Linezolid versus daptomycin treatment for periprosthetic joint infections: a retrospective cohort study

Bactericidal versus bacteriostatic antibacterials: clinical significance, differences and synergistic potential in clinical practice

Antibacterial activity can be classified as either bactericidal or bacteriostatic, using methods such as the MBC/MIC ratio and time-kill curves. However, such categorization has proven challenging in clinical practice, as these definitions only apply under specific laboratory conditions, which may differ from clinical settings. Several factors, such as the specific bacteria or infectious medium, can affect the action of antibiotics, with many antibacterials exerting both activities. These definitions have also led to the belief that bactericidal antibacterials are superior to bacteriostatic, especially in more severe cases, such as endocarditis, neutropenia and bacteraemia. Additionally, current dogma dictates against the combination of bactericidal and bacteriostatic antibacterials in clinical practice, due to potential antagonism. This review aimed to assess the differences in antibacterial activity of bactericidal and bacteriostatic antibacterials based on in vitro and in vivo studies and examine their antagonistic or synergistic effects. Our findings show that specific bacteriostatic agents, such as linezolid and tigecycline, are clinically non-inferior to bactericidals in multiple infections, including pneumonia, intra-abdominal infections, and skin and soft tissue infections. Studies also support using several bacteriostatic agents as salvage therapies in severe infections, such as neutropenic fever and endocarditis. Additionally, not all combinations of bacteriostatic and bactericidal agents appear to be antagonistic, with many combinations, such as linezolid and rifampicin, already being used. The findings should be interpreted with caution, as most evidence is from observational studies and there is a need for randomized controlled trials to assess their effectiveness and combinations, especially within the context of rising antimicrobial resistance.

Validity of a preoperative scoring system for surgical management of periprosthetic hip infection: one-stage vs. two-stage revision

INTRODUCTION

There are no widely accepted algorithms for determining optimal treatment for periprosthetic joint infection (PJI). Our study aimed to confirm the validity of a previously published scoring system in a larger number of patients to support a rational surgical treatment strategy for periprosthetic hip infection.

MATERIALS AND METHODS

Between February 2001 and December 2020, we performed 155 consecutive revision total hip arthroplasties (THAs) for PJI, with mean follow-up of 6 years. One-stage revision THA was performed in 56 hips and two-stage revision THA in 99 hips. Prosthesis survival from recurrent infection was determined by Kaplan-Meier analysis, using implant removal as the endpoint. The pre-operative scoring system (full score of 12 points), including 6 essential elements, was retrospectively evaluated.

RESULTS

The 10-year survival rates were 98% for one-stage (95% confidence interval [CI], 94-100) and 87% (95% CI, 79-96) for two-stage revision THA. Multivariate Cox regression analysis provided a total preoperative score as an independent risk factor for implant removal (hazard ratio, 0.17; 95% CI, 0.06-0.49; p < 0.001). The sensitivity and specificity at the cut-off of 4 points on the scoring system were 80% and 91%, respectively. The average score for one-stage revision THA in successful and failed cases were 8.9 and 6.0, and for two-stage revision THA were 6.5 and 3.9, respectively. We found significant differences between successful cases in one- and two-stage revision THA (p < 0.05).

CONCLUSIONS

The preoperative scoring system was useful for managing PJI. One-stage revision THA is recommended in patients scoring ≥ 9 points, and meticulously performed two-stage revision THA is encouraged for patients scoring ≥ 4 points.

A cost minimisation analysis comparing oral linezolid and intravenous daptomycin administered via an outpatient parenteral antibiotic therapy programme in patients requiring prolonged antibiotic courses

This study is an economic analysis seeking to examine cost savings that may be accrued from usage of oral linezolid in place of OPAT IV daptomycin in patients requiring prolonged courses of IV or highly bioavailable oral antibiotic therapy. In order to do so we conducted a literature review to establish the scenarios in which the agents could be considered equivalent. We then, using a decision-tree model, conducted a cost analysis to establish differences in cost between the approaches. Under the model base-case, the total cost of treatment with OPAT daptomycin was €3,496.84 and the total cost of treatment with oral linezolid was €772.01. Therefore the oral linezolid strategy would be projected to save the Irish health service €2,724.83 per patient. These results were robust to one-way deterministic sensitivity analyses and probabilistic sensitivity analysis. Our study suggests that significant savings could be safely accrued in the management of these patients.

Factors associated with late microbiological documentation of prosthetic joint infection

Purpose: To describe the number of prosthetic joint infections (PJIs) with late documentation and to identify associated factors. Methods: Bacterial PJIs with surgical management between November 2015 and November 2019 in a French center were analyzed. Results of short (72 h) and late culture (at 14 days) were analyzed. Results: A total of 160 PJIs were reported with 215 bacteria. Twenty-nine patients had late documentation (18.1%). The bacteria most involved were coagulase-negative staphylococci and Cutibacterium spp. (60%). In multivariate analysis, late chronic PJI (odds ratio = 2.47) and antibiotic therapy before surgery (odds ratio = 3.13) were associated with late-documented infection. Conclusion: A better knowledge of the factors associated with late-documented infections is essential in order to simplify antibiotic treatment at the appropriate time.

Antibiotic Therapy for Prosthetic Joint Infections: An Overview

Prosthetic joint infection (PJI) is a severe complication after arthroplasty. Its management combines surgical intervention, whose type depends on the clinical situation, and prolonged high-dose antibiotics adapted to the responsible microorganism(s) and the patient. Antibiotics are only one part of the therapeutic regimen and are closely related to the surgical strategy. Their efficacy depends to a large extent on the choice and quality of the surgical procedure, and the quality of the microbiological diagnosis. Although guidelines have been published, many aspects of antibiotic therapy remain poorly established. Choosing the optimal agent(s) is one aspect, with others being optimization of drugs' pharmacokinetic/pharmacodynamic parameters, the choice of administration route, use of monotherapy or combination regimens, therapeutic drug-monitoring and patient education to improve compliance and tolerance. Herein, we address PJI management based on recent literature data, guidelines and the experience of our referral center for complex bone-and-joint infections.

Toward Bactericidal Enhancement of Additively Manufactured Titanium Implants

Implant-associated infections (IAIs) are among the most intractable and costly complications in implant surgery. They can lead to surgery failure, a high economic burden, and a decrease in patient quality of life. This manuscript is devoted to introducing current antimicrobial strategies for additively manufactured (AM) titanium (Ti) implants and fostering a better understanding in order to pave the way for potential modern high-throughput technologies. Most bactericidal strategies rely on implant structure design and surface modification. By means of rational structural design, the performance of AM Ti implants can be improved by maintaining a favorable balance between the mechanical, osteogenic, and antibacterial properties. This subject becomes even more important when working with complex geometries; therefore, it is necessary to select appropriate surface modification techniques, including both topological and chemical modification. Antibacterial active metal and antibiotic coatings are among the most commonly used chemical modifications in AM Ti implants. These surface modifications can successfully inhibit bacterial adhesion and biofilm formation, and bacterial apoptosis, leading to improved antibacterial properties. As a result of certain issues such as drug resistance and cytotoxicity, the development of novel and alternative antimicrobial strategies is urgently required. In this regard, the present review paper provides insights into the enhancement of bactericidal properties in AM Ti implants.