Does adding antibiotics to cement reduce the need for early revision in total knee arthroplasty?

Antibiotic Laden Bone Cement Does Not Reduce Acute Periprosthetic Joint Infection Risk in Primary Total Knee Arthroplasty

BACKGROUND

Periprosthetic joint infection (PJI) can be a serious complication of total knee arthroplasty (TKA). A method believed to decrease the incidence of PJI is antibiotic-laden bone cement (ALBC). Current clinical practice guidelines do not recommend ALBC in primary TKA. The purpose of this study was to compare ALBC to plain cement (PC) in preventing PJI in primary TKA.

METHODS

This retrospective analysis included 109,242 Medicare patients in the American Joint Replacement Registry who underwent a cemented primary TKA from January 2017 to March 2021, and had at least 1 year of follow-up. Patients who received ALBC were compared to patients who received PC. Demographic and case-specific variables such as age, sex, race, body mass index, Charlson Comorbidity Index, anesthesia type, and operative time were used to create propensity scores. A logistic regression was run to predict the probability of receiving ALBC. Also, a multivariate model was run on the full unstratified population, using the same covariates as were used to create the propensity model. The primary outcome was differences in PJI rates.

RESULTS

Logistic regression analysis showed that a higher preoperative diagnosis of osteoarthritis, higher Charlson Comorbidity Index, higher body mass index, women, race, and anesthesia requirements increased a patient's probability of receiving ALBC. In the full unstratified multivariate model, ALBC did not show a statistically significant difference in risk of revision for infection compared to PC.

CONCLUSIONS

The use of ALBC in primary TKA has not been shown to be more efficacious in preventing PJI within the population of Medicare patients in the United States. However, this study is limited given it is a retrospective database study that may inherently have biases and the large dataset has a potential for overpowering the findings.

The Use of Erythromycin and Colistin Cement in Total Knee Arthroplasty Does Not Reduce the Incidence of Infection: A Randomized Study in 2,893 Knees With a 9-year Average Follow-Up

BACKGROUND

One of the most severe complications of primary total knee arthroplasty (TKA) is prosthetic joint infection. Currently, the use of antibiotic-loaded cement for the prevention of infection is still controversial. The aim of the present study was to evaluate if the use of antibiotic-loaded cement reduces the infection rate in primary TKA in long-term follow-up (more than 5 years average follow-up).

METHODS

This study is the follow-up extension of a prospective randomized study, with 2,893 cemented TKA performed between 2005 and 2010 at our institution. There were 2 different cohorts depending on which bone cement was used: without antibiotics (control group) or those loaded with erythromycin and colistin (study group). All patients received the same systemic prophylactic antibiotics. The patients were followed for a minimum of twelve months. The diagnosis of prosthetic joint infection was done according to Zimmerli criteria.

RESULTS

In 1,452 patients, the prosthetic components were fixed using bone cement without antibiotics, whereas in 1,441 patients, bone cement was loaded with erythromycin and colistin. Both groups were comparable in terms of all the possible risk factors studied. We found a total of 53 deep infections, with a mean rate of 1.8%. There were no differences between the groups as to whether bone cement with or without antibiotics had been used (P = .58). The average duration of follow-up was 8.7 years. In terms of prosthetic revision due to aseptic loosening, there were no differences between groups (P = .32), with 33 revision arthroplasties in the control group and 37 in the study group. Moreover, we analyzed the erythromycin resistance rate, with no differences between both groups (P = .6).

CONCLUSIONS

The use of erythromycin and colistin-loaded bone cement in TKA did not lead to a decrease in the rate of infection in long-term follow-up, a finding that suggests that its use would not be indicated in the general population.

Survivorship of Modern Cementless Total Knee Arthroplasty: Analysis From the Canadian Joint Replacement Registry

BACKGROUND

Cementless total knee arthroplasty (TKA) is rising in popularity. The literature supporting its use over cemented TKA remains sparse. Using the Canadian Joint Replacement Registry (CJRR), we sought to investigate cementless versus cemented fixation in modern primary TKA and (1) determine whether there is an overall difference in revision by fixation, (2) perform a subanalysis of the most-commonly used cementless TKA brand in Canada, and (3) identify the reasons for revision.

METHODS

The CJRR data was used to analyze TKA designs with cemented and cementless versions. Revision risk is reported as all-cause cumulative percent revision (CPR). Reasons for revision were analyzed. Cox proportional hazards models were used to report adjusted hazard ratios (HR) controlling for age, sex, patella resurfacing, and bearing constraints. We included 202,880 primary TKAs performed between 2012 and 2021. Of those, 9,163 (4.5%) were cementless.

RESULTS

The CPR at 8 years was 4.49% for cementless and 3.14% for cemented implants. After adjusting for confounders, we did not detect a difference in revision risk overall (HR 0.87 [95% CI (confidence interval) 0.73 to 1.04], P = 0.128). However, the most commonly used cementless TKA brand demonstrated a CPR of 1.95% compared to 2.19% for its cemented version at 4 years. Furthermore, we detected a significantly lower revision risk compared to its cemented version after adjusting for confounders (HR 0.66 [95% CI 0.51 to 0.85], P = 0.001). The 4 most common reasons for revision in both groups were the following: (1) infection, (2) instability, (3) aseptic loosening, and (4) pain of unknown origin.

CONCLUSIONS

Using CJRR data adjusted for confounding factors, no difference in revision risk was detected between cemented and cementless implants overall. However, for the most common brand of cementless TKA used in Canada, there was a lower risk of revision than its corresponding cemented version. The reasons for revision were similar.

In Vivo Intra-Articular Antibiotic Concentrations at 24 Hours After TKA Fall Below the Minimum Inhibitory Concentration for Most Bacteria: A Randomized Study of Commercially Available Bone Cement

BACKGROUND

The use of antibiotic-loaded bone cement (ALBC) to help reduce the risk of infection after primary total knee arthroplasty (TKA) is controversial. There is a paucity of in vivo data on the elution characteristics of ALBC. We aimed to determine whether the antibiotic concentrations of 2 commercially available ALBCs met the minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) for common infecting organisms.

METHODS

Forty-five patients undergoing TKA were randomized to receive 1 of the following: bone cement without antibiotic (the negative control; n = 5), a commercially available formulation containing 1 g of tobramycin (n = 20), or a commercially available formulation containing 0.5 g of gentamicin (n = 20). Intra-articular drains were placed, and fluid was collected at 4 and 24 hours postoperatively. An automated immunoassay measuring antibiotic concentration was performed, and the results were compared against published MIC and MBEC thresholds.

RESULTS

The ALBC treatment groups were predominantly of White (65%) or Black (32.5%) race and were 57.5% female and 42.4% male. The mean age (and standard deviation) was 72.6 ± 7.2 years in the gentamicin group and 67.6 ± 7.4 years in the tobramycin group. The mean antibiotic concentration in the tobramycin group was 55.1 ± 37.7 μg/mL at 4 hours and 19.5 ± 13.0 μg/mL at 24 hours, and the mean concentration in the gentamicin group was 38.4 ± 25.4 μg/mL at 4 hours and 17.7 ± 15.4 μg/mL at 24 hours. Time and antibiotic concentration had a negative linear correlation coefficient (r = -0.501). Most of the reference MIC levels were reached at 4 hours. However, at 24 hours, a considerable percentage of patients had concentrations below the MIC for many common pathogens, including Staphylococcus epidermidis (gentamicin: 65% to 100% of patients; tobramycin: 50% to 85%), methicillin-sensitive Staphylococcus aureus (gentamicin: 5% to 90%; tobramycin: 5% to 50%), methicillin-resistant S. aureus (gentamicin: 5% to 65%; tobramycin: 50%), Streptococcus species (gentamicin: 10% to 100%), and Cutibacterium acnes (gentamicin: 10% to 65%; tobramycin: 100%). The aforementioned ranges reflect variation in the MIC among different strains of each organism. Gentamicin concentrations reached MBEC threshold values at 4 hours only for the least virulent strains of S. aureus and Escherichia coli. Tobramycin concentrations did not reach the MBEC threshold for any of the bacteria at either time point.

CONCLUSIONS

The elution of antibiotics from commercially available ALBC decreased rapidly following TKA, and only at 4 hours postoperatively did the mean antibiotic concentrations exceed the MIC for most of the pathogens. Use of commercially available ALBC may not provide substantial antimicrobial coverage following TKA.

LEVEL OF EVIDENCE

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

Antibiotic-loaded bone cement is associated with a reduction of the risk of revision of total knee arthroplasty: Analysis of the Catalan Arthroplasty Register

PURPOSE

The purpose of this study was to analyse the impact on peri-prosthetic joint infection (PJI) rate and prosthetic survival using antibiotic-loaded bone cement (ALBC) versus plain cement during total knee arthroplasty (TKA).

METHODS

A retrospective cohort study was conducted. The main data source was the Catalan Arthroplasty Register (RACat). TKAs with surgery date between 1 January 2011 and 31 December 2020 were analysed and followed up until 31 December 2023. The main variable of interest was the type of cement (ALBC vs. plain cement), and several endpoints (septic revision, aseptic revision, and all-cause revision) were considered. The analysed outcomes were revision rates, survival rates and risk factors' hazard ratios (HR).

RESULTS

A total of 22,781 TKAs were analysed, 13,125 (57.6%) of them with plain cement and 9656 (42.4%) with ALBC. The septic revision rate was lower in the ALBC group after 3 months of follow-up (0.52% vs. 0.78%, p value = 0.04). Prosthetic survival with respect to the aseptic revision endpoint was also higher for the ALBC group during the whole follow-up period (~158 months). Regarding risk factors for infection, ALBC showed a protective effect, HR: 0.53 (0.44, 0.63), while sex (being male) and the analysed comorbidities increased the risk.

CONCLUSIONS

ALBC is associated with a reduction in both the septic revision and the aseptic revision rate after TKA, and thus with higher prosthetic survival.

LEVEL OF EVIDENCE

Level III, Therapeutic, retrospective.

Periprosthetic Joint Infection After Total Knee Arthroplasty With or Without Antibiotic Bone Cement

Importance

Despite increased use of antibiotic-loaded bone cement (ALBC) in joint arthroplasty over recent decades, current evidence for prophylactic use of ALBC to reduce risk of periprosthetic joint infection (PJI) is insufficient.

Objective

To compare the rate of revision attributed to PJI following primary total knee arthroplasty (TKA) using ALBC vs plain bone cement.

Design, Setting, and Participants

This international cohort study used data from 14 national or regional joint arthroplasty registries in Australia, Denmark, Finland, Germany, Italy, New Zealand, Norway, Romania, Sweden, Switzerland, the Netherlands, the UK, and the US. The study included primary TKAs for osteoarthritis registered from January 1, 2010, to December 31, 2020, and followed-up until December 31, 2021. Data analysis was performed from April to September 2023.

Exposure

Primary TKA with ALBC vs plain bone cement.

Main Outcomes and Measures

The primary outcome was risk of 1-year revision for PJI. Using a distributed data network analysis method, data were harmonized, and a cumulative revision rate was calculated (1 - Kaplan-Meier), and Cox regression analyses were performed within the 10 registries using both cement types. A meta-analysis was then performed to combine all aggregated data and evaluate the risk of 1-year revision for PJI and all causes.

Results

Among 2 168 924 TKAs included, 93% were performed with ALBC. Most TKAs were performed in female patients (59.5%) and patients aged 65 to 74 years (39.9%), fully cemented (92.2%), and in the 2015 to 2020 period (62.5%). All participating registries reported a cumulative 1-year revision rate for PJI of less than 1% following primary TKA with ALBC (range, 0.21%-0.80%) and with plain bone cement (range, 0.23%-0.70%). The meta-analyses based on adjusted Cox regression for 1 917 190 TKAs showed no statistically significant difference at 1 year in risk of revision for PJI (hazard rate ratio, 1.16; 95% CI, 0.89-1.52) or for all causes (hazard rate ratio, 1.12; 95% CI, 0.89-1.40) among TKAs performed with ALBC vs plain bone cement.

Conclusions and Relevance

In this study, the risk of revision for PJI was similar between ALBC and plain bone cement following primary TKA. Any additional costs of ALBC and its relative value in reducing revision risk should be considered in the context of the overall health care delivery system.

Demographics and Early Outcomes of Commercial Antibiotic Cement Usage for Infection Prophylaxis During Primary Total Knee Arthroplasty in Patients Older Than 65 Years: An American Joint Replacement Registry Study

INTRODUCTION

The use of antibiotic-laden bone cement (ALBC) for infection prophylaxis in the setting of primary total knee arthroplasty (TKA) remains controversial. Using data from the American Joint Replacement Registry (AJRR), (1) we examined the demographics of ALBC usage in the United States and (2) identified the effect of prophylactic commercially available ALBC on early revision and readmission for prosthetic joint infection (PJI) after primary TKA.

METHODS

This is a retrospective cohort study of the AJRR from 2017 to 2020. Patients older than 65 years undergoing primary cemented TKA with or without the use of commercially available antibiotic cement were eligible for inclusion (N = 251,506 patients). Data were linked to available Medicare claims to maximize revision outcomes. Demographics including age, sex, race/ethnicity, Charlson Comorbidity Index (CCI), preoperative inflammatory arthritis, region, and body mass index (BMI) class were recorded. Cox proportional hazards regression analysis was used to evaluate the association between the two outcome measures and ALBC usage.

RESULTS

Patients undergoing cemented TKA with ALBC were more likely to be Non-Hispanic Black ( P < 0.001), have a CCI of 2 or 3 ( P < 0.001), reside in the South ( P < 0.001), and had a higher mean BMI ( P < 0.001). In the regression models, ALBC usage was associated with increased risk of 90-day revision for PJI (hazards ratio 2.175 [95% confidence interval] 1.698 to 2.787) ( P < 0.001) and was not associated with 90-day all-cause readmissions. Male sex, higher CCI, and BMI >35 were all independently associated with 90-day revision for PJI.

DISCUSSION

The use of commercial ALBC in patients older than 65 years for primary TKA in the AJRR was not closely associated with underlying comorbidities suggesting that hospital-level and surgeon-level factors influence its use. In addition, ALBC use did not decrease the risk of 90-day revision for PJI and was not associated with 90-day readmission rates.

Effectiveness of antibiotic-loaded bone cement in total joint arthroplasty at a tertiary medical center: A retrospective cohort study

Background

Data regarding the effectiveness of antibiotic-loaded bone cement (ALBC) in preventing prosthetic joint infections (PJI) after total joint arthroplasty (TJA) is inconsistent. The objective of this study was to evaluate if the routine use of ALBC influenced the risk of revision surgery due to PJI.

Methods

This is a retrospective cohort study performed between January 2018 and September 2020. Adult patients aged ≥ 18 years who underwent TJA (knee or hip) and received either ALBC or plain cement (PC) were included. The outcome of this study was the rate of revision due to PJI. Multivariate analysis using logistic regression was used to identify factors that may be associated with increased risk of PJI, using STATA 15.1 (StataCorp LP, College Station, Texas, USA).

Results

A total of 844 patients were screened and 319 patients were included. There were 247 patients in ALBC group and 72 patients in the PC group. Only vancomycin powder was used in all ALBC cases, with a 2 g dose in 50% of the cases (dose ranged between 1 g and 8 g). The status of the prosthetic joint was assessed and recorded up to 2 years of the TJA. Overall, the difference in the rates of PJI between the two groups after primary arthroplasty was not statistically significant (5.6% vs 1.4%; p = 0.173; OR, 4.2; 95% CI, 0.5-33).

Conclusion

ALBC was not associated with a reduction in PJI rates after primary TJA. More research is needed to further evaluate the effectiveness of ALBC in preventing PJI.

Antimicrobials in polymethylmethacrylate: from prevention to prosthetic joint infection treatment: basic principles and risk of resistance

BACKGROUND

Excellent revisions about antibiotic-loaded bone cement (ALBC) have been recently published. In the present article, we review the principles and limitations of local antibiotic delivery in the context of recent advances in the pathogenesis of prosthetic joint infections (PJI), with particular attention paid to the potential association between ALBC and antimicrobial resistance.

MAIN BODY

Recalcitrance of PJI is related to the ability of pathogens to adapt to particular environments present in bone tissue and protect themselves from host immunity in different ways. Accordingly, delivery of high local antimicrobial concentrations using ALBC is needed. Most relevant clinical data showing the efficacy of ALBC for PJI prophylaxis and treatment are reviewed, and we dissected the limitations on the basis of the recent findings from animal models and suggested that aminoglycosides, in particular, could not be the best option. One of the major concerns associated with ALBC is the emergence of resistance because of theoretical prolonged exposure to low antibiotic concentrations. We summarize the mechanisms for the selection of resistant microorganisms, and we critically reviewed the evidence from animal models and clinical data from observational and registry studies and concluded that there is no evidence to support this association.

CONCLUSION

While waiting for better evidence from well-designed clinical trials, ALBC shows a beneficial effect as a prophylaxis in arthroplasty, and to avoid the colonization of spacers used for two-stage revision in patients with PJI. Experimental models and clinical evidence suggest the need to achieve high local antimicrobial concentrations to obtain the highest prophylactic and therapeutic effect. The current evidence does not support the risk of increasing resistance with use of ALBC. In the future, it is necessary to evaluate new carriers and different antimicrobials to improve clinical outcomes.

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.

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.

Surgical Helmet Systems Are Associated With a Lower Rate of Prosthetic Joint Infection After Total Knee Arthroplasty: Combined Results From the New Zealand Joint Registry and Surgical Site Infection Improvement Programme

BACKGROUND

This study aimed to identify the risk factors, in particular the use of surgical helmet systems (SHSs), for prosthetic joint infection (PJI) after total knee arthroplasty (TKA). Data recorded by the New Zealand Surgical Site Infection Improvement Programme (SSIIP) and the New Zealand Joint Registry (NZJR) were combined and analyzed.

METHODS

Primary TKA procedures performed between July 2013 and June 2018 that were recorded by both the SSIIP and NZJR were analyzed. Two primary outcomes were measured: (1) PJI within 90 days as recorded by the SSIIP and (2) revision TKA for deep infection within 6 months as recorded by the NZJR. Univariate and multivariate analyses were performed to identify risk factors for both outcomes with results considered significant at P < .05.

RESULTS

A total of 19,322 primary TKAs were recorded by both databases in which 97 patients had a PJI within 90 days as recorded by the SSIIP (0.50%), and 90 patients had a revision TKA for deep infection within 6 months (0.47%) as recorded by the NZJR. An SHS was associated with a lower rate of PJI (adjusted odds ratio [OR] = 0.50, P = .008) and revision for deep infection (adjusted OR = 0.55, P = .022) than conventional gowning. Male sex (adjusted OR = 2.6, P < .001) and an American Society of Anesthesiologists score >2 were patient risk factors for infection (OR = 2.63, P < .001 for PJI and OR = 1.75, P = .017 for revision for deep infection).

CONCLUSION

Using contemporary data from the SSIIP and NZJR, the use of the SHS was associated with a lower rate of PJI after primary TKA than conventional surgical gowning. Male sex and a higher American Society of Anesthesiologists score continue to be risk factors for infection.

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.

Adjuvant antibiotic-loaded bone cement: Concerns with current use and research to make it work

Antibiotic-loaded bone cement (ALBC) is broadly used to treat orthopaedic infections based on the rationale that high-dose local delivery is essential to eradicate biofilm-associated bacteria. However, ALBC formulations are empirically based on drug susceptibility from routine laboratory testing, which is known to have limited clinical relevance for biofilms. There are also dosing concerns with nonstandardized, surgeon-directed, hand-mixed formulations, which have unknown release kinetics. On the basis of our knowledge of in vivo biofilms, pathogen virulence, safety issues with nonstandardized ALBC formulations, and questions about the cost-effectiveness of ALBC, there is a need to evaluate the evidence for this clinical practice. To this end, thought leaders in the field of musculoskeletal infection (MSKI) met on 1 August 2019 to review and debate published and anecdotal information, which highlighted four major concerns about current ALBC use: (a) substantial lack of level 1 evidence to demonstrate efficacy; (b) ALBC formulations become subtherapeutic following early release, which risks induction of antibiotic resistance, and exacerbated infection from microbial colonization of the carrier; (c) the absence of standardized formulation protocols, and Food and Drug Administration-approved high-dose ALBC products to use following resection in MSKI treatment; and (d) absence of a validated assay to determine the minimum biofilm eradication concentration to predict ALBC efficacy against patient specific micro-organisms. Here, we describe these concerns in detail, and propose areas in need of research.

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.

Antibiotic-Laden Bone Cement Use and Revision Risk After Primary Total Knee Arthroplasty in U.S. Veterans

BACKGROUND

It is controversial whether the use of antibiotic-laden bone cement (ALBC) in primary total knee arthroplasty (TKA) affects periprosthetic joint infection (PJI) or revision rates. The impact of ALBC on outcomes of primary TKA have not been previously investigated in U.S. veterans, to our knowledge. The purposes of this study were to quantify utilization of ALBC among U.S. veterans undergoing primary TKA and to determine if ALBC usage is associated with differences in revision TKA rates.

METHODS

Patients who had TKA with cement from 2007 to 2015 at U.S. Veterans Health Administration (VHA) hospitals with at least 2 years of follow-up were retrospectively identified. Patients who received high-viscosity Palacos bone cement with or without gentamicin were selected as the final study cohort. Patient demographic and comorbidity data were collected. Revision TKA was the primary outcome. All-cause revisions and revisions for PJI were identified from both VHA and non-VHA hospitals. Unadjusted and adjusted regression analyses were performed to identify variables that were associated with increased revision rates.

RESULTS

The study included 15,972 patients who had primary TKA with Palacos bone cement at VHA hospitals from 2007 to 2015. Plain bone cement was used for 4,741 patients and ALBC was used for 11,231 patients. Utilization of ALBC increased from 50.6% in 2007 to 69.4% in 2015. At a mean follow-up of 5 years, TKAs with ALBC had a lower all-cause revision rate than those with plain bone cement (5.3% versus 6.7%; p = 0.0009) and a lower rate of revision for PJI (1.9% versus 2.6%; p = 0.005). On multivariable regression, ALBC use was associated with a lower risk of all-cause revision compared with plain bone cement (hazard ratio [HR]: 0.79, 95% confidence interval [CI]: 0.68 to 0.92; p = 0.0019). Seventy-one primary TKAs needed to be implanted with ALBC to avoid 1 revision TKA.

CONCLUSIONS

The utilization of ALBC for primary TKAs performed at VHA hospitals has increased over time and was associated with a lower all-cause revision rate and a lower rate of revision for PJI.

LEVEL OF EVIDENCE

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

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.

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.

Treatment recommendations for chronic knee osteoarthritis

Primary osteoarthritis (OA) hinders an aging global population as one of the leading causes of years-lost-to-disability (YLD). OA in most patients is considered to be an overuse injury that results in degenerative inflammation of the joints with the associated formation of bony outgrowths. Due to the escalating nature of this chronic pain disease, treatment management for OA can initially begin with a more conservative approach. It can eventually lead to more invasive surgical procedures. At present, the standard of care remains initial conservative management with lifestyle changes, including weight loss with concurrent anti-inflammatory regimens. Injections are frequently used for the escalation of care, but a significant number of patients ultimately resort to total knee arthroplasty. This review will focus specifically on knee OA, providing a brief overview of risk factors and early management and in-depth exploration of the invasive interventions that can offer symptomatic relief and return of function.

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.

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.

Risk factors for periprosthetic joint infection after total knee arthroplasty

INTRODUCTION

Periprosthetic joint infection (PJI) is the most serious and feared complication in total knee arthroplasty (TKA) and can have catastrophic consequences. The number of total knee arthroplasties is increasing, so infections could also be greater in the future. The aim of this study is to identify the most relevant risk factors associated with infection after a total knee arthroplasty.

METHODS

This is a case-control study of patients who underwent total knee arthroplasty at the University Hospital of Salamanca. We included 66 TKA PJI patients and 66 control TKA patients. Demographic and clinical variables were collected. A descriptive and inferential analysis was performed by logistic regression and attributable risk fraction assessed.

RESULTS

Prolonged operative time (> 90') and tourniquet time (> 60') were the most relevant risk factors described (OR 40.77, AFE 0.97, p > 0.001 and OR 37.14, AFE 0.97, p < 0.001, respectively). The use of non-antibiotic-laded cement (OR 3.62), obesity (BMI > 30, OR 8.86), diabetes (OR 2.33), high ASA grade (III-IV, OR 15.30), and blood transfusion requirement (OR 4.60) were also statistically significant risk factors for TKA PJI.

CONCLUSIONS

Our study provides evidence concerning that operative time, tourniquet time, cement type, diabetes, obesity, ASA grade, and blood transfusion requirement as independently associated risk factors for TKA PJI. Modifiable risk factors were specifically relevant, so we should be able to reduce the infection rate.

Consensus statement for perioperative care in total hip replacement and total knee replacement surgery: Enhanced Recovery After Surgery (ERAS®) Society recommendations

Background and purpose - There is a large volume of heterogeneous studies across all Enhanced Recovery After Surgery (ERAS®) components within total hip and total knee replacement surgery. This multidisciplinary consensus review summarizes the literature, and proposes recommendations for the perioperative care of patients undergoing total hip replacement and total knee replacement with an ERAS program.Methods - Studies were selected with particular attention being paid to meta-analyses, randomized controlled trials, and large prospective cohort studies that evaluated the efficacy of individual items of the perioperative treatment pathway to expedite the achievement of discharge criteria. A consensus recommendation was reached by the group after critical appraisal of the literature.Results - This consensus statement includes 17 topic areas. Best practice includes optimizing preoperative patient education, anesthetic technique, and transfusion strategy, in combination with an opioid-sparing multimodal analgesic approach and early mobilization. There is insufficient evidence to recommend that one surgical technique (type of approach, use of a minimally invasive technique, prosthesis choice, or use of computer-assisted surgery) over another will independently effect achievement of discharge criteria.Interpretation - Based on the evidence available for each element of perioperative care pathways, the ERAS® Society presents a comprehensive consensus review, for the perioperative care of patients undergoing total hip replacement and total knee replacement surgery within an ERAS® program. This unified protocol should now be further evaluated in order to refine the protocol and verify the strength of these recommendations.

Antibiotic-loaded bone cement is associated with a lower risk of revision following primary cemented total knee arthroplasty: an analysis of 731,214 cases using National Joint Registry data

AIMS

Antibiotic-loaded bone cements (ALBCs) may offer early protection against the formation of bacterial biofilm after joint arthroplasty. Use in hip arthroplasty is widely accepted, but there is a lack of evidence in total knee arthroplasty (TKA). The objective of this study was to evaluate the use of ALBC in a large population of TKA patients.

MATERIALS AND METHODS

Data from the National Joint Registry (NJR) of England and Wales were obtained for all primary cemented TKAs between March 2003 and July 2016. Patient, implant, and surgical variables were analyzed. Cox proportional hazards models were used to assess the influence of ALBC on risk of revision. Body mass index (BMI) data were available in a subset of patients.

RESULTS

Of 731 214 TKAs, 15 295 (2.1%) were implanted with plain cement and 715 919 (97.9%) with ALBC. There were 13 391 revisions; 2391 were performed for infection. After adjusting for other variables, ALBC had a significantly lower risk of revision for any cause (hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77 to 0.93; p < 0.001). ALBC was associated with a lower risk of revision for all aseptic causes (HR 0.85, 95% CI 0.77 to 0.95; p < 0.001) and revisions for infection (HR 0.84, 95% CI 0.67 to 1.01; p = 0.06). The results were similar when BMI was added into the model, and in a subanalysis where surgeons using only ALBC over the entire study period were excluded. Prosthesis survival at ten years for TKAs implanted with ALBC was 96.3% (95% CI 96.3 to 96.4) compared with 95.5% (95% CI 95.0 to 95.9) in those implanted with plain cement. On a population level, where 100 000 TKAs are performed annually, this difference represents 870 fewer revisions at ten years in the ALBC group.

CONCLUSION

After adjusting for a range of variables, ALBC was associated with a significantly lower risk of revision in this registry-based study of an entire nation of primary cemented knee arthroplasties. Using ALBC does not appear to increase midterm implant failure rates. Cite this article: Bone Joint J 2019;101-B:1331-1347.

Effect of Antibiotic-Impregnated Bone Cement in Primary Total Knee Arthroplasty

BACKGROUND

The purpose of this study is to evaluate the effect of commercially available antibiotic-impregnated bone cement (AIBC) on (1) prosthetic joint infections (PJIs) and (2) surgical site infections (SSIs) after primary total knee arthroplasty (TKA).

METHODS

A review of primary TKAs between 2014 and 2017 from an institutional database was conducted. This identified 12,541 cases which were separated into AIBC (n = 4337) and non-AIBC (8,164) cohorts. Medical records were reviewed for PJIs and SSIs (mean 2-year postoperative period). Infection rates between the cohorts were compared with univariate analyses followed by subanalysis of high risk patients (defined as having 2 or more of the following characteristics: >65 years, body mass index >40, or Charlson Comorbidity Index score >3). To control for confounders, multivariate analyses were performed with regression models adjusted for age, gender, body mass index, comorbidities, year, operative times, and lengths of stay.

RESULTS

On univariate analysis, PJI rates were higher in the AIBC cohort (1.0%) compared to the non-AIBC cohort (0.5%, P < .001). Subanalysis of the high risk patients also showed that PJI rates were higher in the AIBC cohort (1.9% vs 0.6%, P < .01). After adjusting for potential confounders, no significant associations between PJIs and AIBC use were found (odds ratio 1.4, 95% confidence interval 0.9-2.3, P = .133). Similarly, no significant differences in SSI rates were observed between the AIBC (2.9%) and non-AIBC cohorts (2.4%, P = .060) and no significant associations between SSIs and AIBC were found with multivariate analysis (odds ratio 1.0, 95% confidence interval CI 0.8-1.3, P = .948).

CONCLUSION

This study found that there was no clinically or statistically significant decrease in infection rates with AIBC in primary TKAs.

Antibiotic-Loaded Bone Cement in Primary Total Knee Arthroplasty: Utilization Patterns and Impact on Complications Using a National Database

BACKGROUND

The routine usage of antibiotic-loaded bone cement (ALBC) in primary total knee arthroplasty (TKA) is controversial. Its effectiveness in reducing infection risk remains unclear while high-dose antibiotics can lead to multiple adverse effects. The purpose of this population-based study is to evaluate utilization patterns of ALBC in primary TKA and its impact on clinical outcomes.

METHODS

This retrospective cohort study used data from the nationwide Premier Healthcare claims database (2006-2016). Multivariable models estimated associations between ALBC use and early postoperative infection, kidney injury, allergic reaction, hospital readmission, cost, and length of stay.

RESULTS

ALBC was used in 27.2% of all primary TKAs (N = 1,184,270). Usage increased from 17.3% to 30.2% in 2006-2010, then plateaued. Study covariates differed minimally between groups, suggesting nonselective ALBC use. Utilization was lower in rural (21.4%) and higher in large (>500 beds; 29.4%) hospitals. After adjusting for relevant covariates, ALBC use was associated with significantly decreased odds for early postoperative infection (odds ratio, 0.89; confidence interval, 0.83-0.96) and increased odds for acute kidney injury (odds ratio, 1.06; confidence interval, 1.02-1.11).

CONCLUSION

With utilization rates of around 30%, we found that ALBC reduced odds for early postoperative infection and increased odds for kidney injury. Strong consideration should be given for selective use of ALBC in primary TKA.

Studying Biofilm and Clinical Issues in Orthopedics

The association between biofilm-forming microorganisms and prosthetic joint infection influences all aspect of management including approaches to diagnosis, management and prevention. This article will provide an overview of new anti-biofilm strategies for management of prosthetic joint infection.

Routine use of commercial antibiotic-loaded bone cement in primary total joint arthroplasty: a critical analysis of the current evidence

Antibiotic-loaded cement (ABLC) has been widely utilized as an adjuvant treatment for patients with periprosthetic joint infection (PJI) but has also evolved to play a prophylactic role against infection in primary total joint arthroplasties (TJA). Nevertheless, there is currently a paucity of studies that systematically investigated this concept. This review aimed at answering the following questions: (I) Can routine use of ABLC help reduce the current infection rates in primary TJA? (II) What are the risks associated with this approach? And (III) can routine use be justified in primary TJA from an economic standpoint? Multiple databases were queried including PubMed, EMBASE, EBSCO Host, and SCOPUS. Studies published between January 1, 1990 and March 31, 2018 were reviewed. Inclusion criteria were studies reporting: (I) clinical outcomes of routine use of ABLC in primary hip and knee arthroplasty with 2-year minimum follow-up, (II) complications related to the use of ABLC, (III) cost of using ABLC. The final analysis included 24 studies. Data from multiple studies demonstrate contradictory results for infection rates when ABLC is used in all primary procedures with a majority of studies showing similar infection rates between ABLC and plain cement. The main concerns associated with routine use of ABLC are negative effects on the mechanical stability of cement, possible systemic and local toxicity of the absorbed antibiotic, and development of resistant bacterial strains. However, current literature has not clinically validated these concerns. Lastly, with an estimated increase in 117 million dollars with the routine use of ABLC in only 50% of TJAs performed each year, it is difficult to justify the use of ABLC without clear superiority in reducing infection. The use of ABLC has undeniably changed the way orthopaedic surgeons deal with PJI today. However, the large-scale, prophylactic use of ABLC in primary TJAs requires further research and justification.

The Hidden Cost of Commercial Antibiotic-Loaded Bone Cement: A Systematic Review of Clinical Results and Cost Implications Following Total Knee Arthroplasty

BACKGROUND

The purpose of this systematic review is to compare deep prosthetic joint infections (PJIs) between total knee arthroplasty (TKA) patients treated with either antibiotic-loaded bone cement (ALBC) or plain bone cement, and to explore the potential cost implications of commonly used bone cement regimens. We hypothesized that ALBC would not substantially reduce PJIs and would thereby present an unnecessary cost to the healthcare system.

METHODS

Using the PRISMA guidelines, we reviewed articles through May 2017 involving primary TKA patients with both ALBC cohort and plain bone cement cohort. A meta-analysis was performed comparing the prevalence of deep infections between cohorts. A cost comparison for a hypothetical setting with an annual volume of 1000 TKAs was performed to compare 3 commonly used cement regimens: 2 bags of ALBC used during each case, 1 bag of ALBC with 1 bag of plain cement, and 2 bags of plain cement. Pricing at our institution is $215/bag for commercial ALBC and $60/bag for plain cement.

RESULTS

Eight articles were included with a total of 34,664 patients. ALBC did not reduce the PJI (ALBC = 93/8189, 1.1% vs plain = 251/26,475, 0.9%; P = .09). The estimated costs for the 3 bone cement regimens per 1000 primary TKAs were as follows: 2 bags of ALBC = $430,000/y, 1 bag of ALBC +1 bag of plain cement = $275,000/y, and 2 bags of plain cement = $120,000/y.

CONCLUSION

ALBC did not reduce the prevalence of PJI suggesting that ALBC may be an unnecessary cost to the healthcare system. Hospital systems that perform 1000 TKAs/y could save between $155,000 and $310,000/y by switching to plain cement.

Antibiotic-laden Bone Cement in Primary and Revision Hip and Knee Arthroplasty

Antibiotic-laden bone cement (ALBC) has a number of different uses in primary and revision total joint arthroplasty. However, considerable controversy remains regarding how and when it is best used. The prophylactic use of low-dose ALBC in primary cemented total hip arthroplasty is well supported by the literature, conferring both clinical and economic benefits. In contrast, conclusive evidence on the clinical efficacy or economic benefit of the routine use of ALBC in primary total knee arthroplasty remains elusive. Given the currently available evidence, we cannot determine definitively whether the routine use of ALBC in primary total knee arthroplasty is justified, although selective use in patients with a high risk of infection seems warranted. The routine use of ALBC in revision total joint arthroplasty is well accepted, with good supporting evidence in studies of both aseptic and first-stage revision procedures. Although limited clinical evidence exists on the use of ALBC at the time of definitive component reimplantation after septic revision, the rationale for its use is strong.

Standardization of Acrylic Bone Cement Mixing Protocols for Total Knee Arthroplasty Results in Cost Savings

Cost reduction is important in total joint replacement surgery. Bone cement is used to fixate implants in most knee replacement procedures. The authors instituted a 4-pronged approach to reduce the cost of cement. Their approach included reducing the cost of the cement powder, changing the type of mixing method, using less antibiotic cement, and decreasing the amount of cement required for smaller implants. The authors evaluated the implementation of this program and measured the overall costs of cementation during knee replacement. A retrospective review of total knee replacement cementation technique and cost was performed before and after the cost-reduction program was implemented. The type of cement and cement mixing equipment used, the amount of cement used, and the cost of cement and cement mixing equipment were examined. The authors also reported the short-term complication rate including 90-day readmission rate and 30-day revision rate. The program resulted in an overall decrease in cement-related costs from approximately $310 to $105 per case. Reductions in the amount of cement used and the use of antibiotic cement were shown. Among the 3 surgeons, adoption of the program varied. Bone cement is an expense of modern total knee replacement. Implementing a cost-reduction program can reduce cement costs without changing quality of cementation. [Orthopedics. 2018; 41(5):e671-e675.].

Prevention of Periprosthetic Joint Infection: Examining the Recent Guidelines

BACKGROUND

The global rise in infectious disease has led the Center for Disease Control and Prevention and the World Health Organization to release new guidelines for the prevention of surgical site infection.

METHODS

In this article, we summarize current recommendations based on level of evidence, review unresolved and unaddressed issues, and supplement them with new literature.

RESULTS

Although the guidelines discuss major issues in reducing surgical site infection, many questions remain unanswered.

CONCLUSION

These guidelines will hopefully help in setting a standard of care based on best evidence available and focus investigators on areas where evidence is lacking.

Total knee arthroplasty and infection: how surgeons can reduce the risks

Total joint arthroplasty (TJA) is one of the most common orthopaedic procedures. Nevertheless, several complications can lead to implant failure.

Peri-prosthetic joint infections (PJI) certainly represent a significant challenge in TJA, constituting a major cause of prosthetic revision. The surgeon may have an important role in reducing the PJI rate by limiting the impact of significant risk factors associated to either the patient, the operative environment or the post-operative care.

In the pre-operative period, several preventive measures may be adopted to manage reversible medical comorbidities. Other recognised pre-operative risk factors are urinary tract infections, intra-articular corticosteroid injections and nasal colonisation with Staphylococcus (S.) aureus, particularly the methicillin-resistant strain (MRSA).

In the intra-operative setting, protective measures for PJI include antibiotic prophylaxis, surgical-site antisepsis and use of pre-admission chlorhexidine washing and pulsed lavage during surgery. In this setting, the use of plastic adhesive drapes and sterile stockinette, as well as using personal protection systems, do not clearly reduce the risk of infection. On the contrary, using sterile theatre light handles and splash basins as well as an increased traffic in the operating room are all associated with an increased risk for PJI.

In the post-operative period, other infections causing transient bacteraemia, blood transfusion and poor wound care are considered as risk factors for PJI.

Cite this article: Ratto N, Arrigoni C, Rosso F, Bruzzone M, Dettoni F, Bonasia DE, Rossi R. Total knee arthroplasty and infection: how surgeons can reduce the risks. EFORT Open Rev 2016;1: 339-344 DOI: 10.1302/2058-5241.1.000032.

Outcome Assessment in Total Knee Arthroplasty: A Systematic Review and Critical Appraisal

BACKGROUND

The Outcome Measures in Rheumatology (OMERACT) initiative developed a core outcome set (COS) of domains to assess effectiveness of interventions for knee osteoarthritis. These domains (pain, physical function, patient global assessment, imaging at 1 year) should be assessed in every trial to make research evidence meaningful and comparable. We systematically evaluated and critically appraised the use of measurement instruments and outcome domains in prospective studies evaluating patients with knee osteoarthritis undergoing total knee arthroplasty (TKA) and assessed their accordance with the OMERACT COS.

METHODS

Literature search was performed until August 26, 2014, in Medline and Embase. Clinical trials and prospective observational studies with ≥50 participants and a follow-up of ≥1 year were included. We collected general study characteristics, comprehensive information on measurement instruments, and corresponding domains used.

RESULTS

This systematic review identified low accordance of used outcome domains with the OMERACT COS of domains published in 1997. Only 4 of 100 included studies included all recommended core domains. Pain (85% of studies) and physical function (86%) were assessed frequently, whereas patient global assessment (21%) and joint imaging (≥1 year; 27%) were rarely assessed. There was substantial heterogeneity in the use of measurement instruments (n = 111) investigating TKA.

CONCLUSION

More efforts are required to implement the existing COS. In addition, a more consistent use of adequate measurement instruments is important to make research evidence on TKA more relevant, better comparable, and thus more useful for guideline developers and clinical decision makers.

The impact of patient and surgical factors on the rate of infection after primary total knee arthroplasty: an analysis of 64,566 joints from the New Zealand Joint Registry

AIMS

The aim of this study was to identify risk factors for prosthetic joint infection (PJI) following total knee arthroplasty (TKA).

PATIENTS AND METHODS

The New Zealand Joint Registry database was analysed, using revision surgery for PJI at six and 12 months after surgery as primary outcome measures. Statistical associations between revision for infection, with common and definable surgical and patient factors were tested.

RESULTS

A total of 64 566 primary TKAs have been recorded on the registry between 1999 and 2012 with minimum follow-up of 12 months. Multivariate analysis showed statistically significant associations with revision for PJI between male gender (odds ratio (OR) 1.85, 95% confidence interval (CI) 1.24 to 2.74), previous surgery (osteotomy (OR 2.45 95% CI 1.2 to 5.03), ligament reconstruction (OR 1.85, 95% CI 0.68 to 5.00)), the use of laminar flow (OR 1.6, 95% CI 1.04 to 2.47) and the use of antibiotic-laden cement (OR 1.93, 95% CI 1.19 to 3.13). There was a trend towards significance (p = 0.052) with the use of surgical helmet systems at six months (OR 1.53, 95% CI 1.00 to 2.34).

CONCLUSION

These findings show that patient factors remain the most important in terms of predicting early PJI following TKA. Furthermore, we found no evidence that modern surgical helmet systems reduce the risk of PJI and laminar flow systems may actually increase risk in TKA. The use of this registry data assists the estimation of the risk of PJI for individual patients, which is important for both informed consent and the interpretation of infection rates at different institutions.

TAKE HOME MESSAGE

Infection rates in TKA are related to both individual patient and surgical factors, and some modern methods of reducing infection may actually increase infection risk.

Surgical Site Infection After Total Knee Arthroplasty: Risk Factors in Patients With Timely Administration of Systemic Prophylactic Antibiotics

BACKGROUND

Surgical site infection (SSI) after total knee arthroplasty (TKA) is a catastrophic complication. Administration of prophylactic antibiotics within 60 minutes before surgery is a well-established strategy to prevent SSI. The study is aimed to identify the risk factors for SSI regarding primary TKA in patients with timely administration of systemic prophylactic antibiotics.

METHODS

A retrospective review of patients with primary TKA between 2009 and 2013 was conducted. Patients who had prophylactic antibiotics administered after skin incision or >60 minutes before skin incision were excluded.

RESULTS

Of the 3152 patients enrolled, the incidence of SSI and deep-implant SSI was 1.52% and 0.79%, respectively. Charlson Comorbidity Index ≥3 was an independent risk factor for both SSI (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.24-4.44, P = .01) and deep-implant SSI (OR, 3.46; 95% CI, 1.52-7.91, P < .01). Optimal dose of systemic antibiotics adjusted by patients' body weight for prophylaxis (OR, 0.29; 95% CI, 0.17-0.62, P < .01) and using antibiotic-laden bone cement (OR, 0.33; 95% CI, 0.17-0.64, P < .01) were significant protective factors for SSI. Meanwhile, using antibiotic-laden bone cement (OR, 0.31; 95% CI, 0.13-0.76, P = .01) also significantly decreased the risk of deep-implant SSI.

CONCLUSION

Our findings highlight the importance of appropriate dosage of prophylactic antibiotics and use of antibiotic-laden cement in preventing SSI after primary TKA. For prevention of deep-implant SSI, using antibiotic-laden bone cement seems to be an advisable strategy.

Particle-Induced Osteolysis Is Mediated by TIRAP/Mal in Vitro and in Vivo: Dependence on Adherent Pathogen-Associated Molecular Patterns

BACKGROUND

Proinflammatory signaling by toll-like receptors (TLRs) likely contributes to biologic responses to wear particles causing aseptic loosening. We recently reported associations with aseptic loosening in patients with polymorphisms in the locus encoding an adapter protein specific for TLR-2 and TLR-4 known as toll/interleukin-1 receptor domain-containing adapter protein/MyD88 adapter-like (TIRAP/Mal). To directly examine the contribution of TIRAP/Mal, we tested the hypothesis that TIRAP/Mal deficiency reduces the activity of wear particles. Signaling by TLR-2 and TLR-4 through TIRAP/Mal can be activated by bacterial pathogen-associated molecular patterns (PAMPs) such as lipopolysaccharide or endogenous alarmins. To distinguish between those possibilities, we tested the hypothesis that the effects of TIRAP/Mal depend on the adherence of bacterial PAMPs to the particles.

METHODS

In vitro mRNA levels and secretion of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 were measured after incubating wild-type and TIRAP/Mal(-/-) macrophages in the presence or absence of titanium particles with adherent bacterial debris, so-called endotoxin-free particles, or particles with adherent lipopolysaccharide. In vivo osteolysis was measured after implanting titanium particles on the calvaria of wild-type and TIRAP/Mal(-/-) mice.

RESULTS

TIRAP/Mal deficiency significantly inhibited the activity of titanium particles with adherent bacterial debris to stimulate in vivo osteolysis and in vitro cytokine mRNAs and secretion. Those effects are dependent on adherent PAMPs because removal of >99% of the adherent bacterial debris from the particles significantly reduced their activity and the remaining activity was not dependent on TIRAP/Mal. Moreover, adherence of highly purified lipopolysaccharide to the endotoxin-free particles reconstituted the activity and the dependence on TIRAP/Mal.

CONCLUSIONS

TIRAP/Mal deficiency reduces inflammatory responses and osteolysis induced by particles with adherent PAMPs.

CLINICAL RELEVANCE

Our results, coupled with the genetic associations between aseptic loosening and polymorphisms within the TIRAP/Mal locus, support TLR signaling through TIRAP/Mal as one of the factors that enhances the activity of wear particles and further support the hypothesis that bacterial PAMPs likely contribute to aseptic loosening in a subset of patients.

Use of antibiotic-loaded cement in total knee arthroplasty

Bone cement has the capacity to release antibiotic molecules if any antibiotic is included in it, and these elution properties are improved as cement porosity is increased. In vitro studies have shown high local antibiotic concentration for many hours or few days after its use. Antibiotic loaded bone cement (ALBC) is helpful when treating an infection in total knee arthroplasty (TKA) revision surgery. The purpose of this paper was to review the evidence for the routine use of ALBC in TKA in the literature, its pros and cons. Many authors have recommended the use of ALBC also in primary TKA for infection prophylaxis, but the evidence based on data from National Registries, randomized clinical trials and meta-analysis suggest a protective effect of ALBC against infection when used in hips, but not (or only mild) in knees. A possible explanation to this finding is that the duration and quantity of locally elevated antibiotic levels after surgery are smaller in TKA, due to the smaller amount of cement used for fixation in TKA-only a layer in the bone surface. There are some concerns about the routine use of ALBC in primary TKA as prophylaxis against infection: Firstly, there is a risk of hypersensivity or toxicity even when the chance is highly improbable. Secondly, there is a reduction in the mechanical properties of the cement, but this can be probably neglected if the antibiotic is used in low doses, not more than 1 g per 40 g cement package. Another significant concern is the increased economic cost, which could be overlooked if there were enough savings in treating fewer prosthetic infections. Finally, there is also a risk of selection of antibiotic-resistant strains of bacteria and this could be the main concern. If used, the choice of the antibiotic mixed in ALBC should consider microbiological aspects (broad antimicrobial spectrum and low rate of resistant bacteria), physical and chemical aspects (thermal stability, high water solubility), pharmacological characteristics (low risk to allergic reactions or toxicity) and economic aspects (not too expensive). The most commonly used antibiotics in ALBC are gentamicin, tobramycin and vancomycin. In conclusion, there is a paucity of randomized clinical trials in the use of ALBC in primary TKAs and the actual evidence of the effect of ALBC in reducing the risk of infection is insufficient. This, in addition to concerns about patient safety, risks of increase in the antibiotic resistance of microorganisms and the increase in costs in the procedure, lead us to recommend a cautious use of ALBC, perhaps only in high-risk patients (immunocompromised, morbidly obese, diabetic and patients with previous history of fracture or infection around the knee) unless the benefits of ALBC use were fully proven. Meanwhile, the rigorous use of peri-operative prophylactic systemic antibiotics and adoption of efficient antiseptic procedures and improved surgical techniques must be considered the gold standard in infection prevention in TKA surgery.

Prevention of Periprosthetic Joint Infection

Prosthetic joint infection (PJI) is a calamitous complication with high morbidity and substantial cost. The reported incidence is low but it is probably underestimated due to the difficulty in diagnosis. PJI has challenged the orthopaedic community for several years and despite all the advances in this field, it is still a real concern with immense impact on patients, and the healthcare system. Eradication of infection can be very difficult. Therefore, prevention remains the ultimate goal. The medical community has executed many practices with the intention to prevent infection and treat it effectively when it encounters. Numerous factors can predispose patients to PJI. Identifying the host risk factors, patients' health modification, proper wound care, and optimizing operative room environment remain some of the core fundamental steps that can help minimizing the overall incidence of infection. In this review we have summarized the effective prevention strategies along with the recommendations of a recent International Consensus Meeting on Surgical Site and Periprosthetic Joint Infection.

Lack of efficacy of prophylactic application of antibiotic-loaded bone cement for prevention of infection in primary total knee arthroplasty: results of a meta-analysis

BACKGROUND

Deep incisional surgical site infection (SSI) is a devastating and costly complication of primary total knee arthroplasty (TKA). The effectiveness of antibiotic-loaded bone cement (ALBC) in preventing these infections remains controversial.

METHODS

A meta-analysis was conducted to assess the efficacy of ALBC in preventing deep infection in primary TKA after a detailed and systematic search of the PubMed, Embase, CNKI, and Cochrane databases had been performed to identify appropriate comparative trials on the prophylactic use of ALBC in primary TKA.

RESULTS

Five comparative trials were included. In total, 3,461 patients (ALBC group) received ALBC, whereas 3,176 patients (non-antibiotic-loaded cement; NALBC group) did not. The incidence of deep incisional SSI in the ALBC group was 1.32% (n=46) whereas the incidence in the NALBC group was 1.89% (n=60), figures which are not significantly different. No adverse events associated with ALBC were reported in any studies.

CONCLUSION

Statistical analysis did not reveal a significantly different incidence of deep or superficial SSI in patients receiving and not receiving antibiotic-loaded cement. The prophylactic application of ALBC thus did not show efficacy in primary TKA. More large-sample studies are required to confirm this finding.

Do genetic susceptibility, Toll-like receptors, and pathogen-associated molecular patterns modulate the effects of wear?

Overwhelming evidence supports the concept that wear particles are the primary initiator of aseptic loosening of orthopaedic implants. It is likely, however, that other factors modulate the biologic response to wear particles. This review focuses on three potential other factors: genetic susceptibility, Toll-like receptors (TLRs), and bacterial pathogen-associated molecular patterns (PAMPs). WHERE ARE WE NOW?: Considerable evidence is emerging that both genetic susceptibility and TLR activation are important factors that modulate the biologic response to wear particles, but it remains controversial whether bacterial PAMPs also do so. WHERE DO WE NEED TO GO?: Detailed understanding of the roles of these other factors may lead to identification of novel therapeutic targets for patients with aseptic loosening. HOW DO WE GET THERE?: Highest priority should be given to polymorphism replication studies with large numbers of patients and studies to replicate the reported correlation between bacterial biofilms and the severity of aseptic loosening.

Coatings and surface modifications imparting antimicrobial activity to orthopedic implants

Bacterial colonization and biofilm formation on an orthopedic implant surface is one of the worst possible outcomes of orthopedic intervention in terms of both patient prognosis and healthcare costs. Making the problem even more vexing is the fact that infections are often caused by events beyond the control of the operating surgeon and may manifest weeks to months after the initial surgery. Herein, we review the costs and consequences of implant infection as well as the methods of prevention and management. In particular, we focus on coatings and other forms of implant surface modification in a manner that imparts some antimicrobial benefit to the implant device. Such coatings can be classified generally based on their mode of action: surface adhesion prevention, bactericidal, antimicrobial-eluting, osseointegration promotion, and combinations of the above. Despite several advances in the efficacy of these antimicrobial methods, a remaining major challenge is ensuring retention of the antimicrobial activity over a period of months to years postoperation, an issue that has so far been inadequately addressed. Finally, we provide an overview of additional figures of merit that will determine whether a given antimicrobial surface modification warrants adoption for clinical use.

Infection post-total knee replacement: current concepts

Periprosthetic joint infection is a hot topic for investigation because it represents a challenging clinical problem with considerable burden for patients, institutions, and health systems. Despite our substantial knowledge, many details in prevention, pathophysiology, diagnosis, and treatment of infectious complications following total knee arthroplasty remain to be controversial with the available evidence being insufficient and at times conflictive. This manuscript is an attempt to approach the most recently published literature regarding the aforementioned details and aims to provide the reader with an updated perspective in the management of periprosthetic joint infection of the knee.