Treatment options in PJI - is two-stage still gold standard?

Antibiotic Holiday in 2-Stage Exchange for Periprosthetic Joint Infection: A Scoping Review

BACKGROUND

The use of a 2-stage exchange remains a common management strategy for periprosthetic joint infection (PJI). The use of an "antibiotic holiday" before the second stage to confirm the clearance of infection is often employed, but there is little evidence to guide this practice. The aim of this review was to systematically map the literature reporting on the use of an antibiotic holiday as part of a 2-stage revision for chronic PJI and to answer the question: is there a role for an antibiotic holiday in patients undergoing 2-stage exchange arthroplasty for PJI?

METHODS

Given the heterogeneity of the literature on this topic, a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-compliant scoping review was conducted. Two reviewers developed and refined the search strategy and study eligibility criteria and pilot-tested the data charting form prior to data extraction. Data were analyzed descriptively.

RESULTS

Three databases were screened, with 504 full-text articles retrieved for review after screening 2,579 titles and abstracts. Of these, 243 were included for data charting. Most studies (238 of 243; 97.9%) were case series, and the remaining 5 (2.1%) were cohort studies that incorporated a direct comparison between continuous therapy and an antibiotic holiday. Most case series (202 of 238; 84.9%) utilized an antibiotic holiday. The proportion of patients who experienced treatment failure in the continuous therapy group (271 of 2,074 patients; 13.1%) was lower than that in the antibiotic holiday group (2,843 of 17,329 patients; 16.4%; p < 0.001). There was a greater proportion of studies with a between-stage interval of <3 months among case series utilizing continuous antibiotic therapy (66.7%) compared with those utilizing an antibiotic holiday (27.2%; p < 0.001).

CONCLUSIONS

There is no proven superiority of an antibiotic holiday during a 2-stage exchange to treat chronic PJI. Due to the need to extend the duration of the interval between the first and second stages in order to accommodate an antibiotic holiday, patients may be subjected to unnecessary prolongation of their treatment duration without an improvement in outcome.

LEVEL OF EVIDENCE

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

Comparison of Single- Versus Two-Stage Revision Knee Arthroplasty for the Treatment of Periprosthetic Knee Joint Infections

BACKGROUND

Periprosthetic joint infection (PJI) can be a complex and distressing complication following total knee arthroplasty (TKA). Both one-stage and two-stage revisions are the main options for treating chronic PJI of the knee; however, the best treatment option continues to be debated. We aimed to compare the rate of success by comparing the risk of re-infection between the two treatment options.

METHODS

Patients who underwent one-stage from 2009 to 2014 or two-stage revision from 2015 to 2020 for treatment of PJI of the knee were included. The Delphi-based consensus criteria were used to classify infections. The primary outcome was recurrent infection. Time from the index revision surgery to the return to the operating room for infectious reasons and non-infectious reasons was compared between the two groups.

RESULTS

A total of 66 patients underwent knee revision for PJI, in which 46 (69.7%) underwent one-stage and 20 (30.3%) underwent two-stage revision. Mean age (P = 0.57) and body mass index (BMI) (P = 0.33) were similar between the groups. The rate of no recurrence of infection was 89.1% in the one-stage group and 65.0% in the two-stage group (P = 0.034) at the mean follow-up time of 5.4 years (range, 2.2 to 10.3). The one-stage group was significantly more likely to have decreased time between the revision for re-infection (P = 0.012). There were no significant differences in rates of postoperative deep vein thrombosis, acute renal failure, long-term antibiotic use, or length of stay.

CONCLUSIONS

These results indicate that one-stage revision for treatment of PJI of the knee is at least as effective as two-stage revision. To our knowledge, this is the largest single-surgeon, single-protocol series of consecutive cases reported to date, with limited exclusion criteria.

Impact of Spacer Constraint on Outcomes in Two-Stage Exchange Revision Total Knee Arthroplasty

INTRODUCTION

A two-stage revision has long been the gold standard for chronic periprosthetic joint infections (PJI), with real-component articulating spacers becoming overwhelmingly popular. While several studies have evaluated the success of these spacers in revision total knee arthroplasty (rTKA), to our knowledge, this is the first to specifically compare outcomes of spacers stratified by the level of liner constraint.

METHODS

This retrospective analysis reviewed 135 patients who were indicated for two-stage rTKA due to PJI between 2011 and 2023 at a single specialty urban academic institution. Patients were categorized into three groups based on the polyethylene liner constraint used during the first stage: cruciate retaining (CR), posterior stabilized (PS), and varus-valgus constrained (VVC). Of these 135 patients, 60 (44%) were categorized in the CR group, 47 (35%) were in the PS group, and 28 (21%) were in the VVC group. These groups were compared after each stage for peri- and postoperative outcomes such as operative time, length of stay (LOS), discharge disposition, knee range of motion (ROM), as well as incidence of re-revision and reinfection.

RESULTS

The mean postoperative LOS was not different among cohorts for both stages. Operative time was significantly longer in the VVC group after the second stage (P = 0.007), while there was no difference after the first stage (P = 0.085). There were no differences in ROM after both stages. The mean ROM after the first stage was 92° in the CR group, 90° in the PS group, and 85° in the VVC group (P = 0.46). After the second stage, ROM was 101° in both the CR and VVC groups and 107° in the PS group (P = 0.28). There were no differences in the risk of re-revision due to re-infection across the groups after the first or second stage procedures. The re-infection incidence after the first stage was 14% in the VVC group, compared to 5% in the CR group and 4% in the PS group (P = 0.14). After the second stage, the reinfection risk was 21% in the VVC group, 8% in the CR group, and 13% in the PS group (P = 0.21).

CONCLUSION

No significant differences were observed in the risk of complications such as re-infection, re-revisions, and postoperative ROM, suggesting that the choice of liner constraint in two-stage revision can be left up to surgeon's discretion.

The Fate of the DAIR, Outcomes after 1 Year: A Large Database Study

Debridement with antibiotics and implant retention (DAIR) is commonly utilized for treatment of prosthetic joint infection (PJI) in total knee arthroplasty (TKA), particularly in cases of acute PJI. Reported success rates of DAIR have been highly variable, but the overall success rate of DAIR cohort studies is approximately 70 to 80%. However, no large database studies have investigated the success rate of DAIR. Therefore, we seek to provide a framework for large-database analysis of PJI interventions and their outcomes and to assess the success rate of DAIR. We queried the MarketScan Database for patients who underwent a DAIR (CPT 27310 and/or CPT 27486) procedure for indication of PJI (ICD-10 T84.53 OR T84.54) between January 1, 2017 and December 31, 2021. We identified reoperations (i.e., stage 1 revision, amputation, or arthrodesis) indicating failure of DAIR. Failure of DAIR treatment was defined by subsequent reoperation. We also identified prescriptions of suppression antibiotics more than 6 months after DAIR. We identified 1,018 patients who underwent a DAIR procedure for PJI. Of these patients, 195 (19.2%) underwent reoperation within 1 year and an additional 178 (17.5%) were prescribed suppressive antibiotics. For 780 patients with a minimum of 2 years of follow-up, 164 (21%) underwent reoperation and an additional 179 (22.9%) were prescribed suppressive antibiotics. Patients with obesity and patients younger than 60 years had significantly higher rates of having reoperation or suppressive antibiotics at 1 year following DAIR. DAIR is a viable option in the treatment of PJI, with an approximately 19% rate of reoperation at 2 years. Our findings are consistent with that of previously published literature.

Dalí Sign: Characterization and Case Series of Patellar Bony Shell Morphological Changes after Two-Stage Revision for Periprosthetic Joint Infection

The fate of the patella in two-stage revision total knee arthroplasty (TKA) for periprosthetic joint infection (PJI) in which the patella is left as a bony shell is poorly described. The purpose of this case series is to describe a phenomenon we name the Dalí Sign, which is characterized by elongation and curvature of the patella around the lateral edge of the femoral component occasionally observed in patients undergoing two-stage revision without reimplantation of the patellar component.Our institutional surgical database was queried for patients who were treated with two-stage revision arthroplasty for PJI by the two senior authors. All available sequential skyline patellar radiographs were viewed from immediately prior to first-stage explantation to latest image at final outpatient follow-up at our institution and assessed for the abovementioned morphological changes.Included patients underwent a two-stage revision surgery for PJI at our institution, had a patellar component removed during the first stage of their treatment which included implant explantation and insertion of temporary antibiotic spacers, did not have the patellar component reimplanted during their second-stage revision surgery, and demonstrated radiographic patellar morphological changes at final follow-up. Patients' demographic, surgical, and outcome data were recorded.Our review identified six patients meeting these criteria. Mean follow-up after second-stage surgery was 12 months (range 2 to 21 months). At final follow-up, three patients were walking without pain, one patient was exercising to tolerance, one patient was walking with pain, and one was using a wheelchair or a walker for mobility.In this case series, we characterize the Dalí Sign, the elongation and curvature of the patellar bony shell over the femoral component after two-stage revision for PJI. Further comparative cohort studies are necessary to identify the incidence and risk factors for the development of this morphological change and to compare outcomes of patients with and without the Dalí Sign when left with a bony shell after staged revision TKA.

Eligibility for One-Stage Exchange Arthroplasty for Knee Periprosthetic Joint Infection Predicts Survivorship: A Retrospective Analysis of 509 Cases

BACKGROUND

Although two-stage exchange arthroplasty remains the gold standard for chronic total knee arthroplasty (TKA) periprosthetic joint infection (PJI), one-stage exchange arthroplasty is gaining popularity. The proportion of TKA PJIs eligible for one-stage exchange arthroplasty remains unknown. We aimed to determine how many patients who underwent two-stage exchange arthroplasty would have met eligibility criteria for one-stage exchange arthroplasty and the impact of eligibility on outcomes.

METHODS

From 2000 to 2020, we identified 509 two-stage exchange arthroplasties for TKA PJI. The mean age was 66 years, the mean body mass index was 34, and 58% were men. Patients were considered eligible for one-stage exchange arthroplasty if they had unilateral PJI with susceptible bacteria identified preoperatively that was not fungal or multiresistant, were a McPherson A host, had no prior two-stage exchange arthroplasty, had an absence of severe bone or soft tissue loss, and were not septic. Cumulative incidences of reoperation for infection, re-revision for infection, any reoperation, and any re-revision were compared using a competing risk model. The mean follow-up was 5 years.

RESULTS

Only 20% met eligibility criteria for one-stage exchange arthroplasty. The most common reasons for ineligibility were host grade (54%), and unknown organism (22%). The 2-year cumulative incidences of reoperation for infection and re-revision for infection for ineligible and eligible patients were 13 and 11% (P = 0.49), and nine and 6% (P = 0.3), respectively. The 2-year cumulative incidences of any reoperation and any re-revision for ineligible and eligible patients were 20 and 15% (P = 0.09) and 13 and 7% (hazard ratio = 2, P = 0.02), respectively.

CONCLUSIONS

Only 20% of patients who underwent two-stage exchange arthroplasty met published eligibility criteria for one-stage exchange arthroplasty. The two-fold increased re-revision rate in patients ineligible for one-stage exchange arthroplasty should be considered when analyzing evolving data.

LEVEL OF EVIDENCE

IV (retrospective).

1.5-Stage Revision for the Treatment of Periprosthetic Joint Infection: A Systematic Review

BACKGROUND

Although the two-stage exchange is the gold standard for the treatment of periprosthetic joint infection (PJI) in the United States, there is recent data to suggest that the utilization of a well-functioning destination spacer, also known as a "functional" or "1.5-stage revision," can be a viable treatment option in patients who have a PJI. The purpose of this systematic review was to evaluate the outcomes of patients undergoing a 1.5-stage revision for PJI and compare outcomes to a two-stage revision.

METHODS

A systematic review was performed through PubMed, Scopus, and Embase databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines were followed utilizing two reviewers. Following exclusions, 13 studies (n = 924 patients, 704 knees and 228 hips) were identified and included. A standardized template was utilized to capture demographic information (age, body mass index [BMI]), success/failure rate, mean follow-up time (years), and infection-free survivorship compared to two-stage revision. There were 556 patients (428 knees and 136 hips) who had 1.5-stage revisions included in the analyses. The mean age and body mass index were 65 years (range, 60 to 78) and 31 (range, 23.7 to 34.4), respectively.

RESULTS

At a mean follow-up time of 3.8 ± 1.1 years, the mean success rate was found to be 86.8%. The mean failure rate due to infection was 12.6%. In one study, infection-free survivorship was greater in the 1.5-stage revision cohort when compared to the two-stage revision cohort (94 versus 83%, P = 0.048). The remaining five studies that evaluated infection-free survivorship found no significant difference. However, there was a trend toward decreased the 90-day pain scores, postoperative complications, and cost in the 1.5-stage cohort.

CONCLUSIONS

Our systematic review demonstrated that a 1.5-stage revision is a viable and cost-effective treatment option for patients who have PJI. Infection-free survivorship was similar or greater when comparing a 1.5-stage revision to a two-stage revision. A 1.5-revision was associated with lower 90-day pain scores, postoperative complications, and decreased cost when compared to the two-stage revision in short-term follow-up, defined as less than five years. To better describe the procedure, we propose the name change to semipermanent eluting antibiotic revision procedure.

LEVEL OF EVIDENCE

IV.

Microbial Diversity of Periprosthetic Joint Infections in Diabetic and Nondiabetic Patients Following Hip Arthroplasty

BACKGROUND

Periprosthetic joint infection (PJI) is a major complication following hip arthroplasty, leading to prolonged hospital stays, increased health care costs, and major morbidity. Diabetes mellitus is a prevalent comorbidity among hip arthroplasty patients, contributing to an increased risk of surgical complications, including infections. However, limited evidence exists regarding the microbial profiles of PJIs in diabetic patients compared to nondiabetic counterparts.

METHODS

We conducted a retrospective cohort study to investigate the microbial diversity of PJIs in diabetic and nondiabetic patients following hip arthroplasty. Medical records of patients who underwent hip arthroplasty procedures between 1996 and 2021 were reviewed. Patients diagnosed with PJI, based on the international consensus meeting, were included in the study. Microbiological data, including culture results, and risk factors were collected and analyzed. A total of 4,261 culture-positive patients diagnosed with PJI following hip arthroplasty were included in the analysis.

RESULTS

Microbiological analysis revealed a diverse spectrum of microbial pathogens, with Staphylococcus species being the most commonly isolated pathogen. Comparison between diabetic and nondiabetic patients revealed differences in the microbial profiles of PJIs, with diabetic patients more likely to be infected with specific pathogens, including Candida albicans (P = 0.01 odds ratio (OR) 2.8, confidence interval (CI) 1.2 to 6.2), Klebsiella pneumoniae (P = 0.03 OR 2.4, CI 1.0 to 5.6), Staphylococcus aureus (P = 0.04 OR 1.3, CI 1.0 to 1.8), Staphylococcus epidermidis (P < 0.001 (R 1.7, CI 1.4 to 2.2), Polymicrobial infections (P < 0.001 OR 1.5, CI 1.2 to 1.8), and Clostridium perfringens (P = 0.04 OR 5.9, CI 1.0 to 33.1).

CONCLUSIONS

Our study provides valuable insights into the microbial diversity of PJIs in diabetic and nondiabetic patients following hip arthroplasty. The identification of a tendency to different microbial profiles in diabetic patients underscores the need for tailored approaches to infection prevention and management in this high-risk population. Further research is needed to elucidate the underlying mechanisms and develop targeted interventions to improve patient outcomes.

Implementation of Outpatient Parenteral Antimicrobial Therapy (OPAT) in Patients with Complicated Periprosthetic Joint Infections

Periprosthetic joint infections (PJI) are a serious complication of arthroplasty with high morbidity. With growing bacterial resistance and limited disposability of oral antibiotics with sufficient bioavailability, the need for intravenous antibiotic application is raising. This causes long-term hospital stays and rising costs. In the course of transferring procedures into an outpatient setting as well as coping with pressures on hospital capacity, outpatient parenteral antimicrobial therapy (OPAT) can build a bridge for the treatment of such infections.In a single centre analysis, 47 cases treated with OPAT were studied in relation to pathogen, antimicrobial resistance, indication for OPAT and follow up. Furthermore, the patients received an anonymised questionnaire with 4 clusters of interest in terms of internal quality assessment on the success and evaluation of this therapeutic procedure. Special attention was paid to the descriptive analysis of patients with periprosthetic joint infections (n = 30).Between May 2021 and October 2022 out of 47 patients with OPAT, 30 cases with periprosthetic joint infections were identified. For infected hip- and knee arthroplasties, a remarkable spectrum of pathogens was found. In hip infections highly resistant strains of Staphylococcus epidermidis and Enterococci were detected. In knee infections, the pathogens were more susceptible, but however highly virulent Staphylococcus aureus and Streptococci. Difficult to treat, mixed infections were found in both locations. The indication for OPAT was based in half of the cases on the high level of antimicrobial resistance, with availability of only parenteral applicable antibiotics. Further indications were mixed infections and difficult to treat pathogens, with flucloxacillin therapy as well as OPAT as the last therapeutic option. The questionnaire showed 96% patient satisfaction in terms of organisation and acceptance of this kind of therapy. Complications or unexpected outpatient/ hospital treatments were very rare in connection with OPAT. Two thirds of patients reported completion of the treatment. In the clinical follow up (average of 5.7 months), 96.6% of cases were declared free of infection. In one patient the infection persisted.OPAT is a safe and reliable therapeutic option for outpatients to continue parenteral antimicrobial treatment in joint infections. Due to increasing pressure on hospitals in terms of costs and capacity, this therapy offers an alternative to inpatient treatment. The indication for OPAT should be set individually, risk adjusted and not generalised for all patients. The outpatient sector needs financial and structural support for comprehensive roll-out of this treatment in Germany. A further focus should be on the prevention of periprosthetic joint infections. With the knowledge of the expected pathogens and the surgical resources, the standards should be adapted. The choice of the antibiotic should be specified and the intervals of application be shortened, according to the surgical course, in order to yield high levels of agent concentration in the surgical area. Further investigations are required to test the superiority of OPAT versus the oral administration of antibiotics in long-term observations as well as to define the necessary duration of OPAT.

Leukocyte scintigraphy has high specificity but low sensitivity in diagnosing persistent periprosthetic joint infection before reimplantation in two-stage revision

INTRODUCTION

Two-stage revision is considered the gold standard treatment in chronic periprosthetic joint infection (PJI) but no specific criteria or examination exist to determine infection eradication before reimplantation. This study aimed to assess the diagnostic performance of leukocyte scintigraphy after the first-stage procedure in two-stage revision for chronic PJI.

MATERIAL AND METHODS

Patients studied with leukocyte scintigraphy after cement spacer insertion for knee PJI from January 2012 to December 2021 were retrospectively included. Infection was diagnosed using the criteria of the 2018 International Consensus Meeting. When 1 or more minor criteria were positive but the score was < 6, patients were considered not infected if there was no recurrence of infection at least 24 months after the second-stage procedure. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were found.

RESULTS

The final cohort included 67 cases in 61 patients (M: F = 32:35; mean age 74 years). There were 43 true negatives, 8 true positives, 12 false negatives, and 4 false positives. The sensitivity and specificity of leukocyte scintigraphy in diagnosing PJI were respectively 40.0% and 91.5%, PPV was 66.7%, NPV was 78.2%, and accuracy was 76.1%. Staphylococcus Epidermidis was the most frequently isolated microorganism (50%).

CONCLUSION

Due to the high costs and the difficulty in its execution, LLS should not be used routinely but it could represent an additional criterion in doubtful cases. In any case, a thorough evaluation of other pre- and intra-operative tests is essential to determine whether reimplantation or spacer renewal is the best course of action. Special consideration should be given to positive LLS, as its results are highly specific and have a low rate of false positives. Conversely, in over half of infected patients, LLS could give false negatives, making negative LLS results less relevant.

Comparative reinfection rate of one-stage versus two-stage revision in the management of periprosthetic joint infection following total hip arthroplasty: a meta-analysis

BACKGROUND

Debates persist on the optimal surgical approach for treating Periprosthetic joint infection (PJI) following total hip arthroplasty (THA). This meta-analysis aimed to compare the reinfection rate of one-stage revision versus two-stage revision for PJI after THA.

METHODS

A comprehensive search was performed in four databases (PubMed, Embase, Web of Science, and Cochrane Library) to locate articles that assessed the reinfection rate of one-stage revision compared to two-stage revision. Meta-analyses of reinfection rate were performed.

RESULTS

A total of 14 articles including of 1429 patients were chosen for inclusion in this meta-analysis, with 561 patients in the one-stage group and 868 patients in the two-stage group. The meta-analysis of the 14 trials revealed that there was no statistically significant disparity in the reinfection rate between the two groups(OR = 1.34, 95% CI 0.92 ~ 1.93, P = 0.12, I2 = 0). A subgroup analysis was conducted based on the presence of a well-defined algorithm for decision making in either a one-stage or two-stage revision. There was no statistically significant difference in reinfection rate between one-stage and two-stage revision if there was a decision algorithm(OR = 0.83, 95% CI 0.44 ~ 1.54, P = 0.55, I2 = 0). If not, the reinfection rate of one-stage revision was significantly higher than that of two-stage revision(OR = 1.79, 95% CI 1.11 ~ 2.88, P = 0.02, I2 = 0). Postoperative hip function score was significantly better in the one-stage revision group than that of the two-stage revision group(SMD = 0.54, 95% CI 0.31 ~ 0.78, P<0.05, I2 = 79%).

CONCLUSIONS

A strategy that is clearly defined and can be used for decision making in one-stage or two-stage revision is necessary for the treatment of PJI after THA. When there is significant damage to the soft tissue and/or the presence of strong microorganisms, a two-stage revision is recommended in order to decrease the reinfection rate. One-stage revision is recommended for patients with low-toxic infections and intact soft tissue.

TRIAL REGISTRATION

PROSPERO (CRD42023450842, 17 August 2023) https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023450842 .

Accuracy of a New Augmented Reality Assisted Technique for Total Knee Arthroplasty: An In Vivo Study

Background

Total knee arthroplasty (TKA) remains the standard of care for treating end-stage osteoarthritis of the knee. Approximately 15%-20% of the patients are dissatisfied following surgery. To improve accuracy and outcomes of TKA, various assistive technologies have been introduced. For this study, an augmented reality (AR) system was explored and tested.

Methods

The Knee + system (Pixee Medical, Besancon, France) was used to guide TKA. It uses a combination of quick response-code labeled instruments and AR glasses to guide tibial and femoral cuts. The primary research goal was to evaluate its accuracy by direct comparing the planned angular values for lateral distal femoral angle, medial proximal tibial angle, hip-knee-ankle axis, and tibial slope to the intraoperative obtained values and the measured angles on postoperative full leg radiographs. The secondary research goal was to assess its feasibility.

Results

This retrospective study evaluated 124 patients, with a follow-up of at least 1 year. The average absolute difference between planned and measured postop values were 1.39° for lateral distal femoral angle, 1.03° for medial proximal tibial angle, 2.16° for tibial slope, and 1.51° for hip-knee-ankle axis. Within the follow-up period, 8 complications were observed. The average surgical time was 83 minutes.

Conclusions

This study has demonstrated a high accuracy, comparable to robotic-assisted total knee arthroplasty, of the Knee + AR system. It has shown to be a safe, cheap and time-efficient assistive technology for patients undergoing medial pivot TKA.

Increased Involvement of Staphylococcus epidermidis in the Rise of Polymicrobial Periprosthetic Joint Infections

BACKGROUND

In this study, we aimed to analyze the temporal distribution of polymicrobial periprosthetic joint infections (PJIs), while also evaluating the patient risk factors associated with these infections following total joint arthroplasty at our institution across 2 distinct periods.

METHOD

This retrospective cross-sectional study evaluated 259 patients who had knee or hip PJI from 2001 to 2006 and 2018 to 2022. A PJI was diagnosed using the 2018 International Consensus Meeting criteria. We utilized the Polymicrobial Pathogens' Co-occurrence Network Analysis, a novel approach that leverages network theory to map and quantify the complex interplay of organisms in PJIs.

RESULTS

Of the 259 patients who had polymicrobial PJI, 58.7% were men, with mean age 67 years (range, 24 to 90). Of the 579 identified pathogens, Staphylococcus epidermidis was the most common (22.1%), followed by Staphylococcus aureus (9.0%) and Cutibacterium acnes (7.8%). The co-occurrence analysis indicated that Staphylococcus epidermidis frequently coexisted with Cutibacterium acnes (26 cultures) and Staphylococcus capitis (22 cultures). A notable increase in body mass index from 27.7 ± 4.4 in 2001 to 2006 to 29.7 ± 6.2 in 2018 to 2022 was observed (P = .001). Moreover, infections from Staphylococcus epidermidis, Cutibacterium acnes, and Staphylococcus capitis saw a significant uptick (P < .001).

CONCLUSIONS

The study shows that from 2001 to 2022, there was a significant change in the pathogens responsible for polymicrobial PJIs, particularly an increase in Staphylococcus epidermidis, Cutibacterium acnes, and Staphylococcus capitis. Alongside these microbial changes, there was a rise in body mass index and shifts in comorbid conditions, such as more renal disease and fewer cases of congestive heart failure. These changes highlight the dynamic interplay between host and microbial factors in the pathogenesis of polymicrobial PJIs, necessitating adaptive strategies in both surgical and postoperative care to mitigate the rising tide of these complex infections.

Local antibiotic delivery via intra-articular catheter infusion for the treatment of periprosthetic joint infection: a systematic review

INTRODUCTION

There is an increasing interest in the use of intra-articular (IA) antibiotic infusion as a stand-alone or adjuvant therapy to standard revision surgery for periprosthetic joint infection (PJI). The objective of this systematic review is to evaluate the evidence with respect to this up-and-coming treatment modality.

METHODS

A systematic review of studies published until April 2023 was conducted using PubMed, Embase, MEDLINE and Cochrane databases. Quality assessment was performed with the National Institute of Health quality assessment tool. Inclusion criteria were adult patients (≥ 18 years) with a mean follow-up of ≥ 11 months and a score ≥ 6 on the National Institute of Health quality assessment tool. Primary outcome was eradication of infection.

RESULTS

15 articles, encompassing 631 PJIs in 626 patients, were included in the final analysis, all level IV case series. The majority was treated with single-stage revision with adjuvant IA antibiotic infusion (79.1%). The remaining PJIs were treated with stand-alone IA antibiotic infusion (12.2%), DAIR (debridement, antibiotics and implant retention) with adjuvant IA antibiotic infusion (5.7%) or two-stage revision with adjuvant IA antibiotic infusion (3.0%). Mean duration of IA antibiotic infusion was 19 days (range 3-50). An overall failure rate of approximately 11% was found. In total 117 complications occurred, 71 were non-catheter-related and 46 were catheter-related. The most common catheter-related complications were premature loss of the catheter (18/46) and elevated blood urea nitrogen (BUN) and creatinine levels (12/46).

CONCLUSIONS

Due to the lack of comparative studies the (added) benefit of IA antibiotic infusion in the treatment of PJI remains uncertain. Based on the current evidence, we would advise against using it as a stand-alone treatment. A prospective randomized controlled trial using a well-described infusion protocol is needed to see if the potential benefits justify the increased costs and potential complications of this treatment modality.

Antibiotic-loaded cement in total joint arthroplasty: a comprehensive review

This review evaluates the decision-making framework for using antibiotic-loaded cement (ALC) in the management of prosthetic joint infection (PJI). Drawing on available literature, we offer orthopaedic surgeons a guided discussion on several critical considerations. First, we explore the impact of antibiotic-loading on the mechanical properties of polymethylmethacrylate (PMMA) cement, assessing both strength and durability. We then explore the optimal antibiotic dosage to load into cement, aiming to achieve effective local concentrations for infection control without compromising mechanical stability. Furthermore, we explore how cement and antibiotic properties affect the overall antibiotic elution characteristics of ALC. Finally, we discuss risks of systemic toxicity, particularly acute kidney injury, when using ALC. The principal goal in this review is to provide a balanced approach based on best available evidence that optimises antibiotic elution from ALC whilst minimising potential harms associated with its use.

Prosthetic Joint Infection Research Models in NZW Rabbits: Opportunities for Standardization-A Systematic Review

Prosthetic joint infection (PJI) is a major complication following total arthroplasty. Rising antimicrobial resistance (AMR) to antibiotics will further increase therapeutic insufficiency. New antibacterial technologies are being developed to prevent PJI. In vivo models are still needed to bridge the translational gap to clinical implementation. Though rabbit models have been used most frequently, there is no consensus about methodology and measured outcomes. The PubMed, Scopus, and EMBASE databases were searched for literature on PJI in rabbit models. Data extraction included bias control, experimental design, and outcome measures of the NZW rabbit models in the articles. A total of 60 articles were included in this systematic literature review. The articles were divided into six groups based on the PJI intervention: no intervention used (21%), revision surgery (14%), prevention with only antibiotics (21%), prevention with surface modifications (7%), prevention with coatings (23%), and others (14%). Despite the current availability of guidelines and recommendations regarding experimental design, bias control, and outcome measures, many articles neglect to report on these matters. Ultimately, this analysis aims to assist researchers in determining suitable clinically relevant methodologies and outcome measures for in vivo PJI models using NZW rabbits to test new antimicrobial technologies.

No shortening of the patellar tendon during two-stage total knee arthroplasty revision using articulating spacers

BACKGROUND

Surgical techniques in two-stage revision total knee arthroplasty (rTKA) include the use of articulating spacers and static spacers. Shortening of the patellar tendon could be a reason for inferior functional outcomes in two-stage septic rTKA . The aim of this study was to determine if articulating spacers also have negative effects on the extensor mechanism in rTKA.

METHODS

This retrospective study includes 65 consecutive patients (23 women, 42 men, age 71.3 ± 1.2; range, 51.2-88.6 years) undergoing septic two-stage rTKA using an articulating spacer between 2014 and 2021 in a single orthopedic center. For all patients, calibrated true lateral radiographs before total knee arthroplasty (TKA) explantation (T0), directly after TKA explantation (T1), shortly before TKA reimplantation (T2) and 6-8 days after TKA reimplantation (T3) were used to calculate the modified Insall Salvati ratio (mISR).

RESULTS

Overall, the mISR decreased significantly immediately after explantation (T0 vs. T1, p = 0.002) from 1.43 ± 0.03 to 1.36 ± 0.03 and remained stable until T2 (1.37 ± 0.02, p = 0.74). Following TKA reimplantation, the mISR increased again to 1.43 ± 0.03 (T3). There were no significant differences between T0 and T3 (p = 0.88). Six out of 65 patients (9%) experienced patellar tendon shortening > 10% at T3.

CONCLUSIONS

Septic two-stage revision TKA using an articulating spacer does not lead to patellar tendon shortening in the majority of cases. This study suggests that one reason for the improved range of motion after reimplantation may be the use of articulating spacers compared to static spacers.

Nanoparticle ultrasonication outperforms conventional irrigation solutions in eradicating Staphylococcus aureus biofilm from titanium surfaces: an in vitro study

PURPOSE

Bacterial biofilms create a challenge in the treatment of prosthetic joint infection (PJI), and failure to eradicate biofilms is often implicated in the high rates of recurrence. In this study, we aimed to compare the effectiveness of a novel nanoparticle ultrasonication technology on Staphylococcus aureus biofilm eradication compared to commonly used orthopedic irrigation solutions.

METHODS

Twenty-four sterile, titanium alloy discs were inoculated with a standardized concentration of methicillin-resistant S. aureus and cultured for seven days to allow for biofilm formation. Discs were then treated with either ultrasonicated nanoparticle therapy or irrigation with chlorhexidine gluconate, povidone-iodine or normal saline. The remaining bacteria on each surface was subsequently plated for colony-forming units of S. aureus. Bacterial eradication was reported as a decrease in CFUs relative to the control group. Mann-Whitney U tests were used to compare between groups.

RESULTS

Treatment with ultrasonicated nanoparticles resulted in a significant mean decrease in CFUs of 99.3% compared to controls (p < 0.0001). Irrigation with povidone-iodine also resulted in a significant 77.5% reduction in CFUs compared to controls (p < 0.0001). Comparisons between ultrasonicated nanoparticles and povidone-iodine demonstrated a significantly higher reduction in bacterial CFUs in the nanoparticle group (p < 0.0001).

CONCLUSION

Ultrasonicated nanoparticle were superior to commonly used bactericidal irrigation solutions in the eradication of S. aureus from a titanium surface. Future clinical studies are warranted to evaluate this ultrsonication technology in the treatment of PJI.

A Meta-Analysis of Success Rates of One-Stage Versus Two-Stage Revisions in Knee Prosthetic Joint Infections

Prosthetic joint infections (PJIs) pose significant challenges following total joint arthroplasties and cause profound complications. They are associated with significant morbidity and mortality. One-stage revision involves the removal of the infected implant and simultaneous re-implantation of a new prosthesis in a single surgical procedure. The two-stage approach is traditionally more common in the United States and follows a deliberate sequence: the infected implant is first removed, followed by a period of antibiotic therapy, and then a second surgery for implant reinsertion. While two-stage revisions were traditionally considered the gold standard, recent advancements have introduced one-stage revisions as a viable alternative. One-stage revision offers the advantage of being a single procedure, significantly reducing the patient's downtime without a functioning knee. Currently, there has not been a comprehensive exploration of the comparative outcomes between two-stage revisions and one-stage revisions. This systematic review and meta-analysis aimed to assess the outcomes of both one- and two-stage revisions for total knee arthroplasties (TKAs), by utilizing comparison studies as the foundation for analysis. Our search encompassed databases such as MEDLINE (Medical Literature Analysis and Retrieval System Online), Embase, and Cochrane to identify articles examining the comparative efficacy and outcomes of one- and two-stage revision procedures between January 2000 and June 2023. We employed keywords relevant to knee PJIs to identify comparative studies reporting on success rates, reinfection rates, microbiological findings, and other pertinent outcomes. Statistical analysis for this investigation was performed using Review Manager 5.4 (The Cochrane Collaboration, 2020) with a standard significance threshold set at a p-value less than .05. This meta-analysis incorporated six comparison articles and 802 patients. Two-stage revisions (547 patients) were associated with greater success rates (i.e., infection eradication) than one-stage revisions (255 patients) (p = .03). The studies did not suggest a difference in the microbiology of the infections. Two-stage revisions are associated with higher success rates than one-stage revisions in the treatment of knee PJIs. Future randomized controlled trials should evaluate the optimization of the management of these complications.

The Financial Burden of Aspirin versus Oral Factor Xa Inhibitors for Thromboprophylaxis Following Total Knee Arthroplasty

BACKGROUND

Aspirin and oral factor Xa inhibitor thromboprophylaxis regimens are associated with similarly low rates of venous thromboembolism following total knee arthroplasty (TKA). However, the rate of prosthetic joint infection (PJI) is lower with aspirin use. This study aimed to compare the cost differential between aspirin and factor Xa inhibitor thromboprophylaxis with respect to PJI management.

METHODS

We used previously published rates of PJI following aspirin and factor Xa inhibitor thromboprophylaxis in primary TKA patients at a single, large institution. Prices for individual drugs were obtained from our hospital's pharmacy service. The cost of PJI included that of 2-stage septic revision, with or without the cost of 1-year follow-up. National data were obtained to determine annual projected TKA volume.

RESULTS

The per-patient costs associated with a 28-day course of aspirin versus factor Xa inhibitor thromboprophylaxis were $17.36 and $3,784.20, respectively. Including cost of follow-up, per-patient costs for a 28-day course of aspirin versus factor Xa inhibitors increased to $73,358.76 and $77,125.60, respectively. The weighted average per-patient costs for a 28-day course were $237.38 and $4,370.93, respectively. The annual cost difference could amount to over $14.1 billion in the United States by 2040.

CONCLUSIONS

The per-patient cost associated with factor Xa inhibitor thromboprophylaxis is as much as 1,980.6% higher than that of an aspirin regimen due to increased costs of primary treatment, differential PJI rates, and high costs of management. In an era of value-based care, the use of aspirin is associated with major cost advantages.

Host and microbial characteristics associated with recurrent prosthetic joint infections

Approximately 20% of patients after resection arthroplasty and antibiotic spacer placement for prosthetic joint infection develop repeat infections, requiring an additional antibiotic spacer before definitive reimplantation. The host and bacterial characteristics associated with the development of recurrent infection is poorly understood. A case-control study was conducted for 106 patients with intention to treat by two-stage revision arthroplasty for prosthetic joint infection at a single institution between 2009 and 2020. Infection was defined according to the 2018 Musculoskeletal Infection Society criteria. Thirty-nine cases ("recurrent-periprosthetic joint infection [PJI]") received at least two antibiotic spacers before clinical resolution of their infection, and 67 controls ("single-PJI") received a single antibiotic cement spacer before infection-free prosthesis reimplantation. Patient demographics, McPherson host grade, and culture results including antibiotic susceptibilities were compared. Fifty-two (78%) single-PJI and 32 (82%) recurrent-PJI patients had positive intraoperative cultures at the time of their initial spacer procedure. The odds of polymicrobial infections were 11-fold higher among recurrent-PJI patients, and the odds of significant systemic compromise (McPherson host-grade C) were more than double. Recurrent-PJI patients were significantly more likely to harbor Staphylococcus aureus. We found no differences between cases and controls in pathogen resistance to the six most tested antibiotics. Among recurrent-PJI patients, erythromycin-resistant infections were more prevalent at the final than initial spacer, despite no erythromycin exposure. Our findings suggest that McPherson host grade, polymicrobial infection, and S. aureus infection are key indicators of secondary or persistent joint infection following resection arthroplasty and antibiotic spacer placement, while bacterial resistance does not predict infection-related arthroplasty failure.

Systematic review and meta-analysis of single-stage vs two-stage revision for periprosthetic joint infection: a call for a prospective randomized trial

BACKGROUND

Periprosthetic joint infection (PJI) is a severe complication of joint arthroplasty that causes significant pain and economic loss. This study aimed to determine whether the current evidence supports single-stage revision for PJI based on reinfection and reoperation rates.

METHODS

We searched the PubMed, EBSCO, Medline, and Cochrane Library databases from inception to 30 May 2023 to identify studies that compared single-stage revision and two-stage revision for PJI. Data on reinfection and reoperation rates were pooled.

RESULTS

This meta-analysis included a total of 40 studies with 8711 patients. Overall, there was no significant difference between single- and two-stage revision regarding the postoperative reinfection rate and reoperation rate. Subgroup analysis by surgery period and different surgical sites revealed no difference between the two groups in the reinfection and reoperation rates.

CONCLUSIONS

Based on the available evidence, our study did not identify a significant difference in reinfection and reoperation rates between single- and two-stage revision for PJI. Given the limitations in inclusion/exclusion criteria and the observed heterogeneity, we acknowledge the complexity of drawing strong conclusions. Therefore, we suggest that the choice between single- and two-stage revision should be carefully considered on an individual basis, taking into account patient-specific factors and further research developments.

The efficacy of antibiotic-eluting material in a two-stage model of periprosthetic joint infection

Periprosthetic joint infections occur in about 2% of patients who undergo primary total joint arthroplasty, a procedure performed over 1 million times in the United States. The gold standard of treatment is a two-stage revision. This study aimed to establish a two-stage procedure in a preclinical small animal model (rat) to test and compare the efficacy of an antibiotic-eluting material in managing infection. Joint replacement was simulated by transchondylarly implanting a polyethylene (PE) plug into the distal femur and a titanium screw in the proximal tibia. Methicillin-sensitive Staphylococcus aureus (MSSA) 108  CFU/mL was injected into the tibial canal and the joint space before wound closure. The control groups were killed on postoperative day (POD) 18 (n = 12) and on POD 42 (n = 4) to assess both early and later-stage outcomes in the control group. The test group underwent revision surgery on POD 18 for treatment using gentamicin-eluting polyethylene (GPE, n = 4) and was observed until POD 42 to evaluate the efficacy of treatment. Our results showed that the bone loss for the treatment group receiving GPE was significantly less than that of the control (p < 0.05), which was supported by the histology images and an AI-tool assisted infection rate evaluation. Gait metrics duty factor imbalance and hindlimb temporal symmetry were significantly different between the treatment and control groups on Day 42. This animal model was feasible for evaluating treatments for peri-prosthetic joint infections (PJI) with a revision surgery and specifically that revision surgery and local antibiotic treatment largely hindered the peri-prosthetic bone loss. Statement of clinical significance: This revision model of peri-prosthetic infection has the potential of comparatively evaluating prophylaxis and treatment strategies and devices. Antibiotic-eluting UHMWPE is devised as at tool in treating PJI while providing weight bearing and joint space preservation.

Prosthetic joint infections: 6 weeks of oral antibiotics results in a low failure rate

BACKGROUND

Need for parenteral administration and total duration of antibiotic therapy for prosthetic joint infection (PJI) are debated. We report our PJI management, in which outpatient care is privileged.

METHODS

This was a retrospective multicentre cohort study of PJI managed from January 2017 to Jun 2021. Microbial diagnosis was based on surgical samples. Surgical procedures and antibiotic treatments were reported. Chronic PJI was defined by a course >1 month. Oral antibiotic therapy (OAT) was defined by exclusive use of oral antibiotics or by ≤3 days of parenteral treatments. Management failure was defined by clinical and/or microbial relapse of PJI over 24 months after surgical treatment.

RESULTS

One hundred and seventy-two patients from 13 institutions were included: 103 were male (60%) and mean age was (±SD): 73 ± 12 years. Sites for PJI were mainly hip (50%) and knee (35%), being chronic infections in 70 cases (41%). The main bacterial genus in monomicrobial infections was Staphylococcus spp. (60%). We recorded 41 (24%) implant exchanges. An OAT was prescribed in 76 cases (44%), and the median (range) course for parenteral route was 6 days (4-180) for 96 cases. Median (range) duration of antimicrobials was 42 days (21-180). Management failure was observed in 7/76 (9.2%) cases treated with OAT and 15/96 (15.6%) treated with prolonged parenteral therapy. In multivariate analysis, risk factors for failure were a knee PJI [adjusted OR (95% CI) = 3.27 (1.27-8.40)] and a polymicrobial infection [4.09 (1.46-11.49)].

CONCLUSIONS

OAT for 6 weeks for PJI was associated with a low rate of management failure.

Utility of Debridement, Antibiotics, and Implant Retention for Acute Periprosthetic Joint Infection in Revision Total Knee Arthroplasty

Background

Periprosthetic joint infection (PJI) in revision arthroplasty presents as a challenging complication that is difficult to manage. Debridement, antibiotics, and implant retention (DAIR) is a recognized treatment option, although few studies have investigated success rates in addition to eventual amputation rates for failed cases.

Methods

A retrospective review of 365 DAIR cases was performed at a single institution from 2008-2020. Patient records were thoroughly reviewed for inclusion and exclusion criteria by multiple members of the research team, discovering 45 cases met criteria for the study cohort. Demographic information, medical history, culture data, and surgical history, were recorded. DAIR's overall survivorship was evaluated with a Kaplan-Meier (KM) survival curve. Additional KM curves were constructed to compare acute postoperative versus acute hematogenous infections as well as DAIR survivorship relative to infecting organism.

Results

DAIR's success rate in revision TKA was 77% at 0.5 years, 56% at 2 years and 46% at 5 years. No significant difference was noted in survivorship when comparing acute postoperative and acute hematogenous cases at 5 years (29 vs 51%, P=0.64). No significance differences in survivorship were noted according to infecting organism (P =0.30). Median follow up duration was significantly lower in the failed DAIR cohort with a median time of 0.5 years in comparison to 1.7 years for the successful DAIR group (P =0.012). There were 20 DAIR cases that failed, 10 of which resulted in eventual amputation.

Conclusion

DAIR's success rate for managing acute PJI in revision arthroplasty cases was 46% at 5 years. Of the 20 failed DAIR cases, 10 resulted in eventual amputation. DAIRs utility in managing these complicated PJI cases in the setting of revision arthroplasty is concerning with low success rates and high rates of amputation in failed cases. Level of Evidence: III.

The Effect of Prosthetic Joint Infection on Work Status and Quality of Life: A Multicenter, International Study

BACKGROUND

Periprosthetic joint infection (PJI) and subsequent revision surgeries may affect patients' social and physical health, ability to complete daily activities, and disability status. This study sought to determine how PJI affects patients' quality of life through patient-reported outcome measures with minimum 1-year follow-up.

METHODS

Patients who suffered PJI following primary total joint arthroplasty (TJA) from 2012 to 2021 were retrospectively reviewed. Patients met Musculoskeletal Infection Society criteria for acute or chronic PJI, underwent revision TJA surgery, and had at least 1 year of follow-up. Patients were surveyed regarding how PJI affected their work and disability status, as well as their mental and physical health. Outcome measures were compared between acute and chronic PJIs. In total, 318 patients (48.4% total knee arthroplasty and 51.6% total hip arthroplasty) met inclusion criteria.

RESULTS

Following surgical treatment for knee and hip PJI, a substantial proportion of patients reported that they were unable to negotiate stairs (20.5%), had worse physical health (39.6%), and suffered worse mental health (25.2%). A high proportion of patients reported worse quality of life (38.5%) and social satisfaction (35.3%) following PJI. Worse reported patient-reported outcome measures including patients' ability to complete daily physical activities were found among patients undergoing treatment for chronic PJI, and also, 23% of patients regretted their initial decision to pursue primary TJA.

CONCLUSIONS

A PJI negatively affects patients' ability to carry out everyday activities. This patient population is prone to report challenges overcoming disability and returning to work. Patients should be adequately educated regarding the risk of PJI to decrease later potential regrets.

LEVEL OF EVIDENCE

Case series (IV).

Titanium-Dioxide-Nanoparticle-Embedded Polyelectrolyte Multilayer as an Osteoconductive and Antimicrobial Surface Coating

Bioactive surface coatings have retained the attention of researchers and physicians due to their versatility and range of applications in orthopedics, particularly in infection prevention. Antibacterial metal nanoparticles (mNPs) are a promising therapeutic, with vast application opportunities on orthopedic implants. The current research aimed to construct a polyelectrolyte multilayer on a highly porous titanium implant using alternating thin film coatings of chitosan and alginate via the layer-by-layer (LbL) self-assembly technique, along with the incorporation of silver nanoparticles (AgNPs) or titanium dioxide nanoparticles (TiO2NPs), for antibacterial and osteoconductive activity. These mNPs were characterized for their physicochemical properties using quartz crystal microgravimetry with a dissipation system, nanoparticle tracking analysis, scanning electron microscopy, and atomic force microscopy. Their cytotoxicity and osteogenic differentiation capabilities were assessed using AlamarBlue and alkaline phosphatase (ALP) activity assays, respectively. The antibiofilm efficacy of the mNPs was tested against Staphylococcus aureus. The LbL polyelectrolyte coating was successfully applied to the porous titanium substrate. A dose-dependent relationship between nanoparticle concentration and ALP as well as antibacterial effects was observed. TiO2NP samples were also less cytotoxic than their AgNP counterparts, although similarly antimicrobial. Together, these data serve as a proof-of-concept for a novel coating approach for orthopedic implants with antimicrobial and osteoconductive properties.

Failed 2-Stage Revision Knee Arthroplasty for Periprosthetic Joint Infection-Patient Characteristics and Outcomes

BACKGROUND

Chronic prosthetic joint infection (PJI) is most frequently treated with 2-stage revision in conjunction with antibiotic treatment. The aims of this study were 1) to investigate the characteristics of patients who have recurrent infection following 2-stage revision for PJI and 2) to identify risk factors associated with treatment failure.

METHODS

A multicenter retrospective review of 90 total knee arthroplasty (TKA) patients who underwent 2-stage revision for treatment of PJI from March 1, 2003 to July 31, 2019, and had recurrent PJI was conducted. The minimum follow-up was 12 months (median follow up of 2.4 years). Microorganisms, subsequent revision, PJI control status, and final joint status were collected. The infection-free survival after initial 2-stage revision was plotted utilizing the Kaplan-Meier method.

RESULTS

Mean survival time to reinfection was 21.3 months (range, 0.3 to 160.5). There were 14 recurrent infections that were acute PJIs treated with debridement, antibiotics, and implant retention (DAIR), while 76 were chronic and treated with repeat 2-stage revision. The most common pathogen identified for both index and recurrent PJI was coagulase-negative Staphylococci. Pathogen persistence was observed in 14 (22.2%) of recurrent PJIs. In total, 61 (67.8%) patients possessed a prosthetic reimplantation at their most recent follow-up, and 29 (35.6%) patients required intervention following repeat 2-stage.

CONCLUSION

Overall, 31.1% of the patients obtained infection control after treatment of a failed 2-stage revision due to PJI. The high rate of pathogen persistence and the relatively low survival time to recurrence suggests a need to more closely monitor PJIs cases within 2 years.

Characterizing recurrent infections after one-stage revision for periprosthetic joint infection of the knee: a systematic review of the literature

BACKGROUND

Periprosthetic joint infection (PJI) of the knee represents a severe complication after 1.5% to 2% of primary total knee replacement. Although two-stage revision was considered the gold-standard treatment for PJI of the knee, in the last decades, more studies reported the outcomes of one-stage revisions. This systematic review aims to assess reinfection rate, infection-free survival after reoperation for recurrent infection, and the microorganisms involved in both primary and recurrent infection.

MATERIAL AND METHODS

A systematic review of all studies reporting the outcome of one-stage revision for PJI of the knee up to September 2022, according to PRISMA criteria and AMSTAR2 guidelines, was performed. Patient demographics, clinical, surgical, and postoperative data were recorded.

PROSPERO ID

CRD42022362767.

RESULTS

Eighteen studies with a total of 881 one-stage revisions for PJI of the knee were analyzed. A reinfection rate of 12.2% after an average follow-up of 57.6 months was reported. The most frequent causative microorganism were gram-positive bacteria (71.1%), gram-negative bacteria (7.1%), and polymicrobial infections (8%). The average postoperative knee society score was 81.5, and the average postoperative knee function score was 74.2. The infection-free survival after treatment for recurrent infection was 92.1%. The causative microorganisms at reinfections differed significantly from the primary infection (gram-positive 44.4%, gram-negative 11.1%).

CONCLUSION

Patients who underwent a one-stage revision for PJI of the knee showed a reinfection rate lower or comparable to other surgical treatments as two-stage or DAIR (debridement, antibiotics, and implant retention). Reoperation for reinfection demonstrates a lower success compared to one-stage revision. Moreover, microbiology differs between primary infection and recurrent infection. Level of evidence Level IV.

Engineering 3D-Printed Advanced Healthcare Materials for Periprosthetic Joint Infections

The use of additive manufacturing or 3D printing in biomedicine has experienced fast growth in the last few years, becoming a promising tool in pharmaceutical development and manufacturing, especially in parenteral formulations and implantable drug delivery systems (IDDSs). Periprosthetic joint infections (PJIs) are a common complication in arthroplasties, with a prevalence of over 4%. There is still no treatment that fully covers the need for preventing and treating biofilm formation. However, 3D printing plays a major role in the development of novel therapies for PJIs. This review will provide a deep understanding of the different approaches based on 3D-printing techniques for the current management and prophylaxis of PJIs. The two main strategies are focused on IDDSs that are loaded or coated with antimicrobials, commonly in combination with bone regeneration agents and 3D-printed orthopedic implants with modified surfaces and antimicrobial properties. The wide variety of printing methods and materials have allowed for the manufacture of IDDSs that are perfectly adjusted to patients' physiognomy, with different drug release profiles, geometries, and inner and outer architectures, and are fully individualized, targeting specific pathogens. Although these novel treatments are demonstrating promising results, in vivo studies and clinical trials are required for their translation from the bench to the market.

Acute kidney injury in the context of staged revision arthroplasty and the use of antibiotic-laden cement spacers: a systematic review

BACKGROUND

The most common cause of revision arthroplasty is prosthetic joint infection (PJI). Chronic PJI is commonly treated with two-stage exchange arthroplasty involving the placement of antibiotic-laden cement spacers (ACS) in the first stage, often containing nephrotoxic antibiotics. These patients often have significant comorbidity burdens and have higher rates of acute kidney injury (AKI). This systematic review aims to assess the current literature to identify (1) AKI incidence, (2) associated risk factors, and (3) antibiotic concentration thresholds in ACS that increase AKI risk following first-stage revision arthroplasty.

METHODS

An electronic search was performed of the PubMed database of all studies involving patients undergoing ACS placement for chronic PJI. Studies assessing AKI rates and risk factors were screened by two authors independently. Data synthesis was performed when possible. Significant heterogeneity prevented meta-analysis.

RESULTS

Eight observational studies consisting of 540 knee PJIs and 943 hip PJIs met inclusion criteria. There were 309 (21%) cases involving AKI. The most commonly reported risk factors included perfusion-related factors (lower preoperative hemoglobin, transfusion requirement, or hypovolemia), older age, increased comorbidity burden, and nonsteroidal anti-inflammatory drug consumption. Only two studies found increased risk with greater ACS antibiotic concentration (> 4 g vancomycin and > 4.8 g tobramycin per spacer in one study, > 3.6 g of vancomycin per batch or > 3.6 g of aminoglycosides per batch in the other); however, these were reported from univariate analyses not accounting for other potential risk factors.

DISCUSSION

Patients undergoing ACS placement for chronic PJI are at an increased risk for AKI. Understanding the risk factors may lead to better multidisciplinary care and safer outcomes for chronic PJI patients.

LEVEL OF EVIDENCE III

Two-stage revision for treatment of tuberculous prosthetic hip infection: an outcome analysis

OBJECTIVES

Prosthetic joint infections (PJI) and especially tuberculosis (TB) PJI are rare diseases and hard to cure. The effectiveness of treatments for tuberculous PJI still remains a problem. The objective of this research was to indicate the success of two-stage revision replacement and also giving the associated criteria.

METHODS

From 2015 to 2020, five patients with tuberculous PJI were treated with two-stage revision at Cho Ray hospital, Vietnam. We collected the dataset which included demographic data, the interval from the time of joint replacement to reported infection, records of tuberculous PJI, administration of anti-TB medications (duration, months), history of operation(s), duration of follow-up, and specific type(s) of antibiotics loaded in bone cement. The approval for this study was made by the institutional review board from Cho Ray Hospital, Vietnam. We conducted a literature review based on the keywords "PJI" and "TB" on PubMed.

RESULTS

Five patients [median age 66 years (range 35-84)] had found tuberculous PJI. The median time from arthroplasty to diagnosis was 19 months (range 4-48). The diagnosis was confirmed by joint aspirates or synovial tissue. Positive PCR was also reported in all cases. The average duration of anti-tuberculosis polytherapy administration was 14.4 months. The operative techniques on five patients included debridement and using spacer loaded with 2 g streptomycin (and 2 g vancomycin if they got a coinfection) for 1 pack of bone cement, and revision arthroplasty. In most cases, the outcome of treatment using two-stage revision replacement was 80%. Overall, the auxiliary bacterial infections were recognized in three patients with tuberculous PJI and Staphylococcus aureus. Streptomycin and vancomycin were loaded in a cement spacer to increase the success rate, and tuberculous PJI was controlled for all patients.

CONCLUSION

Tuberculous PJI can be controlled with two-stage revision replacement with an antibiotic-loaded cement spacer that is molded intraoperatively with custom mold and prolonged anti-tuberculosis treatment in all cases.

LEVEL OF EVIDENCE

IV.

A Permanent Articulating Spacer Versus Two-Stage Exchange for Chronic Periprosthetic Joint Infection: A Propensity Score-Matched Study

BACKGROUND

Although 2-stage revision has been proposed as gold standard for periprosthetic joint infection treatment, limited evidence exists for the role of articulating spacers as definitive management. The purpose of this study was to compare clinical outcomes and costs associated with articulating spacers (1.5-stage) and a matched 2-stage cohort.

METHODS

A retrospective review was performed for patients who had chronic periprosthetic joint infections after total knee arthroplasty defined by Musculoskeletal Infection Society criteria and were matched via propensity score matching using cumulative Musculoskeletal Infection Society scores and a comorbidity index. Patients who maintained an articulating spacer (cemented cobalt-chrome femoral component and all-poly tibia) were included in the 1.5-stage cohort. Patients who underwent a 2-stage reimplantation procedure were included in the 2-stage cohort. Outcomes included visual analog scale pain scores, 90-day emergency department visits, 90-day readmission, unplanned reoperation, reinfection, as well as cost at 1 and 2-year intervals. A total of 116 patients were included for analyses.

RESULTS

The 90-day pain scores were lower in the 1.5-stage cohort compared to the 2-stage cohort (2.9 versus 4.6, P = .0001). There were no significant differences between readmission and reoperation rates. Infection clearance was equivalent at 79.3% for both groups. Two-stage exchange demonstrated an increased cost difference of $26,346 compared to 1.5-stage through 2 years (P = .0001). Regression analyses found 2 culture-positive results with the same organism decreased the risk for reinfection [odds ratio: 0.2, 95% confidence interval 0.04-0.8, P = .03].

CONCLUSION

For high-risk candidates, articulating spacers can preserve knee function, reduce morbidity from second-stage surgery, and lower the costs with similar rates of infection clearance as 2-stage exchange.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The Creation of Articulating Cement Spacer Using Custom-Fabricated Silicone Mold for the Treatment of Periprosthetic Joint Infection: Two Case Reports

Joint replacement surgeries have been performed to treat joint arthropathies with excellent outcomes. As the number of joint replacement surgeries surges, the incidence of periprosthetic joint infection (PJI) has also increased. Currently, two-stage revision surgery is the gold standard in the treatment of periprosthetic joint infection. Two-stage revision surgery involves joint washout, the removal of the primary implant, the insertion of a cement spacer, and subsequently the reimplantation of prosthesis after the infection has been eliminated. Custom-made articulating cement spacer has been used with success to improve the patient's ambulatory status and quality of life. Nevertheless, custom-made articulating cement spacer or commercialized cement mold is generally costly. By the modification of previous authors' techniques, we manage to fabricate reusable silicone molds, which can be used to create articulating cement spacers for both hip and knee joints. We share two case reports to illustrate how these fabricated silicone molds can be a cost-effective technique to create articulating cement spacers to manage periprosthetic joint infection in both hip and knee joints. Surgeons in resource-deprived countries can utilize this technique to create articulating cement spacers with minimal cost, but they need to discuss with their patients and check with the local regulatory board on the feasibility of this technique to create cement spacer that will be used in a patient.

Moderate-to-Severe Malnutrition Identified by the Controlling Nutritional Status (CONUT) Score Is Significantly Associated with Treatment Failure of Periprosthetic Joint Infection

The prevalence and role of malnutrition in periprosthetic joint infection (PJI) remain unclear. This study aimed to use measurable nutritional screening tools to assess the prevalence of malnutrition in PJI patients during two-stage exchange arthroplasty and to explore the association between malnutrition and treatment failure. Our study retrospectively included 183 PJI cases who underwent 1st stage exchange arthroplasty and had available nutritional parameters, of which 167 proceeded with 2nd stage reimplantation. The recently proposed Musculoskeletal Infection Society (MSIS) Outcome Reporting Tool was used to determine clinical outcomes. The Controlling Nutritional Status (CONUT), Nutritional Risk Index (NRI), and Naples Prognostic Score (NPS) were used to identify malnutrition at 1st and 2nd stage exchange, respectively. Multivariate logistic regression analyses were performed to determine the association between malnutrition and treatment failure. Restricted cubic spline models were further used to explore the dose−response association. Additionally, risk factors for moderate-to-severe malnutrition were evaluated. Malnourished patients identified by CONUT, NPS, and NRI accounted for 48.1% (88/183), 98.9% (181/183), and 55.7% (102/183) of patients at 1st stage, and 9.0% (15/167), 41.9% (70/167), and 43.1% (72/167) at 2nd stage, indicating a significant improvement in nutritional status. We found that poorer nutritional status was a predictor of treatment failure, with CONUT performing best as a predictive tool. Moderate-to-severe malnutrition at 1st stage identified by CONUT was significantly related to treatment failure directly caused by PJI (odds ratio [OR] = 5.86), while the OR was raised to 12.15 at 2nd stage (OR = 12.15). The linear dose−response associations between them were also confirmed (P for nonlinearity at both 1st and 2nd stage > 0.05). As for total treatment failure, moderate-to-severe malnutrition as determined by CONUT was associated with a 1.96-fold and 8.99-fold elevated risk at the 1st and 2nd stages, respectively. Age ≥ 68 years (OR = 5.35) and an increased number of previous surgeries (OR = 2.04) may be risk factors for moderate-to-severe malnutrition. Overall, the prevalence of malnutrition in PJI patients is very high. Given the strong association between moderate-to-severe malnutrition identified by CONUT and PJI treatment failure, COUNT could be a promising tool to evaluate the nutritional status of PJI patients to optimize treatment outcomes.

Effective single-stage revision using intra-articular antibiotic infusion after multiple failed surgery for periprosthetic joint infection : a mean seven years' follow-up

AIMS

Periprosthetic joint infections (PJIs) with prior multiple failed surgery for reinfection represent a huge challenge for surgeons because of poor vascular supply and biofilm formation. This study aims to determine the results of single-stage revision using intra-articular antibiotic infusion in treating this condition.

METHODS

A retrospective analysis included 78 PJI patients (29 hips; 49 knees) who had undergone multiple prior surgical interventions. Our cohort was treated with single-stage revision using a supplementary intra-articular antibiotic infusion. Of these 78 patients, 59 had undergone more than two prior failed debridement and implant retentions, 12 patients had a failed arthroplasty resection, three hips had previously undergone failed two-stage revision, and four had a failed one-stage revision before their single-stage revision. Previous failure was defined as infection recurrence requiring surgical intervention. Besides intravenous pathogen-sensitive agents, an intra-articular infusion of vancomycin, imipenem, or voriconazole was performed postoperatively. The antibiotic solution was soaked into the joint for 24 hours for a mean of 16 days (12 to 21), then extracted before next injection. Recurrence of infection and clinical outcomes were evaluated.

RESULTS

A total of 68 patients (87.1%) were free of infection at a mean follow-up time of 85 months (24 to 133). The seven-year infection-free survival was 87.6% (95% confidence interval (CI) 79.4 to 95.8). No significant difference in infection-free survival was observed between hip and knee PJIs (91.5% (95% CI 79.9 to 100) vs 84.7% (95% CI 73.1 to 96.3); p = 0.648). The mean postoperative Harris Hip Score was 76.1 points (63.2 to 92.4) and Hospital for Special Surgery score was 78. 2 (63.2 to 92.4) at the most recent assessment. Polymicrobial and fungal infections accounted for 14.1% (11/78) and 9.0% (7/78) of all cases, respectively.

CONCLUSION

Single-stage revision with intra-articular antibiotic infusion can provide high antibiotic concentration in synovial fluid, thereby overcoming reduced vascular supply and biofilm formation. This supplementary route of administration may be a viable option in treating PJI after multiple failed prior surgeries for reinfection. Cite this article: Bone Joint J 2022;104-B(7):867-874.

Detailed Revision Risk Analysis after Single- vs. Two-Stage Revision Total Knee Arthroplasty in Periprosthetic Joint Infection: A Retrospective Tertiary Center Analysis

Periprosthetic joint infection (PJI) remains one of the most common causes of revision knee arthroplasty. Controversy continues to surround the proper operative technique of PJI in knee arthroplasty with single- or two-stage replacement. Significant variations are seen in the eradication rates of PJI and in implant survival rates. This detailed retrospective analysis of a single tertiary center is intended to provide further data and insight comparing single- and two-stage revision surgery. A retrospective analysis of all revision total knee arthroplasty (TKA) surgeries from 2013 to 2019 was performed and screened with respect to single- or two-stage TKA revisions. Single- and two-stage revisions were analyzed with regard to implant survival, revision rate, microbiological spectrum, and other typical demographic characteristics. A total of 63 patients were included, with 15 patients undergoing single-stage revision and 48 patients undergoing two-stage revision. The mean follow-up time was 40.7 to 43.7 months. Statistically, no difference was found between both groups in overall survival (54.4% vs. 70.1%, p = 0.68) and implant survival with respect to reinfection (71.4% vs. 82.4%, p = 0.48). Further, high reinfection rates were found for patients with difficult-to-treat organisms and low- to semi-constrained implant types, in comparison to constrained implant types. A statistically comparable revision rate for recurrence of infection could be shown for both groups, although a tendency to higher reinfection rate for single-stage change was evident. The revision rate in this single-center study was comparably high, which could be caused by the high comorbidity and high proportion of difficult-to-treat bacteria in patients at a tertiary center. In this patient population, the expectation of implant survival should be critically discussed with patients.