Efficacy of antibiotic-impregnated cement in total hip replacement

Evidence for cemented TKA and THA based on a comparison of international register data

BACKGROUND

Hip and knee implants can either be fixed without cement, press-fit, or with bone cement. Real-world data from arthroplasty registers, as well as studies provide a broad database for the discussion of cemented versus uncemented arthroplasty procedures.

OBJECTIVE

What does current evidence from international arthroplasty registries and meta-analyses recommend regarding cemented or cementless fixation of hip and knee implants?

METHODS

A recommendation is generated by means of direct data comparison from the arthroplasty registries of eight countries (USA, Germany, Australia, UK, Sweden, Norway, New Zealand, Netherlands), the comparison of 22 review studies and meta-analyses based on registry data, as well as an evaluation of recommendations of healthcare systems from different nations. For this purpose, reviews and meta-analyses were selected where the results were statistically significant, as were the annual reports of the arthroplasty registries that were current at the time of writing.

RESULTS

For knee arthroplasties, long survival time as well as lower risk of revision can be achieved with the support of cemented fixation with antibiotic-loaded bone cement. In patients aged 70 years and older, cemented fixation of hip stem implants significantly reduces risk of intraoperative or postoperative periprosthetic fracture (quadruple). This applies both to elective total hip arthroplasties and to hemiarthroplasty after femoral neck fractures. Antibiotic-loaded bone cement significantly (p = 0.041) reduces the risk of periprosthetic infection, especially in patients with femoral neck fractures.

CONCLUSION

Total knee replacement with antibiotic-loaded bone cement is well established internationally and is evidence-based. Registry data and meta-analyses recommend cemented fixation of the hip stem in older patients. In Germany, USA and Australia these evidence-based recommendations still must be transferred to daily practice.

[Translated article] Vancomycin powder in the prevention of infection in primary knee and hip arthroplasty: Case-control study with 1151 arthroplasties

BACKGROUND AND OBJECTIVE

Vancomycin powder (VP) has been positively used in spinal surgery to reduce the rate of infections. Hardly any data have been published on hip and knee joint replacement surgery, and its usefulness is questioned. Our objective was to investigate the effectiveness of VP in reducing prosthetic infection and its possible complications.

METHODS

Primary hip (THA) and knee (TKA) arthroplasties were reviewed, performed by five surgeons in one hospital centre, between 2017 and 2018. One gram of VP was used on the implant prior to surgical closure based on the surgeon's preferences. With a 5-year follow-up in which the infection rate and local complications were analysed.

RESULTS

One thousand one hundred and fifty-one arthroplasties were performed, 748 were TKA and 403 were THA. Nine patients were diagnosed with prosthetic infection, of which five received VP and four did not (p=0.555). Likewise, another 15 patients suffered wound complications, of which 11 received VP and 4 did not (p=0.412). There were no differences, either, in the rest of the complications depending on the use or not of VP (p=0.101). Likewise, the number of patients who needed reintervention was similar (p=0.999). No systemic complications were detected due to the use of VP.

CONCLUSIONS

It has not been possible to demonstrate that the use of VP reduces the rates of prosthetic infection in the hip and knee, so we cannot recommend its use.

[Register data on cemented arthroplasty : A proof for cementless fixation?]

BACKGROUND

Hip and knee implants can be either fixated without cement, press-fit, or with bone cement. Real-world data from arthroplasty registers, as well as studies, provide a broad database for the discussion of cemented versus uncemented arthroplasty procedures.

OBJECTIVES

What is the recommendation for cemented or cementless anchorage of hip and knee implants based on the current evidence from international arthroplasty registries and meta-analyses?

METHODS

A recommendation is generated by means of a direct comparison of data from the arthroplasty registries of eight different countries (USA, Germany, Australia, UK, Sweden, Norway, New Zealand, and The Netherlands), the comparison of 22 review studies and meta-analyses based on registry data, as well as the evaluation of the recommendation of healthcare systems of different nations. For this purpose, reviews and meta-analyses whose results were statistically significant were selected, as were the annual reports of the arthroplasty registries that were current at the time of writing.

RESULTS

For knee endoprostheses, a long survival time, as well as a lower risk of revision can be achieved with the help of cemented anchorage with antibiotic-laden bone cement. In patients aged 70 years and older, cemented anchorage of the hip stem implant significantly reduces the risk of intraoperative or postoperative periprosthetic fracture (times four), this applies both to elective total hip arthroplasties (TEPs) and to hemiarthroplasty after femoral neck fractures. Antibiotic-loaded bone cement significantly (p = 0.041) reduces the risk of periprosthetic infection, especially in patients with femoral neck fractures.

CONCLUSIONS

Total knee replacement with antibiotic-loaded bone cement is well established in Germany and evidence based. Registry data and meta-analyses recommend cemented fixation of the hip stem in older patients-in Germany the evidence-based recommendations must still be transferred to daily practice.

The Effect of Povidone-Iodine Irrigation on the Efficacy of Antibiotic Cement In Vitro

Povidone-iodine is a common antiseptic demonstrating success in reducing infection rates in primary arthroplasty; however, recent data suggest that its use in revision arthroplasty may increase infection rates. This study evaluated the effect of povidone-iodine solution on antibiotic cement and investigated the connection between povidone-iodine and increased infection rates in revision arthroplasty. Sixty antibiotic cement samples (ACSs) were formed using gentamicin-impregnated cement. The ACSs were divided into three groups: group A (n=20) was subject to a 3-minute povidone-iodine soak followed by a saline rinse; group B (n=20) underwent a 3-minute saline soak; and group C (n=20) underwent only a saline rinse. The antimicrobial activity of the samples was tested using a Kirby-Bauer-like assay using Staphylococcus epidermidis. The zone of inhibition (ZOI) was measured every 24 hours for 7 days. All groups possessed the greatest antimicrobial activity at 24 hours. Group C displayed a mass-corrected ZOI of 395.2 mm/g, which was statistically greater than the group B ZOI (313.2 mm/g, P<.05) but not the group A ZOI (346.5 mm/g, P>.05). All groups demonstrated a decrease in antimicrobial activity at 48 through 96 hours, with no significant difference at any time point. Prolonged soaking of antibiotic cement in a povidone-iodine or saline solution results in elution of the antibiotic into the irrigation solution, blunting initial antibiotic concentration. When using antibiotic cement, antiseptic soaks or irrigation should be focused prior to cementation. [Orthopedics. 2024;47(1):10-14.].

Vancomycin powder in the prevention of infection in primary knee and hip arthroplasty: Case-control study with 1151 arthroplasties

BACKGROUND AND OBJECTIVE

Vancomycin powder (VP) has been positively used in spinal surgery to reduce the rate of infections. Hardly any data have been published on hip and knee joint replacement surgery, and its usefulness is questioned. Our objective was to investigate the effectiveness of VP in reducing prosthetic infection and its possible complications.

METHODS

Primary hip (THA) and knee (TKA) arthroplasties were reviewed, performed by five surgeons in one hospital center, between 2017 and 2018. 1g of VP was used on the implant prior to surgical closure based on the surgeon's preferences. With a 5-year follow-up in which the infection rate and local complications were analyzed.

RESULTS

One thousand one hundred and fifty one arthroplasties were performed, 748 were TKA and 403 were THA. Nine patients were diagnosed with prosthetic infection, of which five received VP and four did not (P=.555). Likewise, another 15 patients suffered wound complications, of which 11 received VP and 4 did not (P=.412). There were no differences, either, in the rest of the complications depending on the use or not of VP (P=.101). Likewise, the number of patients who needed reintervention was similar (P=.999). No systemic complications were detected due to the use of VP.

CONCLUSIONS

It has not been possible to demonstrate that the use of VP reduces the rates of prosthetic infection in the hip and knee, so we cannot recommend its use.

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.].

Nanocomposite orthopaedic bone cement combining long-acting dual antimicrobial drugs

Antibiotic loaded bone cements are widely used in total joint replacement (TJR); despite many limitations such as a burst release which leads to antibiotic concentration below inhibitory levels and possibly contributing to the selection of antibiotic resistant strains. In order to address such limitations and to simultaneously address antibiotic resistance and short-term antimicrobial activity, we developed a nanocomposite bone cement capable of providing a controlled release of antimicrobial agents from bone cement to act as prophylaxis or treatment against prosthetic joint infections (PJIs). Gentamicin and chlorhexidine were loaded in combination on silica nanoparticles surface using layer-by-layer coating technique (LbL) combining hydrolysable and non-hydrolysable polymers. The drug release from the nanocomposite continued for >50 days at concentrations higher than the commercial formulation containing the same amount of antimicrobial drugs, where burst release for few days were observed. Moreover, the nanocomposite bone cement showed superior antimicrobial inhibition without adversely affecting the mechanical properties or the ability of osteoblasts to grow. In vivo experiments with an infected bone lesion model along with mass-spectrometric analysis also provided further evidence of efficacy and safety of the implanted nanocomposite material as well as its prolonged drug eluting profile. The developed nanocomposite bone cement has the potential to reduce PJIs and enable treatment of resistant established infections; moreover, the newly developed LbL based nano-delivery system may also have wider applications in reducing the threat posed by antimicrobial resistance.

Evaluating the Translational Potential of Bacteriocins as an Alternative Treatment for Staphylococcus aureus Infections in Animals and Humans

Antibiotic resistance remains a global threat to human and animal health. Staphylococcus aureus is an opportunistic pathogen that causes minor to life-threatening infections. The widespread use of antibiotics in the clinical, veterinary, and agricultural setting combined with the increasing prevalence of antibiotic-resistant S. aureus strains makes it abundantly clear that alternatives to antibiotics are urgently needed. Bacteriocins represent one potential alternative therapeutic. They are antimicrobial peptides that are produced by bacteria that are generally nontoxic and have a relatively narrow target spectrum, and they leave many commensals and most mammalian cells unperturbed. Multiple studies involving bacteriocins (e.g., nisin, epidermicin, mersacidin, and lysostaphin) have demonstrated their efficacy at eliminating or treating a wide variety of S. aureus infections in animal models. This review provides a comprehensive and updated evaluation of animal studies involving bacteriocins and highlights their translational potential. The strengths and limitations associated with bacteriocin treatments compared with traditional antibiotic therapies are evaluated, and the challenges that are involved with implementing novel therapeutics are discussed.

Robotic-assisted knee replacement surgery & infection: A historical foundation, systematic review and meta-analysis

Background

An increasing proportion of Knee arthroplasty is performed using robotic-assisted surgical techniques. This study sought to use a meta-analytical approach to establish summary rates of surgical site infection in robotic-assisted procedures and compare the rate of deep infections to those seen in conventional knee arthroplasty.

Methods

This study performed a literature search across four online databases to establish a summary rate of surgical site infection across two categories: deep infection and superficial and pin-site infections. This was processed with the aid of a bespoke data-extraction tool. Risk of Bias analysis was performed using the Cochrane RoB2 tool. Meta-analysis was then performed with tests for heterogeneity and a DerSimonian-Laird random effects model.

Results

A total of 17 studies were identified as appropriate for inclusion in the meta-analysis. The summary rate of overall surgical site infections within one year of robotic knee arthroplasty was found to be 0.568% (SE = 0.183, 95% CI = 0.209-0.927). Deep infections fell to 0.154% (SE = 0.069, 95% CI = 0.018-0.290) and to 0.347% (SE = 0.109, 95% CI = 0.133-0.561) in superficial and pin-site infections.

Conclusion

The surgical site infection rates were found to be low across robotic knee arthroplasty. Further research is required to prove its superiority compared to the conventional, non-robotic technique.

Evidence for Local Antibiotics in the Prevention of Infection in Orthopaedic Trauma

Prevention of fracture-related infection (FRI) remains a substantial challenge in orthopaedic trauma care. There is evolving evidence to support the use of local antibiotics for both the prevention and treatment of musculoskeletal infection. Local antibiotics can achieve higher local tissue concentrations with a lower risk of systemic complications compared to intravenously administered antibiotics. These antibiotics may be administered in powder or liquid form without carrier, or if sustained release is desired, using a carrier. Polymethylmethacrylate (PMMA), ceramics, and hydrogels are examples of antibiotic carriers. Unlike PMMA, ceramics and hydrogels have the advantage of not requiring a second surgery for removal. The VANCO trial supported the use of powdered vancomycin in high-risk fracture cases for the reduction of Gram-positive infections; although, data is limited. Future studies will evaluate the use of aminoglycoside antibiotics to address Gram-negative infection prevention. While theoretical concerns exist with the use of local antibiotics, available studies suggest local antibiotics are safe with a low-risk of adverse effects.

Strategies to Mitigate and Treat Orthopaedic Device-Associated Infections

Orthopaedic device implants play a crucial role in restoring functionality to patients suffering from debilitating musculoskeletal diseases or to those who have experienced traumatic injury. However, the surgical implantation of these devices carries a risk of infection, which represents a significant burden for patients and healthcare providers. This review delineates the pathogenesis of orthopaedic implant infections and the challenges that arise due to biofilm formation and the implications for treatment. It focuses on research advancements in the development of next-generation orthopaedic medical devices to mitigate against implant-related infections. Key considerations impacting the development of devices, which must often perform multiple biological and mechanical roles, are delineated. We review technologies designed to exert spatial and temporal control over antimicrobial presentation and the use of antimicrobial surfaces with intrinsic antibacterial activity. A range of measures to control bio-interfacial interactions including approaches that modify implant surface chemistry or topography to reduce the capacity of bacteria to colonise the surface, form biofilms and cause infections at the device interface and surrounding tissues are also reviewed.

Diagnosis and treatment of periprosthetic infection after hip replacement (a review)

Introduction. The frequency of hip arthroplasty is steadily increasing throughout the world and, although this operation has become routine, the likelihood of postoperative complications reaches 4.3 % [1]. The most dangerous of them are infectious lesions in the area of the endoprosthesis and adjacent tissues. At the same time, in addition to the threat of generalization of the infectious process, there are functional disorders in the joint area and a general deterioration in the quality of life of the patient. Timely diagnosis and treatment of the infectious process and related disorders can minimize the adverse effects of infection.

Target. The purpose of this review is to analyze modern methods for diagnosing and treating periprosthetic infection resulting from hip replacement.

Materials and methods. The subject literature was searched using the PubMed and Google Sholar databases.

Results. The main methods for diagnosing periprosthetic infection include histological and bacteriological examination of the biopsy specimen, determination of sensitivity to antibiotics, blood, and synovial fluid analysis for the content of leukocytes, IL-6, CRP, PCR diagnostics of infectious agents. Treatment consists of re-intervention and/or antibiotic therapy.

Conclusion. The most optimal method for diagnosing periprosthetic infection is a bacteriological study of biopsy specimens taken intraoperatively. The preferred method of treatment is determined by the severity of the infection, the degree of involvement of tissues adjacent to the prosthesis, the comorbid background, the nature of the infectious agent, and includes repeated revision surgery.

Comprehensive meta-analysis of antibiotic-impregnated bone cement versus plain bone cement in primary total knee arthroplasty for preventing periprosthetic joint infection

PURPOSE

Antibiotic-loaded bone cement (ALBC) was usually used to prevent periprosthetic joint infection (PJI) in primary total knee arthroplasty (PTKA), but whether to use ALBC or plain bone cement in PTKA remains unclear. We aimed to compare the occurrence rate of PJI using two different cements, and to investigate the efficacy of different antibiotic types and doses administered in preventing surgical site infection (SSI) with ALBC.

METHODS

The availability of ALBC for preventing PJI was evaluated by using a systematic review and meta-analysis referring to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Existing articles until December 2021 involving PTKA patients with both ALBC and plain bone cement cohorts were scanned by searching "total knee arthroplasty", "antibiotic-loaded cement", "antibiotic prophylaxis", "antibiotic-impregnated cement" and "antibiotic-laden cement" in the database of PubMed/MEDLINE, Embase, Web of Science and the Cochrane Library. Subgroup analysis included the effectiveness of different antibiotic types and doses in preventing SSI with ALBC. The modified Jadad scale was employed to score the qualities of included articles.

RESULTS

Eleven quantitative studies were enrolled, including 34,159 knees undergoing PTKA. The meta-analysis results demonstrated that the use of prophylactic ALBC could significantly reduce the prevalence of deep incisional SSI after PTKA, whereas there was no significant reduction in the rate of superficial incisional SSI. Moreover, gentamicin-loaded cement was effective in preventing deep incisional SSI, and the use of high-dose ALBC significantly reduced the rate of deep incisional SSI after PTKA. Besides, no significant adverse reactions and complications were stated during the use of ALBC in PTKA.

CONCLUSION

The preventive application of ALBC during PTKA could reduce the rates of deep PJI. Furthermore, bone cement containing gentamicin and high-dose ALBC could even better prevent deep infection after PTKA. However, the existing related articles are mostly single-center and retrospective studies, and further high-quality ones are needed for confirmation.

The Cost-Effectiveness of Extended Oral Antibiotic Prophylaxis for Infection Prevention After Total Joint Arthroplasty in High-Risk Patients

BACKGROUND

Extended oral antibiotic prophylaxis may decrease rates of prosthetic joint infection (PJI) after total joint arthroplasty (TJA) in patients at high risk for infection. However, the cost-effectiveness of this practice is not clear. In this study, we used a break-even economic model to determine the cost-effectiveness of routine extended oral antibiotic prophylaxis for PJI prevention in high-risk TJA patients.

METHODS

Baseline PJI rates in high-risk patients, the cost of revision arthroplasty for PJI, and the costs of extended oral antibiotic prophylaxis regimens were obtained from the literature and institutional purchasing records. These variables were incorporated in a break-even economic model to calculate the absolute risk reduction (ARR) in infection rate necessary for extended oral antibiotic prophylaxis to be cost-effective. ARR was used to determine the number needed to treat (NNT).

RESULTS

Extended oral antibiotic prophylaxis with Cefadroxil in patients at high risk for PJI was cost-effective at an ARR in baseline infection rate of 0.187% (NNT = 535) and 0.151% (NNT = 662) for TKA and THA, respectively. Cost-effectiveness was preserved with varying costs of antibiotic regimens, PJI treatment costs, and infection rates.

CONCLUSION

The use of extended oral antibiotic prophylaxis may reduce PJI rates in patients at high risk for infection following TJA and appears to be cost-effective. However, the current evidence supporting this practice is limited in quality. The use of extended oral antibiotic prophylaxis should be weighed against the possible development of future antimicrobial resistance, which may change the value proposition.

Femoral Stem Cementation in Primary Total Hip Arthroplasty

➢

Femoral stem cementation has undergone considerable investigation since bone cement was first used in arthroplasty, leading to the evolution of modern femoral stem cementation techniques.

➢

Although there is a worldwide trend toward the use of cementless components, cemented femoral stems have shown superiority in some studies and have clear indications in specific populations.

➢

There is a large evidence base regarding cement properties, preparation, and application techniques that underlie current beliefs and practice, but considerable controversy still exists.

➢

Although the cementing process adds technical complexity to total hip arthroplasty, growing evidence supports its use in certain cohorts. As such, it is critical that orthopaedic surgeons and investigators have a thorough understanding of the fundamentals and evidence underlying modern cementation techniques.

Prevention of Orthopedic Prosthetic Infections Using Evidence-Based Surgical Site Infection Care Bundles: A Narrative Review

Background: The number of primary/revision total joint replacements (TJR) are expected to increase substantially with an aging population and increasing prevalence of comorbid conditions. The 30-day re-admission rate, in all orthopedic specialties, is 5.4% (range, 4.8%-6.0%). A recent publication has documented that the surgical site infection (SSI) infection rate associated with revision total knee (rTKR, 15.6%) and revision total hip (rTHR, 8.6%) arthroplasties are four to seven times the rate of the primary procedures (2.1%-2.2%). These orthopedic infections prolong hospital stays, double re-admissions, and increase healthcare costs by a factor of 300%. Methods: A search of PubMed/MEDLINE, EMBASE and the Cochrane Library publications, which reported the infection risk after TKR and THR, was undertaken (January 1, 1995 to December 31, 2021). The search also included documentation of evidence-based practices that lead to improved post-operative outcomes. Results: The evidence-based approach to reducing the risk of SSI was grouped into pre-operative, peri-operative, and post-operative periods. Surgical care bundles have existed within other surgical disciplines for more than 20 years, although their use is relatively new in peri-operative orthopedic surgical care. Pre-admission chlorhexidine gluconate (CHG) showers/cleansing, staphylococcal decolonization, maintenance of normothermia, wound irrigation, antimicrobial suture wound closure, and post-operative wound care has been shown to improve clinical outcome in randomized controlled studies and meta-analyses. Conclusions: Evidence-based infection prevention care bundles have improved clinical outcomes in all surgical disciplines. The significant post-operative morbidity, mortality, and healthcare cost, associated with SSIs after TJR can be reduced by introduction of evidence-based pre-operative, intra-operative, and post-operative interventions.

When and How Should I Use Antibiotic Cement in Primary and Revision Joint Arthroplasty?

Periprosthetic joint infections (PJIs) remain one of the most challenging and devastating complications associated with total joint arthroplasty. Therefore, prevention and the ability to effectively treat PJIs are critical. One such tool for both the prevention and treatment of PJIs is the use of antibiotic-loaded bone cement (ALBC). ALBC provides an effective local delivery method of antibiotics. Low dose (<2 g per 40-g batch) is commonly used for prophylaxis, while high dose (>3.6 g per 40-g batch) is used for the treatment of PJIs. This review focuses on the efficacy, safety, and cost-effectiveness of ALBC for both the prevention as well as the treatment of PJIs.

Lyophilized Human Bone Allograft as an Antibiotic Carrier: An In Vitro and In Vivo Study

Background: Antibiotics delivered from implanted bone substitute materials (BSM) can potentially be used to prevent acute infections and biofilm formation, providing high concentrations of antibiotics at the surgical site without systemic toxicity. In addition, BSM should allow osteoconductivity supporting bone healing without further surgery. Promising results have been achieved using lyophilized bone allografts mixed with antibiotics. Methods: In this study specially prepared human bone allografts were evaluated as an antibiotic carrier in vitro and in vivo. The efficacy of different antibiotic-impregnated bone allografts was measured by drug release tests in vitro and in vivo and bacterial susceptibility tests using four bacterial species usually responsible for implant-associated infections. Results: The loading procedures of allograft bone substitutes with antibiotics were successful. Some of the antibiotic concentrations exceeded the MIC90 for up to 7 days in vitro and for up to 72 h in vivo. The susceptibility tests showed that S. epidermidis ATCC 12228 was the most susceptible bacterial species in comparison to the other strains tested for all antibiotic substances. Vancomycin and rifampicin showed the best results against standard and patient-isolated strains in vitro. In vivo, new bone formation was comparable in all study groups including the control group without antibiotic loading. Conclusions: Human bone allografts showed the capacity to act as customized loaded antibiotic carriers to prevent acute infections and should be considered in the management of bone infections in combination with systemic antimicrobial therapy.

Antibiotic Cement Utilization for the Prophylaxis and Treatment of Infections in Spine Surgery: Basic Science Principles and Rationale for Clinical Use

Antibiotic bone cement (ABC) is an effective tool for the prophylaxis and treatment of osteomyelitis due to the controlled, sustained release of local antibiotics. ABC has been proven to be effective in the orthopedic fields of arthroplasty and extremity trauma, but the adoption of ABC in spine surgery is limited. The characteristics of ABC make it an optimal solution for treating vertebral osteomyelitis (VO), a serious complication following spine surgery, typically caused by bacterial and sometimes fungal and parasitic pathogens. VO can be devastating, as infection can result in pathogenic biofilms on instrumentation that is dangerous to remove. New techniques, such as kyphoplasty and novel vertebroplasty methods, could amplify the potential of ABC in spine surgery. However, caution should be exercised when using ABC as there is some evidence of toxicity to patients and surgeons, antibiotic allergies, bone cement structural impairment, and possible development of antibiotic resistance. The purpose of this article is to describe the basic science of antibiotic cement utilization and review its usage in spine surgery.

The use of antibiotic-loaded bone cement does not increase antibiotic resistance after primary total joint arthroplasty

PURPOSE

One of the preventive strategies for periprosthetic joint infection (PJI) is the use of antibiotic-loaded bone cement (ALBC) in primary total joint arthroplasty (TJA). Even though it is widely used, there are concerns about the development of antibacterial resistance. The aim of the study was to investigate whether using ALBC in primary TJA increases the antibiotic-resistant PJI. The hypothesis was that the regular use of ALBC does not increase the rate of resistant PJI.

METHODS

Patients with confirmed PJI who had revision surgery from year 2010 to 2019 were included in this international multicenter study. The ALBC group was compared to the non-ALBC TJA group from the same time period. Medical records were used to collect clinical (age, gender, body mass index, comorbidities), TJA-related (type of operation, implant type and survival) and PJI-related (cultured microorganism, antibiogram) data. Resistance to gentamicin, clindamycin and vancomycin were recorded from the antibiograms. Multiple logistic regression model was used to identify risk factors and account for the potential confounders.

RESULTS

218 patients with PJI were included in the study: 142 with gentamicin-loaded bone cement and 76 in the non-ALBC group. The average age in the ALBC group was 71 ± 10 years and 62 ± 12 years in the comparison group (p < 0.001). Coagulase negative Staphylococci (CONS) were the most common (49%) isolated pathogens. The use of ALBC did not increase the rate of any resistant bacteria significantly (OR = 0.79 (0.42-1.48), p = 0.469). The presence of CONS was associated with higher risk of antibiotic resistance.

CONCLUSIONS

The current study demonstrates no increase in antibiotic resistance due to ALBC after primary TJA. Thus, the use of ALBC during primary TJA should not be feared in the context of antimicrobial resistance.

LEVEL OF EVIDENCE

III.

"Smart" Polylactic Acid Films with Ceftriaxone Loaded Microchamber Arrays for Personalized Antibiotic Therapy

Bacterial infections are a severe medical problem, especially in traumatology, orthopedics, and surgery. The local use of antibiotics-elution materials has made it possible to increase the effectiveness of acute infections treatment. However, the infection prevention problem remains unresolved. Here, we demonstrate the fabrication of polylactic acid (PLA) “smart” films with microchamber arrays. These microchambers contain ceftriaxone as a payload in concentrations ranging from 12 ± 1 μg/cm² to 38 ± 8 μg/cm², depending on the patterned film thickness formed by the different PLA concentrations in chloroform. In addition, the release profile of the antibiotic can be prolonged up to 72 h in saline. At the same time, on the surface of agar plates, the antibiotic release time increases up to 96 h, which has been confirmed by the growth suppression of the Staphylococcus aureus bacteria. The efficient loading and optimal release rate are obtained for patterned films formed by the 1.5 wt % PLA in chloroform. The films produced from 1.5 and 2 wt % PLA solutions (thickness—0.42 ± 0.12 and 0.68 ± 0.16 µm, respectively) show an accelerated ceftriaxone release upon the trigger of the therapeutic ultrasound, which impacted as an expansion of the bacterial growth inhibition zone around the samples. Combining prolonged drug elution with the on-demand release ability of large cargo amount opens up new approaches for personalized and custom-tunable antibacterial therapy.

Antibiotic cement coating in orthopedic surgery: a systematic review of reported clinical techniques

Background

Antibiotic-containing cement and bone graft substitute-coated orthopedic implants provide the advantages of simultaneous local antibiotic delivery and internal stable fixation, aiding in both infection eradication and osseous healing. Standardized protocols pertaining to implant coating techniques in various clinical and particularly intraoperative settings are scarce, and available literature is limited. This systematic review aims to provide a summary of the available current literature reporting on custom-made coating techniques of orthopedic implants, indications, outcomes, and associated complications in clinical use.

Methods

A systematic search of the literature in PubMed, Medline, Embase, and Cochrane Library databases was performed in accordance with PRISMA guidelines. Articles reporting specifically on custom-made coating techniques of orthopedic implants in a clinical setting were eligible.

Results

A total of 41 articles with a cumulative total number of 607 cases were included. Indications for treatment mostly involved intramedullary infections after previous plate osteosynthesis or nailing. A variety of implants ranging from intramedullary nails, plates, wires, and rods served as metal cores for coating. Polymethylmethacrylate (PMMA) bone cement was most commonly used, with vancomycin as the most frequently added antibiotic additive. Chest tubes and silicone tubes were most often used to mold. Common complications are cement debonding and breakage of the metallic implant.

Conclusion

Adequate coating techniques can reduce the burden of treatment and be associated with favorable outcomes. Lack of general consensus and heterogeneity in the reported literature indicate that the perfect all-in-one implant coating method is yet to be found. Further efforts to improve implant coating techniques are warranted.

Level of evidence

III.

Novel dual-functional implants via oxygen non-thermal plasma and quaternary ammonium to promote osteogenesis and combat infections

OBJECTIVE

Implant-related infections are a primary reason for implant failures that affect millions of patients. It is of paramount importance to develop novel implants that possess the dual functions of osteogenesis-promotion and antibacterial activity. The objectives of this study were to: (1) develop novel dual-functional titanium (Ti) implants by combining oxygen non-thermal plasma and covalent bonding of antibacterial organosilicon quaternary ammonium monomers; (2) investigate the physicochemical properties, bioactivity and antibacterial effects of the modified implants for the first time.

METHODS

Surface characteristics of the modified Ti surfaces were tested. Adherence and viability of rat bone marrow-derived stem cells (rBMSCs) on the surface were evaluated. Metabolic activity of biofilm on the surfaces were measured. The stability of the dual-function after 5000 thermal cycles was also evaluated.

RESULTS

The presence of chemical bonding between Ti and organosilicon monomers demonstrated covalent immobilization of the antibacterial agents. The water contact angle of the treated Ti surfaces decreased from 70.98 ± 3.68° to 59.86 ± 4.91°. The adhesion and proliferation of rBMSCs on the modified Ti were increased by 40%, compared to control group (P < 0.05). The metabolic level of biofilms on modified Ti were reduced by more than half, compared to control (P < 0.05). The modified Ti implants exhibited cell-promotion and antibacterial stability after thermal cycles.

SIGNIFICANCE

The new dual-functional Ti implant is promising to promote osteogenesis while simultaneously preventing infections. Furthermore, the novel surface modification and processing methods have applicability to enhancing a wide range of other implants to improve bioactivity and combat infections.

PMMA bone cement containing long releasing silica-based chlorhexidine nanocarriers

Prosthetic joint infections (PJI) are still an extremely concerning eventuality after joint replacement surgery; growing antibiotic resistance is also limiting the prophylactic and treatment options. Chlorhexidine (a widely used topical non-antibiotic antimicrobial compound) coatings on silica nanoparticles capable of prolonged drug release have been successfully developed and characterised. Such nanocarriers were incorporated into commercial formulation PMMA bone cement (Cemex), without adversely affecting the mechanical performance. Moreover, the bone cement containing the developed nanocarriers showed superior antimicrobial activity against different bacterial species encountered in PJI, including clinical isolates already resistant to gentamicin. Cytocompatibility tests also showed non inferior performance of the bone cements containing chlorhexidine releasing silica nanocarriers to the equivalent commercial formulation.

Influence of Tranexamic Acid on Elution Characteristics and Compressive Strength of Antibiotic-Loaded PMMA-Bone Cement with Gentamicin

PURPOSE

The topical application of tranexamic acid (TXA) into the joint space during total joint arthroplasty (TJA) with no increase of complications, has been widely reported. We investigated the influence of TXA on antibiotic release, activity of the released antibiotic against a clinical isolate of S. aureus, and compressive strength of a widely used commercially prepared gentamicin-loaded cement brand (PALACOS R + G).

METHOD

12 bone cement cylinders (diameter and height = 6 and 12 mm, respectively) were molded. After curing in air for at least 1 h, six of the cylinders were completely immersed in 5 mL of fetal calf serum (FCS) and the other six were completely immersed in a solution consisting of 4.9 mL of FCS and 0.1 mL (10 mg) of TXA. Gentamicin elution tests were performed over 7 d. Four hundred µL of the gentamicin eluate were taken every 24 h for the first 7 d without renewing the immersion fluid. The gentamicin concentration was determined in a clinical analyzer using a homogeny enzyme immuno-assay. The antimicrobial activity of the eluate, obtained after day 7, was tested. An agar diffusion test regime was used with Staphylococcus aureus. Bacteria were grown in a LB medium and plated on LB agar plates to get a bacterial lawn. Fifty µL of each eluate were pipetted on 12-mm diameter filter discs, which were placed in the middle of the agar gel. After 24 h of cultivation at 37 °C, the zone of inhibition (ZOI) for each specimen was measured. The compressive strength of the cements was determined per ISO 5833.

RESULTS

At each time point in the gentamicin release test, the difference in gentamicin concentration, obtained from specimens immersed in the FCS solution only and those immersed in the FCS + TXA solution was not significant (p = 0.055-0.522). The same trend was seen in each of the following parameters, after 7 d of immersion: (1) Cumulative gentamicin concentration (p < 0.297); (2) gentamicin activity against S. aureus (strongly visible); (3) ZOI size (mostly > 20 mm) (p = 0.631); and (4) compressive strength (p = 0.262).

CONCLUSIONS

For the PALACOS R + G specimens, the addition of TXA to FCS does not produce significant decreases in gentamicin concentration, in the activity of the gentamicin eluate against a clinical isolate of S. aureus, the zone of inhibition of S. aureus, and in the compressive strength of the cement, after 7 d of immersion in the test solution.

Cold-Injection Molded Gentamicin-Impregnated Polymethyl Methacrylate Implants for Cranioplasty

BACKGROUND

Cranioplasty can be carried out using either fresh, frozen autologous bone or synthetic substitutes. Ordering artificial 3 dimensional (3D) implants is challenging and time consuming depending on geographical location. In this article, we share our experience using a streamlined process of producing 3D computer-assisted design (CAD) implants using commercially available 3D printers and silicone molds that can be easily replicated with consistent results and are associated with good outcomes.

OBJECTIVE

To develop patient-specific implants for patients with cranial defects that are accurate, consistent, low cost, and easy to replicate while reducing operator-dependent factors.

METHODS

We present data from 15 patients who underwent cranioplasty with 3D CAD-designed gentamicin-impregnated bone cement implants that were molded using the cold injection technique.

RESULTS

The technique was consistent in result production, required little postdemolding manipulation, and showed no dimensional variation in design. Postoperative computed tomography scans showed excellent implant fit, and patients had a low complication rate.

CONCLUSION

We have demonstrated a technique of mold preparation that is efficient and that produces a reliable result. Polymethyl methacrylate implants molded using this technique showed better reproducibility, higher accuracy, and precision than other types of implants and required minimal postdemolding clean-up.

Influence of Antibiotic-Loaded Acrylic Bone Cement Composition on Drug Release Behavior and Mechanism

Periprosthetic joint infection (PJI) is a devastating complication after total joint replacement with considerable morbidity and large economic burdens. Antibiotic-Loaded Bone Cement (ALBC) has been developed as a valuable tool for local administration and is becoming one of the most effective methods for the prevention and treatment of orthopedic infections. Controlling antibiotic release from ALBC is critical to achieve effective infection control, however, the antibiotic elution rates are generally low, and the mechanisms are poorly understood. Thus, the present study aims to investigate the effects of the basic acrylic bone cement components, including liquid/powder (monomer-to-polymer) ratios, radiopacifier, initiator, and doses of antibiotics on the porosity, antibiotic elution rates and mechanical properties of polymethylmethacrylate (PMMA) based ALBC. The obtained results from the in vitro studies suggested that a reduction in the liquid/powder ratio and an increase in the radiopacifier ratio and gentamicin doses led to increased porosity and release of antibiotic, while the initiator ratio exerted no effect on elution rates. In conclusion, we hope that by varying the composition of ALBC, we could considerably enhance the antibiotic elution rates by increasing porosity, while maintaining an adequate mechanical strength of the bone cements. This finding might provide insights into controlling antibiotic release from ALBC to achieve effective infection control after total joint replacement surgery.

Is serum gentamicin concentration modified with autologous cell-saved blood transfusion after total knee arthroplasty using tranexamic acid? A randomised control trial

BACKGROUND

Self-transfusion has been proven as an effective management of blood loss after total knee arthroplasty (TKA). Considering that the high local concentration of antibiotic from bone cement is delivered intravenously through the self-transfusion process, systematic toxicity has never been evaluated. In addition, the effectiveness of self-transfusion with the routine concomitant use of other modern blood-salvage strategies, like tranexamic acid, should also be assessed. Therefore, we performed a randomised study to assess: 1) the safety of self-transfusion in TKA by comparing the gentamicin concentrations resulting from the use or not of autologous blood transfusion; 2) the efficacy of self-transfusion in TKA, with the concomitant administration of tranexamic acid.

HYPOTHESIS

Self-transfusion in TKA elevates the serum gentamicin concentration and the potential risk of nephrotoxicity.

METHODS

The serum concentration of aminoglycosides was measured in two groups of 20 patients each, after TKA, according to the use of self-transfusion. Hemoglobin, renal function and calculated blood loss were compared at several points in time between groups.

RESULTS

The only time where there was a statistically significant difference in serum gentamicin, was at 48h postoperatively between groups [0.3 ug/mL±0.21, range: 0.15 to 0.72 vs. 0.14ug/mL±0.1, range: 0 to 0.35 (p=0.02)]. There were no significant differences in total blood loss [1341mL±501, range: 830 to 2230 vs. 1263mL±459 range: 840 to 2480 (p=0.67)] and need of allogeneic blood transfusion [3 units vs. 2 units] between groups.

CONCLUSION

The use of autologous blood transfusion was found to be safe, in terms of nephrotoxicity of aminoglycosides after TKA, but it seemed to be ineffective as a blood salvage strategy, when used concomitantly with the administration of tranexamic acid.

LEVEL OF EVIDENCE

II; low-powered randomised study. CLINICALTRIALS.

GOV REGISTRATION NUMBER

NCT04505748.

Periprosthetic Joint Infection Prophylaxis in the Elderly after Hip Hemiarthroplasty in Proximal Femur Fractures: Insights and Challenges

We review antibiotic and other prophylactic measures to prevent periprosthetic joint infection (PJI) after hip hemiarthroplasty (HHA) surgery in proximal femoral fractures (PFFs). In the absence of specific guidelines, those applied to these individuals are general prophylaxis guidelines. Cefazolin is the most widely used agent and is replaced by clindamycin or a glycopeptide in beta-lactam allergies. A personalized antibiotic scheme may be considered when colonization by a multidrug-resistant microorganism (MDRO) is suspected. Particularly in methicillin-resistant Staphylococcus aureus (MRSA) colonization or a high prevalence of MRSA-caused PJIs a glycopeptide with cefazolin is recommended. Strategies such as cutaneous decolonization of MDROs, mainly MRSA, or preoperative asymptomatic bacteriuria treatment have also been addressed with debatable results. Some areas of research are early detection protocols in MDRO colonizations by polymerase-chain-reaction (PCR), the use of alternative antimicrobial prophylaxis, and antibiotic-impregnated bone cement in HHA. Given that published evidence addressing PJI prophylactic strategies in PFFs requiring HHA is scarce, PJIs can be reduced by combining different prevention strategies after identifying individuals who will benefit from personalized prophylaxis.

Increasing but levelling out risk of revision due to infection after total hip arthroplasty: a study on 108,854 primary THAs in the Norwegian Arthroplasty Register from 2005 to 2019

Background and purpose - Focus on prevention, surveillance, and treatment of infection after total hip arthroplasty (THA) in the last decade has resulted in new knowledge and guidelines. Previous publications have suggested an increased incidence of surgical revisions due to infection after THA. We assessed whether there have been changes in the risk of revision due to deep infection after primary THAs reported to the Norwegian Arthroplasty Register (NAR) over the period 2005-2019.Patients and methods - Primary THAs reported to the NAR from January 1, 2005 to December 31, 2019 were included. Adjusted Cox regression analyses with the first revision due to deep infection after primary THA were performed. We investigated changes in the risk of revision as a function of time of primary THA. Time was stratified into 5-year periods. We studied the whole population of THAs, and the subgroups: all-cemented, all-uncemented, reverse hybrid (cemented cup), and hybrid THAs (cemented stem). In addition, we investigated factors that were associated with the risk of revision, and changes in the time span from primary THA to revision.Results - Of the 108,854 primary THAs that met the inclusion criteria, 1,365 (1.3%) were revised due to deep infection. The risk of revision due to infection, at any time after primary surgery, increased through the period studied. Compared with THAs implanted in 2005-2009, the relative risk of revision due to infection was 1.4 (95% CI 1.2-1.7) for 2010-2014, and 1.6 (1.1-1.9) for 2015-2019. We found an increased risk for all types of implant fixation. Compared to 2005-2009, for all THAs, the risk of revision due to infection 0-30 days postoperatively was 2.2 (1.8-2.8) for 2010-2014 and 2.3 (1.8-2.9) for 2015-2019, 31-90 days postoperatively 1.0 (0.7-1.6) for 2010-2014 and 1.6 (1.0-2.5) for 2015-2019, and finally 91 days-1 year postoperatively 1.1 (0.7-1.8) for 2010-2014 and 1.6 (1.0-2.6) for 2015-2019. From 1 to 5 years postoperatively, the risk of revision due to infection was similar to 2005-2009 for both the subsequent time periodsInterpretation - The risk of revision due to deep infection after THA increased throughout the period 2005-2019, but appears to have levelled out after 2010. The increase was mainly due to an increased risk of early revisions, and may partly have been caused by a change of practice rather than a change in the incidence of infection.

A randomized clinical trial of low dose single antibiotic-loaded cement versus high dose dual antibiotic-loaded cement in patients receiving a hip hemiarthroplasty after fracture: A protocol for the WHiTE 8 COPAL study

AIMS

Patients receiving cemented hemiarthroplasties after hip fracture have a significant risk of deep surgical site infection (SSI). Standard UK practice to minimize the risk of SSI includes the use of antibiotic-loaded bone cement with no consensus regarding type, dose, or antibiotic content of the cement. This is the protocol for a randomized clinical trial to investigate the clinical and cost-effectiveness of high dose dual antibiotic-loaded cement in comparison to low dose single antibiotic-loaded cement in patients 60 years and over receiving a cemented hemiarthroplasty for an intracapsular hip fracture.

METHODS

The WHiTE 8 Copal Or Palacos Antibiotic Loaded bone cement trial (WHiTE 8 COPAL) is a multicentre, multi-surgeon, parallel, two-arm, randomized clinical trial. The pragmatic study will be embedded in the World Hip Trauma Evaluation (WHiTE) (ISRCTN 63982700). Participants, including those that lack capacity, will be allocated on a 1:1 basis stratified by recruitment centre to either a low dose single antibiotic-loaded bone cement or a high dose dual antibiotic-loaded bone cement. The primary analysis will compare the differences in deep SSI rate as defined by the Centers for Disease Control and Prevention within 90 days of surgery via medical record review and patient self-reported questionnaires. Secondary outcomes include UK Core Outcome Set for hip fractures, complications, rate of antibiotic prescription, resistance patterns of deep SSI, and resource use (more specifically, cost-effectiveness) up to four months post-randomization. A minimum of 4,920 patients will be recruited to obtain 90% power to detect an absolute difference of 1.5% in the rate of deep SSI at 90 days for the expected 3% deep SSI rate in the control group.

CONCLUSION

The results of this trial will provide evidence regarding clinical and cost-effectiveness between low dose single and high dose dual antibiotic-loaded bone cement, which will inform policy and practice guidelines such as the National Institute for Health and Care Excellence guidance on management of hip fractures. Cite this article: Bone Jt Open 2021;2(2):72-78.

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 effect of antibiotic-loaded bone cement on risk of revision following hip and knee arthroplasty

AIMS

This study aimed to compare the effect of antibiotic-loaded bone cement (ALBC) versus plain bone cement (PBC) on revision rates for periprosthetic joint infection (PJI) and all-cause revisions following primary elective total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

MEDLINE, Embase, Web of Science, and Cochrane databases were systematically searched for studies comparing ALBC versus PBC, reporting on revision rates for PJI or all-cause revision following primary elective THA or TKA. A random-effects meta-analysis was performed. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO ID CRD42018107691).

RESULTS

Nine studies and one registry report were identified, enabling the inclusion of 371,977 THA and 671,246 TKA. Pooled analysis for THA demonstrated ALBC was protective against revision for PJI compared with PBC (relative risk (RR) 0.66, 95% confidence interval (CI) 0.56 to 0.77; p < 0.001), however, no differences were seen for all-cause revision rate (RR 0.62, 95% CI 0.35 to 1.09; p = 0.100). For TKA, there were no significant differences in revision rates for PJI or all causes between ALBC and PBC (RR 0.92, 95% CI 0.59 to 1.45; p = 0.730, and RR 0.73, 95% CI 0.53 to 1.02; p = 0.060, respectively).

CONCLUSION

ALBC demonstrated a protective effect against revision for PJI compared with PBC in THA with no difference in all-cause revisions. No differences in revision rates for PJI and all-cause revision between ALBC and PBC for TKA were observed. Cite this article: Bone Joint J 2021;103-B(1):7-15.

Antimicrobial Resistance, the COVID-19 Pandemic, and Lessons for the Orthopaedic Community

Antimicrobial resistance (AMR) is widely regarded as one of the most important global public health challenges of the twenty-first century. The overuse and the improper use of antibiotics in human medicine, food production, and the environment as a whole have unfortunately contributed to this issue. Many major international scientific, political, and social organizations have warned that the increase in AMR could cost the lives of millions of people if it is not addressed on a global scale. Although AMR is already a challenge in clinical practice today, it has taken on a new importance in the face of the coronavirus disease 2019 (COVID-19) pandemic. While improved handwashing techniques, social distancing, and other interventional measures may positively influence AMR, the widespread use of antibiotics to treat or prevent bacterial coinfections, especially in unconfirmed cases of COVID-19, may have unintended negative implications with respect to AMR. Although the exact number of bacterial coinfections and the rate at which patients with COVID-19 receive antibiotic therapy remain to be accurately determined, the pandemic has revived the discussion on antibiotic overuse and AMR. This article describes why the COVID-19 pandemic has increased our awareness of AMR and presents the immense global impact of AMR on society as a whole. Furthermore, an attempt is made to stress the importance of tackling AMR in the future and the role of the orthopaedic community in this worldwide effort.

Implications for diagnosis and treatment of peri-spinal implant infections from experiences in periprosthetic joint infections-a literature comparison and review

Both, periprosthetic joint infection (PJI) and peri-spinal implant infection (PSII) are serious complications occurring in arthroplasty and spine instrumentation with absolute numbers expected to rise in the next years. The currently existing literature data describing the characteristics of PSII are limited when compared to PJI studies. However, both PJI and PSII exhibit similarities concerning pathogenesis, symptoms, diagnosis, treatment and prognosis. This literature review aims at comparing PJI and PSII and to develop implications for diagnosis and treatment of PSII from existing studies about PJI. The review was performed on the basis of a structured PubMed, Cochrane Library, and Medline analysis and existing guidelines, with 99 references being included. The results indicate that specific terms like re-infection should be defined in the context of PSII based on existing definitions of PJI, that in vitro biofilm studies and studies analyzing different prosthesis surfaces in arthroplasty could be used for PSII, and that histopathology as an additional standard tool in PSII diagnosis might be helpful. In addition, the development of a standardized algorithm-based treatment system with antibiotic protocols, including long term suppression, for PSII similar to the ones existing for PJI is necessary.

Is Dual Antibiotic-Loaded Bone Cement More Effective and Cost-Efficient Than a Single Antibiotic-Loaded Bone Cement to Reduce the Risk of Prosthetic Joint Infection in Aseptic Revision Knee Arthroplasty?

BACKGROUND

Higher rates of prosthetic joint infections (PJIs) are related to patient risk factors and/or to special surgical procedures such as revision total knee arthroplasty (rTKA). Among the measures discussed to better protect those patients from the higher infection risks use of dual antibiotic-loaded bone cement has emerged as a further prophylactic option.

METHODS

This retrospective study included 246 patients undergoing strictly aseptic revision knee arthroplasty at our institution in the time period 2015-2018. Based on the type of bone cement used for the cementation of the revision prosthesis, 2 groups were defined. In total, 143 patients received the low-dose single antibiotic-loaded bone cement (SALBC) PALACOS R+G and 103 patients received the high-dose dual antibiotic-loaded bone cement (DALBC) COPAL G+C. The number of PJI cases in each group over a follow-up time of minimum 1 year was compared and the extra costs for the DALBC use calculated against the economic savings per each avoided PJI case on basis of 3 different assumptions (treatment costs and amount of cement use).

RESULTS

Use of DALBC in aseptic rTKA was associated with a significant reduction in PJI cases (relative risk = 57%, PJI rate in the SALBC group 4.1% vs 0% in the DALBC group, P = 0.035). The calculated total savings per patient was $1367. Depending on the economic assumptions the range of savings was between $1413 (less favorable calculation model) and $3661 (most favorable calculation model).

CONCLUSION

The use of DALBC in rTKA has been found to be more effective in preventing PJI and proved cost-efficient in all our cost-calculation models.

Commercially Prepared Antibiotic-Loaded Bone Cement and Infection Risk Following Cemented Primary Total Knee Arthroplasty

BACKGROUND

The efficacy of commercially available antibiotic-loaded bone cement (ABC) in preventing infection in total knee arthroplasty (TKA) is unclear. We sought to determine the effectiveness of commercially available ABC in reducing the risk of infection following TKA, both overall and among 3 subgroups of patients with a higher risk of infection (diabetes, body mass index ≥35 kg/m, and American Society of Anesthesiologists classification ≥3), and to evaluate the association between the use of ABC and the risks of aseptic revision and revision for aseptic loosening.

METHODS

The Kaiser Permanente Total Joint Replacement Registry was utilized to evaluate 87,018 primary cemented TKAs performed from 2008 to 2016. The primary outcome was time to infection (90-day deep infection or septic revision). Reduced infection risk with ABC relative to regular cement was tested with use of propensity-score-weighted Cox proportional-hazards models with superiority and noninferiority testing. All analyses were replicated for each of the 3 high-risk subgroups. For the secondary revision outcomes, propensity-score-weighted Cox proportional-hazards models were utilized.

RESULTS

Regular cement was found to be noninferior to ABC with respect to risk infection (hazard ratio [HR], 1.14; 95% confidence interval [CI], 0.93 to 1.40) and cost across all TKA patients. However, a lower risk of infection was observed with ABC among TKA patients with diabetes (HR, 0.72; 95% CI, 0.52 to 0.99). There was no evidence of a difference in risk of revision for ABC compared with regular cement.

CONCLUSIONS

We found that the additional cost associated with the use of commercially prepared ABC in primary TKA was not justified in all patients; however, the risk of reduction was lower among patients with diabetes who received ABC. Further study is warranted to identify the efficacy of ABC among other high-risk populations.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Is the use of antibiotic-loaded bone cement associated with a lower risk of revision after primary total hip arthroplasty?

AIMS

The aim of this study was to investigate whether the use of antibiotic-loaded bone cement influenced the risk of revision surgery after primary total hip arthroplasty (THA) for osteoarthritis.

METHODS

The study involved data collected by the National Joint Registry (NJR) for England and Wales, Northern Ireland and the Isle of Man between 1 September 2005 and 31 August 2017. Cox proportional hazards were used to investigate the association between use of antibiotic-loaded bone cement and the risk of revision due to prosthetic joint infection (PJI), with adjustments made for the year of the initial procedure, age at the time of surgery, sex, American Society of Anesthesiologists (ASA) grade, head size, and body mass index (BMI). We looked also at the association between use of antibiotic-loaded bone cement and the risk of revision due to aseptic loosening or osteolysis.

RESULTS

The cohort included 418,857 THAs of whom 397,896 had received antibiotic-loaded bone cement and 20,961 plain cement. After adjusting for putative confounding factors, the risk of revision for PJI was lower in those in whom antibiotic-loaded bone cement was used (hazard ration (HR) 0.79; 95% confidence interval (CI) 0.64 to 0.98). There was also a protective effect on the risk of revision due to aseptic loosening or osteolysis, in the period of > 4.1 years after primary THA, HR 0.57, 95% CI 0.45, 0.72.

CONCLUSION

Within the limits of registry analysis, this study showed an association between the use of antibiotic-loaded bone cement and lower rates of revision due to PJI. The findings support the continued use of antibiotic-loaded bone cement in cemented THA. Cite this article: Bone Joint J 2020;102-B(8):997-1002.

Antibiotics and cement: what I need to know?

We conducted a systematic review about antibiotic-loaded bone cement (ALBC) with a focus on clinical evidence about ALBC in general, concerns about ALBC and ALBC cost.

The role of antibiotic-loaded bone cement in complicated knee arthroplasty: relevance of gentamicin allergy and benefit from revision surgery - a case control follow-up study and algorithmic approach

BACKGROUND

Antibiotic-loaded (particularly gentamicin) bone cement (BC) is widely used in total joint arthroplasty (TJA) to prevent periprosthetic infections (PPIs), but may itself cause implant failure. In light of a complete lack in literature, the objective was to assess the clinical relevance of gentamicin allergy for failure of cemented total knee arthroplasties in 25 out of 250 patients with positive patch test reactions to gentamicin and otherwise unexplained symptoms by evaluating benefits from revision with change to gentamicin-free cement.

METHODS

Fifteen of these 25 patients and their treating orthopaedic surgeons agreed to a re-assessment. They were surveyed regarding interim course of therapy and symptoms, including re-assessment of the Knee Injury and Osteoarthritis Outcome Score (KOOS), and underwent follow-up clinical and radiographic investigations. The initial use of gentamicin-loaded BC was reaffirmed by review of the primary implantation operative reports and respective implant passports. Primary and follow-up KOOS scores were analyzed regarding benefits from revision surgery by comparing nine patients with revision to six without revision.

RESULTS

Mean follow-up time was 38 months. The entirety of patients experienced an improvement of self-reported symptoms, with revision surgery (i.e., switching to gentamicin-free BC or uncemented total knee arthroplasty) yielding significantly greater improvement (p = 0.031): the nine revised patients reported a significant symptom relief (p = 0.028), contrary to the six unrevised patients (p = 0.14). Interestingly, the decision to proceed with revision surgery was significantly correlated with higher symptom severity (p = 0.05).

CONCLUSION

In symptomatic total knee arthroplasty with gentamicin allergy, uncemented revision arthroplasty or change to gentamicin-free BC provides significant symptom relief.

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.

Prevention and Killing Efficacy of Carbapenem Resistant Enterobacteriaceae (CRE) and Vancomycin Resistant Enterococci (VRE) Biofilms by Antibiotic-Loaded Calcium Sulfate Beads

Carbapenem-resistant Enterobacteriaceae (CRE) and vancomycin-resistant Enterococci (VRE) have emerged as multidrug-resistant (MDR) pathogens associated with periprosthetic joint infections (PJI). In this study, we evaluated the efficacy of antibiotic-loaded calcium sulfate beads (ALCSB) in inhibiting bacterial growth, encouraging biofilm formation and killing preformed biofilms of CRE and VRE. Three strains of Klebsiella pneumoniae (KP) and a strain of Enterococcus faecalis (EF) were used. ALCSB of 4.8-mm diameter were loaded with vancomycin (V) and gentamicin (G), V and rifampicin (R), V and tobramycin (T) or R and meropenem (M), and placed onto tryptic soy agar (TSA), spread with one of the test strains and incubated for 24 h at 37 °C. Beads were transferred daily onto fresh TSA spread plates and the zone of inhibition (ZOI) was recorded until no inhibition was observed. ALCSB containing R + M or R + V produced the most extensive ZOI up to 5 weeks. Biofilm prevention efficacy was investigated by challenging ALCSB daily with 5 × 10⁵ CFU/mL bacterial cells and analyzing for biofilm formation at challenges 1, 2 and 3. In the biofilm killing experiments, ALCSB were added to pre-grown 3-day biofilms of KP and EF strains, which were then analyzed at days 1 and 3 post-exposure. The CFU counts and confocal images of the attached cells showed that ALCSB treatment reduced colonization and biofilm formation significantly (5–7 logs) with combinations of R + M or R + V, compared to unloaded beads. This study provides evidence that the local release of antibiotics from ALCSB may be useful in treating the biofilms of multidrug-resistant strains of CRE and VRE.

Meta-analysis in periprosthetic joint infection: a global bibliometric analysis

Background

Periprosthetic joint infection (PJI) is the most serious complication of joint replacement surgery. Further comorbidities include bedsore, deep vein thrombosis, reinfection, or even death. An increasing number of researchers are focusing on this challenging complication. The aim of the present study was to estimate global PJI research based on bibliometrics from meta-analysis studies.

Methods

A database search was performed in PubMed, Scopus, and Web of Science. Relevant studies were assessed using the bibliometric analysis.

Results

A total of 117 articles were included. The most relevant literature on PJI was found on Scopus. China made the highest contributions to global research, followed by the USA and the UK. The institution with the most contributions was the University of Bristol. The journal with the highest number of publications was The Journal of Arthroplasty, whereas the Journal of Clinical Medicine had the shortest acceptance time. Furthermore, the top three frequently used databases were Embase, MEDLINE, and Cochrane. The most frequent number of authors in meta-analysis studies was four. Most studies focused on the periprosthetic hip and knee. The alpha-defensin diagnostic test, preventive measures on antibiotics use, and risk factors of intra-articular steroid injections were the most popular topic in recent years.

Conclusion

Based on the results of the present study, we found that there was no single database that covered all relevant articles; the optimal method for bibliometric analysis is a combination of databases. The most popular research topics on PJI focused on alpha-defensin, antibiotic use, risk factors of intra-articular steroid injections, and the location of prosthetic hip and knee infection.

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

BACKGROUND

Prosthetic joint infection (PJI) is the most serious total joint arthroplasty (TJA) complication despite several aseptic and antiseptic preventive measures. There is no clear evidence or even consensus, whether antibiotic-loaded bone cement (ALBC) should be used, in addition to systemic short-term routine antibiotic prophylaxis, to reduce the risk of PJI in primary TJA. We aimed to analyze the efficacy of ALBC for prevention of PJI in patients undergoing primary TJA.

METHODS

We searched systematically for randomized controlled trials (RCTs) in PubMed, Scopus, Embase, Web of Science and Cochrane library. Two reviewers independently screened potentially eligible studies according to predefined selection criteria and assessed the risk of bias using a modified version of the Cochrane risk of bias tool. PJI was prespecified as the primary outcome of interest. The meta-analyses were based on risk ratios using random-effects model per default. For the purpose of sensitivity, the corresponding fixed effects model odds ratios were calculated with the use of the Peto method as well. To evaluate a potential difference in effect sizes using different types (subgroups) of antibiotics used in bone cement, and at different follow-up periods, we performed stratified meta-analyses.

RESULTS

Thirty-seven studies were eligible for the systematic review and qualitative synthesis, and 9 trials (6507 total joint arthroplasties) were included in this meta-analysis. Overall ALBC significantly reduced the risk of PJI following primary TJAs (RRs, 0.36; 95% CIs, 0.16 to 0.80; P = 0.01) with a moderate degree of inconsistency (I2 = 47%). Based on stratified meta-analyses the use of gentamicin appeared to have a better effect (P = 0.0005) in the total hip arthroplasty. Pooled data of different antibiotics used in knee arthroplasties showed a significant association of cefuroxime (RRs, 0.08; 95% CIs, 0.01 to 0.63; P = 0.02). Further, ALBCs significantly reduced the PJI at one and two years of follow-up (P = 0.03 and P = 0.005 respectively).

CONCLUSIONS

The evidence suggests that ALBCs are effective in reducing the PJI following primary TJA; i.e. between 20 and 84% reduced risk. However, the clear limitations of the available trial evidence highlight the need for joint-specific confirmatory trials, that will need to be designed as cluster-randomized trials of clinics in countries with well-functioning arthroplasty registries.The translational potential of this article: This meta-analysis highlights the prophylactic potential of ALBCs in lowering the risk of infection following primary hip or knee arthroplasties but emphasizes the need for more recent confirmatory trials.

The Effect of Irrigation Fluid on Periprosthetic Joint Infection in Total Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis

Introduction Rates of osteoarthritis and total joint arthroplasty (TJA) are on the rise globally. Periprosthetic joint infection (PJI) is the most devastating complication of TJA. A number of different intraoperative interventions have been proposed in an effort to reduce infection rates, including antibiotic cements, local antibiotic powder, and various irrigation solutions. The evidence on the importance of irrigation solutions is limited but has gained prominence recently, including the publication of a large randomized controlled trial (RCT). Thus, the purpose of this study was to evaluate the effectiveness of various irrigation solutions and pressures at reducing the rates of PJI. Methods A systematic review was performed using the electronic databases MEDLINE, Embase, and Web of Science. All records were screened in duplicate. Data collected included basic study characteristics, the details of the intervention and comparison solutions, if applicable, and rates of superficial and deep infection. A meta-analysis of comparative studies was performed to assess for consistency and potential direction of effect.  Results A total of ten studies were included, of which one was an RCT, eight were retrospective cohorts, and one was a case series. In total, there were 29,630 TJAs in 29,596 patients. The mean age ranged from 61 to 80 years. Six studies compared povidone-iodine (Betadine®) to normal saline, two studies compared chlorhexidine to saline, one study compared "triple prophylaxis" to standard practice, and one study used gentamicin but had no comparison group. The pooled risk ratio for deep infection in studies using Betadine® compared to saline was 0.62 (95% confidence interval [CI]: 0.33-1.19), while for chlorhexidine it was 0.74 (95%CI: 0.33-1.65). Discussion Current evidence on the relative efficacy of irrigating solutions as prophylaxis for infection following TJA remains inconclusive. Imprecision of estimates vindicates the need for a definitive trial to further inform their use in surgical practice.  Conclusion Antiseptic irrigation during TJA with solutions (Betadine®, chlorhexidine) may decrease PJI risk in patients undergoing primary and revision total hip and knee arthroplasties. Wide confidence intervals and heterogeneity among studies, however, render conclusions untrustworthy. Well-conducted RCTs are very much needed to help further investigate this issue.

Risk Factors for Periprosthetic Joint Infection Following Primary Total Hip Arthroplasty: A 15-Year, Population-Based Cohort Study

BACKGROUND

Periprosthetic joint infection (PJI) is one of the most devastating complications following total hip arthroplasty. The purposes of this study were to determine risk factors for PJI after primary total hip arthroplasty for osteoarthritis using a Canadian population-based database collected over 15 years and to determine the incidence of PJI, the time to PJI following primary total hip arthroplasty, and whether the PJI rate had changed over 15 years.

METHODS

We performed a population-based cohort study using linked administrative databases in Ontario. We included all primary total hip arthroplasties performed for osteoarthritis in patients who were ≥55 years of age. We used a Cox proportional hazards model to analyze the effect of surgical and patient factors on the risk of developing PJI. We calculated 1, 2, 5, and 10-year PJI rates. We used the Cochran-Armitage test to assess the evidence of trends in PJI rates over time.

RESULTS

A total of 100,674 patients who were ≥55 years of age underwent a primary total hip arthroplasty for osteoarthritis. The cumulative incidence for PJI at 15 years was 1.44% (95% confidence interval [CI], 1.38% to 1.50%). Risk factors associated with the development of PJI include male sex (hazard ratio [HR], 1.43 [95% CI, 1.30 to 1.51]), type-2 diabetes mellitus (HR, 1.51 [95% CI, 1.31 to 1.70]), and being discharged to convalescent care (HR, 1.36 [95% CI, 1.05 to 1.77]). Sixty-two percent of PJI cases occurred within 2 years after the surgical procedure and 98% occurred within 10 years. The rate of PJI following primary total hip arthroplasty did not change over the 15 years of our study period.

CONCLUSIONS

The risk of developing PJI following primary total hip arthroplasty did not change in 15 years, despite improvements in other arthroplasty outcomes. Male sex, type-2 diabetes mellitus, and discharge to convalescent care were associated with an increased risk of PJI. The surgical approach, income quintile, and use of bone-grafting or cement were not significantly associated with increased risk of infection in our cohort.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Intraoperative and Postoperative Infection Prevention

Implementation of strategies for prevention of surgical site infection and periprosthetic joint infection is gaining further attention. We provide an overview of the pertinent evidence-based guidelines for infection prevention from the World Health Organization, the Centers for Disease Control and Prevention, and the second International Consensus Meeting on Musculoskeletal Infection. Future work is needed to ascertain clinical efficacy, optimal combinations, and the cost-effectiveness of certain measures.

Two-staged time-dependent materials for the prevention of implant-related infections

Infection is a main cause of implant failure. Early implant-related infections often occur in the first 4 weeks post-operation. Inhibiting bacterial adhesion and biofilm formation at the early stage and promoting subsequent implant osseointegration are important for implant success. Our previous studies demonstrated that dimethylaminododecyl methacrylate (DMADDM) provided dental materials with antibacterial effects. In the present study, DMADDM and hydroxyapatite (HA) are loaded on to the titanium (Ti) surface via poly dopamine (PDA) self-polymerization. This local DMADDM-delivery Ti is referred as Ti-PHD. Here we report the two-staged capability of Ti-PHD: (1) in the first stage, releasing DMADDM during the high-infection-risk initial period post-implantation for 4 weeks; (2) then in the second stage, enhancing osteogenesis and promoting osseointegration. Ti-PHD has a porous surface with higher average roughness and greater hydrophilicity than pure Ti. Its biocompatibility is verified in vitro and in vivo. During the first 4 weeks of release, both DMADDM remaining on Ti surface and DMADDM released into the soaking medium greatly reduced the adherence and growth of pathogens. This is further confirmed by the prevention of bone destruction in a rat osteomyelitis model. After releasing DMADDM for 4 weeks, Ti-PHD promotes osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) and new bone formation around the implants in vivo. This article represents the first report on the two-staged, time-dependent antibacterial and osteogenesis effects of Ti-PHD, demonstrating its potential for clinical applications to inhibit implant-associated infections. STATEMENT OF SIGNIFICANCE: The present study develops a two-staged time-dependent system for local dimethylaminododecyl methacrylate (DMADDM) delivery via Ti implant (referred to as Ti-PHD). DMADDM and hydroxyapatite (HA) are loaded on to the Ti surface with poly dopamine (PDA). Ti-PHD can release DMADDM during the high-risk period of infection in the first stage, and then promote osseointegration and new bone formation in the second stage. This bioactive and therapeutic Ti is promising to inhibit infections and enhance implant success.

Cutibacterium acnes Infection in Orthopedics: Microbiology, Clinical Findings, Diagnostic Strategies, and Management

Cutibacterium (formerly called Propionibacterium) acnes is a human skin flora often implicated in orthopedic infections. The unique characteristics of this microorganism make the diagnosis of infection difficult. The diagnosis often is made based on clinical evidence, radiographic signs, and laboratory and/or surgical findings combined. Treatment often involves both pharmacologic and surgical methods. In addition, formation of biofilms and increased resistance to drugs exhibited by the microorganism can require combined antimicrobial therapy. Prophylactic measures are particularly important, but no single method has been shown to fully eliminate the risk of C acnes infections. Previous reports have focused on C acnes infections involving surgical implants or after certain orthopedic procedures, particularly in the shoulder and spine. This article reviews current clinical, diagnostic, and treatment principles for C acnes in orthopedics in general. [Orthopedics. 2020; 43(1):52-61.].