patient data (IPD) meta-analysis was conducted. MEDLINE (Ovid), EMBASE (Ovid), Web of Science, and Google Scholar were searched, and IPD was requested via e-mail. Patients who underwent DAIR after developing PJI within 12 months of a primary total hip or knee arthroplasty were included in the analysis. Treatment failure was defined by the Delphi International Consensus criteria. Adjusted odds ratios for treatment failure were calculated using a mixed-effects logistic regression.

RESULTS

The study collected and analyzed IPD of 1,116 patients from 21 cohorts. The odds of treatment failure were 29% lower in women (odds ratio, 0.71; 95% CI 0.54 to 0.017; P = 0.017), after adjusting for duration of symptoms >7 days and Staphylococcus aureus infection (methicillin-susceptible Staphylococcus aureus or any infection with S aureus). None of the 64 studies included in the systematic review conducted a sex-specific analysis.

CONCLUSION

For patients who developed a PJI within 1 year postsurgery, females have lower odds of DAIR failure than males. Other factors also have varying effects on outcome for men and women. It is essential to implement sex-specific analysis in orthopaedic research.

Does Postoperative Spine Infection Bacterial Gram Type Affect Surgical Debridement or Antibiotic Duration?

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

The aim was to evaluate differences in readmission rates, number of debridements, and length of antibiotic therapy when comparing bacterial gram type following lumbar spinal fusion infections.

SUMMARY OF BACKGROUND DATA

Surgical site infections (SSIs) after spinal fusion serve as a significant source of patient morbidity. It remains to be elucidated how bacterial classification of the infecting organism affects the management of postoperative spinal SSI.

METHODS

Patients who underwent spinal fusion with a subsequent diagnosis of SSI between 2013 and 2019 were retrospectively identified. Patients were grouped based on bacterial infection type (gram-positive, gram-negative, or mixed infections). Poisson regressions analyzed the relationship between the type of bacterial infection and the number of irrigation and debridement (I&D) reoperations, and the duration of intravenous (IV) antibiotic therapy. Significance was set at P <0.05.

RESULTS

Of 190 patients, 92 had gram-positive (G+) infections, 57 had gram-negative (G-) infections, and 33 had mixed (M) infections. There was no difference in 30 or 90-day readmissions for infection between groups (both P =0.051). Patients in the M group had longer durations of IV antibiotic treatment (G+: 46.4 vs. G-: 41.0 vs. M: 55.9 d, P =0.002). Regression analysis demonstrated mixed infections were 46% more likely to require a greater number of debridements ( P =0.001) and 18% more likely to require an increased duration of IV antibiotic therapy ( P <0.001), while gram-negative infections were 10% less likely to require an increased duration of IV antibiotic therapy ( P <0.001) when compared with G- infections.

CONCLUSION

Spinal SSI due to a mixed bacterial gram type results in an increased number of debridements and a longer duration of IV antibiotics required to resolve the infection compared with gram-negative or gram-positive infections.

LEVEL OF EVIDENCE

Level III.

Gut permeability may be associated with periprosthetic joint infection after total hip and knee arthroplasty

A growing number of recent investigations on the human genome, gut microbiome, and proteomics suggests that the loss of mucosal barrier function, particularly in the gastrointestinal tract, may substantially affect antigen trafficking, ultimately influencing the close bidirectional interaction between the gut microbiome and the immune system. This cross-talk is highly influential in shaping the host immune system function and ultimately affecting the outcome of interventions. We hypothesized that the loss of mucosal barrier in the gut may be associatedto acute and chronic periprosthetic joint infections (PJI). Zonulin, soluble CD14 (sCD14), and lipopolysaccharide (LPS) were tested in plasma as part of a prospective cohort study of patients undergoing primary arthroplasty or revision arthroplasty because of an aseptic failure or PJI (as defined by the 2018 criteria). All blood samples were collected before antibiotic administration. Samples were tested using commercially available enzyme-linked immunosorbent assays as markers for gut permeability. A total of 134 patients were included in the study of which 44 patients had PJI (30 chronic and 14 acute), and the remaining 90 patients were categorized as non-infected that included 64 patients revised for aseptic failure, and 26 patients undergoing primary total joint arthroplasty. Both Zonulin (7.642 ± 6.077 ng/mL vs 4.560 ± 3.833 ng/mL; p < 0.001) and sCD14 levels (555.721 ± 216.659 ng/mL vs 396.872 ± 247.920 ng/mL; p = 0.003) were significantly elevated in the PJI group compared to non-infected cases. Higher levels of Zonulin were found in acute infections compared to chronic PJI (11.595 ± 6.722 ng/mL vs. 5.798 ± 4.841 ng/mL; p = 0.005). This prospective study reveals a possible link between gut permeability and the ‘gut-immune-joint axis’ in PJI. If this association continues to be borne out with a larger cohort and more in-depth analysis, it will have a clinically significant implication in managing patients with PJI. It may be that in addition to the administration of antimicrobials, patients with PJI and other orthopaedic infections may benefit from administration of gastrointestinal modulators such as pro and prebiotics.

Differing Microorganism Profile in Early and Late Prosthetic Joint Infections Following Primary Total Knee Arthroplasty - Implications for Empiric Antibiotic Treatment

BACKGROUND

Prosthetic joint infection (PJI) is the leading cause of revision following total knee arthroplasty (TKA). Prior to microorganism identification, the choice of the correct empiric antibiotics is critical to treatment success. This study aims to 1) compare the microorganism and resistance profile in early and late PJIs; 2) recommend appropriate empiric antibiotics.

METHODS

A multicentre retrospective review was performed over a 15-year period. First episode PJIs were classified by both the Tsukayama Classification and Auckland Classification. For each PJI case, the causative organism and antibiotic sensitivity were recorded.

RESULTS

Of eligible patients, 232 culture-positive PJI cases were included. Using either classification system, early PJIs (<4 weeks or <1 year since primary) were significantly more likely to be resistant and polymicrobial. The predominant organisms were coagulase-negative Staphylococci in early PJIs while Staphylococcus aureus was the most common in late PJIs. The distribution of gram-negative cases was higher in early Class-A than late Class-C PJIs (25% versus 6%, P = .004). Vancomycin provided significantly superior coverage when compared to Flucloxacillin for early infections, and addition of a gram-negative agent achieved coverage over 90% using both classification systems.

CONCLUSION

Based on the microbiological pattern in Tsukayama criteria, Vancomycin with the consideration of Gram-negative agent should be considered for Class-A infections given the high proportion of resistant and polymicrobial cases. For Class-C infections, Cephazolin or Flucloxacillin is likely sufficient. We recommend antibiotics to be withheld in Class-B infections until cultures and sensitivities are known.

Septic Arthritis Complicating Arthroscopic Anterior Cruciate Ligament Reconstruction: An Experience from a Tertiary-Care Hospital

Background

Septic arthritis (SA) of the knee following anterior cruciate ligament reconstruction (ACLR) is considered a catastrophic complication in terms of reduced or loss function of the involved joint. The aims of this study were to gauge the incidence, risk factors, and causative organisms of SA after ACLR.

Methods

We conducted a retrospective review of 836 patients who underwent primary ACLR at our institution from October 2018 to September 2021. Patients’ demographics, onset of presentation, clinical symptoms, laboratory findings, and management details were obtained from patients’ electronic medical records.

Results

Out of the 836 primary ACLRs, 12 were complicated with SA (1.43%). Independent risk factors associated with SA included age (OR; 11.12, 95% CI; 1.3–94.97), obesity (OR; 8.51, 95% CI; 1.02–71.13), and diabetes mellitus (OR; 12.58, 95% CI; 2.39–66.3). Staphylococcus aureus was the most frequent culprit organism (66.7%), followed by Streptococcus species (25%), and Pseudomonas aeruginosa (8.3%). No fungal, mycobacterial, or polymicrobial growth were recovered from synovial fluid cultures. All of the infected cases underwent arthroscopic joint lavage and debridement in the operating room followed by intravenous antibiotics. Graft removal was not done in any of the involved patients, with eradication of infection in all cases.

Conclusion

SA after ACLR is uncommon, with S. aureus identified in about two-thirds of the patients. Prompt diagnosis and treatment are crucial to avoid graft loss and arthritis-associated joint damage. Orthopedic surgeons should consider rigorous implementation of infection control strategies to minimize the incidence of this devastating morbidity.

Periprosthetic Joint Infection and the Trojan Horse Theory: Examining the Role of Gut Dysbiosis and Epithelial Integrity

BACKGROUND

Periprosthetic joint infection (PJI) is an uncommon yet dreadful complication after total joint arthroplasty. Emerging evidence suggested a role for the gut microbiome in the pathogenesis of such infections as a reservoir of opportunistic pathogens.

METHODS

A secondary analysis of an ongoing trial looking at gut dysbiosis and PJI was performed on patients that had next-generation sequencing done as part of their workup. Gut permeability and dysbiosis were measured using known biomarkers such as Zonulin. Statistical analysis consisted of descriptive statistics and logistic regression modeling.

RESULTS

Among the cohort of 46 (47.8% female) patients, with a mean age of 68.47 years (range, 40 to 91) and a mean BMI 31.15 ± 6.49 kg/m², 38 patients underwent a revision for PJI (29 chronic and 9 acute infections), and 8 patients were classified as aseptic failures. Then, a review of each of the bacteria retrieved was performed. Those known to be gut commensal based on available literature were noted. When regression modeling was performed, Zonulin levels were found to be associated with an increased probability of a similar finding (Estimate: 0.377, OR: 1.458; P = .001).

CONCLUSION

In our study, we report the first clinical evidence of the translocation of bacteria from the gut to the joint in patients with PJI. In particular, when evaluating the microbiological profile of the NGS signal, a great number of known gut commensals were seen in patients with a highly permeable dysbiotic gut. Manipulation of the gut microbiome may become part of an essential and comprehensive approach for management of patients with PJI.

Connecting the Human Microbiome and Pancreatic Cancer

Pancreatic cancer is a deadly disease that is increasing in incidence throughout the world. There are no clear causal factors associated with the incidence of pancreatic cancer; however, some correlation to smoking, diabetes and alcohol has been described. Recently, a few studies have linked the human microbiome (oral and gastrointestinal tract) to pancreatic cancer development. A perturbed microbiome has been shown to alter normal cells while promoting cancer-related processes such as increased cell signaling, immune system evasion and invasion. In this article, we will review in detail the alterations within the gut and oral microbiome that have been linked to pancreatic cancer and explore the ability of other microbiomes, such as the lung and skin microbiome, to contribute to disease development. Understanding ways to identify a perturbed microbiome can result in advancements in pancreatic cancer research and allow for prevention, earlier detection and alternative treatment strategies for patients.

Fracture Related Infections and Their Risk Factors for Treatment Failure—A Major Trauma Centre Perspective

Fracture related infections (FRI) are debilitating and costly complications of musculoskeletal trauma surgery that can result in permanent functional loss or amputation. Surgical treatment can be unsuccessful, and it is necessary to determine the predictive variables associated with FRI treatment failure, allowing one to optimise them prior to treatment and identify patients at higher risk. The clinical database at a major trauma centre was retrospectively reviewed between January 2015 and January 2021. FRI treatment failure was defined by infection recurrence or amputation. A univariable logistic regression analysis was performed, followed by a multivariable regression analysis for significant outcomes between groups on univariable analysis, to determine risk factors for treatment failure. In total, 102 patients were identified with a FRI (35 open, 67 closed fractures). FRI treatment failure occurred in 24 patients (23.5%). Risk factors determined by our multivariate logistic regression model were obesity (OR 2.522; 95% CI, 0.259–4.816; p = 0.006), Gustilo Anderson type 3c (OR 4.683; 95% CI, 2.037–9.784; p = 0.004), and implant retention (OR 2.818; 95% CI, 1.588–7.928; p = 0.041). Given that FRI treatment in 24 patients (23.5%) ended up in failure, future management need to take into account the predictive variables analysed in this study, redirect efforts to improve management and incorporate adjuvant technologies for patients at higher risk of failure, and implement a multidisciplinary team approach to optimise risk factors such as diabetes and obesity.

Positivity Trends of Bacterial Cultures from Cases of Acute and Chronic Periprosthetic Joint Infections

Background: There is no clear distinction in the literature regarding the positivity trends of bacterial cultures in acute and chronic prosthetic joint infections. Methods: We prospectively included in this study all consecutive patients, aged over 18 years, that were hospitalized from September 2016 through December 2019, that underwent a joint arthroplasty revision surgery. Results: Forty patients were included in our analysis, 11 acute/acute hematogenous and 29 chronic PJIs. We were able to identify all strains of acute/acute hematogenous PJIs within 3 days, whereas this took 8 days for chronic PJIs. Sonication fluid cultures increased the positivity rate and helped in identifying rare pathogens such as Ralstonia pickettii from chronic PJIs, but also increased the number of identified strains from acute PJIs. Culturing synovial fluid in our study did not seem to have a clear benefit compared to sonication fluid and periprosthetic tissue cultures. Conclusion: There was a different positivity trend in bacterial cultures. Empiric broad-spectrum antibiotic therapy can be re-evaluated after 3 days for acute PJIs. A prolonged incubation time, especially in the case of chronic PJIs, is mandatory; however, extending the incubation period beyond 14 days would not further improve the ability to identify microorganisms.

Staphylococcus aureus α-Toxin Effect on Acinetobacter baumannii Behavior

Polymicrobial infections are more challenging to treat and are recognized as responsible for significant morbidity and mortality. It has been demonstrated that multiple Gram-negative organisms take advantage of the effects of Staphylococcus aureus α-toxin on mucosal host defense, resulting in proliferation and dissemination of the co-infecting pathogens. Through phenotypic approaches, we observed a decrease in the motility of A. baumannii A118 after exposure to cell-free conditioned media (CFCM) of S. aureus strains, USA300 and LS1. However, the motility of A. baumannii A118 was increased after exposure to the CFCM of S. aureus strains USA300 Δhla and S. aureus LSI ΔagrA. Hemolytic activity was seen in A118, in the presence of CFCM of S. aureus LS1. Further, A. baumannii A118 showed an increase in biofilm formation and antibiotic resistance to tetracycline, in the presence of CFCM of S. aureus USA300. Transcriptomic analysis of A. baumannii A118, with the addition of CFCM from S. aureus USA300, was carried out to study A. baumannii response to S. aureus’ released molecules. The RNA-seq data analysis showed a total of 463 differentially expressed genes, associated with a wide variety of functions, such as biofilm formation, virulence, and antibiotic susceptibility, among others. The present results showed that A. baumannii can sense and respond to molecules secreted by S. aureus. These findings demonstrate that A. baumannii may perceive and respond to changes in its environment; specifically, when in the presence of CFCM from S. aureus.

Fatal Clostridium Infection in a Leg-Amputated Patient after Unsuccessful Knee Arthroplasty

Prosthetic joint infection (PJI) is a possible complication occurring after prosthesis implantation. We describe the case of a patient with early postoperative multidrug-resistant polymicrobial PJI and mixed infection of the surgical wound. Despite the removal of the prosthesis, the positioning of double-stage exchange, and dehiscence debridement of the surgical wound, the infection continued. Positioning of an external fixator, plastic reconstruction with a skin graft, and continuous (two years) multiple antimicrobial therapy led to the resolution of the knee infection; a knee prosthesis was implanted, but a new infection of the extensus apparatus by multidrug-resistant Klebsiella pnumoniae followed. It was complicated by surgical wound dehiscence, forcing us to remove the prosthesis, put a new external fixator, and continue with the antibiotic treatment, with no results, and, finally, proceed to a leg amputation. Fourteen days after, the patient was discharged in good clinical condition but, fifteen days later, during rehabilitation in another hospital, the patient developed a severe Clostridium difficilis infection with profuse, intense diarrhea, toxic megacolon, and septic shock; despite colectomy and treatment in an intensive care unit, he died four months later. Patients affected by polymicrobial PJI are at high risk of treatment failure and, therefore, should be given a warning, in good time and appropriate form, of the likelihood of leg amputation.

Direct Anterior Approach to the Hip Does Not Increase the Risk for Subsequent Periprosthetic Joint Infection

BACKGROUND

Recent studies suggest an increased risk for periprosthetic joint infection (PJI) utilizing the direct anterior (DA) approach to the hip. The purpose of this study was to investigate whether such an increased risk does indeed exist on a large cohort of patients, operated by experienced surgeons and taking into account various confounders.

METHODS

This was a single institutional study, including all patients who underwent primary total hip arthroplasty during the last decade, who were operated on by four high-volume arthroplasty surgeons utilizing a single surgical approach. Three of them utilized the direct lateral (DL) approach while one of them used the DA approach throughout the entire study. Patient characteristics, demographics, and comorbidities were assessed as well as operative and perioperative factors and their association with PJI. Association between surgical approach and PJI was evaluated in a univariate followed by a multivariate regression analysis.

RESULTS

A total of 10,201 patients were included in the study. Of those, 4390 (43.0%) underwent total hip arthroplasty through the DA approach and 5811 (57.0%) through the DL approach. PJI rates were 0.9% (38/4390) in the DA group compared with 1.3% (73/5811) in the DL group (P = .068). Results from a regression analysis showed no significant association between PJI and DA approach (adjusted odds ratio 0.760, 95% confidence interval 0.428-1.348, P = .348). The risk remained nonsignificant in patients with higher body mass index. There were also no significant differences in the infecting organisms between the two groups.

CONCLUSION

The DA approach to the hip does not increase the risk for subsequent PJI.

Time to positivity of acute and chronic periprosthetic joint infection cultures

INTRODUCTION

A prolonged incubation time is generally recommended for diagnosing periprosthetic joint infections (PJI). However, in literature, no distinction is made between acute and chronic infections.

METHODS

All patients with a PJI that underwent surgical debridement between November 2015 and February 2019 with or without revision of the prosthesis were retrospectively evaluated. Synovial fluid, 5 intraoperative periprosthetic tissue samples, and the sonicated prosthesis were cultured.

RESULTS

Fifty-nine patients were analyzed, including 21 acute PJIs (33 isolates) and 38 chronic PJIs (46 isolates). In acute PJIs, all isolates grew within 5 days, while this took 11 days for chronic PJIs. Sonication fluid showed the shortest time to positivity (78% at day 2) for chronic PJIs, but no difference was observed for acute PJIs compared to tissue cultures.

CONCLUSION

In contrast to cultures from chronic PJIs, acute PJIs do not need a prolonged incubation time and no clear benefit is observed for sonication.

Infection Risk-Adjusted Antibiotic Prophylaxis Strategies in Arthroplasty: Short Review of Evidence and Experiences of a Tertiary Center in Spain

There is growing body of evidence that important patient-, procedure- and pathogen-related factors are linked to higher risks for prosthetic joint infections (PJI) following arthroplasty surgeries. The prior identification and optimization of such risk factors is considered paramount to minimize the incidence of these infections. Without any doubt, antibiotic prophylaxis remains one of the cornerstones among all preventive measures. However, the ideal antibiotic prophylaxis is still in debate and discussions have emerged, whether certain situations deserve adjustments or variations of the standard protocol taking into account antibiotic resistance surveillance data and patient risk factors for infections. This review aims to provide the reader with an overview of possible antibiotic prophylaxis strategies in response to these risks and discusses the clinical experiences so far obtained. We further present preliminary evidence that the use of a reinforced local antibiotic prophylaxis regimen with high-dose dual antibiotic-loaded bone cement may be an effective and easy-to-apply option in patients at high infection risks.

A Second Surgical Debridement for Acute Periprosthetic Joint Infections Should Not Be Discarded

BACKGROUND

In acute periprosthetic joint infections (PJIs), a second surgical debridement (debridement, antibiotics, and implant retention [DAIR]) is generally not recommended after a failed first one. We identified the failure rate of a second DAIR and aimed to identify patients in whom an additional debridement might still be beneficial.

METHODS

Patients with acute PJI of the hip or knee and treated with DAIR between 2006 and 2016 were retrospectively evaluated. A second DAIR was routinely performed provided that the soft tissue was intact. Failure of a second DAIR was described as (1) the need for additional surgical intervention to achieve infection control, (2) the need for antibiotic suppressive therapy due to persistent clinical and/or biochemical signs of infection, or (3) PJI related death.

RESULTS

From the 455 cases treated with DAIR, 144 cases underwent a second debridement (34.6%). Thirty-seven cases failed (37/144, 25.7%). The implant needed to be removed in 23 cases (23/144, 16%). Positive cultures during the second DAIR (odds ratio 3.16, 95% confidence interval 1.29-7.74) and chronic renal insufficiency (odds ratio 13.6, 95% confidence interval 2.03-91.33) were independent predictors for failure in the multivariate analysis. No difference in failure was observed between persistent infection with the same microorganism and reinfection with a new microorganism (failure rate 31.6% vs 34.6%, P = .83).

CONCLUSION

A second DAIR had a low failure rate in our cohort of patients and the implant could be retained in the majority of them. Therefore, a second DAIR should not be discarded in acute PJIs.

Endocarditis after transcatheter aortic valve implantation: a new fiend we hardly know

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Patient Characteristics Influence Revision Rate of Total Hip Arthroplasty: American Society of Anesthesiologists Score and Body Mass Index Were the Strongest Predictors for Short-Term Revision After Primary Total Hip Arthroplasty

BACKGROUND

Outcome and survival after primary total hip arthroplasty (THA) can be affected by patient characteristics. We examined the effect of case-mix on revision after primary THA using the Dutch Arthroplasty Register.

METHODS

Our cohort included all primary THAs (n = 218,214) performed in patients with osteoarthritis in the Netherlands between 2007 and 2018. Multivariable logistic regression analysis was used to calculate the difference in survivorship in patients with different patient characteristics (age, gender, American Society of Anesthesiologists [ASA] score, body mass index [BMI], Charnley score, smoking, and previous operations to the hip).

RESULTS

Case-mix factors associated with an increased risk for revision 1 year after THA were the following: a high ASA score (II and III-IV) (odds ratio [OR] 1.5, 95% confidence interval [CI] 1.1-2.0 and OR 3.0, 95% CI 1.7-5.3), a higher BMI (30-40 and >40) (OR 1.4, 95% CI 1.2-1.5 and OR 2.0, 95% CI 1.4-1.7), age ≥75 years (OR 1.5, 95% CI 1.1-2.0), and male gender (OR 1.3, 95% CI 1.2-1.4). A similar model for 3-year revision showed comparable results. High BMI (OR 1.9, 95% CI 1.3-2.9), a previous hip operation (OR 1.8, 95% CI 1.3-2.5), ASA III-IV (OR 1.2, 95% CI 1-1.6), and Charnley score C (OR 1.5, 95% CI 1.1-2.2) were associated with increased risk for revision. Main reasons for revision in obese and ASA II-IV patients were infection, dislocation, and periprosthetic fracture. Patients with femoral neck fracture and late post-traumatic pathology were more likely to be revised within 3 years, compared to osteoarthritis patients (OR 1.5, 95% CI 1.3-1.7 and OR 1.5, 95% CI 1.2-1.7).

CONCLUSION

The short-term risk for revision after primary THA is influenced by case-mix factors. ASA score and BMI (especially >40) were the strongest predictors for 1-year revision after primary THA. After 3 years, BMI and previous hip surgery were independent risk factors for revision. This will help surgeons to identify and counsel high-risk patients and take appropriate preventive measures.