Hip and Knee Section, Treatment, Debridement and Retention of Implant: Proceedings of International Consensus on Orthopedic Infections

Early Periprosthetic Joint Infections in Total Hip and Knee Arthroplasty: Microorganisms, Mortality, and Implant Survival Using a Combined Dataset from the Dutch Arthroplasty Register and the Dutch National Nosocomial Surveillance Network

BACKGROUND

Periprosthetic joint infections (PJIs) can lead to higher re-revision rates and even higher mortality rates that may be associated with the responsible microorganism. We evaluated microorganisms that cause early PJIs in primary total hip and knee arthroplasty (THA and TKA), and examined mortality as well as PJI re-revision rates after these PJIs, using a combined dataset from the Dutch Arthroplasty Register (LROI) and the Dutch National Nosocomial Surveillance Network (PREZIES). Secondly, the most common microorganisms that cause PJIs were described according to patient and implant survival.

METHODS

We included all PREZIES-confirmed PJIs (n = 1,648) from the combined dataset in which primary THAs and TKAs (2012 to 2018) from the LROI and PREZIES were case-level matched. Kaplan-Meier survival analyses were performed to determine mortality and PJI re-revision rates following PJI revision.

RESULTS

The most prevalent microorganism in THAs and TKAs was Staphylococcus aureus (THA 34%; TKA 39%), followed by Coagulase-negative staphylococci (CoNS) (THA 20%; TKA 19%), with Staphylococcus epidermidis (THA 12%; TKA 11%) as the most common subtype, and Enterococcus species (THA 8.6%; TKA 5.9%). The 5-year mortality was 15% (95% confidence interval [CI]: 13 to 18) and 18% (CI: 14 to 21) for THA and TKA patients, respectively. The 5-year PJI re-revision rate was 28% (CI: 24 to 34) for THAs and 30% (CI: 24 to 38) for TKAs. In deceased THA patients who had a PJI, Enterococcus species (14%) were more often registered as microorganisms responsible for the PJI than S. epidermidis (8.5%).

CONCLUSION

Over half of the early PJIs in THAs and TKAs in the Netherlands were caused by Staphylococcus aureus and CoNS including Staphylococcus epidermidis. Both 5-year mortality and PJI re-revision rates following PJI were relatively high.

Enhanced antibiofilm potential of low-intensity pulsed ultrasound combined with 0.35% povidone-iodine in a rat model of periprosthetic joint infection

Aims

Although low-intensity pulsed ultrasound (LIPUS) combined with disinfectants has been shown to effectively eliminate portions of biofilm in vitro, its efficacy in vivo remains uncertain. Our objective was to assess the antibiofilm potential and safety of LIPUS combined with 0.35% povidone-iodine (PI) in a rat debridement, antibiotics, and implant retention (DAIR) model of periprosthetic joint infection (PJI).

Methods

A total of 56 male Sprague-Dawley rats were established in acute PJI models by intra-articular injection of bacteria. The rats were divided into four groups: a Control group, a 0.35% PI group, a LIPUS and saline group, and a LIPUS and 0.35% PI group. All rats underwent DAIR, except for Control, which underwent a sham procedure. General status, serum biochemical markers, weightbearing analysis, radiographs, micro-CT analysis, scanning electron microscopy of the prostheses, microbiological analysis, macroscope, and histopathology evaluation were performed 14 days after DAIR.

Results

The group with LIPUS and 0.35% PI exhibited decreased levels of serum biochemical markers, improved weightbearing scores, reduced reactive bone changes, absence of viable bacteria, and decreased inflammation compared to the Control group. Despite the greater antibiofilm activity observed in the PI group compared to the LIPUS and saline group, none of the monotherapies were successful in preventing reactive bone changes or eliminating the infection.

Conclusion

In the rat model of PJI treated with DAIR, LIPUS combined with 0.35% PI demonstrated stronger antibiofilm potential than monotherapy, without impairing any local soft-tissue.

Patient-Reported Outcomes Following Periprosthetic Joint Infection of the Hip and Knee: A Longitudinal, Prospective Observational Study

BACKGROUND

The role of patient-reported outcome measures (PROMs) as tools for monitoring the impact and outcomes of periprosthetic joint infection (PJI) is not well described. This study analyzed the Oxford Hip Score (OHS) or Oxford Knee Score (OKS) in a prospective observational cohort of patients with hip or knee PJI.

METHODS

The PIANO (Prosthetic joint Infection in Australia and New Zealand, Observational study) cohort prospectively enrolled patients with newly diagnosed PJI from multiple centers. The OHS and OKS were evaluated at PJI diagnosis (baseline) and at 3, 12, and 24 months. Scores and score changes were examined according to PJI type, patient characteristics, and management. A successful functional outcome at 12 months was defined as an OHS of >38 or OHS of >36 and/or an improvement from baseline of >12 or >9, respectively.

RESULTS

Of the 741 participants, PROMs were available at 12 months for 233 with hip and 342 with knee PJI. Significant improvements (p < 0.0001) were seen at 12 months for both the OHS (24.5 to 36) and OKS (25 to 34), with no further improvement at 24 months. Patients with late-acute PJI had a higher median baseline OHS (35; interquartile range [22 to 46]) and OKS (30 [18 to 41]) than those with early PJI (OHS: 19 [15 to 29]; OKS: 22 [16 to 29.5]) or chronic PJI (OHS: 23 [14 to 34]; OKS 22 [14 to 28]). Logistic regression showed that a clinical cure (adjusted odds ratio [aOR] = 1.88, 95% confidence interval [CI] = 1.28 to 2.76, p = 0.001) and early PJI (aOR = 2.56, 95% CI = 1.64 to 4.07, p < 0.0001) independently predicted a successful functional outcome. Chronic renal impairment (aOR = 0.31, 95% CI = 0.13 to 0.71, p = 0.007), congestive cardiac failure (aOR = 0.41, 95% CI = 0.17 to 0.95, p = 0.04), and clinical signs of inflammation (aOR = 0.53, 95% CI = 0.33 to 0.85, p = 0.009) at diagnosis independently predicted failure to achieve a successful functional outcome.

CONCLUSIONS

The OHS and OKS varied significantly at baseline and 12 months according to PJI type, emphasizing the need to consider the PJI type when evaluating treatment success. This study highlights superior functional outcomes associated with early PJI and with achievement of a clinical cure.

LEVEL OF EVIDENCE

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

Impact of unplanned second debridement, antibiotics and implant retention on long-term outcomes in knee exchange arthroplasty: Elevated risk of failure and reinfection

Purpose

This study investigates the outcomes of two-stage exchange arthroplasty (EA) for periprosthetic joint infection (PJI) following initial or unplanned repeat debridement antibiotics, and implant retention (DAIR).

Methods

We retrospectively reviewed cases of knee arthroplasty infection treated with two-stage EA after DAIR, spanning from January 1994 to December 2010. A total of 138 patients were included, comprising 112 with initial DAIR and 26 with an unplanned second DAIR. Data on demographics, comorbidities, infection characteristics and causative organisms were analyzed. The primary outcome was implant failure or reinfection, observed over a minimum follow-up of 10 years.

Results

The overall success rate for two-stage EA was 87% (119/138 patients). Factors identified for treatment failure included reinfection with the same pathogen for unplanned second DAIR (hazard ratio [HR] = 3.41; 95% confidence interval [CI] = 1.35-4.38; p = 0.004), higher reinfection rates in patients undergoing EA after an unplanned second DAIR, especially with a prior history of PJI within 2 years (HR = 4.23; 95% CI = 2.39-5.31; p = 0.002), pre-first DAIR C-reactive protein (CRP) levels over 100 mg/dL (HR = 2.52; 95% CI = 1.98-3.42; p = 0.003) and recurrence with the same pathogen (HR = 2.35; 95% CI = 1.32-4.24; p = 0.007). Additional factors such as male gender (HR = 3.92; 95% CI = 1.21-5.25; p = 0.007) and osteoporosis (T score < -2.5; HR = 3.27; 95% CI = 1.23-5.28; p = 0.005) were identified as risk factors for implant failure in all EA cases.

Conclusions

This study identifies key risk factors for worse knee EA outcomes following DAIR, including a pre-first DAIR CRP level over 100 mg/L, same pathogen recurrence, and PJI history within 2 years. It shows implant failure rates remain constant across EA cases, regardless of DAIR sequence, particularly with risk factors like male gender and severe osteoporosis (T score < -2.5). These results underscore the need for careful evaluation before an unplanned second DAIR, given its significant impact on EA success.

Level of Evidence

Level III.

KLIC Score Does Not Predict Failure After Early Prosthetic Joint Infection: An External Validation With 153 Knees and 130 Hips

BACKGROUND

A preoperative risk score, the KLIC score (chronic renal failure [K], liver cirrhosis [L], indication of the index surgery [I], cemented prosthesis [C], and C-reactive protein >115 mg/L), has been developed to predict the risk of treatment failure after early prosthetic joint infection (PJI). This study aimed to validate the KLIC score for the debridement, antibiotics, and implant retention (DAIR) procedure and one-stage revisions in a Northern European cohort.

METHODS

Revisions due to early PJI of the hip or knee between January 1, 2008, and September 12, 2021, were identified retrospectively. The primary outcome was early failure, which was considered when the patient needed an unscheduled surgery, the patient died, or the patient was prescribed long-term suppressive antibiotics. To examine the association between KLIC score and failure risk, univariable logistic regression with area under the curve (AUC) was used. In addition, models were calibrated to assess prognostic ability and clinical utility was examined with decision-curve analyses.

RESULTS

An increase in KLIC score had a moderate predictive value for early failure after DAIR (odds ratio [OR] 1.45; confidence interval [CI] 1.13 to 1.90). For one-stage revision, it was only slightly predictive of failure (OR 1.20; CI 0.93 to 1.56). After 60 days, the AUC for DAIR was 0.63 (CI 0.55 to 0.72) and 0.56 (CI 0.46 to 0.66) for one-stage revisions, indicating poor discriminative ability. The decision-curve analyses revealed that the model did not offer a remarkable net benefit across a range of threshold probabilities.

CONCLUSIONS

We demonstrated that the KLIC score is not a reliable predictor of early failure after early PJI in a Northern European cohort. Using the model to guide treatment decisions does not provide any additional clinical utility beyond the baseline strategies.

Fellowship Training in Arthroplasty Improves Treatment Success of Debridement, Antibiotics, and Implant Retention for Periprosthetic Knee Infections

Background

Debridement, antibiotics, and implant retention (DAIR) is a well-accepted surgical strategy for periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). DAIR in TKA may be incorrectly thought of as a "simple" procedure not requiring formal specialized training in arthroplasty. Currently, there are no studies comparing the risk of treatment failure based on surgeon fellowship training.

Methods

A retrospective review was performed of consecutive patients who underwent DAIR for TKA PJI at our institution. Two cohorts were created based on whether DAIR was performed by an arthroplasty fellowship-trained (FT) surgeon or nonarthroplasty fellowship-trained (NoFT) surgeon. Primary outcome was treatment failure following DAIR at a minimum of 1 year postoperatively. Treatment failure was based on the Tier 1 International Consensus Meeting definition of infection control. Secondary outcomes were also recorded including death during the totality of PJI treatment.

Results

A total of 112 patients were identified (FT = 68, NoFT = 44). At a mean follow-up of 7.3 years [standard deviation = 3.9], 73 patients (59.8%) failed treatment. Fellowship training in arthroplasty significantly improved treatment success rates (FT, 35/68 [51.5%]; NoFT, 10/44 [22.7%]; odds ratio 2.5 [95% confidence interval 1.1 to 5.9; P = .002]). Survivorship also differed significantly between the cohorts; at timepoints of 1.5 months, 5 months, 30 months, and 180 months, survivorship of the FT cohort was 79.4%, 67.6%, 54.4%, and 50.7%, respectively, compared with a survivorship of 65.9%, 52.3%, 25%, and 22.7% in the NoFT cohort (P = .002).

Conclusions

TKA PJI treated with DAIR should not be considered a simple procedure. Improved treatment success may be associated with subspecialty fellowship training in arthroplasty.

Level of Evidence

IV.

Debridement, Antibiotic Pearls, and Retention of the Implant (DAPRI) in the Treatment of Early Periprosthetic Knee Joint Infections: A Literature Review

(1) Background: Periprosthetic joint infections (PJIs) are severe and frightening complications in orthopaedic surgery, and they are generally divided into three categories: early infections (those occurring within the first 4-6 weeks), delayed infections (those occurring between 3 and 24 months), and late infections (those occurring more than 2 years after surgery). PJI treatment comprises "debridement, antibiotics, and implant retention" (DAIR), single-stage revision, and double-stage revision. Nowadays, to improve the chances of retaining an infected implant and to improve the traditional DAIR method, a modified surgical technique has been developed, named DAPRI (debridement, antibiotic pearls, and retention of the implant). Our study aims to present an up-to-date concept evaluation of the DAPRI technique and its success rate. (2) Methods: Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards were followed, applying a protocol defined by the authors: a total of 765 articles were identified, and at the end of the screening process only 7 studies were included. (3) Results: Currently, the DAPRI procedure can be performed only on patients who have had PJI symptoms for less than 4 weeks, and in order to achieve the highest success rate, indications are quite strict: it is appropriate in patients with acute, superficial infections without sinus tract presence, and well-fixed implants with known sensitive bacteria. The DAPRI surgical method follows a step-by-step process consisting of a first phase of biofilm identification with intra-articular injection of methylene blue, followed by biofilm removal (thermic, mechanical, and chemical aggression), and a last step consisting of prevention of PJI recurrence by using calcium sulphate antibiotic-added beads. (4) Conclusions: The DAPRI approach improves the traditional DAIR technique. It is a correct treatment for acute and early haematogenous PJI, and improves the DAIR success rate.

Acute Haematogenous Revision Total Knee Arthroplasty Infection by Streptococcus canis Treated by Debridement, Antibiotics, and Implant Retention: A Case Report

Prosthetic joint infections (PJIs) are one of the most feared complications by orthopaedic surgeons. Haematogenous PJI represents an important part of PJI cases. Streptococcus canis is an extremely rare cause of haematogenous PJI and its medical and surgical treatment and prognosis are not well established. We present a 79-year-old female patient who had a revision total knee arthroplasty (rTKA) surgery three years before. She was admitted to the hospital referring to three days of knee pain, restricted range of motion, and fever. Blood tests demonstrated leukocyte and C-reactive protein elevation. Joint fluid aspiration showed elevated white blood cell count with a high neutrophil differential and its conventional culture was positive for Streptococcus canis. She did not have pets but she took care of her daughter's dog. An acute haematogenous infection of the rTKA was diagnosed and treated with debridement, antibiotics (eight weeks of IV ceftriaxone), and implant retention (DAIR). After one year, the patient remains clinically asymptomatic without changes on X-rays and with normal serum levels of inflammatory blood markers. Streptococcus canis has to be kept in mind as a possible cause of haematogenous TKA infection in patients who have contact with domestic pets and patients should be asked for this contact. We recommend DAIR as a viable treatment option for this type of infection, which may show excellent results.

Lower Rates of Reoperation Following Partial or Complete Revision Arthroplasty Compared to Debridement, Antibiotics, and Implant Retention for Early Postoperative and Acute Hematogenous Periprosthetic Hip Infection

BACKGROUND

This study aimed to: 1) compare treatment outcomes between debridement, antibiotics, and implant retention (DAIR) and partial or complete revision arthroplasty (RA) for early postoperative and acute hematogenous total hip arthroplasty periprosthetic joint infection (PJI) and 2) identify factors associated with treatment outcome.

METHODS

The study consisted of a retrospective cohort of patients who underwent surgery for PJI between 2004 and 2021. There were 76 patients (74.5%) who underwent DAIR and 26 patients (25.5%) who underwent RA. Treatment success was defined as treatment eradication at a minimum of a 2-year follow up. Bivariate regression analysis was used to assess the effect of different factors on treatment outcomes. Kaplan-Meier survivorship was performed to compare survivorship between cohorts.

RESULTS

At a mean follow-up of 8.2 years (range, 2.2 to 16.4), significantly more DAIR failed treatment (DAIR, 50 [65.8%]; 10 [38.5%]; P = .015). The 8-year Kaplan-Meier survivorship was 35.1% [95% confidence interval (CI), 24.3 to 45.9] for patients treated with DAIR and 61.5% [95% CI, 42.9 to 80.1] for those treated with RA (log rank = 0.039). Bivariate regression analysis showed performing a RA was associated with a higher likelihood of treatment success (odds ratio 4.499, 95% CI 1.600 to 12.647, P = .004), whereas a higher body mass index was associated with treatment failure (odds ratio 0.934, 95% CI 0.878 to 0.994, P = .032).

CONCLUSIONS

To reduce the rate of recalcitrant infection following early postoperative or acute hematogenous total hip arthroplasty PJI, RA may be of benefit over DAIR. This is especially relevant in the early postoperative period, when components can be readily exchanged.

Appropriate Duration of Antimicrobial Treatment for Prosthetic Joint Infections: A Narrative Review

Prosthetic joint infections are considered difficult to treat they needing aggressive surgery and long antimicrobial treatments. However, the exact duration of these therapies has been established empirically. In the last years, several studies have explored the possibility of reducing the length of treatment in this setting, with conflicting results. In this narrative review, we critically appraise the published evidence, considering the different surgical approaches (implant retention [DAIR] and one-step and two-step exchange procedures) separately. In patients managed with DAIR, usually treated for at least 12 weeks, a large, randomized trial failed to show that 6 weeks were non-inferior. However, another randomized clinical trial supports the use of 8 weeks, as long as the surgical conditions are favorable and antibiotics with good antibiofilm activity can be administered. In patients managed with a two-step exchange procedure, usually treated during 6 weeks, a randomized clinical trial showed the efficacy of a 4-week course of antimicrobials. Also, the use of local antibiotics may allow the use of even shorter treatments. Finally, in the case of one-step exchange procedures, there is a trend towards reducing the length of therapy, and the largest randomized clinical trial supports the use of 6 weeks of therapy.

Suppressive Antibiotic Therapy After Debridement, Antibiotics, and Implant Retention is Well-Tolerated Without Inducing Resistance: A Multicenter Study

BACKGROUND

Suppressive antibiotic therapy (SAT) after total joint arthroplasty (TJA) debridement, antibiotics, and implant retention (DAIR) maximizes reoperation-free survival. We evaluated SAT after DAIR of acutely infected primary TJA regarding: 1) adverse drug reaction (ADR)/intolerance; 2) reoperation for infection; and 3) antibiotic resistance.

METHODS

Patients who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA) DAIR for acute periprosthetic joint infection at two academic medical centers from 2015 to 2020 were identified (n = 115). Data were collected on patient demographics, infecting organisms, antibiotics, ADR/intolerances, reoperations, and antibiotic resistances. Median SAT duration was 11 months. Stepwise multivariate logistic regressions were used to identify covariates significantly associated with outcomes of interest.

RESULTS

There were 11.1 and 16.3% of TKA and THA DAIR patients, respectively, who had ADR/intolerance to SAT. Patients prescribed trimethoprim/sulfamethoxazole (P = .0014) or combination antibiotic therapy (P = .0169) after TKA DAIR had increased risk of ADR/intolerance. There was no difference in reoperation-free survival between TKA (83.3%) and THA (65.1%) DAIR (P = .5900) at mean 2.8-year follow-up. Risk of reoperation for infection was higher among TKA Staphylococcus aureus infections (P = .0004) and lower with increased SAT duration (P < .0450). The optimal duration of SAT was nearly 2 years. No cases of antibiotic resistance developed due to SAT.

CONCLUSIONS

Consider SAT after TJA DAIR due to improved reoperation-free survival and favorable safety profile. Prolonged SAT did not induce antibiotic resistance. Use trimethoprim/sulfamethoxazole with caution because of the increased likelihood of ADR/intolerance.

LEVEL OF EVIDENCE

Therapeutic Level III.

Two-dimensional liquid chromatography measurement of meropenem concentration in synovial fluid of patients with periprosthetic joint infection

Periprosthetic joint infection (PJI) is a catastrophic complication following joint replacement surgery. One potential treatment approach for PJI could be the combination of one-stage revision and intra-articular infusion of antibiotics. Meropenem is one of the commonly used intra-articular antibiotics in our institution. Determining the concentration of meropenem in the joint cavity could be crucial for optimizing its local application, effectively eradicating biofilm infection, and improving PJI treatment outcomes. In this study, we developed a simple, precise, and accurate method of two-dimensional liquid chromatography (2D-LC) for determining the concentration of meropenem in human synovial fluid. The method was then validated based on the guidelines of the Food and Drug Administration and the Chinese Pharmacopoeia. Meropenem showed good linearity in the range of 0.31-25.01 μg/mL (r ≥ .999). Selectivity, intra-day and inter-day precision and accuracy, extraction recovery, and stability validation results were all within the acceptance range. This method has been successfully applied to the determination of synovial fluid samples from PJI patients, providing a useful detection method for meropenem therapeutic drug monitoring (TDM) in PJI patients.

Validation of a Classification System for Optimal Application of Debridement, Antibiotics, and Implant Retention in Prosthetic Joint Infections following Total Knee Arthroplasty: A Retrospective Review

INTRODUCTION

Periprosthetic joint infection (PJI) remains a serious complication after total knee arthroplasty (TKA). While debridement, antibiotics, and implant retention (DAIR) are considered for acute PJI, success rates vary. This study aims to assess a new scoring system's accuracy in predicting DAIR success.

METHODS

119 TKA patients (2008-2019) diagnosed with PJI who underwent DAIR were included for analysis. Data were collected on demographics, laboratory values, and clinical outcomes. This was used for validation of the novel classification system consisting of PJI acuteness, microorganism classification, and host health for DAIR indication. Statistical analysis was carried out using SPSS programming.

RESULTS

Mean follow-up was 2.5 years with an average age of 65.5 ± 9.1 years, BMI of 31.9 ± 6.2 kg/m2, and CCI of 3.04 ± 1.8. Successful infection eradication occurred in 75.6% of patients. The classification system demonstrated 61.1% sensitivity, 72.4% specificity, and 87.3% positive predictive value (PPV) when the DAIR cutoff was a score less than 6. For a cutoff of less than 8, sensitivity was 100%, specificity was 37.9%, and PPV was 83.3%.

CONCLUSIONS

To date, no consensus exists on a classification system predicting DAIR success. This novel scoring system, with high PPV, shows promise. Further refinement is essential for enhanced predictive accuracy.

Proceedings of the United Kingdom Periprosthetic Joint Infection Meeting 2022: Combined and Arthroplasty Sessions

Considerable variation in practice exists in the prevention, diagnosis, and treatment of periprosthetic joint infection (PJI), which is a devastating complication for patients and surgeons. The consensus principle has been increasingly embraced by the orthopaedic community to help guide practice, especially where high-level evidence remains unavailable. The third United Kingdom Periprosthetic Joint Infection (UK PJI) Meeting was held in Glasgow on April 1, 2022, with more than 180 delegates in attendance, representing orthopaedics, microbiology, infectious diseases, plastic surgery, anesthetics, and allied health professions, including pharmacy and arthroplasty nurses. The meeting comprised a combined session for all delegates, and separate breakout sessions for arthroplasty and fracture-related infection. Consensus questions for each session were prepared in advance by the UK PJI working group, based upon topics that were proposed at previous UK PJI Meetings, and delegates participated in an anonymized electronic voting process. We present the findings of the combined and arthroplasty sessions of the meeting in this article, and each consensus topic is discussed in relation to the contemporary literature.

Debridement, antibiotics and implant retention (DAIR) is successful in the management of acutely infected unicompartmental knee arthroplasty: a case series

BACKGROUND

Infections are rare and poorly studied complications of unicompartmental knee arthroplasty (UKA) surgery. They are significantly less common compared to infections after total knee arthroplasties (TKAs). Optimal management of periprosthetic joint infections (PJIs) after a UKA is not clearly defined in the literature. This article presents the results of the largest multicentre clinical study of UKA PJIs treated with Debridement, Antibiotics and Implant Retention (DAIR).

MATERIALS AND METHODS

In this retrospective case series, patients presenting between January 2016 and December 2019 with early UKA infection were identified at three specialist centres using the Musculoskeletal Infection Society (MSIS) criteria. All patients underwent a standardized treatment protocol consisting of the DAIR procedure and antibiotic therapy comprising two weeks of intravenous (IV) antibiotics followed by six weeks of oral therapy. The main outcome measure was overall survivorship free from reoperation for infection.

RESULTS

A total of 3225 UKAs (2793 (86.2%) medial and 432 (13.8%) lateral UKAs) were performed between January 2016 and December 2019. Nineteen patients had early infections necessitating DAIR. The mean follow-up period was 32.5 months. DAIR showed an overall survivorship free from septic reoperation of 84.2%, with overall survivorship free from all-cause reoperation of 78.95%.The most common bacteria were Coagulase-negative Staphylococci, Staphylococcus aureus and Group B Streptococci. Three patients required a second DAIR procedure but remained free from re-infection at follow-up obviating the need for more demanding, staged revision surgery.

CONCLUSIONS

In infected UKAs, the DAIR procedure produces a high rate of success, with a high survivorship of the implant.Key messagesDebridement, Antibiotics and Implant Retention (DAIR) is a successful and minimally invasive surgical option for the management of periprosthetic joint infections (PJIs) after UKA.The surface area available for bacteria to colonise is much smaller in UKAs compared to total knee arthroplasties (TKAs), and this may account for the higher success rates of the DAIR procedure in infected UKAs versus infected TKAs.A second DAIR procedure can be considered in the management of the early recurrence of PJIs with a well-fixed UKA.

Current knowledge and clinical perspectives for a unique new phylum: Nanaorchaeota

Nanoarchaea measuring less than 500 nm and encasing an average 600-kb compact genome have been studied for twenty years, after an estimated 4193-million-year evolution. Comprising only four co-cultured representatives, these symbiotic organisms initially detected in deep-sea hydrothermal vents and geothermal springs, have been further distributed in various environmental ecosystems worldwide. Recent isolation by co-culture of Nanopusillus massiliensis from the unique ecosystem of the human oral cavity, prompted us to review the evolutionary diversity of nanaorchaea resulting in a rapidly evolving taxonomiy. Regardless of their ecological niche, all nanoarchaea share limited metabolic capacities correlating with an obligate ectosymbiotic or parasitic lifestyle; focusing on the dynamics of nanoarchaea-bacteria nanoarchaea-archaea interactions at the morphological and metabolic levels; highlighting proteins involved in nanoarchaea attachment to the hosts, as well metabolic exchanges between both organisms; and highlighting clinical nanoarchaeology, an emerging field of research in the frame of the recent discovery of Candidate Phyla radiation (CPR) in human microbiota. Future studies in clinical nanobiology will expand knowledge of the nanaorchaea repertoire associated with human microbiota and diseases, to improve our understanding of the diversity of these nanoorganims and their intreactions with microbiota and host tissues.

Intraarticular vancomycin decreased the risk of acute postoperative periprosthetic joint infection without increasing complication in primary total joint arthroplasty-a prospective study

OBJECTIVES

To investigate the preventive effect of intraarticularly administered vancomycin on acute postoperative periprosthetic joint infection (PJI) in total joint arthroplasty (TJA).

METHODS

Consecutive patients who underwent unilateral primary TJA were prospectively enrolled. The patients were divided into vancomycin group and control group according to whether 1 g of vancomycin powder suspended in 30 ml normal saline was intraarticularly administered after arthrotomy closure. Acute postoperative PJI and aseptic wound complication were evaluated within 3 months postoperatively. Vancomycin-associated toxicity including acute renal failure, ototoxicity and anaphylaxis was also evaluated.

RESULTS

In terms of demographic parameters and comorbidities, no significant difference was found between the two groups. Intra-articular vancomycin significantly lowered the risk of acute postoperative PJI after primary TJA (P = 0.015) and primary total knee arthroplasty (P = 0.031). However, for patients who underwent total hip arthroplasty, the PJI rate was comparable between the two groups. Overall, the risk of aseptic wound complication between the two groups was also similar. Vancomycin-associated acute renal injury, ototoxicity, or anaphylaxis was not observed.

CONCLUSIONS

Intra-articular injection of 1 g of vancomycin suspension after arthrotomy closure during TJA lowered the risk of acute postoperative PJI without increasing the risk of aseptic wound complication and vancomycin-associated systemic toxicity.

The Use of Oral Antibiotics After Total Joint Arthroplasty: A Critical Analysis Review

» There is conflicting and insufficient evidence that extended oral antibiotic (EOA) therapy prevents infection in high-risk patients undergoing primary total joint arthroplasty (TJA), limiting recommendation for or against the practice.» In the case of aseptic revision TJA, the evidence is also conflicting and limited by underlying confounders, preventing recommendation for use of EOA.» There is fair evidence that use of EOA after debridement antibiotic therapy and implant retention of the prosthesis prolongs infection-free survival, but randomized controlled trials are needed. On the other hand, there is strong evidence that patients undergoing 2-stage revision should receive a period of suppressive oral antibiotics after the second stage.» The optimal duration of EOA in primary TJA, aseptic revision, and debridement antibiotic therapy and implant retention of the prosthesis is unknown. However, there is strong evidence that 3 months of EOA suppression may be appropriate after reimplantation as part of 2-stage exchange arthroplasty.» Complications secondary to EOA are reported to be between 0% and 13.7%, yet are inconsistently reported and poorly defined. The risks associated with antibiotic use, including development of antimicrobial resistance, must be weighed against a possible decrease in infection rate.

Local Administration of Antibiotics in Orthopedics and Traumatology

2022 marks the 50th anniversary of the development of the antibiotic loaded PMMA chain. The loading of bone cements with antibiotics was a major advance in the treatment of musculoskeletal infections and is still a proven standard today. The research and use of novel antibiotic carriers continues to be an important part of research in the context of musculoskeletal infections. The article provides an overview of the various local antibiotics available and their specifics. In addition, current adapted treatment concepts are discussed.

Design Characteristics and Recruitment Rates for Randomized Trials of Peri-Prosthetic Joint Infection Management: A Systematic Review

Prosthetic joint infections (PJI) present a major management challenge for practicing orthopedic surgeons and infectious disease physicians. There are few high-quality data to inform treatment guidelines. The aim of this systematic review was to report the design characteristics and recruitment rates for randomized controlled trials (RCTs) of PJI management. Trials were considered eligible for inclusion if human participants were randomized to any management intervention for PJI. We searched Medline, PubMed, Embase, Web of Science, Cochrane Database, ANZ Clinical Trials Registry, ClinicalTrials.gov, and the EU Clinical Trials Register until the end of May 2023. The systematic review was registered with PROSPERO (CRD42018112646). We identified 15 published RCTs with a total of 1743 participants with PJI. The median (interquartile range [IQR]) number of successfully recruited participants was 63 (38-140), with 0.28 (0.13-0.96) enrolments per site per month. Only four trials (36.4%) achieved the target recruitment. All RCTs applied different primary endpoints and varying definitions of a 'good' outcome. Despite recent improvements, PJI RCTs are characterized by slow recruitment and heterogeneous endpoint assessments, which preclude synthesis in a standard meta-analytic framework. To inform international guidelines, future PJI trials should be run as multi-country trials at high-recruiting sites.

Hydrogel Coating versus Calcium Sulphate Beads as a Local Antibiotic Carrier for Debridement Procedures in Acute Periprosthetic Joint Infection: A Preliminary Study

Periprosthetic joint infections (PJI) are among the most difficult complications to treat in orthopaedic surgery. Debridement, antibiotics, and implant retention (DAIR) represent an efficient strategy for acute PJI, especially when resorbable local antibiotic carriers and coatings are used. The aim of this pilot study was to evaluate the difference between using antibiotic-loaded hydrogel (ALH) and calcium sulphate (CS) beads in the DAIR procedure. We analysed 16 patients who had been treated since 2018 for acute PJI, namely eight patients with knee PJI (50%), seven with hip PJI (43.7%), and one with shoulder PJI (6.2%). Nine patients were treated with the Debridement, Antibiotic Coating and Retention of the Implant (DACRI) method, while seven were treated with the Debridement, Antibiotic Pearls, Retention of the Implant (DAPRI) method. We found no significant differences between the two groups in terms of age, sex, the American Society of Anesthesiologists risk score, Charlson Comorbidity Index, localisation, days from onset to diagnosis and pathogenesis. Furthermore, no differences were found between the DACRI and DAPRI groups in terms of infection control (15 patients, 93.75% with p = 0.36) and last C-Reactive Protein values (p = 0.26), with a mean follow-up of 26.1 ± 7.7 months. Treatment for one patient affected by knee Candida albicans PJI in the DACRI group was not successful. In conclusion, DAPRI and DACRI appear to be safe and effective treatments for PJIs. This evidence will encourage the development of new clinical research into local carriers and coatings for use in acute implant-associated infections.

Debridement, Antibiotics and Implant Retention: A Systematic Review of Strategies for Treatment of Early Infections after Revision Total Knee Arthroplasty

GOAL

The purpose of this review is to provide a systematic and comprehensive overview of the available literature on the treatment of an early prosthetic joint infection (PJI) after revision total knee arthroplasty (TKA) and provide treatment guidelines.

METHODS

This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The search was conducted using the electronic databases of PubMed, Trip, Cochrane, Embase, LILACS and SciElo. After the inclusion of the relevant articles, we extracted the data and results to compose a treatment algorithm for early and acute PJI after revision TKA.

RESULTS

After applying the in- and exclusion criteria, seven articles were included in this systematic review focusing on debridement, antibiotics and implant retention (DAIR) for PJI following revision TKA, of which one was prospective and six were retrospective. All studies were qualified as level IV evidence.

CONCLUSIONS

The current literature suggests that DAIR is a valid treatment option for early infections after revision TKA with success rates of 50-70%. Repeat DAIR shows success rates of around 50%. Further research should be aimed at predicting successful (repeat/two-stage) DAIRs in larger study populations, antibiotic regimes and the cost effectiveness of a second DAIR after revision TKA.

Enough is enough: salvage procedures in severe periprosthetic joint infection

BACKGROUND

In severe cases of periprosthetic joint infection involving negative host-dependent factors, individual-based decisions between a curative therapy vs. salvage procedure are necessary. We aimed to review salvage procedures in severe periprosthetic joint infection cases, where a gold standard of a curative two-stage exchange can no longer be achieved. The options of knee arthrodesis, amputation, persistent fistula (stable drainage), or a debridement, antibiotics, and implant retention procedure in late-onset cases are discussed, including lifelong antibiotic suppression alone.

METHODS

We focused on known salvage procedures for severe periprosthetic joint infection of the hip and knee, such as amputation, arthrodesis, antibiotic suppression, persistent fistula, and debridement, antibiotics, and implant retention in late-stage infections, and the role of local antibiotics. The current literature regarding indications and outcomes was reviewed.

RESULTS

Whereas a successful single-stage above-knee amputation can be a curative effort in younger patients, this is associated with limited outcome in older patients, as the proportion who receive an exoprosthesis leading to independent mobility is low. Therefore, arthrodesis using an intramedullary modular nail is an option for limb salvage, pain reduction, and preservation of quality of life and everyday life mobility, when revision total knee arthroplasty is not an option. Carrying out a persistent fistula using a stable drainage system, as well as a lifelong antibiotic suppression therapy, can be an option, in cases where no other surgery is possible. Active clinical surveillance should then be carried out. A debridement, antibiotics, and implant retention procedure in combination with local degradable antibiotics can be used and is an encouraging new option, but should not been carried out twice.

CONCLUSION

Whereas the gold standard in periprosthetic joint infection treatment of late infections remains the exchange of the prosthesis, salvage procedures should be considered in the cases of reduced life expectancy, several recurrences of the infection, patients having preference and negative host factors. In these cases, the appropriate salvage procedure can temporarily lead to remission of the infection and the possibility to maintain mobility.

Clinical outcomes of various types of revision surgeries after unicompartmental knee arthroplasty failure

PURPOSE

The advantages of unicompartmental knee arthroplasty (UKA) have led to the procedure being increasingly performed worldwide. However, revision surgery is required after UKA failure. According to the literature review, the choice of implant in revision surgery remains a debatable concern. This study analyzed the clinical results of different types of prostheses used in treating failed UKA.

MATERIALS AND METHODS

This is a retrospective review of 33 failed medial UKAs between 2006 and 2017. Demographic data, failure reason, types of revision prostheses, and the severity of bone defects were analyzed. The patients were classified into three groups: primary prosthesis, primary prosthesis with a tibial stem, and revision prosthesis. The implant survival rate and medical cost of the procedures were compared.

RESULTS

A total of 17 primary prostheses, 7 primary prostheses with tibial stems, and 9 revision prostheses were used. After a mean follow-up of 30.8 months, the survival outcomes of the three groups were 88.2%, 100%, and 88.9%, respectively (P = 0.640). The common bone defect in tibia site is Anderson Orthopedic Research Institute [AORI] grade 1 and 2a (16 versus 17). In patients with tibial bone defects AORI grade 2a, the failure rates of primary prostheses and primary prostheses with tibial stems were 25% and 0%, respectively.

CONCLUSIONS

The most common cause for UKA failure was aseptic loosening. The adoption of a standardized surgical technique makes it easier to perform revision surgeries. Primary prostheses with tibial stems provided higher stability, leading to a lower failure rate due to less risk of aseptic loosening in patients with tibial AORI grade 2a. In our experience, we advise surgeons may try using primary prostheses in patients with tibial AORI grade 1 and primary prostheses with tibial stems in patients with tibial AORI grade 2a.

Debridement, Antibiotic Pearls, and Retention of the Implant (DAPRI) in the Treatment of Early Periprosthetic Joint Infections: A Consecutive Series

INTRODUCTION

Periprosthetic joint infections (PJI) represent a devastating consequence following total joint arthroplasty (TJA). In this study, the authors describe a modified surgical technique developed to enhance the classical irrigation and debridement procedure (DAIR) to improve the possibilities of retaining an acutely infected TJA.

MATERIALS AND METHODS

This technique, debridement antibiotic pearls and retention of the implant (DAPRI), aims to remove the intra-articular biofilm allowing a higher and prolonged local antibiotic concentration by using calcium sulphate antibiotic-added beads in a setting of acute (<4 weeks from symptoms onset) PJI with pathogen identification. The combination of three different surgical techniques (tumor-like synovectomy, argon beam/acetic acid application and chlorhexidine gluconate brushing) aims to remove the bacterial biofilm from the implant without explanting the original hardware.

RESULTS

In total, 62 patients met the acute infection criteria (<4 weeks of symptoms); there were 57 males and five females. The patients' average age at the time of treatment was 71 years (62-77) and the average BMI was 37 kg/m². The micro-organism, always identified through synovial fluid analysis (culture, multiplex PCR or Next Generation Sequencing), was an aerobic Gram + in 76% (S. Coag-Neg 41%; S. aureus 16%), Gram-in 10% (E. coli 4%) and anaerobic Gram + in 4%. The DAPRI treatment was performed at an average of 3 days from symptoms onset (1-7 days). All patients underwent a 12-week course of post-operative antibiotic therapy (6 weeks I.V. and 6 weeks oral). All patients were available at the 2-year minimum FU (24-84 months). A total of 48 (77.5%) patients were infection-free at the final FU, while 14 patients underwent 2-stage revision for PJI recurrence. In total, four patients (6.4%) had a prolonged drainage from the wound after placement of the calcium sulphate beads.

CONCLUSIONS

This study suggests that the DAPRI technique could represent a valid alternative to the classic DAIR procedure. The current authors do not recommend this procedure outside of the main inclusive criteria (acute scenario micro-organism identification).

The Challenge of Emerging Resistant Gram-Positive Pathogens in Hip and Knee Periprosthetic Joint Infections

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An increase in resistant bacterial pathogens has occurred over the last 4 decades.

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Careful patient selection and improving or correcting risk factors for periprosthetic joint infection (PJI) before elective surgical treatment are strongly recommended.

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Appropriate microbiological methods, including those used to detect and grow Cutibacterium acnes, are recommended.

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Antimicrobial agents used in the prevention or management of infection should be selected appropriately and the duration of therapy should be carefully considered in order to mitigate the risk of developing bacterial resistance.

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Molecular methods including rapid polymerase chain reaction (PCR) diagnostics, 16S sequencing, and/or shotgun and/or targeted whole-genome sequencing are recommended in culture-negative cases of PJI.

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Expert consultation with an infectious diseases specialist (if available) is recommended to assist with the appropriate antimicrobial management and monitoring of patients with PJI.

Principles of mechanical and chemical debridement with implant retention

BACKGROUND

Periprosthetic joint infection (PJI) is one of the most common causes of early revision for total hip and knee arthroplasty. Mechanical and chemical debridement typically referred to as debridement, antibiotics, and implant retention (DAIR) can be a successful technique to eradicate PJI in acute postoperative or acute hematogenous infections. This review will focus specifically on the indications, techniques, and outcomes of DAIR.

DISCUSSION

The success of mechanical and chemical debridement, or a DAIR operation, is reliant on a combination of appropriate patient selection and meticulous technique. There are many technical considerations to take into consideration. One of the most important factors in the success of the DAIR procedure is the adequacy of mechanical debridement. Techniques are surgeon-specific and perhaps contribute to the large variability in the literature on the success of DAIR. Factors that have been shown to be associated with success include the exchange of modular components, performing the procedure within seven days or less of symptom onset, and possibly adjunctive rifampin or fluoroquinolone therapy, though this remains controversial. Factors that have been associated with failure include rheumatoid arthritis, age greater than 80 years, male sex, chronic renal failure, liver cirrhosis, and chronic obstructive pulmonary disease.

CONCLUSIONS

DAIR is an effective treatment option for the management of an acute postoperative or hematogenous PJI in the appropriately selected patient with well-fixed implants.

Poor outcome after debridement and implant retention for acute hematogenous periprosthetic joint infection: a cohort study of 43 patients

BACKGROUND AND PURPOSE

The management of acute hematogenous periprosthetic joint infection (AHI) is challenging and the optimal treatment is not clearly defined. The aim of this study was to evaluate the treatment outcome of AHI, and secondarily to investigate potential risk factors that affect outcome.

PATIENTS AND METHODS

We retrospectively analyzed 43 consecutive AHIs in a total hip or knee arthroplasty between 2013 and 2020 at a single center. We used the Delphi international consensus criteria to define infection. Patients were treated by either debridement, antibiotics, and implant retention (DAIR) (n = 25), implant exchange/removal (n = 15), or suppressive antibiotics only (n = 3). AHI was defined as abrupt symptoms of infection ≥ 3 months after implantation in an otherwise well-functioning arthroplasty.

RESULTS

AHI was most often caused by Staphylococcus aureus (16/43) and streptococcal species (13/43), but a broad spectrum of microbes were identified. 25 of 43 were treated with DAIR, with success in 10 of 25, which was significantly lower than in patients treated with removal of the implant with success in 14 of 15. S. aureus infection, knee arthroplasty, and implant age < 2 years were associated with treatment failure. The 2-year mortality rate was 8 of 43.

CONCLUSION

The outcome following DAIR in AHIs was poor. The majority of infections were caused by virulent microbes, and we found a high mortality rate. Removal of the implant should more often be considered.

Antimicrobial treatment of patients with a periprosthetic joint infection: basic principles

The antibiotic treatment of periprosthetic joint infections (PJI) is complicated by the presence of biofilm produced by bacteria on the abiotic surface of the implant. Bacteria within the deeper layers of the biofilm become metabolically less active, resulting in antibiotic tolerance due to several mechanisms. This review describes the basic principles of antibiotic treatment in PJI in relation to the behavior of bacteria within the biofilm. The concept of biofilm-active antibiotics will be explained from an in vitro as well as in vivo perspective. Evidence from clinical studies on biofilm-active antibiotics in PJI will be highlighted, mainly focusing on the role of rifampicin for Gram-positive microorganisms and fluoroquinolones for Gram-negative microorganisms. The optimal treatment duration will be discussed as the timing of switching to oral antibiotic therapy.

Outcomes and risk factors for failure after débridement, antibiotics, and implant retention for elbow periprosthetic joint infection

BACKGROUND

Evidence for the management of periprosthetic joint infection (PJI) after total elbow arthroplasty is sparse, particularly in regard to débridement, antibiotics, and implant retention (DAIR). This study explored the outcomes of DAIR and analyzed risk factors for failure.

METHODS

A retrospective cohort study of patients 18 years or older diagnosed with elbow PJI and managed with DAIR between January 1, 2003, and December 31, 2018, at a single institution was performed. Twenty-six elbows met the inclusion criteria during the study period. All DAIR procedures included in this study represented an attempt to manage an acute PJI with surgical irrigation and débridement without removal of the elbow arthroplasty components, followed by long-term systemic antimicrobial therapy. DAIR failure was defined as recurrence of PJI, unplanned re-operation for infection, or death secondary to infection. A Cox proportional hazards model was used to identify possible risk factors for failure.

RESULTS

DAIR failed in 17 cases of elbow PJI with a failure rate of 65% at 2 years (95% confidence interval: 41.3%-79.6%). The median time to failure from DAIR was 43 days (interquartile range: 27-114). We found that DAIR failed in all cases with sinus tracts or negative cultures. The group with favorable outcomes had a shorter median duration of symptoms (5 vs. 18 days, P = .65) and a higher proportion of monomicrobial infections (58.8% vs. 88.9%, P = .19) compared to those with unfavorable outcomes. However, with the numbers available, none of the possible risk factors analyzed for association with failure reached statistical significance.

CONCLUSION

DAIR for elbow PJI was associated with high rates of failure. Possible risk factors for failure may include the presence of sinus tract, longer duration of symptoms, and culture-negative infection. Although the relatively low morbidity of DAIR compared with total elbow arthroplasty implant resection for a one-stage or two-stage reimplantation is attractive, patients considered for DAIR must know that the chance of success is limited to approximately 35%.

[Update bone infections]

Bone and joint infections are becoming of great concern in an elderly population with growing numbers of prosthetic joints and comorbidities. This paper summarizes recently published literature on periprosthetic joint infections, vertebral osteomyelitis and diabetic foot infections. According to a new study, in the presence of a hematogenous periprosthetic infection and other inserted joint prostheses that are unremarkable on clinical examination, further invasive or imaging diagnostics may not be necessary. Periprosthetic infections that occur late (> 3 months after joint installation) have a worse outcome. New studies tried to identify factors when prosthesis preservation might still be an option. A new randomized landmark trial from France failed to show non-inferiority for 6 versus 12 weeks of therapy length. Thus, it can be assumed that this will currently become the standard therapy length for all surgical modalities (retention or replacement). Vertebral osteomyelitis is a rather rare bone infection, but the incidence has continued to rise sharply in recent years. A retrospective study from Korea provides information on the distribution of pathogens in different age groups and with selected comorbidities; this could help in the selection of an empiric therapy when pathogen identification is not successful before starting the treatment. The guidelines by the "International Working Group on the Diabetic Foot (IWGDF)" have been updated with a slightly different classification. New practice recommendations of the German society of diabetology emphasize an early interdisciplinary interprofessional management. Empirical therapy continues to be based on the severity of the infection and other risk factors (such as previous therapies or ischemia). Microbiological diagnosis from tissue samples is described as superior to smears. According to a randomized pilot study, 3 weeks therapy length for osteomyelitis after debridement appears to be noninferior to 6 weeks.

Advances in the Microbiological Diagnosis of Prosthetic Joint Infections

A significant number of prosthetic joint infections (PJI) are culture-negative and/or misinterpreted as aseptic failures in spite of the correct implementation of diagnostic culture techniques, such as tissue sample processing in a bead mill, prolonged incubation time, or sonication of removed implants. Misinterpretation may lead to unnecessary surgery and needless antimicrobial treatment. The diagnostic value of non-culture techniques has been investigated in synovial fluid, periprosthetic tissues, and sonication fluid. Different feasible improvements, such as real-time technology, automated systems and commercial kits are now available to support microbiologists. In this review, we describe non-culture techniques based on nucleic acid amplification and sequencing methods. Polymerase chain reaction (PCR) is a frequently used technique in most microbiology laboratories which allows the detection of a nucleic acid fragment by sequence amplification. Different PCR types can be used to diagnose PJI, each one requiring the selection of appropriate primers. Henceforward, thanks to the reduced cost of sequencing and the availability of next-generation sequencing (NGS), it will be possible to identify the whole pathogen genome sequence and, additionally, to detect all the pathogen sequences present in the joint. Although these new techniques have proved helpful, strict conditions need to be observed in order to detect fastidious microorganisms and rule out contaminants. Specialized microbiologists should assist clinicians in interpreting the result of the analyses at interdisciplinary meetings. New technologies will gradually be made available to improve the etiologic diagnoses of PJI, which will remain an important cornerstone of treatment. Strong collaboration among all specialists involved is essential for the correct diagnosis of PJI.

Study protocol: short against long antibiotic therapy for infected orthopedic sites - the randomized-controlled SALATIO trials

BACKGROUND

Few studies address the appropriate duration of post-surgical antibiotic therapy for orthopedic infections; with or without infected residual implants. We perform two similar randomized-clinical trials (RCT) to reduce the antibiotic use and associated adverse events.

METHODS

Two unblinded RCTs in adult patients (non-inferiority with a margin of 10%, a power of 80%) with the primary outcomes "remission" and "microbiologically-identical recurrences" after a combined surgical and antibiotic therapy. The main secondary outcome is antibiotic-related adverse events. The RCTs allocate the participants between 3 vs. 6 weeks of post-surgical systemic antibiotic therapy for implant-free infections and between 6 vs. 12 weeks for residual implant-related infections. We need a total of 280 episodes (randomization schemes 1:1) with a minimal follow-up of 12 months. We perform two interim analyses starting approximately after 1 and 2 years. The study approximatively lasts 3 years.

DISCUSSION

Both parallel RCTs will enable to prescribe less antibiotics for future orthopedic infections in adult patients.

TRIAL REGISTRATION

ClinicalTrial.gov NCT05499481. Registered on 12 August 2022.

PROTOCOL VERSION

2 (19 May 2022).

2022 American Association of Hip and Knee Surgeons Symposium: Periprosthetic Joint Infection

Periprosthetic joint infection (PJI) is the leading cause of failure in patients undergoing total joint arthroplasty. This article is a brief summary of a symposium on PJI that was presented at the annual AAHKS meeting. It will provide an overview of current technqiues in the prevention, diagnosis, and management of PJI. It will also highlight emerging technologies in this setting.

Redo DAIR: The Game Is Seldom Worth the Candle

Debridement, antibiotics and implant retention (DAIR) remains a commonly utilized technique in the treatment of acute prosthetic joint infections despite its inconsistent outcomes. The performance of a second DAIR after a failed first debridement is controversial as outcomes are uncertain and the final prognosis in the event of failure may be unfavorable. This study analyzes 84 cases of acute prosthetic (hip & knee) joint infection treated with DAIR between 2011 and 2020 at the same institution. In 12 failed cases, a second DAIR was performed, whose success rate was significantly lower than that of the first procedure (8% [95% CI, 0-38] vs. 57% [46-68]). Moreover, the ultimate outcome of the second failed DAIRs was unfavorable with eradication of the infection being achieved in none of the patients. Due to the high likelihood of failure and the potentially grim final prognosis following a second debridement, removal of the components should be considered.

Assessment of antimicrobial mismatches in empirical treatment in early PJI after aseptic revision arthroplasty

Background

In early periprosthetic joint infection (PJI), 'debridement, antibiotics and implant retention' (DAIR) is a widely accepted form of treatment. Empirical antimicrobial treatment is started while culture results of tissue samples taken during debridement are pending.

Objectives

In this retrospective study we assessed the antimicrobial mismatch rate between empirical treatment and the susceptibility of the causative microorganisms of PJI after aseptic revision arthroplasty. We analysed risk factors for antimicrobial mismatches and the impact of mismatches on the outcome of PJI treatment.

Results

A total of 119 patients were included in the analysis. In 72% (86/119) of the cases there was an antimicrobial mismatch in empirical treatment. Most of the antimicrobial mismatches were caused by multidrug-resistant (MDR) Staphylococcus spp. (77%, 66/86). In multivariable analysis, polymicrobial PJI was significantly associated with antimicrobial mismatch (OR: 6.89; 95% CI: 2.38-19.53; P < 0.001), and antimicrobial mismatch was significantly associated with reduced success rate of PJI treatment (OR: 0.20; 95% CI: 0.05 ± 0.82; P = 0.026). There was no difference in successful outcome between PJI caused by Gram-negative bacilli (61%) and Gram-positive bacteria (69%, P = 0.516).

Conclusions

Mismatching empirical antimicrobial treatment after DAIR following aseptic revision arthroplasty was significantly associated with failure of PJI treatment. Polymicrobial PJI is a risk factor for antimicrobial mismatch of the empirical treatment of PJI. Antimicrobial mismatch and delay in targeted treatment should be integrated in the approach to optimize antibiotic treatment to improve clinical outcomes, while minimizing unintended side effects of antimicrobial use (antimicrobial stewardship).

Adjunctive Rifampin Following Debridement and Implant Retention for Staphylococcal Prosthetic Joint Infection: Is it Effective if not Combined With a Fluoroquinolone?

Whether rifampin benefits retained staphylococcal prosthetic joint infection is unsettled. In a meta-analysis of 8 studies, we found greater clinical cure with fluoroquinolone-rifampin vs all other regimens (odds ratio [OR], 2.68; 95% CI, 1.43-5.02), but no greater cure with other rifampin combinations vs regimens without rifampin (OR, 1.22; 95% CI, 0.79-1.88).

Treatment patterns and failure rates associated with prosthetic joint infection in unicompartmental knee arthroplasty: A systematic review

Background

Prosthetic joint infection (PJI) following unicompartmental knee arthroplasty (UKA) is a rare but challenging complication. A paucity of literature exists regarding the management of PJI in UKA. This systematic review aims to assess current treatment patterns in UKA PJI and analyze the failure rates associated with treatment.

Methods

PubMed, Scopus, and EMBASE were systematically searched for studies that presented cases of PJI following UKA. Data regarding study design, country of publication, index procedure type, diagnosis of PJI, number and incidence of PJI, timing of PJI (acute versus chronic), treatment, and outcomes were recorded. Failure rates in acute and chronic PJI as well as total failure rates were analyzed.

Results

Sixteen articles were identified that met inclusion criteria. These included 97 PJI cases (37 acute, 58 chronic, 2 unknown timing); incidence across all studies of 0.80%. The most common treatment for all PJI cases was debridement, antibiotics, and implant retention (DAIR) (40.2%), followed by two-stage conversion to total knee arthroplasty (TKA) (33.0%), one-stage conversion to TKA (23.7%), and one-stage exchange UKA (3.1%). There were no significant differences in failure rates across procedures for acute, chronic or overall PJI management (p > 0.05 for all).

Conclusion

This systematic review found relatively few studies reporting on PJI after UKA compared to the available TKA evidence. Further research is warranted to better elucidate the most appropriate treatment of PJI after UKA in both the acute and chronic setting along with risk factors for failure.

Is There Harm in Debridement, Antibiotics, and Implant Retention Versus Two-Stage Revision in the Treatment of Periprosthetic Knee Infection? Experiences Within a Large US Health Care System

BACKGROUND

When faced with a periprosthetic joint infection (PJI) following total knee arthroplasty, the treating surgeon must determine whether 2-stage revision or "liner exchange," aka debridement, antibiotics, exchange of the modular polyethylene liner, and retention of fixed implants (DAIR), offers the best balance of infection eradication versus treatment morbidity. We sought to determine septic re-revision risk following DAIR compared to initial 2-stage revision.

METHODS

We conducted a cohort study using data from Kaiser Permanente's total joint replacement registry. Primary total knee arthroplasty patients who went on to have a PJI treated by DAIR or 2-stage revision were included (2005-2018). Propensity score-weighted Cox regression was used to evaluate risk for septic re-revision.

RESULTS

In total, 1,410 PJIs were included, 1,000 (70.9%) treated with DAIR. Applying propensity score weights, patients undergoing DAIR had a higher risk for septic re-revision compared to initial 2-stage procedures (hazard ratio 3.09, 95% CI 2.22-4.42). Of DAIR procedures, 150 failed (15%) and went on to subsequent 2-stage revision (DAIR-F). When compared to patients undergoing an initial 2-stage revision, we failed to observe a difference in septic re-revision risk following DAIR-F (hazard ratio 1.11, 95% CI 0.58-2.12).

CONCLUSION

Although DAIR had a higher risk of septic re-revision, we failed to observe a difference in risk following DAIR-F when compared to those who initially underwent 2-stage revision. Functional outcome, patient, and organism factors are important to consider when discussing PJI management options.

LEVEL OF EVIDENCE

Level III.

Symptom duration is associated with failure of periprosthetic joint infection treated with debridement, antibiotics and implant retention

Background

Debridement, antibiotics, and implant retention (DAIR) is an alternative treatment strategy for periprosthetic joint infection (PJI). However, no consensus exists regarding which patient population(s) may be most suitable for DAIR. This study aims to investigate the overall infection control rate and explore the prognostic factors associated with acute, hematogenous, and chronic PJIs treated with DAIR.

Methods

We retrospectively reviewed the included patients who were diagnosed with PJI and underwent DAIR at two institutions from 2009 to 2018 (n = 104). We collected the clinical data, including demographics, preoperative laboratory tests, Charlson Comorbidity Index, surgical information, and culture organism results. Treatment success was defined according to the criteria reported by Diaz-Ledezma. All patients were followed for at least one year unless failure preceded that time point. A multivariable analysis was utilized to identify prognostic factors associated with treatment, and a Kaplan-Meier survival analysis was used to depict the infection control rate.

Results

The overall treatment success rate in the current cohort of patients was 67.3% at a median 38.6 (interquartile range: 23.5, 90.7) months follow-up. Patients with a duration of infectious symptoms of more than ten days were more likely to fail (P = 0.035, hazard ratio 8.492, 95% confidence interval 1.159–62.212). There was no difference among acute, hematogenous, and chronic infections in terms of failure rate (P = 0.161).

Conclusions

DAIR is a reasonable treatment option for PJI, and its use in the setting of chronic infection does not appear to be a contraindication. Performing DAIR within ten days of the presentation of symptoms had a higher rate of treatment success.

Accuracy of a Novel Preoperative Failure Risk Model for Debridement Antibiotics and Implant Retention (DAIR) in Acute Prosthetic Joint Infection

Given the variable success of the debridement, antibiotics and implant retention (DAIR) procedure in patients with acute prosthetic joint infection (PJI), an accurate selection of candidates is critical. In this study, we set about calculating the predictive value of a novel algorithm for predicting outcome following DAIR developed by Shohat et al. Sixty-four patients who underwent debridement for (early and late) acute PJI in a tertiary-level university hospital were selected, and the aforementioned algorithm was retrospectively applied. Patients with model scores of 40−50%, 50−60%, 60−70%, 70−80% and 80−90% displayed success rates of 33.34%, 41.18%, 57.9%, 78.27% and 100%, respectively. The receiver operating characteristic curve showed an area under the curve of 0.69. The calibration intercept value was 0, and the calibration slope value was 1. Failure rates were significantly higher for the following variables: revision surgery (p = 0.012) index surgery for reasons other than osteoarthritis (p = 0.01), and C-reactive protein level >30 mg/L (p = 0.042). This analysis demonstrated that the Shohat algorithm is associated with an optimal calibration value and a moderate predictive value for failure of a DAIR procedure in patients with acute PJI. Its validation is recommended before it can be routinely applied in daily practice.

Truth in DAIR: Duration of Therapy and the Use of Quinolone/Rifampin-Based Regimens following Debridement and Implant Retention for Periprosthetic Joint Infections

Background

The optimal duration of antibiotic therapy after debridement and implant retention (DAIR) for periprosthetic joint infections (PJIs) is debated. Furthermore, the best antibiotic regimens for staphylococcal PJI are also unclear. In this study, we evaluated the impact of antibiotic therapy duration on the risk of failure. We assessed the utility of rifampin-based regimens for staphylococcal PJI managed with DAIR.

Methods

We performed a retrospective cohort study of patients 18 years and older diagnosed with hip and knee PJI who underwent DAIR between January 1, 2008 and 31 December 31, 2018 at Mayo Clinic, USA. The outcome was failure of DAIR. For statistical analysis, joint-stratified Cox regression models adjusted for age, sinus tract, symptom duration, and primary/revision arthroplasty were performed.

Results

We examined 247 cases of PJI with a median follow-up of 4.4 years (interquartile range [IQR], 2.3–7) after DAIR. The estimated 5-year cumulative incidence of failure was 28.1% (n = 65). There was no association between the duration of intravenous (IV) antibiotics (median 42 days; IQR, 38–42) and treatment failure (P = .119). A shorter duration of subsequent oral antibiotic therapy was associated with a higher risk of failure (P = .005; eg, 90-day vs 1-year duration; hazard ratio [HR], 3.50; 95% confidence interval [CI], 1.48–8.25). For staphylococcal knee PJI, both the use and longer duration of a rifampin-based regimen were associated with a lower risk of failure (both P = .025). There was no significant association between fluoroquinolone (FQ) use and failure (HR, 0.62; 95% CI, .31–1.24; P = .172).

Conclusions

The duration of initial IV antibiotic therapy did not correlate with treatment failure in this cohort of patients. Rifampin use is recommended for staphylococcal knee PJI. There was no apparent benefit of FQ use in staphylococcal PJI.

Periprosthetic Knee Infection - Part 2: Treatment

Several treatment modalities are proposed for periprosthetic infections, with variable success rates. However, efficacy is related to the appropriate selection of cases for each type of treatment.

Debridement with implant retention is indicated in acute infections with fixed implant, and its success depends on the type of infection, comorbidities of the host, and virulence of the etiological agent.

One- or two-stage revision is required in cases in which biofilm is forming, or of implant loosening. The choice between performing the review in one or two stages depends on factors such as etiological agent identification, pathogen virulence, local and systemic host factors.

Rescue procedures such as arthrodesis, amputation, resection arthroplasty or even antibiotic suppression are reserved for cases in which the infection has not been eradicated.

Intra-articular versus systemic vancomycin for the treatment of periprosthetic joint infection after debridement and spacer implantation in a rat model

Aims

Treatment outcomes for methicillin-resistant Staphylococcus aureus (MRSA) periprosthetic joint infection (PJI) using systemic vancomycin and antibacterial cement spacers during two-stage revision arthroplasty remain unsatisfactory. This study explored the efficacy and safety of intra-articular vancomycin injections for PJI control after debridement and cement spacer implantation in a rat model.

Methods

Total knee arthroplasty (TKA), MRSA inoculation, debridement, and vancomycin-spacer implantation were performed successively in rats to mimic first-stage PJI during the two-stage revision arthroplasty procedure. Vancomycin was administered intraperitoneally or intra-articularly for two weeks to control the infection after debridement and spacer implantation.

Results

Rats receiving intra-articular vancomycin showed the best outcomes among the four treatment groups, with negative bacterial cultures, increased weight gain, increased capacity for weightbearing activities, increased residual bone volume preservation, and reduced inflammatory reactions in the joint tissues, indicating MRSA eradication in the knee. The vancomycin-spacer and/or systemic vancomycin failed to eliminate the MRSA infections following a two-week antibiotic course. Serum vancomycin levels did not reach nephrotoxic levels in any group. Mild renal histopathological changes, without changes in serum creatinine levels, were observed in the intraperitoneal vancomycin group compared with the intra-articular vancomycin group, but no changes in hepatic structure or serum alanine aminotransferase or aspartate aminotransferase levels were observed. No local complications were observed, such as sinus tract or non-healing surgical incisions.

Conclusion

Intra-articular vancomycin injection was effective and safe for PJI control following debridement and spacer implantation in a rat model during two-stage revision arthroplasties, with better outcomes than systemic vancomycin administration.

Cite this article: Bone Joint Res 2022;11(6):371–385.

Outcomes of Debridement, Antibiotics and Implant Retention (DAIR) for Periprosthetic Joint Infection in a High-Volume Arthroplasty Centre

PURPOSE

Prosthetic joint infection (PJI) following total knee arthroplasty (TKA) and total hip arthroplasty (THA) can be a devastating diagnosis. Debridement, antibiotics and implant retention (DAIR) is a preferred treatment modality for acute PJI. A retrospective analysis of infected primary arthroplasties to evaluate the success of DAIR and factors influencing its outcomes.

METHODS

We retrospectively reviewed all patients who underwent DAIR for PJI at our unit between 2010 and 2018. Patients who underwent revision surgery as an index procedure, arthroscopic washout and those with less than two years of follow-up were excluded. Treatment failure was defined as revision arthroplasty for recurrence of infection within 2 years of the index procedure. Chi-square and Fischer's exact test were used to compare between patient factors and DAIR outcomes. Kaplan-Meier survival curve and log-rank test were used to analyse implant survivorship following DAIR.

RESULTS

Of the sixty patients (40 knees, 20 hips) who underwent DAIR, eighteen (13 knees, 5 hips) required revision arthroplasty within 2 years accounting for a success rate of 70%. Predictive factors for revision were American Society of Anaesthesiologist (ASA) score of greater than 2 (p = 0.021), BMI > 35 (p = 0.046), C Reactive protein (CRP) > 200 mg/L (p = 0.007) and Staphylococcus aureus growth (p = 0.012). The five-year survival rate for DAIR was 70%, which remained constant after two years from DAIR.

CONCLUSION

Success rate of DAIR in PJI was 70% which was comparable to similar studies in the literature. ASA > 2, BMI > 35, CRP > 200 and staphylococcus aureus growth were predictors for DAIR failure. Implant survival rate and duration were better following DAIR in early-onset PJI.

Serum and Synovial Markers in Patients with Rheumatoid Arthritis and Periprosthetic Joint Infection

Current diagnostic standards for PJI rely on inflammatory markers that are typically elevated in autoimmune diseases, thus making the diagnosis of PJI in patients with rheumatoid arthritis and joint replacement particularly complicated. There is a paucity of data on differentiating PJI from rheumatoid arthritis in patients with previous arthroplasty. In this study, we retrospectively analyzed the cases of 17 patients with rheumatoid arthritis and 121 patients without rheumatoid disease who underwent surgical intervention due to microbiology-positive PJI of the hip or knee joint. We assessed clinical patient characteristics, laboratory parameters, and prosthesis survival rates in patients with and without rheumatoid arthritis and acute or chronic PJI. ROC analysis was conducted for the analyzed parameters. In patients with chronic PJI, peripheral blood CRP (p = 0.05, AUC = 0.71), synovial WBC count (p = 0.02, AUC = 0.78), synovial monocyte cell count (p = 0.04, AUC = 0.75), and synovial PMN cell count (p = 0.02, AUC = 0.80) were significantly elevated in patients with rheumatoid arthritis showing acceptable to excellent discrimination. All analyzed parameters showed no significant differences and poor discrimination for patients with acute PJI. Median prosthesis survival time was significantly shorter in patients with rheumatoid arthritis (p = 0.05). In conclusion, routinely used laboratory markers have limited utility in distinguishing acute PJI in rheumatoid patients. In cases with suspected chronic PJI but low levels of serum CRP and synovial cell markers, physicians should consider the possibility of activated autoimmune arthritis.

Debridement and implant retention in acute hematogenous periprosthetic joint infection after knee arthroplasty: a systematic review

Debridement, antibiotic, and implant retention (DAIR) can be used as a first surgical procedure for acute infections in patients who have well-fixed components. However, its use in hematogenous or late acute infections is still debated. This systematic review of literature aims to clarify the effectiveness of DAIR procedure in the treatment of hematogenous periprosthetic knee infections. DAIR is an effective way to treat acute hematogenous PJIs of the knee and reaches its best efficacy when performed within one week from the onset of symptoms, modular components are exchanged, and a pathogen-oriented antibiotic therapy can be set. It is safe, economic, and effective technique, but has to be performed in a very narrow temporal window.

Can "domino" therapy effectively treat the infection around the prosthesis after the limb salvage surgery of bone tumor? - A study of sequential therapy

BACKGROUND

Tumor resection and prosthetic replacement have become the treatments of choice for malignant bone tumors. Infections are the leading cause of failure of limb salvage surgeries. Therefore, treating infections around prostheses after limb salvage is essential and challenging. Our research team designed a "domino" sequential treatment plan to treat postoperative infections around tumor prostheses and evaluated its efficacy.

PURPOSE

To introduce the new domino sequential treatment plan for postoperative infections of tumor prostheses, and evaluate the technical points of the plan and prognosis in medium- and long-term follow-ups.

METHODS

Between January 2015 and August 2021, 14 patients were treated with prosthesis-preserving domino sequential therapy for peripheral prosthesis infections after bone-tumor limb salvage. The sample included eight cases of distal femur tumor, two of proximal tibia tumor, three of pelvic tumor, and one of middle femur tumor. We evaluated routine blood test results, C-reactive protein level, the erythrocyte sedimentation rate, and other indicators. X-rays and CT scans of the surgical site were obtained and the Musculoskeletal Tumor Society (MSTS) score was calculated. Treatment involved debridement and lavage of the prosthesis, and systemic and local antibiotics.

RESULTS

The positivity rate of microbial culture was 78.6%. There were three cases of Staphylococcus aureus, one of Staphylococcus epidermidis, two of methicillin-resistant Staphylococcus epidermidis, one of methicillin-resistant Staphylococcus aureus, two of Acinetobacter baumannii, one of Streptococcus lactis (group C), one of Streptococcus mitis, and three with negative cultures. In three cases, sequential treatment failed to control the infection. The operation success rate was 78.6% (11/14). One case eventually required amputation, and another required long-term wound dressings. To control the infection, a third had to be treated using antibiotic bone cement combined with the "intramedullary nail reverse double insertion" technique. The MSTS scores of patients before infection debridement and at the last follow-up showed statistically significant differences (t = 5.312, p = 0.02).

CONCLUSIONS

The prosthesis-preserving domino sequential method has certain advantages for treating bone-tumor limb salvage infections around the prosthesis.

LEVEL OF EVIDENCE

Level IV, therapeutic.

Debridement, antibiotics, and implant retention after revision arthroplasty : antibiotic mismatch, timing, and repeated DAIR associated with poor outcome

AIMS

Debridement, antibiotics, and implant retention (DAIR) is a widely accepted form of surgical treatment for patients with an early periprosthetic joint infection (PJI) after primary arthroplasty. The outcome of DAIR after revision arthroplasty, however, has not been reported. The aim of this study was to report the success rate of DAIR after revision arthroplasty with a follow-up of two years.

METHODS

This retrospective study, conducted at the Sint Maartenskliniek, Nijmegen, the Netherlands, included 88 patients who underwent DAIR within 90 days of revision total hip or total knee arthroplasty between 2012 and 2019. Details of the surgical procedures and PJI were collected. Univariate analysis and a subgroup analysis of the culture-positive group were performed. Kaplan-Meier survivorship curves were constructed.

RESULTS

The overall success rate of DAIR, with respect to the retention of components and the cure of infection, was 68% after two years. DAIR performed with an interval of > 30 days after the index revision procedure (odds ratio (OR) 0.24 (95% confidence interval (CI) 0.08 to 0.72); p = 0.008), a repeated DAIR within 90 days (OR 0.37 (95% CI 0.14 to 0.97); p = 0.040), and the use of an immunosuppressive agent (OR 0.13 (95% CI 0.02 to 0.67); p = 0.012) were associated with a significantly reduced success rate. In the culture-positive group, a mismatch between the antibiotic treatment and the susceptibility of the organism was associated with a significantly lower success rate (OR 0.13 (95% CI 0.03 to 0.62); p = 0.007).

CONCLUSION

DAIR is an acceptable form of surgical treatment for patients with a suspected early PJI after revision arthroplasty of the hip or knee. DAIRs performed after a prolonged interval, multiple DAIRs, and antibiotic mismatches were significantly associated with an increased risk of failure. Optimization of the host immune response and the prevention of antibiotic mismatch are modifiable factors that may improve the outcome. The high rate of mismatches was an important finding, underlining the need for a review of the local microbiological data, which might improve the outcome. Cite this article: Bone Joint J 2022;104-B(4):464-471.