Antibiotic containing bone cement in prevention of hip and knee prosthetic joint infections: A systematic review and meta-analysis

A systematic review and meta-analysis of antibiotic-loaded bone cement for prevention of deep surgical site infections following primary total joint replacement

BACKGROUND

The use of antibiotic-loaded bone cement (ALBC) as a mean for preventing deep surgical site infections (SSI) after total joint replacement is controversial. Therefore, we have conducted a meta-analysis to evaluate the prophylactic effect of ALBC for SSI prevention in patients undergoing arthroplasty. This study was conducted to revise treatment guidelines for MRSA infections in Japan.

METHODS

PubMed (Medline), Scopus, Embase, Web of Science and Cochrane library were searched for relevant articles comparing preventive effect of ALBC for patients undergoing primary total joint arthroplasty by August 2022. Primary outcome was the incidence of deep SSI. Subgroup analyses by type of surgery (total hip (THA) or knee (TKA) arthroplasty) and by causative pathogen (methicillin-resistant Staphylococcus aureus (MRSA)) were performed.

RESULTS

Of the 3379 studies identified for screening, six studies involving 5745 patients were included. The use of ALBC significantly reduced the incidence of deep SSI in overall patients (risk ratio [RR] 0.60, 95% confidential interval [CI] 0.39-0.92), but the evidence level was very low. There was no significant preventive effect for ALBC compared with non-ALBC in both THA and TKA (THA, RR 0.52, 95% CI 0.23-1.16; TKA, RR 0.64, 95% CI 0.38-1.06), and for preventing MRSA-SSI (RR 0.27, 95% CI 0.03-2.41).

CONCLUSIONS

Although the overall preventive effect of ALBC was significant, the evidence level was very low. Thus, the routine use of ALBC as a mean to prevent SSI in arthroplasty may not be suggested.

The effect of different preventive strategies during total joint arthroplasty on periprosthetic joint infection: a network meta-analysis

BACKGROUND

Periprosthetic joint infection after total joint arthroplasty has a large incidence, and it may often require two or more stages of revision, placing an additional burden on clinicians and patients. The purpose of this network meta-analysis is to evaluate the effect of four different preventive strategies during total joint arthroplasty on the prevention of periprosthetic joint infection.

METHODS

The study protocol was registered at PROSPERO (CRD: 42,023,448,868), and the literature search databases included Web of Science, PubMed, OVID Cochrane Central Register of Controlled Trials, OVID EMBASE, and OVID MEDLINE (R) ALL that met the requirements. The network meta-analysis included randomized controlled trials, retrospective cohort studies and prospective cohort studies with the outcome of periprosthetic joint infection. The gemtc R package was applied to perform the network meta-analysis to evaluate the relative results of different preventive strategies.

RESULTS

This network meta-analysis study included a total of 38 articles with 4 preventive strategies and negative controls. No improvement was observed in antibiotic-loaded bone cement compared with negative controls. Chlorhexidine showed the highest probability of delivering the best preventive effect, and povidone iodine had the second highest probability. Although vancomycin ranked after chlorhexidine and povidone iodine, it still showed a significant difference compared with negative controls. In addition, the incidence after applying chlorhexidine was significantly lower than that after applying negative controls and vancomycin. In the heterogeneity test between direct and indirect evidence, there was no apparent heterogeneity between them.

CONCLUSION

The study indicated that chlorhexidine, povidone iodine and vancomycin showed significant efficacy in preventing periprosthetic joint infection after total joint arthroplasty, while antibiotic-loaded bone cement did not. Therefore, more high-quality randomized controlled trials are needed to verify the results above.

Biomineral-Based Composite Materials in Regenerative Medicine

Regenerative medicine aims to address substantial defects by amplifying the body's natural regenerative abilities and preserving the health of tissues and organs. To achieve these goals, materials that can provide the spatial and biological support for cell proliferation and differentiation, as well as the micro-environment essential for the intended tissue, are needed. Scaffolds such as polymers and metallic materials provide three-dimensional structures for cells to attach to and grow in defects. These materials have limitations in terms of mechanical properties or biocompatibility. In contrast, biominerals are formed by living organisms through biomineralization, which also includes minerals created by replicating this process. Incorporating biominerals into conventional materials allows for enhanced strength, durability, and biocompatibility. Specifically, biominerals can improve the bond between the implant and tissue by mimicking the micro-environment. This enhances cell differentiation and tissue regeneration. Furthermore, biomineral composites have wound healing and antimicrobial properties, which can aid in wound repair. Additionally, biominerals can be engineered as drug carriers, which can efficiently deliver drugs to their intended targets, minimizing side effects and increasing therapeutic efficacy. This article examines the role of biominerals and their composite materials in regenerative medicine applications and discusses their properties, synthesis methods, and potential uses.

3D-printed antibiotic-loaded bone cement spacers as adjunctive therapy for hip periprosthetic infection after arthroplasty: A clinical assessment

OBJECTIVE

To explore the effect of three-dimensional (3D) printing to create personalized antibiotic-loaded bone cement (ALBC) spacers to assist in treatment of periprosthetic infection after total hip arthroplasty (THA).

METHODS

The data of 40 patients with postoperative infection after THA were analysed retrospectively. The patients were divided into two groups: the 3D-printing group (age 47-78 years, n = 20) and the conventional group (age 57-78 years, n = 20). In stage I surgery, 3D-printed silicone moulds were used to create ALBC spacers for the 3D-printing group, while traditional manual methods were used to create spacers for the conventional group. After the infection was controlled, both groups underwent conventional hip revision surgery (stage II surgery). All patients were evaluated using the Harris Hip Score (HHS) (primary outcome) for hip function.

RESULTS

All 40 patients had follow-up data from 3 months after stage I surgery and 12 months after stage II surgery. The intergroup difference in HHS was 11.25 points [97.5% confidence interval (CI) 7.92-14.58; P < 0.01] at 3 months after stage I surgery, and 9.15 points (97.5% CI 4.82-13.48; P < 0.01) at 12 months after stage II surgery. The overall difference between the two groups was 9.55 points (97.5% CI 5.83-13.27; P < 0.01), which was significant (P < 0.05).

CONCLUSION

During the follow-up period, the hip function of the 3D-printing group was superior to that of the conventional group following the treatment of infections after THA.

Utilization of Antibiotic Bone Cement in Spine Surgery: Pearls, Techniques, and Case Review

Vertebral osteomyelitis (VO) encompasses a spectrum of spinal infections ranging from isolated mild vertebral osteomyelitis to severe diffuse infection with associated epidural abscess and fracture. Although patients can often be treated with an initial course of intravenous antibiotics, surgery is sometimes required in patients with sepsis, spinal instability, neurological compromise, or failed medical treatment. Antibiotic bone cement (ABC) has been widely used in orthopedic extremity surgery for more than 150 years, both for prophylaxis and treatment of bacterial infection. However, relatively little literature exists regarding its utilization in spine surgery. This article describes ABC utilization in orthopedic surgery and explains the technique of ABC utilization in spine surgery. Surgeons can choose from multiple premixed ABCs with variable viscosities, setting times, and antibiotics or can mix in antibiotics to bone cements themselves. ABC can be used to fill large defects in the vertebral body or disc space or in some cases to coat instrumentation. Surgeons should be wary of complications such as ABC extravasation as well as an increased difficulty with revision. With a thorough understanding of the properties of the cement and the methods of delivery, ABC is a powerful adjunct in the treatment of spinal infections.

Rank-Ordered List of Cost-effective Strategies for Preventing Prosthetic Joint Infection in Total Joint Arthroplasty in an Academic US Hospital

Although the overall rate of prosthetic joint infection (PJI) is low, it remains a major complication associated with total joint arthroplasty (TJA). PJI represents a significant economic burden to the health care system that is projected to increase commensurate with increasing joint replacement volumes. This review provides a rank-ordered list of cost-effective strategies that are performable intraoperatively and have data supporting their efficacy at preventing PJI after TJA. This study may be helpful in assisting surgeons, ambulatory surgery center owners, and hospital acquisition committees to make reasonable and cost-conscious decisions in the face of changing reimbursement. [Orthopedics. 2023;46(6):327-332.].

Modern Description of Antibiotic Spacer Options for PJI in Revision Total Knee Arthroplasty: Clinical Outcomes and Infection Eradication Rates

BACKGROUND

As the burden of periprosthetic joint infections (PJI) increases there is growing interest in understanding the efficacy and morbidity reduction of two-stage revision and various antibiotic spacer options. This study aimed to expand the description and evaluation of spacers from solely their articulation status to include their ability to support full (functional) or partial weight-bearing (non-functional).

METHODS

Between 2002 and 2021, 391 patients who had Musculoskeletal Infection Society criteria for PJI with one- or two-stage revision were included. Demographics, functional outcomes, and subsequent revision data was collected. The study population had a mean follow-up of 2.9 years (range, 0.05 to 13.0) with an average age of 67 years (range, 34.7 to 93.4). Spacer failure was defined by surgical intervention following definitive surgery, and infection eradication was defined by the Delphi criteria. Spacers were classified as nonfunctional static, nonfunctional dynamic, functional static, or functional dynamic. Two tailed t-tests were performed.

RESULTS

There were no significant differences in infection eradication or mechanical outcomes across spacer types; notably, 97.3% of functional dynamic spacers achieved infection eradication. Functional spacers had a longer time to the second stage procedure and a greater number of patients who had not been reimplanted. There was no difference in reoperation rates in nonfunctional versus functional spacers.

CONCLUSION

Within this cohort, infection eradication and spacer exchange rates were non-inferior among spacers. Functional spacers may allow for earlier return to daily living given the weightbearing capability when compared to non-functional, without sacrificing clinical outcome.

A systematic review and meta-analysis of cemented and uncemented bipolar hemiarthroplasty for the treatment of femoral neck fractures in elderly patients over 60 years old

Background

Currently, whether bone cement can be applied in bipolar hemiarthroplasty to treat femoral neck fractures (FNFs) in elderly patients is controversial. The aim of this systematic review and meta-analysis was to compare the effectiveness and safety of cemented bipolar hemiarthroplasty (CBH) versus uncemented bipolar hemiarthroplasty (UCBH) in the treatment of FNFs among elderly patients over 60 years old.

Materials and methods

The Pubmed, Web of science, Cochrane Library and EMBASE databases were searched comprehensively for relevant articles from their inception to May 2022. Studies about comparing outcomes between CBH and UCBH for FNFs in elderly patients aged more than 60 years were included. Outcomes including operation time, intra-operative blood loss, length of hospital stay, wound infections, residual pain, revisions, re-operations, complications related to prosthesis, general complications, and mortality. The Review Manager 5.3 software provided by the Cochrane Collaboration Network was used to perform the meta-analysis of comparable data.

Results

A total of 6 randomized controlled trials (RCTs) and 9 observational studies were included in this analysis, with 33,118 patients (33,127 hips). Results of the meta-analysis indicated that the operation time [WMD = 13.01 min, 95% CI (10.79, 15.23)], intra-operative blood loss [WMD = 80.57 ml, 95% CI (61.14, 99.99)], incidence of heterotrophic ossification [OR = 2.07, 95% CI (1,14, 3.78)], were increased in the CBH group but the incidence of intra-operative fractures [OR = 0.24, 95% CI (0.07, 0.86)], periprosthetic fractures [OR = 0.24, 95% CI (0.18, 0.31)], aseptic loosening of prosthesis [OR = 0.20, 95% CI (0.09, 0.44)], wound infections [OR = 0.80, 95% CI (0.68, 0.95)] and re-operation rates [OR = 0.61, 95% CI (0.54, 0.68)] were lower in the CBH group by comparison with the UCHB group. However, there were no significant differences in residual pain, length of hospital stay, prosthetic dislocation, prosthetic subsidence (> 5 mm), acetabulum erosion, revisions, pulmonary infections, pulmonary embolisms, urinary tract infections, deep venous thromboses, decubitus, cardiovascular accidents (arrhythmia/myocardial infarction), and respiratory failure between the two groups. In terms of mortality, perioperative mortality (within 72 h) [OR = 2.39, 95% CI (1.71, 3.32)] and 1-week mortality postoperatively [OR = 1.22, 95% CI (1.05, 1.41)] in CBH group were higher than those in UCBH group, but there were no significant differences in mortality at 1 month, 3 months, 1 year, and 2 years postoperatively between CBH group and UCBH group.

Conclusion

This meta-analysis found that elderly patients over 60 years old with FNFs who underwent CBH had longer operation time, higher incidence of heterotrophic ossification, intra-operative blood loss, and mortality within 72 h of operation and at 1-week postoperatively, but lower incidence of periprosthetic fractures, aseptic loosening of prosthesis, intra-operative fractures, wound infections and re-operations. Other outcomes were not significantly different between the two groups.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021274253.

Different Modification Methods of Poly Methyl Methacrylate (PMMA) Bone Cement for Orthopedic Surgery Applications

In clinical practice, bone defects that occur alongside tumors, infections, or other bone diseases present significant challenges in the orthopedic field. Although autologous and allogeneic grafts are introduced as common traditional remedies in this field, their applications have a series of limitations. Various approaches have been attempted to treat large and irregularly shaped bone defects; however, their success has been less than optimal due to a range of issues related to material and design. However, in recent years, additive manufacturing has emerged as a promising solution to the challenge of creating implants that can be perfectly tailored to fit individual defects during surgical procedures. By fabrication of constructs with specific designs using this technique, surgeons are able to achieve much better outcomes for patients. Polymers, ceramics, and metals have been used as biomaterials in Orthopedic Surgery fields. Polymeric scaffolds have been used successfully in total joint replacements, soft tissue reconstruction, joint fusion, and as fracture fixation devices. The use of polymeric biomaterials, either in the form of pre-made solid scaffolds or injectable pastes that can harden in situ, shows great promise as a substitute for commonly used autografts and allografts. Polymethyl methacrylate (PMMA) is one of the most widely used polymer cement in orthopedic surgery. The present paper begins with an introduction and will then provide an overview of the properties, advantages/disadvantages, applications, and modifications of PMMA bone cement.

Implant surface modifications as a prevention method for periprosthetic joint infection caused by Staphylococcus aureus: a systematic review and meta-analysis

Abstract. Background: Periprosthetic joint infection is the most common infection due to joint replacement. It has been reported that, over a 5-year time span, 3.7 % of cases occurred annually. This statistic has increased to 6.86 % over 16 years. Thus, an effective method is required to reduce these complications. Several strategies such as coating methods with various materials, such as antibiotics, silver, and iodine, have been reported. However, the best preventive strategy is still undetermined. Therefore, this systematic review aims to evaluate the outcome of coating methods on joint arthroplasty as a treatment or preventive management for infection complications. Methods: Eligible articles were systematically searched from multiple electronic databases (PubMed, Cochrane library, and ScienceDirect) up to 2 June 2022. Based on the criterion inclusion, eight articles were selected for this study. The Newcastle–Ottawa scale (NOS) was used to assess the quality of the study, and the meta-analysis test was conducted with Review Manager 5.4. Results: The quality of the articles in this study is in the range of moderate to good. It was found that the application of modified antibiotic coatings significantly reduced the occurrence of periprosthetic joint infection (PJI) (p 0.03), and silver coating could not significantly (p 0.47) prevent the occurrence of PJI. However, according to the whole aspect of coating modification, the use of antibiotics, silver, and iodine can minimize the occurrence of PJI (p <0.0001). Conclusion: Coating methods using antibiotics are an effective method that could significantly prevent the occurrence of PJI. On the other hand, coating with non-antibiotic materials such as silver could not significantly prevent the incidence of PJI.

Effectiveness of antibiotics loaded bone cement in primary total knee arthroplasty: A systematic review and meta-analysis

INTRODUCTION

The application of antibiotics loaded bone cement (ALBC) in the revision of failed total knee arthroplasty (TKA) has been widely accepted to reduce risk of peri-prosthetic infection. However, the prophylactic use of ALBC in primary TKA remains controversial. This study was aimed to identify the prophylactic effect on peri-prosthetic infection and safety of ALBC in primary TKA.

HYPOTHESIS

The application of ALBC could reduce the risk of peri-prosthetic infection in primary TKA.

MATERIALS AND METHODS

Electronic platforms including PubMed, EMBASE, and CENTRAL were retrieved to identify studies comparing outcomes of prophylactic ALBC and plain cement in primary TKA. For outcomes reported as dichotomous variable and continuous variable, risk ratio (RR) and weighted mean difference (WMD) as well as their 95% confidence intervals (95% CI) were selected as the effect sizes for pooling. While for those outcomes reported the adjusted effect sizes such as odds ratio (OR, derived from multivariate logistic regression), and hazard ratio (HR, derived from multivariate COX proportional hazard model), the reported effect sizes were selected for pooling.

RESULTS

A total of 17 studies with 2,074,844 patients (1,093,920 in ALBC group and 980,924 in plain cement group) were eligible for final inclusion. No significant difference was found between ALBC and plain cement groups both for the unadjusted (RR=1.02, 95% CI: 0.86∼1.21, p=0.832) and adjusted (OR=0.94, 95% CI: 0.76∼1.17, p=0.596) peri-prosthetic infection rate. ALBC application was related to significantly increased length of hospital stay (WMD=0.13, 95% CI: 0.10∼0.17, p<0.001). There was no significance on the difference of operation related adverse events between two groups (RR=1.31, 95% CI: 0.68∼2.52, p=0.420). Significantly increased risks of acute renal failure and readmission, and temporarily increased ototoxicity in ALBC group were reported in one of the primary study.

DISCUSSION

There is no sufficient evidence supporting decreased peri-prosthetic infection rate with ALBC application in primary TKA. What's more, it must be taken into consideration about the safety and added cost of additional impregnated antibiotics.

LEVEL OF EVIDENCE

III; meta-analysis.

A PMMA bone cement with improved antibacterial function and flexural strength

A novel non-leaching antibacterial bone cement has been developed and evaluated. An antibacterial furanone derivative was synthesized and covalently coated onto the surface of alumina filler particles, followed by mixing into a conventional poly(methyl methacrylate) bone cement. Flexural strength and bacterial viability were used to evaluate the modified cements. Effects of coated antibacterial moiety content, coated alumina filler particle size and loading were investigated. Results showed that almost all the modified cements showed higher flexural strength (up to 10%), flexural modulus (up to 18%), and antibacterial activity (up to 67% to S. aureus and up to 84% to E. coli), as compared to original poly(methyl methacrylate) cement. Increasing antibacterial moiety and filler loading significantly enhanced antibacterial activity. On the other hand, increasing coated filler particle size decreased antibacterial activity. Increasing antibacterial moiety content and particle size did not significantly affect flexural strength and modulus. Increasing filler loading did not significantly affect flexural modulus but reduced flexural strength. Antibacterial agent leaching tests showed that it seems no leachable antibacterial component from the modified experimental cement to the surrounding environment. Within the limitations of this study, the modified poly(methyl methacrylate) bone cement may potentially be developed into a clinically useful bone cement for reducing in-surgical and post-surgical infection.

Antibiotic-free antimicrobial poly (methyl methacrylate) bone cements: A state-of-the-art review

Prosthetic joint infection (PJI) is the most serious complication following total joint arthroplasty, this being because it is associated with, among other things, high morbidity and low quality of life, is difficult to prevent, and is very challenging to treat/manage. The many shortcomings of antibiotic-loaded poly (methyl methacrylate) (PMMA) bone cement (ALBC) as an agent for preventing and treating/managing PJI are well-known. One is that microorganisms responsible for most PJI cases, such as methicillin-resistant S. aureus, have developed or are developing resistance to gentamicin sulfate, which is the antibiotic in the vast majority of approved ALBC brands. This has led to many research efforts to develop cements that do not contain gentamicin (or, for that matter, any antibiotic) but demonstrate excellent antimicrobial efficacy. There is a sizeable body of literature on these so-called "antibiotic-free antimicrobial" PMMA bone cements (AFAMBCs). The present work is a comprehensive and critical review of this body. In addition to summaries of key trends in results of characterization studies of AFAMBCs, the attractive features and shortcomings of the literature are highlighted. Shortcomings provide motivation for future work, with some ideas being formulation of a new generation of AFAMBCs by, example, adding a nanostructured material and/or an extract from a natural product to the powder and/or liquid of the basis cement, respectively.

Regulatory perspectives of combination products

Combination products with a wide range of clinical applications represent a unique class of medical products that are composed of more than a singular medical device or drug/biological product. The product research and development, clinical translation as well as regulatory evaluation of combination products are complex and challenging. This review firstly introduced the origin, definition and designation of combination products. Key areas of systematic regulatory review on the safety and efficacy of device-led/supervised combination products were then presented. Preclinical and clinical evaluation of combination products was discussed. Lastly, the research prospect of regulatory science for combination products was described. New tools of computational modeling and simulation, novel technologies such as artificial intelligence, needs of developing new standards, evidence-based research methods, new approaches including the designation of innovative or breakthrough medical products have been developed and could be used to assess the safety, efficacy, quality and performance of combination products. Taken together, the fast development of combination products with great potentials in healthcare provides new opportunities for the advancement of regulatory review as well as regulatory science.

Contribution of Minimally Invasive Bone Augmentation With PMMA Cement in Primary Fixation of Schatzker Type II Tibial Plateau Fractures

Background: The most common type of fracture of the lateral tibial plateau is the Schatzker type II split-depressed fracture. Minimally invasive surgery using balloon reduction appears to be very promising compared to the gold standard using a bone tamp. This surgery aims to have the best reduction and stabilization to benefit from an early passive and active rehabilitation to avoid stiffening and muscle wasting. Using a balloon for fracture reduction has allowed the use of semi-liquid Injectable Bone Cement (IBC) fillers. These fillers can be phosphocalcic or polymethyl methacrylate (PMMA). The latest recommendations on these IBCs in spinal surgery increasingly rule out phosphocalcic fillers because of their low mechanical strength.

Questions/purposes: 1) What is the mechanical influence of IBC filling (PMMA) regarding the split and depression components of a Schatzker type II fracture? 2) What is the mechanical influence of osteosynthesis regarding the split and depression components of a Schatzker type II fracture with or without PMMA filing in three different kinds of percutaneous fixations?

Methods: This biomechanical study was performed on 36 fresh frozen tibia/fibula specimens. Six groups were formed according to the type of percutaneous osteosynthesis or possible PMMA filling. Mechanical strength tests were carried out using a Unicompartmental Knee prosthesis and displacement components were measured on either side of the separation on the anterolateral facet by optical method.

Results: We found a significant difference between cementless and cemented osteosynthesis for depression fracture stabilization (difference −507.56N with 95% confidence interval [−904.17; −110.94] (p-value = 0.026)). The differences between the different types of osteosynthesis were not significant (p-value = 0.58). There was a significant difference between osteosynthesis without cement and osteosynthesis with cement on separation (difference −477.72N [−878.52; −76.93] (p-value = 0.03)). The differences between the different types of fixations were not significant regarding separation (p-value = 0.99).

Conclusion: PMMA cement significantly improves primary stability, regardless of the type of osteosynthesis for a Schatzker type II plateau fracture. Filling with PMMA cement during tuberoplasty seems to be a very promising strategy in association with percutaneous osteosynthesis to allow rapid recovery after surgery.

Influence of Different Nanometals Implemented in PMMA Bone Cement on Biological and Mechanical Properties

Cemented arthroplasty is a common process to fix prostheses when a patient becomes older and his/her bone quality deteriorates. The applied cements are biocompatible, can transfer loads, and dampen vibrations, but do not provide antibacterial protection. The present work is aimed at the development of cement with antibacterial effectivity achieved with the implementation of nanoparticles of different metals. The powders of Ag, Cu with particles size in a range of 10–30 nm (Cu10) and 70–100 nm (Cu70), AgCu, and Ni were added to PMMA cement. Their influence on compression strength, wettability, and antibacterial properties of cement was assessed. The surface topography of samples was examined with biological and scanning electron microscopy. The mechanical properties were determined by compression tests. A contact angle was observed with a goniometer. The biological tests included an assessment of cytotoxicity (XTT test on human cells Saos-2 line) and bacteria viability exposure (6 months). The cements with Ag and Cu nanopowders were free of bacteria. For AgCu and Ni nanoparticles, the bacterial solution became denser over time and, after 6 months, the bacteria clustered into conglomerates, creating a biofilm. All metal powders in their native form in direct contact reduce the number of eukaryotic cells. Cell viability is the least limited by Ag and Cu particles of smaller size. All samples demonstrated hydrophobic nature in the wettability test. The mechanical strength was not significantly affected by the additions of metal powders. The nanometal particles incorporated in PMMA-based bone cement can introduce long-term resistance against bacteria, not resulting in any serious deterioration of compression strength.

Anti-infection mechanism of a novel dental implant made of titanium-copper (TiCu) alloy and its mechanism associated with oral microbiology

This work was focused on study of anti-infection ability and its underlying mechanism of a novel dental implant made of titanium-copper (TiCu) alloy. In general, most studies on antibacterial implants have used a single pathogen to test their anti-infection ability using infectious animal models. However, dental implant-associated infections are polymicrobial diseases. We innovatively combine the classic ligature model in dogs with sucrose-rich diets to induce oral infections via the canine native oral bacteria. The anti-infection ability, biocompatibility and underlying mechanism of TiCu implant were systematically investigated in comparison with pure Ti implant via general inspection, hematology, imageology (micro-CT), microbiology (16S rDNA and metagenome), histology, and Cu ion detections. Compared with Ti implant, TiCu implant demonstrated remarkable anti-infection potentials with excellent biocompatibility. Additionally, the underlying anti-infection mechanism of TiCu implant was considered to involve maintaining the oral microbiota homeostasis. It was found that the carbohydrates in the plaques formed on the surface of TiCu implant were metabolized through the tricarboxylic acid cycle (TCA) cycles, which prevented the formation of an acidic microenvironment and inhibited the accumulation of acidogens and pathogens, thereby maintaining the microflora balance between aerobic and anaerobic bacteria.

Prophylactic Antibiofilm Activity of Antibiotic-Loaded Bone Cements against Gram-Negative Bacteria

Gram-negative bacilli can be responsible for prosthetic joint infection (PJI) even if staphylococci are the main involved pathogens. Gram-negative PJIs (GN-PJI) are considered difficult-to-treat infections due to the increase in antimicrobial resistance and biofilm formation. To minimize the risk of infection in cases of arthroplasties with cemented prosthesis, bone cement can be loaded with antibiotics, especially gentamicin. In this study, we aimed to compare the prophylactic antibiofilm activity of ready-to-use antibiotic-loaded bone cements (ALBC), already commercialized or new prototypes. We compared ALBCs containing gentamicin alone, gentamicin plus vancomycin, gentamicin plus clindamycin, gentamicin plus Fosfomycin, and fosfomycin alone, to plain cement (no antibiotic); these comparisons were conducted to investigate the biofilm formation of three strains of Escherichia coli, three strains of Pseudomonas aeruginosa and two strains of Klebsiella pneumoniae, with or without specific resistance to gentamicin or fosfomycin. We reported that ALBC containing gentamicin and clindamycin (COPAL G+C) seems to be the most interesting ALBC of our tested panel for the prevention of biofilm formation by gentamicin-susceptible strains, even if clindamycin is not effective against Gram-negative bacteria. However, gentamicin-resistant strains are still a problem, and further studies are needed to identify an antibiotic to associate with gentamicin for an efficient dual ALBC against Gram-negative bacteria.

Cement Loaded With High-Dose Gentamicin and Clindamycin Reduces the Risk of Subsequent Infection After One-Stage Hip or Knee Arthroplasty Exchange for Periprosthetic Infection: A Preliminary Study

BACKGROUND

The use of antibiotic-loaded acrylic cement for treating periprosthetic joint infections remains controversial. We hypothesized that the raw rate of surgical site infection (SSI) is lower after using cement loaded with high-dose gentamicin and clindamycin than after using cement loaded with standard-dose gentamicin for implant fixation during 1-stage hip and knee revision arthroplasty for infection.

METHODS

One hundred seventy-one continuous patients operated by 2 experienced surgeons during a 2-year period were included in the study. All patients were followed for 24 months. The primary endpoint was the raw rate of SSI after 2 years of follow-up time.

RESULTS

The raw rate of SSI after 2 years of follow-up time was significantly lower in the study group (13%) than in the control group (26%) (P = .03) with an odds ratio of 0.42 (P = .03). These SSIs were new infections rather than a recurrence/persistence of the initial infection.

CONCLUSION

The cement used in the study group significantly reduced the risk of SSI relative to the cement used in the control group. Routine use of this high-dose dual antibiotic-loaded cement can be considered during 1-stage knee or hip revision arthroplasty for infection.

Different microbial and resistance patterns in primary total knee arthroplasty infections - a report on 283 patients from Lithuania and Sweden

Background

The microbiology and the susceptibility patterns of infected total knee arthroplasties (TKAs) vary depending on demographic, local antimicrobial stewardship, and surgical factors. We wanted to compare the recent microbial profile and antimicrobial resistance pattern in revisions due to infections after primary TKAs in Sweden and Lithuania. Our hypothesis was that there is a difference in bacteriology and resistance pattern based on patient related, societal and local hospital factors as almost similar praxis have been applied for TKA surgery, short term systemic prophylaxis and routine use of local gentamicin containing bone cement.

Methods

Primary TKAs revised for the first time due to verified or suspected infection were collected nationwide in Sweden during 2018, and in Lithuania between 2011 and 2020 from a single major TKA revision centre in Kaunas. We identified 202 TKAs in Sweden from the Swedish Knee Arthroplasty Register and 84 from Kaunas revised due to infection. We collected available culture reports and evaluated the type of microorganisms with antimicrobial resistance pattern at revision.

Results

The majority of the infected cases in Sweden were early-type prosthetic joint infection (PJI) (44%), whereas late-type PJI (52%) were more common in the Kaunas cases. Gram-positive bacteria prevailed in both Sweden (55%) and Lithuania (80%). Staphylococcus aureus was the most frequent organism identified in both countries (33% in Sweden and 34% in Lithuania). More polymicrobial infections were observed in Sweden than in Lithuania (16 and 6% respectively). Methicillin resistance in Staphylococcus aureus and coagulase-negative staphylococci were higher in Lithuania (4/28 and 19/29) than in Sweden (1/42 and 9/41).

Conclusions

The type of infections, microbial profile, and drug resistance pattern differed between Sweden and Lithuania. Societal and local hospitals factors with emerging resistance in Lithuania are the most plausible explanation for the difference. Lack of complete data on a national level in Lithuania underlines the importance of adding microbiology of PJIs in implant registers for national aggregation and allow cross country comparisons.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04689-5.

Patients' risk factors for periprosthetic joint infection in primary total hip arthroplasty: a meta-analysis of 40 studies

BACKGROUND

Periprosthetic joint infection (PJI) is a catastrophic complication after total hip arthroplasty (THA). Our meta-analysis aimed to identify the individual-related risk factors that predispose patients to PJI following primary THA.

METHODS

Comprehensive literature retrieval from Pubmed, Web of Science, and the Cochrane Library was performed from inception to Feb 20th, 2021. Patient-related risk factors were compared as per the modifiable factors (BMI, smoke and alcohol abuse), non-modifiable factors (gender, age), and medical history characteristics, such as diabetes mellitus (DM), avascular necrosis (AVN) of femoral head, femoral neck fracture, rheumatoid arthritis (RA), cardiovascular disease (CVD), and osteoarthritis (OA) etc. The meta-analysis was applied by using risk ratios with 95% corresponding intervals. Sensitivity analysis and publication bias were performed to further assess the credibility of the results.

RESULTS

Overall, 40 studies with 3,561,446 hips were enrolled in our study. By implementing cumulative meta-analysis, higher BMI was found associated with markedly increased PJI risk after primary THA [2.40 (2.01-2.85)]. Meanwhile, medical characteristics including DM [1.64 (1.25-2.21)], AVN [1.65 (1.07-2.56)], femoral neck fracture [1.75 (1.39-2.20)], RA [1.37 (1.23-1.54)], CVD [1.34 (1.03-1.74)], chronic pulmonary disease (CPD) [1.22 (1.08-1.37)], neurological disease [1.19 (1.05-1.35)], opioid use [1.53 (1.35-1.73)] and iron-deficiency anemia (IDA) [1.15 (1.13-1.17)] were also significantly correlated with higher rate of PJI. Conversely, dysplasia or dislocation [0.65 (0.45-0.93)], and OA [0.70 (0.62-0.79)] were protective factors. Of Note, female gender was protective for PJI only after longer follow-up. Besides, age, smoking, alcohol abuse, previous joint surgery, renal disease, hypertension, cancer, steroid use and liver disease were not closely related with PJI risk.

CONCLUSION

Our finding suggested that the individual-related risk factors for PJI after primary THA included high BMI, DM, AVN, femoral neck fracture, RA, CVD, CPD, neurological disease, opioid use and IDA, while protective factors were female gender, dysplasia/ dislocation and OA.

Antibiotic-Loaded Bone Cement in Prevention of Periprosthetic Joint Infections in Primary Total Knee Arthroplasty: A Register-based Multicentre Randomised Controlled Non-inferiority Trial (ALBA trial)

INTRODUCTION

The current evidence on the efficacy of antibiotic-loaded bone cement (ALBC) in reducing the risk of periprosthetic joint infections (PJI) after primary joint reconstruction is insufficient. In several European countries, the use of ALBC is routine practice unlike in the USA where ALBC use is not approved in low-risk patients. Therefore, we designed a double-blinded pragmatic multicentre register-based randomised controlled non-inferiority trial to investigate the effects of ALBC compared with plain bone cement in primary total knee arthroplasty (TKA).

METHODS AND ANALYSIS

A minimum of 9,172 patients undergoing full-cemented primary TKA will be recruited and equally randomised into the ALBC group and the plain bone cement group. This trial will be conducted in Norwegian hospitals that routinely perform cemented primary TKA. The primary outcome will be risk of revision surgery due to PJI at 1-year of follow-up. Secondary outcomes will be: risk of revision due to any reason including aseptic loosening at 1, 6, 10 and 20 years of follow-up; patient-related outcome measures like function, pain, satisfaction and health-related quality of life at 1, 6 and 10 years of follow-up; risk of changes in the microbial pattern and resistance profiles of organisms cultured in subsequent revisions at 1, 6, 10 and 20 years of follow-up; cost-effectiveness of routine ALBC versus plain bone cement use in primary TKA. We will use 1:1 randomisation with random permuted blocks and stratify by participating hospitals to randomise patients to receive ALBC or plain bone cement. Inclusion, randomisation and follow-up will be through the Norwegian Arthroplasty Register.

ETHICS AND DISSEMINATION

The trial was approved by the Western Norway Regional Committees on Medical and Health Research Ethics (reference number: 2019/751/REK vest) on 21 June 2019. The findings of this trial will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04135170.

The Role of Chitosan and Graphene Oxide in Bioactive and Antibacterial Properties of Acrylic Bone Cements

Acrylic bone cements (ABC) are widely used in orthopedics for joint fixation, antibiotic release, and bone defect filling, among others. However, most commercially available ABCs exhibit a lack of bioactivity and are susceptible to infection after implantation. These disadvantages generate long-term loosening of the prosthesis, high morbidity, and prolonged and expensive treatments. Due to the great importance of acrylic bone cements in orthopedics, the scientific community has advanced several efforts to develop bioactive ABCs with antibacterial activity through several strategies, including the use of biodegradable materials such as chitosan (CS) and nanostructures such as graphene oxide (GO), with promising results. This paper reviews several studies reporting advantages in bioactivity and antibacterial properties after incorporating CS and GO in bone cements. Detailed information on the possible mechanisms by which these fillers confer bioactive and antibacterial properties to cements, resulting in formulations with great potential for use in orthopedics, are also a focus in the manuscript. To the best of our knowledge, this is the first systematic review that presents the improvement in biological properties with CS and GO addition in cements that we believe will contribute to the biomedical field.

Prevention of Prosthetic Joint Infection: From Traditional Approaches towards Quality Improvement and Data Mining

A projected increased use of total joint arthroplasties will naturally result in a related increase in the number of prosthetic joint infections (PJIs). Suppression of the local peri-implant immune response counters efforts to eradicate bacteria, allowing the formation of biofilms and compromising preventive measures taken in the operating room. For these reasons, the prevention of PJI should focus concurrently on the following targets: (i) identifying at-risk patients; (ii) reducing “bacterial load” perioperatively; (iii) creating an antibacterial/antibiofilm environment at the site of surgery; and (iv) stimulating the local immune response. Despite considerable recent progress made in experimental and clinical research, a large discrepancy persists between proposed and clinically implemented preventative strategies. The ultimate anti-infective strategy lies in an optimal combination of all preventative approaches into a single “clinical pack”, applied rigorously in all settings involving prosthetic joint implantation. In addition, “anti-infective” implants might be a choice in patients who have an increased risk for PJI. However, further progress in the prevention of PJI is not imaginable without a close commitment to using quality improvement tools in combination with continual data mining, reflecting the efficacy of the preventative strategy in a particular clinical setting.