Culture-Negative Periprosthetic Joint Infection: An Update on What to Expect

Performance characteristics of genus or species-specific Polymerase Chain Reaction (PCR) for the microbial diagnosis of joint infections: A systematic review and meta-analysis

Joint infections cause significant morbidity and mortality. Rapid diagnosis enables prompt initiation of appropriate antimicrobial therapy and surgical treatment. We conducted a systematic review and meta-analysis to evaluate the accuracy of genus- or species-specific polymerase chain reaction (PCR) in diagnosing joint infections. The literature databases were searched for articles from January 2010 to December 2022. The meta-analysis using the split component synthesis (SCS) method, included 20 studies with 2,457 adult participants. The pooled sensitivity, specificity, diagnostic odds ratio, and AUC of PCR were 49 % (95 % CI [37.9-60.2]), 95.7 % (95 % CI [91.6-97.8]), 21.32, and 0.82 respectively. Sensitivity was highest for sonicate fluid and lowest for periprosthetic tissue. The mean turnaround time to results was 4.7 hours (SD 1.1). PCR is a favourable option for diagnosing joint infections due to its rapid results, but it has low sensitivity. To enhance diagnostic yield, the test should be used in conjunction with other methods.

Detection of rare microorganisms in bone and joint infections by metagenomic next-generation sequencing

Aims

This aim of this study was to analyze the detection rate of rare pathogens in bone and joint infections (BJIs) using metagenomic next-generation sequencing (mNGS), and the impact of mNGS on clinical diagnosis and treatment.

Methods

A retrospective analysis was conducted on 235 patients with BJIs who were treated at our hospital between January 2015 and December 2021. Patients were divided into the no-mNGS group (microbial culture only) and the mNGS group (mNGS testing and microbial culture) based on whether mNGS testing was used or not.

Results

A total of 147 patients were included in the no-mNGS group and 88 in the mNGS group. The mNGS group had a higher detection rate of rare pathogens than the no-mNGS group (21.6% vs 10.2%, p = 0.016). However, the mNGS group had lower rates of antibiotic-related complications, shorter hospital stays, and higher infection control rates compared with the no-mNGS group (p = 0.017, p = 0.003, and p = 0.028, respectively), while there was no significant difference in the duration of antibiotic use (p = 0.957). In culture-negative cases, the mNGS group had lower rates of antibiotic-related complications, shorter hospital stays, and a higher infection control rate than the no-mNGS group (p = 0.036, p = 0.033, p = 0.022, respectively), while there was no significant difference in the duration of antibiotic use (p = 0.748).

Conclusion

mNGS improves detection of rare pathogens in BJIs. mNGS testing reduces antibiotic-related complications, shortens hospital stay and antibiotic use duration, and improves treatment success rate, benefits which are particularly evident in culture-negative cases.

The role of BioFire Joint Infection Panel in diagnosing periprosthetic hip and knee joint infections in patients with unclear conventional microbiological results

Aims

This study aimed to evaluate the BioFire Joint Infection (JI) Panel in cases of hip and knee periprosthetic joint infection (PJI) where conventional microbiology is unclear, and to assess its role as a complementary intraoperative diagnostic tool.

Methods

Five groups representing common microbiological scenarios in hip and knee revision arthroplasty were selected from our arthroplasty registry, prospectively maintained PJI databases, and biobank: 1) unexpected-negative cultures (UNCs), 2) unexpected-positive cultures (UPCs), 3) single-positive intraoperative cultures (SPCs), and 4) clearly septic and 5) aseptic cases. In total, 268 archived synovial fluid samples from 195 patients who underwent acute/chronic revision total hip or knee arthroplasty were included. Cases were classified according to the International Consensus Meeting 2018 criteria. JI panel evaluation of synovial fluid was performed, and the results were compared with cultures.

Results

The JI panel detected microorganisms in 7/48 (14.5%) and 15/67 (22.4%) cases related to UNCs and SPCs, respectively, but not in cases of UPCs. The correlation between JI panel detection and infection classification criteria for early/late acute and chronic PJI was 46.6%, 73%, and 40%, respectively. Overall, the JI panel identified 12.6% additional microorganisms and three new species. The JI panel pathogen identification showed a sensitivity and specificity of 41.4% (95% confidence interval (CI) 33.7 to 49.5) and 91.1% (95% CI 84.7 to 94.9), respectively. In total, 19/195 (9.7%) could have been managed differently and more accurately upon JI panel evaluation.

Conclusion

Despite its microbial limitation, JI panel demonstrated clinical usefulness by complementing the traditional methods based on multiple cultures, particularly in PJI with unclear microbiological results.

The Impact of Culture Negativity on the Outcomes of Revision Total Knee Arthroplasty for Chronic PJI

Culture-positive (CP) and culture-negative (CN) periprosthetic joint infections (PJI) remain a crucial area of research; however, current studies comparing these infections rely on unstandardized outcome reporting tools. Our study aimed to compare the outcomes of two-stage revision of CP and CN PJI using the standardized Musculoskeletal Infection Society (MSIS) outcome reporting tool. We retrospectively reviewed 138 patients who were diagnosed with PJI and indicated for two-stage revision total knee arthroplasty (rTKA). The majority of patients in both CP and CN cohorts achieved infection control without the need for reoperation (54.1% and 62.5%, respectively). There was a significant difference in the overall distribution of MSIS outcomes (p = 0.043), with a significantly greater rate of CN patients falling into Tier 1 (infection control without the use of suppressive antibiotics) (52.5% versus 29.6%, p = 0.011). There was also a significant difference in the distribution of septic versus aseptic reoperations after 2nd stage (p = 0.013), with more CP reoperations being septic and more CN reoperations being aseptic. The duration from first to second stage was significantly shorter in the CN cohort (p = 0.002). While overall infection control was similar between cohorts, these data suggest that the outcomes of two-stage rTKA are favorable in cases of CN PJI.

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.

Modern Microbiological Methods to Detect Biofilm Formation in Orthopedy and Suggestions for Antibiotic Therapy, with Particular Emphasis on Prosthetic Joint Infection (PJI)

Biofilm formation is a serious problem that relatively often causes complications in orthopedic surgery. Biofilm-forming pathogens invade implanted foreign bodies and surrounding tissues. Such a condition, if not limited at the appropriate time, often requires reoperation. This can be partially prevented by selecting an appropriate prosthesis material that prevents the development of biofilm. There are many modern techniques available to detect the formed biofilm. By applying them we can identify and visualize biofilm-forming microorganisms. The most common etiological factors associated with biofilms in orthopedics are: Staphylococcus aureus, coagulase-negative Staphylococci (CoNS), and Enterococcus spp., whereas Gram-negative bacilli and Candida spp. also deserve attention. It seems crucial, for therapeutic success, to eradicate the microorganisms able to form biofilm after the implantation of endoprostheses. Planning the effective targeted antimicrobial treatment of postoperative infections requires accurate identification of the microorganism responsible for the complications of the procedure. The modern microbiological testing techniques described in this article show the diagnostic options that can be followed to enable the implementation of effective treatment.

Practical Guidance for Clinical Microbiology Laboratories: Microbiologic diagnosis of implant-associated infections

SUMMARYImplant-associated infections (IAIs) pose serious threats to patients and can be associated with significant morbidity and mortality. These infections may be difficult to diagnose due, in part, to biofilm formation on device surfaces, and because even when microbes are found, their clinical significance may be unclear. Despite recent advances in laboratory testing, IAIs remain a diagnostic challenge. From a therapeutic standpoint, many IAIs currently require device removal and prolonged courses of antimicrobial therapy to effect a cure. Therefore, making an accurate diagnosis, defining both the presence of infection and the involved microorganisms, is paramount. The sensitivity of standard microbial culture for IAI diagnosis varies depending on the type of IAI, the specimen analyzed, and the culture technique(s) used. Although IAI-specific culture-based diagnostics have been described, the challenge of culture-negative IAIs remains. Given this, molecular assays, including both nucleic acid amplification tests and next-generation sequencing-based assays, have been used. In this review, an overview of these challenging infections is presented, as well as an approach to their diagnosis from a microbiologic perspective.

Investigation of the pathogen-specific antibody response in periprosthetic joint infection

PURPOSE

Periprosthetic joint infections (PJIs) are a very demanding complication of arthroplasty. Diagnosis of PJI and pathogen identification pose considerable challenges in clinical practice. We hypothesized that the pathogen-specific immune response to PJI reflects the infection process, provides clinically relevant information on disease course, and has the potential to further optimize antimicrobial therapy.

METHODS

We conducted a prospective matched cohort pilot study with 13 patients undergoing two-stage septic revision arthroplasty (PJI patients) between 06/2020 and 06/2021, as well as 11 control patients undergoing one-stage aseptic revision arthroplasty (Non-PJI patients). Pre-, intra- and postoperative serum samples were collected at standardized time points. We developed a custom Luminex®-based quantitative bead-based suspension array (Infection Array; IA), and used it for simultaneous measurement of antibody specificities against 32 pathogens commonly associated with PJI in 267 serum samples.

RESULTS

The IA was able to trace the dynamics of the pathogen-specific humoral immune response in all patients against PJI-related pathogens, prominently coagulase-negative staphylococci and streptococci. Pathogen-specific serum antibody titers declined in 62% of PJI patients over the course of treatment, while no changes in antibody titers were observed in 82% of Non-PJI patients during this study. Our serological data strongly suggested that antibody signatures reflect an immune response to microbial invasion.

CONCLUSION

Our results provide insights into the pathophysiology of PJI and information on the individual disease courses. The IA is therefore a promising and novel serological tool of high resolution for monitoring the immunoproteomic footprints of infectious pathogens in the course of PJI.

Development of an automated amplicon-based next-generation sequencing pipeline for rapid detection of bacteria and fungi directly from clinical specimens

The timely identification of microbial pathogens is essential to guide targeted antimicrobial therapy and ultimately, successful treatment of an infection. However, the yield of standard microbiology testing (SMT) is directly related to the duration of antecedent antimicrobial therapy as SMT culture methods are dependent on the recovery of viable organisms, the fastidious nature of certain pathogens, and other pre-analytic factors. In the last decade, metagenomic next-generation sequencing (mNGS) has been successfully utilized as a diagnostic tool for various applications within the clinical laboratory. However, mNGS is resource, time, and labor-intensive-requiring extensive laborious preliminary benchwork, followed by complex bioinformatic analysis. We aimed to address these shortcomings by developing a largely Automated targeted Metagenomic next-generation sequencing (tmNGS) PipeLine for rapId inFectIous disEase Diagnosis (AMPLIFIED) to detect bacteria and fungi directly from clinical specimens. Therefore, AMPLIFIED may serve as an adjunctive approach to complement SMT. This tmNGS pipeline requires less than 1 hour of hands-on time before sequencing and less than 2 hours of total processing time, including bioinformatic analysis. We performed tmNGS on 50 clinical specimens with concomitant cultures to assess feasibility and performance in the hospital laboratory. Of the 50 specimens, 34 (68%) were from true clinical infections. Specimens from cases of true infection were more often tmNGS positive compared to those from the non-infected group (82.4% vs 43.8%, respectively, P = 0.0087). Overall, the clinical sensitivity of AMPLIFIED was 54.6% with 85.7% specificity, equating to 70.6% and 75% negative and positive predictive values, respectively. AMPLIFIED represents a rapid supplementary approach to SMT; the typical time from specimen receipt to identification of potential pathogens by AMPLIFIED is roughly 24 hours which is markedly faster than the days, weeks, and months required to recover bacterial, fungal, and mycobacterial pathogens by culture, respectively.

IMPORTANCE

To our knowledge, this represents the first application of an automated sequencing and bioinformatics pipeline in an exclusively pediatric population. Next-generation sequencing is time-consuming, labor-intensive, and requires experienced personnel; perhaps contributing to hesitancy among clinical laboratories to adopt such a test. Here, we report a strong case for use by removing these barriers through near-total automation of our sequencing pipeline.

Two-stage revision for periprosthetic joint infection after hip and knee arthroplasty

Aims

Histology is widely used for diagnosis of persistent infection during reimplantation in two-stage revision hip and knee arthroplasty, although data on its utility remain scarce. Therefore, this study aims to assess the predictive value of permanent sections at reimplantation in relation to reinfection risk, and to compare results of permanent and frozen sections.

Methods

We retrospectively collected data from 226 patients (90 hips, 136 knees) with periprosthetic joint infection who underwent two-stage revision between August 2011 and September 2021, with a minimum follow-up of one year. Histology was assessed via the SLIM classification. First, we analyzed whether patients with positive permanent sections at reimplantation had higher reinfection rates than patients with negative histology. Further, we compared permanent and frozen section results, and assessed the influence of anatomical regions (knee versus hip), low- versus high-grade infections, as well as first revision versus multiple prior revisions on the histological result at reimplantation. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), chi-squared tests, and Kaplan-Meier estimates were calculated.

Results

Overall, the reinfection rate was 18%. A total of 14 out of 82 patients (17%) with positive permanent sections at reimplantation experienced reinfection, compared to 26 of 144 patients (18%) with negative results (p = 0.996). Neither permanent sections nor fresh frozen sections were significantly associated with reinfection, with a sensitivity of 0.35, specificity of 0.63, PPV of 0.17, NPV of 0.81, and accuracy of 58%. Histology was not significantly associated with reinfection or survival time for any of the analyzed sub-groups. Permanent and frozen section results were in agreement for 91% of cases.

Conclusion

Permanent and fresh frozen sections at reimplantation in two-stage revision do not serve as a reliable predictor for reinfection.

Efficacy and safety of two-stage revision for patients with culture-negative versus culture-positive periprosthetic joint infection: a single-center retrospective study

BACKGROUND

The safety and efficacy of two-stage revision for culture-negative PJI remain controversial. This study analyzed outcomes after two-stage revision in patients with culture-negative and culture-positive periprosthetic joint infection (PJI) during follow-up lasting at least two years.

METHODS

Data were retrospectively analysed patients who underwent hip or knee revision arthroplasty from January 2008 to October 2020 at our medical center. The primary outcome was the re-revision rate, while secondary outcomes were the rates of reinfection, readmission, and mortality. Patients with culture-negative or culture-positive PJI were compared in terms of these outcomes, as well as survival time without reinfection or revision surgery, based on Kaplan‒Meier analysis.

RESULTS

The final analysis included 87 patients who were followed up for a mean of 72.3 months (range, 24-123 months). The mean age was 58.1 years in the culture-negative group (n = 24) and 59.1 years in the culture-positive group (n = 63). The two groups (culture-negative versus culture-positive) did not differ significantly in rates of re-revision (0.0% vs. 3.2%, p > 0.05), reinfection (4.2% vs. 3.2%, p > 0.05), readmission (8.4% vs. 8.0%, p > 0.05), or mortality (8.3% vs. 7.9%, p > 0.05). They were also similar in survival rates without infection-related complications or revision surgery at 100 months (91.5% in the culture-negative group vs. 87.9% in the culture-positive group; Mantel‒Cox log-rank χ2 = 0.251, p = 0.616).

CONCLUSION

The two-stage revision proves to be a well-tolerated and effective procedure in both culture-negative and culture-positive PJI during mid to long-term follow-up.

Dogs can detect an odor profile associated with Staphylococcus aureus biofilms in cultures and biological samples

Introduction

The study investigated the utilization of odor detection dogs to identify the odor profile of Staphylococcus aureus (S. aureus) biofilms in pure in vitro samples and in in vivo biosamples from animals and humans with S. aureus periprosthetic joint infection (PJI). Biofilms form when bacterial communities aggregate on orthopedic implants leading to recalcitrant infections that are difficult to treat. Identifying PJI biofilm infections is challenging, and traditional microbiological cultures may yield negative results even in the presence of clinical signs.

Methods

Dogs were trained on pure in vitro S. aureus biofilms and tested on lacrimal fluid samples from an in vivo animal model (rabbits) and human patients with confirmed S. aureus PJI.

Results

The results demonstrated that dogs achieved a high degree of sensitivity and specificity in detecting the odor profile associated with S. aureus biofilms in rabbit samples. Preliminary results suggest that dogs can recognize S. aureus volatile organic compounds (VOCs) in human lacrimal fluid samples.

Discussion

Training odor detection dogs on in vitro S. aureus, may provide an alternative to obtaining clinical samples for training and mitigates biosecurity hazards. The findings hold promise for culture-independent diagnostics, enabling early disease detection, and improved antimicrobial stewardship. In conclusion, this research demonstrates that dogs trained on in vitro S. aureus samples can identify the consistent VOC profile of PJI S. aureus biofilm infections. The study opens avenues for further investigations into a retained VOC profile of S. aureus biofilm infection. These advancements could revolutionize infectious disease diagnosis and treatment, leading to better patient outcomes and addressing the global challenge of antimicrobial resistance.

Outcomes of culture-negative or -positive periprosthetic joint infections: A systematic review and meta-analysis

OBJECTIVES

This study overviewed the current database of studies on periprosthetic joint infections (PJIs) to compare outcomes and antibiotic side effects in culture-negative or culture-positive PJIs and assess treatment options for culture-negative PJIs.

PATIENTS AND METHODS

A systematic review and meta-analysis was undertaken using studies published before July 2022 in MEDLINE, EMBASE, and Cochrane Library. All studies comparing treatment of culture-negative or -positive PJIs were included. Afterward, the infection control rate, periprosthetic or spacer fracture, hip joint or spacer dislocation, and antibiotic side effects in different treatment methods of PJI were analyzed.

RESULTS

Eleven studies involving 1,747 patients were included. Most studies clearly defined the infection control criteria: no pain or swelling, no wound drainage, normal serology, and normal radiographic findings. Patients were followed until treatment failure, death, or until the last clinical visit without evidence of treatment failure. The two types of PJIs did not differ significantly in infection control rates (culture-negative PJI 79.2% vs. culture-positive PJI 76.6%; odds ratio [OR]=1.20, 95% confidence interval [CI]: 0.84 to 1.70), either after all types of surgical treatment or after two-stage revision arthroplasty (OR=1.12, 95% CI: 0.72 to 1.75), single-stage revision arthroplasty (OR=0.51, 95% CI: 0.19 to 1.37), or debridement, antibiotics, and implant retention (OR=0.88, 95% CI: 0.50 to 1.54). Similarly, we did not find differences in periprosthetic or spacer fracture and hip joint or spacer dislocation. For culture-negative PJIs, the infection control rate was 85.2% after two-stage revision arthroplasty, 90.6% after single-stage revision arthroplasty, and 69.7% after debridement, antibiotics, and implant retention. Data pooled from three studies showed higher incidence of antibiotic side effects for culture-negative PJIs.

CONCLUSION

The clinical outcomes of one-stage revision and two-stage revision are comparable. Therefore, both of them can be considered in surgical treatment for culture-negative PJIs. In addition, limited data showed a higher incidence of antibiotic side effects in culture-negative PJIs.

Arthrofibrosis After Total Knee Arthroplasty: A Critical Analysis Review

» Arthrofibrosis after total knee arthroplasty (TKA) is the new formation of excessive scar tissue that results in limited ROM, pain, and functional deficits.» The diagnosis of arthrofibrosis is based on the patient's history, clinical examination, absence of alternative diagnoses from diagnostic testing, and operative findings. Imaging is helpful in ruling out specific causes of stiffness after TKA. A biopsy is not indicated, and no biomarkers of arthrofibrosis exist.» Arthrofibrosis pathophysiology is multifactorial and related to aberrant activation and proliferation of myofibroblasts that primarily deposit type I collagen in response to a proinflammatory environment. Transforming growth factor-beta signaling is the best established pathway involved in arthrofibrosis after TKA.» Management includes both nonoperative and operative modalities. Physical therapy is most used while revision arthroplasty is typically reserved as a last resort. Additional investigation into specific pathophysiologic mechanisms can better inform targeted therapeutics.

Periprosthetic Joint Infection Diagnosis: A Narrative Review

Replacement of native joints aims to restore patients' quality of life by relieving pain and improving joint function. While periprosthetic joint infection (PJI) affects a small percentage of patients, with an estimated incidence of 1-9% following primary total joint replacement, this postoperative complication necessitates a lengthy hospitalisation, extended antibiotic treatment and further surgery. It is highlighted that establishing the correct diagnosis of periprosthetic infections is critical in order for clinicians to avoid unnecessary treatments in patients with aseptic failure. Of note, the PJI diagnosis could not purely rely upon clinical manifestations given the fact that heterogeneity in host factors (e.g., age and comorbidities), variability in infection period, difference in anatomical location of the involved joint and discrepancies in pathogenicity/virulence of the causative organisms may confound the clinical picture. Furthermore, intra-operative contamination is considered to be the main culprit that can result in early or delayed infection, with the hematogenous spread being the most prevalent mode. To elaborate, early and hematogenous infections often start suddenly, whereas chronic late infections are induced by less virulent bacteria and tend to manifest in a more quiescent manner. Last but not least, viruses and fungal microorganisms exert a role in PJI pathogenesis.

Borrelia burgdorferi-A Bacterium Worthy of Consideration in Culture-Negative Prosthetic Joint Infection

A 68-year-old woman presented to the orthopaedic office with 2 weeks of atraumatic right prosthetic knee pain and swelling. She previously lived pain free and fully functional after a total knee arthroplasty 8 years ago. Initial radiographs showed a small joint effusion, and serum inflammatory markers were elevated. Arthrocentesis yielded 12ccs of culture-negative cloudy serous fluid containing 3,270 white blood cells, 92% polymorphonuclear neutrophils. The patient underwent prosthesis explant, antibiotic spacer placement, and began empiric IV antibiotic therapy as stage one of a planned two-stage revision. Intraoperative tissue cultures were negative, and the postoperative plan was to continue IV vancomycin for a total of 6 weeks. Two weeks post-op, serum Lyme antibody testing returned positive. The patient was switched to doxycycline and ceftriaxone for a total duration of 4 weeks, followed by a successful second-stage revision and remains asymptomatic after 1 year. Five cases of culture-negative prosthetic joint infections caused by the spirochete, Borrelia burgdorferi, have been reported in the orthopaedic literature.1-4 We present a sixth case, occurring in a 68-year-old woman in Northwestern Pennsylvania, 8 years after a primary right total knee arthroplasty.

Higher sensitivity and accuracy of synovial next-generation sequencing in comparison to culture in diagnosing periprosthetic joint infection: a systematic review and meta-analysis

PURPOSE

The purpose of this meta-analysis was to compare the diagnostic parameters of synovial next-generation sequencing (NGS) and cultures in diagnosing periprosthetic joint infections (PJI).

METHODS

PubMed, Web of Science, Cochrane, and Google Scholar were searched from inception until 8 Jan 2022 for literature investigating the role of NGS in comparison to culture in the diagnosis of PJI. The studies were included if they investigated the diagnostic value of culture and NGS in diagnosing PJIs against the Musculoskeletal Infection Society (MSIS) criteria. Diagnostic parameters, such as sensitivity, specificity, positive predictive value, negative predictive value, positive-likelihood ratio, negative-likelihood ratio, accuracy, and area under the curve (AUC), were calculated for the included studies to evaluate the performance of NGS in comparison to culture in PJI diagnosis.

RESULTS

The total number of the included patients was 341 from seven articles. The pooled sensitivity, specificity, and diagnostic odds ratio of NGS were 94% (95% CI 91-97%), 89% (95% CI 82-95%), and 138.5 (95% CI 49.1-390.5), respectively. NGS has positive- and negative-likelihood ratios of 7.9 (95% CI 3.99-15.6) and 0.1 (95% CI 0.0-0.1), respectively. On the other hand, the pooled sensitivity, specificity, and diagnostic odds ratio of culture were 70% (95% CI 61-79%), 94% (95% CI 88-98%), and 28.0 (95% CI 12.6-62.2), respectively. The SROC curve for NGS showed that the accuracy (AUC) was 91.9%, and that the positive and negative predictive values were 8.6 (95% CI 5.0-19.5) and 0.1 (95% CI 0.0-0.1), respectively. While, culture SROC curve demonstrated that the accuracy (AUC) was 80.5% and the positive- and negative-likelihood ratio were 12.1 (95% CI 4.5-49.6) and 0.3 (95% CI 0.2-0.4).

CONCLUSIONS

NGS has a potential role in diagnosing hip and knee PJIs due to its high sensitivity, specificity, and accuracy. However, the sensitivity and specificity reported by the studies varied according to the time of synovial sampling (preoperative, postoperative, or mixed).

Prosthetic joint infection caused by an atypical gram-negative bacilli: Odoribactersplanchnicus

Prosthetic joint infection (PJI) is a devastating complication after total hip arthroplasty. Its management consists of both: a radical debridement and implant retention or exchange (depending on the timing of symptoms) and directed antibiotic therapy. Thus, the isolation of atypical microorganisms implies a challenge, where anaerobes are responsible for only 4% of cases. However, Odoribacter splanchnicus has not been reported as a cause of PJI yet. We present an 82 year-old woman who was diagnosed with hip PJI. A radical debridement, prosthetic withdrawal, and spacer introduction was performed. Despite the directed antibiotic therapy against E. coli which was first isolated, the patient persisted clinically febrile. An anaerobic Gram-negative rod was isolated and finally, Odoribacter splanchnicus was identified and confirmed by 16S rRNA gene sequencing. Then, antibiotic bitherapy with ciprofloxacin and metronidazole was started until 6 weeks after surgery. The patient had no signs of infection recurrence after then. This case report also shows the importance of genomic identification of rare microorganisms causing PJI, and also allows setting a directed antibiotic therapy which is crucial for infection eradication.

Microbiological Profile of Periprosthetic Knee Infections in a Brazilian Unified Health System Hospital Specialized in Highly Complex Orthopedic Surgeries

Objective  We studied the microbiological profile of periprosthetic knee infections treated in a Brazilian tertiary hospital. Methods  The study included all patients undergoing revision surgery for total knee arthroplasty (RTKA) between November 2019 and December 2021, with a diagnosis of periprosthetic infection confirmed per the 2018 International Consensus Meeting (ICM) criteria. Results  Sixty-two patients had a periprosthetic joint infection (PJI) per the 2018 ICM criteria. Cultures were monomicrobial in 79% and polymicrobial in 21% of cases. The most frequent bacterium in microbiological tissue and synovial fluid cultures was Staphylococcus aureus , observed in 26% of PJI patients. Periprosthetic joint infection with negative cultures occurred in 23% of patients. Conclusion  Our results show the following: i) a high prevalence of Staphylococcus as an etiological agent for knee PJI; ii) a high incidence of polymicrobial infections in early infections; iii) the occurrence of PJI with negative cultures in approximately one fourth of the subjects.

Clinical and Histological Features of Prosthetic Joint Infections May Differ in Patients With Inflammatory Arthritis and Osteoarthritis

Background: Patients with inflammatory arthritis are at increased risk of prosthetic joint infections (PJIs), but diagnosis in these patients can be challenging because active inflammatory arthritis produces elevated inflammatory markers that may mimic those seen in PJI. Purpose: In this pilot study, we sought to identify the clinical, microbiologic, and histopathologic features of culture-positive and culture-negative PJI in patients with inflammatory arthritis who underwent total hip arthroplasty (THA) or total knee arthroplasty (TKA). We also sought to obtain preliminary data to support a definitive study of optimal methods for PJI diagnosis in patients with inflammatory arthritis. Methods: We performed a retrospective analysis of TKA and THA patients treated for PJI from 2009 to 2018 at a single tertiary care orthopedic institution. Data were extracted from a longitudinally maintained hospital infection database. We reviewed hematoxylin and eosin slides of osteoarthritis and inflammatory arthritis PJI cases matched 3:1, respectively, by age, sex, and culture status. Clinical characteristics were evaluated using the Fisher exact test, χ² test, Student t test, and Mann-Whitney U test where appropriate. Results: A total of 807 PJI cases were identified (36 inflammatory arthritis and 771 osteoarthritis cases). Patients with inflammatory arthritis presented younger, had a higher Charlson Comorbidity Index, more frequently used glucocorticoids, were more likely women, and had a higher proportion of culture-negative PJI compared with osteoarthritis patients. Of the 88 inflammatory arthritis cases reviewed for histopathology, a higher proportion of culture-positive than culture-negative PJI cases had >10 polymorphonuclear leucocytes per high-power field and met Musculoskeletal Infection Society criteria but presented with less chronic inflammation. Conclusions: This retrospective prognostic study suggests that culture-negative PJI may be more frequent in patients with inflammatory arthritis than in those with osteoarthritis. Chronic infections, antibiotic use, or misdiagnosis may be contributing factors to unclear PJI diagnoses among culture-negative cases. This preliminary work supports the need for further studies to assess the differences in clinical features between culture-negative and culture-positive PJI in patients with inflammatory arthritis and the ability of biological diagnostic markers to discriminate between them in this population.

Metagenomic Next-Generation Sequencing for Periprosthetic Joint Infections

Periprosthetic joint infection (PJI) after arthroplasty is a major complication, which requires significant resources, resulting in high costs for the medical system. In recent years, significant progress has been made in the diagnosis and treatment of periprosthetic infections, the identification of the pathogen being the central element in the establishment of targeted antibiotic therapy. Next-generation sequencing (NGS) or metagenomic NGS (mNGS) represents a promising, fast alternative, with increased specificity and sensitivity compared to identification methods using conventional culture media, thus enabling an increased rate of identification of pathogenic microorganisms and antibiotic resistance genes (ARG). The purpose of this article was to highlight new molecular diagnostic methods for periprosthetic joint infections and their involvement in treatment efficiency. NGS technologies are cutting-edge techniques that may challenge the PJI diagnostic model.

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.

Microbial Persistence, Replacement and Local Antimicrobial Therapy in Recurrent Bone and Joint Infection

We report microbiological results from a cohort of recurrent bone and joint infection to define the contributions of microbial persistence or replacement. We also investigated for any association between local antibiotic treatment and emerging antimicrobial resistance. Microbiological cultures and antibiotic treatments were reviewed for 125 individuals with recurrent infection (prosthetic joint infection, fracture-related infection, and osteomyelitis) at two UK centres between 2007 and 2021. At re-operation, 48/125 (38.4%) individuals had an organism from the same bacterial species as at their initial operation for infection. In 49/125 (39.2%), only new species were isolated in culture. In 28/125 (22.4%), re-operative cultures were negative. The most commonly persistent species were Staphylococcus aureus (46.3%), coagulase-negative Staphylococci (50.0%), and Pseudomonas aeruginosa (50.0%). Gentamicin non-susceptible organisms were common, identified at index procedure in 51/125 (40.8%) and at re-operation in 40/125 (32%). Gentamicin non-susceptibility at re-operation was not associated with previous local aminoglycoside treatment (21/71 (29.8%) vs. 19/54 (35.2%); p = 0.6). Emergence of new aminoglycoside resistance at recurrence was uncommon and did not differ significantly between those with and without local aminoglycoside treatment (3/71 (4.2%) vs. 4/54 (7.4%); p = 0.7). Culture-based diagnostics identified microbial persistence and replacement at similar rates in patients who re-presented with infection. Treatment for orthopaedic infection with local antibiotics was not associated with the emergence of specific antimicrobial resistance.

Successful eradication rate following one-stage septic knee and hip exchange in selected pre-operative culture-negative periprosthetic joint infections

PURPOSE

The main requirement for performing the one-stage septic exchange is the pre-operative identification of the pathogen and its susceptibility. The purpose of this study is to evaluate the success rate with special focus on reinfection in a cohort of patients who underwent one-stage septic knee or hip revision for pre-operative culture-negative PJI.

METHODS

We retrospectively analyzed 640 patients treated by one-stage revision for chronic knee or hip PJI between January 1, 2016, and December 31, 2018. Only cases with pre-operative culture-negative PJI, with culture-negative synovial aspirations and one negative open biopsy, were analyzed. We evaluated the septic and aseptic complication and the rate of complication-free survival defined as the time from the date of first operation and the date of complication events.

RESULTS

A total of 22 patients fulfilled the inclusion and were enrolled. The mean age of the group was 73.2 ± 9.8 years, with a median ASA score of 3 (range 3-4). After mean follow-up of 3.6 ± 2.6 years, 86.4% (19 out of 22) of patients reported no complications. Two patients (9.1%) after one-stage hip required revision arthroplasty due to septic failure, while one patient (4.5%) with one-stage knee had revision for femoral component aseptic loosening.

CONCLUSION

Our analysis suggests that the absence of pre-operative pathogen detection may not be contraindication to the one-stage revision in selected patients. The one-stage exchange might be considered in patients with pre-operative negative cultures in presence of ASA > 3 and multiple comorbidities that are not able to tolerate multiple surgeries.

Application of Nucleic Acid-Based Strategies to Detect Infectious Pathogens in Orthopaedic Implant-Related Infection

➤

Implant-associated infection in orthopaedic surgery remains an enormous and largely unsolved clinical problem with a high rate of persistent or recurrent infection. This may be due, at least in part, to the potential for underdiagnosis by traditional microbial culture or the potential for culture to incompletely identify the microbial species present.

➤

Nucleic acid-based diagnostic techniques, focused on using the diagnostic information contained in DNA or RNA to identify microbial species, have been developing rapidly and have garnered escalating interest for both clinical and research applications.

➤

Commonly applied techniques include end-point polymerase chain reaction (PCR), quantitative PCR, Sanger sequencing, and next-generation sequencing. Understanding the specific strengths and weaknesses of each technique is critical to understanding their utility, applying the correct assessment strategy, and critically understanding and interpreting research.

➤

The best practices for interpreting nucleic acid-based diagnostic techniques include considering positive and negative controls, reads per sample, detection thresholds (for differentiating contaminants from positive results), and the primer set or targeted regions.

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.

Microbiological profiles and antibiotic resistance of periprosthetic joint infection after hip replacement in patients with fracture or non-fracture: A comparative study

BACKGROUND

Periprosthetic joint infection (PJI) is one of the worst complications following total joint arthroplasty (TJA). Unfortunately, effective prevention strategies to reduce the burden of PJI have not been fully determined in hip replacement patients with fracture and non-fracture.

OBJECTIVE

This study aimed to analyze and compare the demographic characteristics, microbiological profiles and antibiotic resistance of PJI after hip replacement between patients with fracture and non-fracture.

METHODS

We retrospectively analyzed the data of 132 patients who treated PJI. There were divided into two groups: non-fracture group (64 patients infected after hip replacement for fracture) and non-fracture group (68 patients infected after hip replacement for non-fracture). Microorganisms were obtained from the synovial fluid and infected necrotic tissue in the joint capsule, medullary cavity, or acetabulum in all patients, and microbiological profiles and antibiotic resistance were evaluated.

RESULTS

Coagulase-negative staphylococci (CoNS) were the most common pathogenic microorganisms in all patients. Methicillin-resistant Staphylococcus (MRS) accounted for 25% in all pathogenic microbes. Staphylococci showed high drug resistance rates to clindamycin, levofloxacin, and all of the first- and second-generation cephalosporins. MRS isolates in non-fracture group had higher drug resistance rates to clindamycin and levofloxacin than than those in fracture group. Gram-negative bacilli (GNB) showed high drug resistance rates to Aztreonam, gentamicin and all of the third- and fourth-generation cephalosporins. Furthermore, GNB isolates in the non-fracture group showed higher resistance rates to gentamicin and all of the third- and fourth-generation cephalosporins.

CONCLUSIONS

MRS isolates in the non-fracture group showed higher drug resistance rates to clindamycin and levofloxacin, and GNB isolates in non-fracture group showed higher drug resistance rates to gentamicin and all of the third- and fourth-generation cephalosporins.

C9 immunostaining as a tissue biomarker for periprosthetic joint infection diagnosis

Background

Culture-negative periprosthetic joint infections (PJI) are often false diagnosed as aseptic implant failure leading to unnecessary revision surgeries due to repeated infections. A marker to increase the security of e PJI diagnosis is therefore of great importance. The aim of this study was to test C9 immunostaining of periprosthetic tissue as a novel tissue-biomarker for a more reliable identification of PJI, as well as potential cross-reactivity.

Method

We included 98 patients in this study undergoing septic or aseptic revision surgeries. Standard microbiological diagnosis was performed in all cases for classification of patients. Serum parameters including C-reactive protein (CRP) serum levels and white blood cell (WBC) count were included, and the periprosthetic tissue was immunostained for C9 presence. The amount of C9 tissue staining was evaluated in septic versus aseptic tissue and the amount of C9 staining was correlated with the different pathogens causing the infection. To exclude cross-reactions between C9 immunostaining and other inflammatory joint conditions, we included tissue samples of a separate cohort with rheumatoid arthritis, wear particles and chondrocalcinosis.

Results

The microbiological diagnosis detected PJI in 58 patients; the remaining 40 patients were classified as aseptic. Serum CRP values were significantly increased in the PJI cohort. Serum WBC was not different between septic and aseptic cases. We found a significant increase in C9 immunostaining in the PJI periprosthetic tissue. To test the predictive value of C9 as biomarker for PJI we performed a ROC analyses. According to the Youden's criteria C9 is a very good biomarker for PJI detection with a sensitivity of 89% and a specificity of 75% and an AUC of 0.84. We did not observe a correlation of C9 staining with the pathogen causing the PJI. However, we observed a cross reactivity with the inflammatory joint disease like rheumatoid arthritis and different metal wear types. In addition, we did not observe a cross reactivity with chondrocalcinosis.

Conclusion

Our study identifies C9 as a potential tissue-biomarker for the identification of PJI using immunohistological staining of tissue biopsies. The use of C9 staining could help to reduce the number of false negative diagnoses of PJI.

Prosthetic Joint Infections of the Hip and Knee Among the Elderly: A Retrospective Study

BACKGROUND

As the population ages and demand for total joint arthroplasty increases, rates of periprosthetic joint infection are expected to increase in the geriatric population. Studies comparing prevalence of risk factors, etiology, management, and mortality of prosthetic joint infection in older patients are lacking.

METHODS

We compared clinical characteristics, management, and mortality of patients <75 vs ≥75 years of age with first prosthetic joint infection of the hip or knee admitted to a tertiary medical center between September 2017 and December 2019.

RESULTS

Ninety-eight patients (<75 years of age [n = 63]; ≥75 years of age (n = 35) were studied. Groups were similar in terms of etiology, culture-directed therapy, antibiotic suppression, and length of stay. There was no difference in surgical management, performed in almost 97% of cases in both groups. Arrhythmia and heart failure were more prevalent in those aged ≥75 years. Readmission related to prosthetic joint infection occurred less often in older individuals (P = .005). Deaths within 1 year of diagnosis were rare (n = 4; 4.1%), occurring in older patients and resulting mostly from sepsis.

CONCLUSION

In our single-center study, patients with first prosthetic joint infection had similar management, regardless of age. We identified cardiac history as one of the host factors for prosthetic joint infection most seen in patients ≥75 years of age. Although deaths were rare, 1-year mortality was higher in patients aged ≥75. Prospective, multicenter studies are needed to explore risk factors and management strategies of prosthetic joint infection among elderly populations.

Comparison of the BioFire Joint Infection Panel to 16S Ribosomal RNA Gene-Based Targeted Metagenomic Sequencing for Testing Synovial Fluid from Patients with Knee Arthroplasty Failure

The diagnosis of periprosthetic joint infection (PJI) is challenging, often requiring multiple clinical specimens and diagnostic techniques, some with prolonged result turnaround times. Here, the diagnostic performance of the Investigational Use Only (IUO) BioFire Joint Infection (JI) Panel was compared to 16S rRNA gene-based targeted metagenomic sequencing (tMGS) applied to synovial fluid for PJI diagnosis. Sixty synovial fluid samples from knee arthroplasty failure archived at -80°C were tested. Infectious Diseases Society of America (IDSA) diagnostic criteria were used to classify PJI. For culture-positive PJI with pathogens targeted by the JI panel, JI panel sensitivity was 91% (21/23; 95% confidence interval [CI], 73 to 98%), and tMGS sensitivity was 96% (23/24; 95% CI, 80 to 99%) (P = 0.56). Overall sensitivities of the JI panel and tMGS for PJI diagnosis were 56% (24/43; 95% CI, 41 to 70%) and 93% (41/44; 95% CI, 82 to 98%), respectively (P < 0.001). JI panel and tMGS overall specificities were 100% (16/16; 95% CI, 81 to 100%) and 94% (15/16; 95% CI, 72 to 99%), respectively. While the clinical sensitivity of the JI panel was excellent for on-panel microorganisms, overall sensitivity for PJI diagnosis was low due to the absence of Staphylococcus epidermidis, a common causative pathogen of PJI, on the panel. A PJI diagnostic algorithm for the use of both molecular tests is proposed.

Alpha-defensin as a diagnostic tool in revision total knee arthroplasties with unexpected positive intraoperative cultures and unexpected culture negative intraoperative cultures

PURPOSE

Unexpected-positive-intraoperative-cultures (UPIC) are common in presumed aseptic revision-total-knee-arthroplasties (rTKA). However, the clinical significance is not entirely clear. In contrast, in some presumably septic rTKA, identification of an underlying pathogen was not possible, so-called unexpected-negative-intraoperative-cultures (UNIC). The purpose of this study was to evaluate the potential use of synovial alpha-defensin (AD) levels in these patients.

METHODS

Synovial AD levels from 143 rTKAs were evaluated retrospectively from our prospectively maintained institutional periprostetic joint infection (PJI) biobank and database. The 2018-International Consensus Meeting (ICM) criteria was used to define the study groups. Samples from UPICs with a minimum of one positive intraoperative culture (ICM 2- ≥ 6) (n = 20) and UNIC's (ICM ≥ 6) (n = 14) were compared to 34 septic culture-positive samples (ICM ≥ 6) and 75 aseptic culture-negative (ICM 0-1). Moreover, AD-lateral-flow-assay (ADLF) and an enzyme-linked-immunosorbent-assay (ELISA) in detecting the presence of AD in native and centrifuged synovial fluid specimens was performed. Concentration of AD determined by ELISA and ADLF methods, as well as microbiological, and histopathological results, serum and synovial parameters along with demographic factors were analysed.

RESULTS

AD was positive in 31/34 (91.2%) samples from the septic culture-positive group and in 14/14 (100%) samples in the UNIC group. All UPIC samples showed a negative AD result. Positive AD samples were highly associated with culture positive and histopathological results (p < 0.001). No high-virulent microorganisms (0/20) were present in the UPIC group, compared to infected-group (19/34; 55.9%). High virulent microorganisms showed a positive AD result in 89.5% (17/19) of the cases. Methicillin resistant Staphylococcus epidermis (MRSE) infections had significantly higher AD levels than with methicillin susceptible S. epidermdis (MSSE) (p = 0.003). ELISA and ADLF tests were positive with centrifuged (8/8) and native (8/8) synovial fluid.

CONCLUSION

AD showed a solid diagnostic performance in infected and non-infected revisions, and it provided an additional value in the diagnosis of UPIC and UNIC associated to rTKAs. Pathogen virulence as well as antibiotic resistance pattern may have an effect on AD levels. Centrifugation of synovial fluid had no influence on ADLF results.

Cell-free Deoxyribonucleic Acid: A Potential Biomarker of Chronic Periprosthetic Knee Joint Infection

BACKGROUND

The correct diagnosis of a chronic periprosthetic joint infection (PJI) is a major challenge in clinical practice, with the "gold standard" for diagnosis yet to be established. Synovial fluid analysis has been proven to be a useful tool for that purpose. Cell-free DNA (cf-DNA) levels have been shown to be increased in several conditions such as cancer, trauma, and sepsis. Therefore, this study was designed to evaluate the potential of synovial fluid cf-DNA quantification for the diagnosis of chronic periprosthetic infections following total knee arthroplasty.

METHODS

A prospective study with patients undergoing total knee arthroplasty revision surgery for any indication was performed. PJI diagnosis was defined according to the Second International Consensus Meeting on Musculoskeletal Infection (2018) criteria. The study cohort consisted of 26 patients classified as infected and 40 as noninfected. Synovial fluid cf-DNA direct quantification by fluorescent staining was made. Sensitivity, specificity, and receiver operating characteristic curve were calculated.

RESULTS

The cf-DNA levels were significantly higher in patients who had PJIs (122.5 ± 57.2 versus 4.6 ± 2.8 ng/μL, P < .0001). With a cutoff of 15 ng/μL, the area under the receiver operating characteristic, sensitivity, and specificity of cf-DNA were 0.978, 96.2%, and 100%, respectively.

CONCLUSION

The present study has shown that cf-DNA is increased in synovial fluid of patients who have chronic PJIs. It is a promising biomarker for knee PJI diagnosis and further studies are needed to confirm its utility.

"Recommendations for periprosthetic joint infections (PJI) prevention: the European Knee Associates (EKA)-International Committee American Association of Hip and Knee Surgeons (AAHKS)-Arthroplasty Society in Asia (ASIA) survey of members"

PURPOSE

Periprosthetic joint infections (PJIs) represent a devastating consequence of total joint arthroplasty. The European Knee Associates (EKA), the American Association of Hip and Knee Surgeons (AAHKS) International Committee, and the Arthroplasty Society in Asia (ASIA) board members were interested in quantifying differences in arthroplasty surgeons' use of various PJI prevention measures to provide clinical recommendations to reduce PJI incidence.

METHODS

A prospective Microsoft Forms online survey was distributed among EKA, AAHKS International Committee, and ASIA members and their affiliated arthroplasty surgeons. The survey consisted of 20 single and multiple response questions focused on PJI prevention strategies at three perioperative periods: preoperatively, intraoperatively, and postoperatively.

RESULTS

Three hundred and ninety-four arthroplasty surgeons from 6 different continents completed the survey. Preoperative: (A) PJI Risk Stratification: 40.6% routinely set thresholds (e.g., BMI, HgbA1C) to be met to qualify for surgery, 36.5% only review past medical history; 9.1% use machine learning to personalize PJI risk; (B) BMI limit: 36% no limit; 15.4% BMI < 35; 30.9% BMI < 40; 17.2% BMI < 45; (C) Nutritional status: 55.3% do not screen; among those who screen their patients (44.7%), albumin is the single most used marker (86.3%); (D) Hyperglycemia/Diabetes: 83.3% check this comorbidity; 88.1% use HgbA1C as single best screening test; (E) MRSA nasal colonization: 63.7% do not test; 28.9% test all patients; 7.4% test selectively. Intraoperative: (A) Antibiotic prophylaxis in high-risk patients: 43.4% use single antibiotic for 24 h; 21.3% use double antibiotic for 24 h; 14.2% use single/double antibiotic for 7 days postoperatively; (B) Skin-cleansing: 68.7% at home (45.6% chlorhexidine sponge; 11.9% clippers); (C) Intraoperative skin disinfection: 46.9% single chlorhexidine; 25% double chlorhexidine-povidone-iodine;15.4% single povidone-iodine; (D) Tranexamic acid (TXA) to reduce bleeding/SSI: 96% yes (51% double IV dose, 35.2% single IV dose, 23.6% intra-articular injection); (E) Surgical suction drain: 52% do not use drains; 19.7% use a drain < 24 h; (F) Intra-articular lavage: 64.9% use only saline; 28.1% use dilute povidone-iodine; (G) Antibiotic local delivery to prevent PJI: 82.4% use antibiotic-added cement. Postoperative: (A) Routine monitoring of PJI serologic markers: 42% only in symptomatic patients; 34.2% do not; 20.8% in all patients; (B) Serologic markers to rule in/out PJI: 95.9% CRP; 71% SEDRATE; 60.6% WBC; (C) Synovial fluid test to rule in/out PJI: 79.6% culture/sensitivity; 69.5% WBC count; 31.4% CRP.

CONCLUSIONS

This survey demonstrated that notable differences still exist in the application of PJI preventive measures across different geographic areas: Optimizing the patient preoperatively and applying multimodal intraoperative strategies represent newer, clinically relevant steps in the effort to reduce the burden of PJI. More uniform guidelines still need to be produced from international scientific societies in order facilitate a more comprehensive approach to this devastating complication.

LEVEL OF EVIDENCE

IV.

Periprosthetic joint infections of the shoulder: A 10-year retrospective analysis outlining the heterogeneity among these patients

Background

Diagnosis and treatment of shoulder periprosthetic joint infection is a difficult problem. The purpose of this study was to utilize the 2018 International Consensus Meeting definition of shoulder periprosthetic joint infection to categorize revision shoulder arthroplasty cases and determine variations in clinical presentation by presumed infection classification.

Methods

Retrospective review of patients undergoing revision shoulder arthroplasty at a single institution. Likelihood of periprosthetic joint infection was determined based on International Consensus Meeting scoring. All patients classified as definitive or probable periprosthetic joint infection were classified as periprosthetic joint infection. All patients classified as possible or unlikely periprosthetic joint infection were classified as aseptic. The periprosthetic joint infection cohort was subsequently divided into culture-negative, non-virulent microorganism, and virulent microorganism cohorts based on culture results.

Results

Four hundred and sixty cases of revision shoulder arthroplasty were reviewed. Eighty (17.4%) patients were diagnosed as definite or probable periprosthetic joint infection, of which 29 (36.3%), 39 (48.8%), and 12 (15.0%) were classified as virulent, non-virulent, or culture-negative periprosthetic joint infection, respectively. There were significant differences among periprosthetic joint infection subgroups with regard to preoperative C-reactive protein (p = 0.020), erythrocyte sedimentation rate (p = 0.051), sinus tract presence (p = 0.008), and intraoperative purulence (p < 0.001). The total International Consensus Meeting criteria scores were also significantly different between the periprosthetic joint infection cohorts (p < 0.001).

Discussion

While the diagnosis of shoulder periprosthetic joint infection has improved with the advent of International Consensus Meeting criteria, there remain distinct differences between periprosthetic joint infection classifications that warrant further investigation to determine the accurate diagnosis and optimal treatment.

Positive Cultures Can Be Safely Ignored in Revision Arthroplasty Patients That Do Not Meet the 2018 International Consensus Meeting Criteria

BACKGROUND

During aseptic revision total joint arthroplasty (TJA), one or more cultures may occasionally isolate an organism. The hypothesis of this study was that in a portion of patients undergoing revision arthroplasty for aseptic failure, culture may isolate an organism(s) that can be left untreated.

METHODS

All patients undergoing revision TJA from 2000 to 2017 at two institutions were retrospectively reviewed. Patients were categorized as aseptic if they were appropriately investigated preoperatively and did not meet the 2018 International Consensus Meeting criteria. In the aseptic revision cohort, patients with a single positive culture or multiple cultures positive for different organisms ("organism-positive") and patients who had negative intraoperative cultures ("organism-negative") were compared based on demographics, comorbidities, operative details, subsequent reoperations, and periprosthetic joint infection (PJI).

RESULTS

In total, 3,234 International Consensus Meeting-negative aseptic revision TJAs were included, of which 215 patients (6.6%) were organism-positive, 196 (91.2%) had a single positive culture, and 19 (8.8%) were positive for 2 or more distinct organisms (ie, polymicrobial). The most prevalent organisms were coagulase-negative Staphylococci (37.5%), Staphylococcus epidermidis (9.6%), and Cutibacterium acnes (8.0%). Demographics and operative details were comparable between the groups. Using multiple regressions there was no association between culture positivity and the rate of reoperation or PJI.

CONCLUSION

Isolation of organisms by culture in patients undergoing revision for aseptic failure was not uncommon. As long as these patients were appropriately investigated preoperatively and PJI was excluded, these findings suggest that culture results may be ignored without subjecting patients to additional antimicrobial treatment.

Immune checkpoint upregulation in periprosthetic joint infection

Periprosthetic joint infections (PJI) induce an immunosuppressive cytokine profile through an unknown mechanism. Immune checkpoints, like programmed cell death 1 (PD-1) and its ligand (PD-L1), initiate innate immunosuppressive pathways essential for self-tolerance. Several malignancies and chronic infections co-opt these pathways to derive a survival advantage. This study evaluates PD-1/PD-L1 expression in periprosthetic tissue from patients undergoing revision hip or knee arthroplasty for a PJI versus an aseptic failure. PD-1/PD-L1 in the global tissue sample and the high-power microscopic field of maximum expression was analyzed prospectively using immunohistochemistry. Fifteen patients with a PJI (45%) and 16 patients with an aseptic failure (52%) were included. PD-1 expression was uniformly low. Maximum PD-L1 expression was upregulated in patients with a PJI (25%, interquartile range [IQR]: 5%-75%) versus an aseptic failure, (8%, IQR: 1%-48%, p = 0.039). In the PJI cohort, maximum PD-L1 expression was higher among patients who developed a recurrent PJI (68%, IQR: 53%-86% vs. 15%, IQR: 5%-70%, p = 0.039). Patients with global PD-L1 over 5% trended toward a near 22-fold increase in the odds of reinfection (odds ratio [OR]: 21.9, 95% confidence interval [CI]: 0.9-523.5, p = 0.057) and patients with maximum PD-L1 over 20% trended toward a 15-fold increase in the odds of reinfection (OR: 15.0, 95% CI: 0.6-348.9, p = 0.092). These results support immune checkpoint upregulation as a mechanism of PJI-induced local immune dysfunction. Future studies should confirm PD-L1 as a risk factor for reinfection in larger cohorts.

Next-Generation Sequencing Supports Targeted Antibiotic Treatment for Culture Negative Orthopedic Infections

The isolation of an infective pathogen can be challenging in some patients with active, clinically apparent infectious diseases. Despite efforts in the microbiology lab to improve the sensitivity of culture in orthopedic implant-associated infections, the clinically relevant information often falls short of expectations. The management of peri-prosthetic joint infections (PJI) provides an excellent example of the use and benefits of newer diagnostic technologies to supplement the often-inadequate yield of traditional culture methods as a substantial percentage of orthopedic infections are culture-negative. Next-generation sequencing (NGS) has the potential to improve upon this yield. Bringing molecular diagnostics into practice can provide critical information about the nature of the infective organisms and allow targeted therapy in these otherwise challenging situations. This review article describes the current state of knowledge related to the use and potential of NGS to diagnose infections, particularly in the setting of PJIs.

An Enhanced Understanding of Culture-Negative Periprosthetic Joint Infection with Next-Generation Sequencing: A Multicenter Study

BACKGROUND

The challenges of culture-negative periprosthetic joint infection (PJI) have led to the emergence of molecular methods of pathogen identification, including next-generation sequencing (NGS). While its increased sensitivity compared with traditional culture techniques is well documented, it is not fully known which organisms could be expected to be detected with use of NGS. The aim of this study was to describe the NGS profile of culture-negative PJI.

METHODS

Patients undergoing revision hip or knee arthroplasty from June 2016 to August 2020 at 14 institutions were prospectively recruited. Patients meeting International Consensus Meeting (ICM) criteria for PJI were included in this study. Intraoperative samples were obtained and concurrently sent for both routine culture and NGS. Patients for whom NGS was positive and standard culture was negative were included in our analysis.

RESULTS

The overall cohort included 301 patients who met the ICM criteria for PJI. Of these patients, 85 (28.2%) were culture-negative. A pathogen could be identified by NGS in 56 (65.9%) of these culture-negative patients. Seventeen species were identified as common based on a study-wide incidence threshold of 5%. NGS revealed a polymicrobial infection in 91.1% of culture-negative PJI cases, with the set of common species contributing to 82.4% of polymicrobial profiles. Escherichia coli, Cutibacterium acnes, Staphylococcus epidermidis, and Staphylococcus aureus ranked highest in terms of incidence and study-wide mean relative abundance and were most frequently the dominant organism when occurring in polymicrobial infections.

CONCLUSIONS

NGS provides a more comprehensive picture of the microbial profile of infection that is often missed by traditional culture. Examining the profile of PJI in a multicenter cohort using NGS, this study demonstrated that approximately two-thirds of culture-negative PJIs had identifiable opportunistically pathogenic organisms, and furthermore, the majority of infections were polymicrobial.

LEVEL OF EVIDENCE

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

Diagnosing periprosthetic joint infections : a comparison of infection definitions: EBJIS 2021, ICM 2018, and IDSA 2013

AIMS

This study evaluated the definitions developed by the European Bone and Joint Infection Society (EBJIS) 2021, the International Consensus Meeting (ICM) 2018, and the Infectious Diseases Society of America (IDSA) 2013, for the diagnosis of periprosthetic joint infection (PJI).

METHODS

In this single-centre, retrospective analysis of prospectively collected data, patients with an indicated revision surgery after a total hip or knee arthroplasty were included between 2015 and 2020. A standardized diagnostic workup was performed, identifying the components of the EBJIS, ICM, and IDSA criteria in each patient.

RESULTS

Of 206 included patients, 101 (49%) were diagnosed with PJI with the EBJIS definition. IDSA and ICM diagnosed 99 (48%) and 86 (42%) as infected, respectively. A total of 84 cases (41%) had an infection based on all three criteria. In 15 cases (n = 15/206; 7%), PJI was present when applying only the IDSA and EBJIS criteria. No infection was detected by one definition alone. Inconclusive diagnoses occurred more frequently with the ICM criteria (n = 30/206; 15%) compared to EBJIS (likely infections: n = 16/206; 8%) (p = 0.029). A better preoperative performance of the EBJIS definition was seen compared with the ICM and IDSA definitions (p < 0.001).

CONCLUSION

The novel EBJIS definition identified all PJIs diagnosed by any other criteria. Use of the EBJIS definition significantly reduced the number of uncertain diagnoses, allowing easier clinical decision-making.Cite this article: Bone Joint Res 2022;11(9):608-618.

Culture-negative Peri-prosthetic Joint Infection after Total Hip Arthroplasty Treatment Protocol and Outcomes in Acute and Chronic Cases

The treatment of culture-negative periprosthetic joint infections (CN PJI) of the hip represents complex entities. We, as a result of this, report on 12 cases. Irrigation and debridement (I&D) with implant retention were performed in acute cases and two-stage revisions in chronic infections. Combined antibiotic therapy was administered in all cases for 12 weeks. Infection control was achieved in all patients with an infection-free rate of 100% at 7.5 years of average follow-up.

Quantitative alpha-defensin testing: Is synovial fluid dilution important?

BACKGROUND

Alpha-defensin has been widely studied for the diagnosis of periprosthetic joint infection (PJI). However, there is a lack of detailed information regarding the proper laboratory technique of the enzyme-linked immunosorbent assay (ELISA) method, such as sample dilution.

AIM

To assess the influence of dilution in the synovial fluid during ELISA for the diagnosis of knee PJI; and determine which dilution presents a better performance.

METHODS

Forty samples of synovial fluid from arthroplasty knees were included, 17 in the infected group and 23 in the aseptic group, according to Musculoskeletal Infection Society criteria. Initially, five synovial fluid samples from each group were assessed for quantitative analysis of alpha-defensin using ELISA. Different dilution ratios (1:10, 1:100, 1:500, 1:1000 and 1:5000) were tested based on the predetermined cutoff value of 5.2 mg/L. The dilutions that performed better were used to compare the results of all samples.

RESULTS

For infected cases, a gradual increase in the dilution of synovial fluid samples led to an equivalent increase in alpha-defensin level. The same was not observed in the aseptic cases. Both 1:1000 and 1:5000 dilutions presented satisfactory results to differentiate infected and aseptic cases. Further analyses were performed using 1:1000 and 1:5000 for all 40 samples. The 1:1000 dilution resulted in a sensitivity of 88.2% (95%CI, 66%-98%) and specificity of 95.7% (95%CI, 79%-99%), whereas the 1:5000 dilution presented a sensitivity of 94.1% (95%CI, 73%-99%) and a specificity of 100% (95%CI, 86%-100%).

CONCLUSION

The synovial fluid dilution had an important influence on the alpha-defensin ELISA results. Dilutions of 1:5000 showed the best performance for the diagnosis of knee PJI. The results of this study set the basis for a more reliable and reproducible alpha-defensin ELISA during the investigation of PJI, contributing to the expansion of this technique in different treatment centers worldwide.

Diagnosis and Treatment of Culture-Negative Periprosthetic Joint Infection

Identification of the causative organism(s) in periprosthetic joint infection (PJI) is a challenging task. The shortcomings of traditional cultures have been emphasized in recent literature, culminating in a clinical entity known as "culture-negative PJI." Amidst the growing burden of biofilm infections that are inherently difficult to culture, the field of clinical microbiology has seen a paradigm shift from culture-based to molecular-based methods. These novel techniques hold much promise in the demystification of culture-negative PJI and revolutionization of the microbiology laboratory. This article outlines the clinical implications of culture-negative PJI, common causes of this diagnostic conundrum, established strategies to improve culture yield, and newer molecular techniques to detect infectious organisms.

Efficacy of Infection Eradication in Antibiotic Cement-Coated Intramedullary Nails for Fracture-Related Infections, Nonunions, and Fusions

Antibiotic cement-coated intramedullary nails (ACCINs) are increasing in popularity as a viable solution for the treatment of fracture-related infections (FRIs), infected long bone nonunions, and arthrodeses without an external fixator. ACCINs effectively manage to fulfill three of the basic principles for eradicating osteomyelitis: dead space management, antibiotic delivery, and bone stability. We performed a retrospective review of 111 patients who were treated with ACCINs between January 2014 and December 2020. In our series, 87.4% (n = 97) of patients achieved healed and uninfected bone or stable arthrodesis at a mean follow-up of 29.2 months (range, 6–93 months). Additionally, 69.1% (n = 67) of healed patients were resolved after only one procedure, and the remainder (30.9%, n = 30) healed after one or more additional procedures. The mean number of additional procedures was 2.1 (range, 1–6 additional procedures). The overall limb salvage rate was 93.7% (n = 104). The majority of the total cohort were successfully treated in only one surgery. This study suggests that ACCINs are effective in the treatment of FRIs, infected long bone nonunions, and infected ankle and knee arthrodeses.

Microbiological Advantages of Open Incisional Biopsies for the Diagnosis of Suspected Periprosthetic Joint Infections

Background: Periprosthetic joint infection (PJI) represents a serious complication following total hip (THA) and knee arthroplasty (TKA). When preoperative synovial fluid cultures remain inconclusive, open incisional joint biopsy (OIB) can support causative microorganism identification. Objective: This study investigates the potential benefit of OIB in THA and TKA patients with suspected PJI and ambigious diagnostic results following synovial fluid aspiration. Methods: We retrospectively assessed all patients treated from 2016 to 2020 with suspected PJI. Comparing the microbiology of OIB and the following revision surgery, we calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the number needed to treat (NNT). Results: We examined the diagnostic validity of OIB in 38 patients (20 female) with a median age of 66.5 years. In THA patients (n = 10), sensitivity was 75%, specificity was 66.67%, PPV was 60%, NPV was 80%, and NNT was 2.5. In TKA patients (n = 28), sensitivity was 62.5%, specificity was 95.24%, PPV was 83.33%, NPV was 86.96%, and NNT was 1.42. Conclusions: Our results indicate that OIB represents an adequate diagnostic tool when previously assessed microbiological results remain inconclusive. Particularly in TKA patients, OIB showed an exceptionally high specificity, PPV, and NPV, whereas the predictive validity of the diagnosis of PJI in THA patients remained low.

Evaluation of multi-sample 16S ribosomal DNA sequencing for the diagnosis of postoperative bone and joint infections during antimicrobial treatment

Objectives

Clinicians worldwide struggle to identify the bacterial aetiology of bone and joint infections. Failure to unequivocally identify the pathogen is linked to poor clinical outcomes. We explored the added value of analysing multiple samples per patient with 16S ribosomal DNA (16S rDNA) sequencing in diagnosing postoperative bone and joint infections. All patients had received antimicrobials prior to sampling, and false-negative cultures could be suspected. Bone biopsies obtained from patients with postoperative bone and joint infections for cultures were also subjected to 16S rDNA sequencing.

Results

In 5/28 infectious episodes, sequencing identified the causative organism of the infection when cultures failed. In 8/28 episodes, the methods led to different results, potentially leading to different antimicrobial choices. The analysis of multiple samples per patient helped rule out potential contaminating pathogens. We conclude that 16S rDNA sequencing has diagnostic value for patients receiving antibiotic treatment. We regard the method as a complement to culturing when the cultures are negative. Multiple samples per patient should be analysed to determine the clinical significance of positive findings.

Evaluation of a syndromic panel polymerase chain reaction (spPCR) assay for the diagnosis of device-associated bone and joint infections (BJI)

OBJECTIVE

Pathogen detection is crucial for diagnosis and targeted therapy in implant-associated bone and joint infections (BJI). Culture-based microbiology regularly fails to identify causative pathogens. This study evaluated the diagnostic accuracy and clinical usefulness of a syndromic panel polymerase chain reaction (spPCR) assay targeting common BJI pathogens in tissue specimens from patients with implant-associated BJI.

METHODS

Results obtained by spPCR assay and a 16S rDNA PCR were compared with results obtained from a standard of care (SOC) culture-based diagnostics, serving as a gold standard. In total, 126 specimens obtained from 73 patients were analyzed.

RESULTS

The spPCR assay correctly identified 33/40 culture-positive samples (82.5 %) and was positive in 9/86 (10.5 %) culture-negative samples, resulting in an overall sensitivity of 84.6 % (95% confidence interval [CI] 68.79-93.59%) and specificity of 89.35% (95% CI 80.6-94.81%). The spPCR was more sensitive compared with the 16S rDNA PCR (37.5%). The spPCR identified pathogens in 7/51 (13.7%) SOC-negative patients. Re-evaluation of spPCR results in clinical context suggested their clinical significance.

CONCLUSION

An spPCR assay targeting common pathogens causing implant-associated BJI may help to identify causative agents in culture-negative cases. As false-negative results are possible, spPCR assays appear as an add-on approach for pathogen detection in implant-associated BJI.

A guide to debridement, antibiotics, and implant retention

Debridement, antibiotics, and implant retention (DAIR) is an alternative management strategy for the treatment of periprosthetic joint infection (PJI). While infection eradication rates are lower with DAIR, the benefits including decreased morbidity, improved functional outcomes, and decreased cost may justify the risks when considering this form of treatment compared to traditional one or two stage exchange arthroplasty. Implant longevity in the setting of a successful DAIR is similar to matched patients who have not experienced a PJI. An experienced arthroplasty surgeon well versed in extensile exposure should perform the DAIR. This procedure should not be viewed as a simple "washout." While PJI may be considered a surgical urgency, DAIR can be performed on a planned list if it allows for appropriate staffing and implants for the procedure. Arthroscopic irrigation may be performed for a patient in extremis but it should not be viewed as a definitive procedure to address PJI. Keys to a successful DAIR include accurate tissue sampling to determine the infective organism, meticulous, radical debridement, and exchange of modular components if possible. A multidisciplinary team (MDT) including an infectious disease specialist should be involved prior to surgery in order to guide appropriate antimicrobial therapy throughout the patient's course of treatment. In the article below we present our indications, considerations, and technique for performing a DAIR for PJI for hip and knee arthroplasty.

Long-Term Outcomes of Staged Revision Surgery for Chronic Periprosthetic Joint Infection of Total Hip Arthroplasty

Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty. Staged revision surgery is considered effective in eradicating PJI. We aimed to determine the rate of infection resolution after each stage of staged revision surgery (first stage, repeat first stage, second stage, excision arthroplasty, and reimplantation) and to assess functional outcomes and the mortality rate at ten years in a consecutive series of 30 chronic PJI of total hip arthroplasties. Infection resolution was defined as no clinical nor laboratory evidence of infection at 24 months after the last surgery and after a minimum of 12 months following cessation of antimicrobial treatment. Four patients died within 24 months of their final surgery. Nineteen patients, 73% (worst-case analysis (wca) 63%), were infection free after 1 surgery; 22 patients, 85% (wca 73%), were infection free after 2 surgeries; and 26 patients, 100% (wca 87%), were infection free after three and four surgeries. The median Harris Hip Score was 41 prior to first revision surgery and improved to 74 at twelve months and 76 at ten years after the final surgery. Thirteen patients died at a mean of 64 months from first revision, giving a mortality rate of 43% at ten years, which is approximately 25% higher than that of an age-matched general population. The results show that with repeated aggressive surgical treatment, most PJIs of the hip are curable. Ten years after successful treatment of PJI, functional outcomes and pain are improved and maintained compared to before initial surgery, but this must be balanced against the high 10-year mortality. Level of evidence: cohort studies.

Diagnostic Value of Next-Generation Sequencing in Periprosthetic Joint Infection: A Systematic Review

Next‐generation sequencing (NGS) has developed rapidly in the last decade and is emerging as a promising diagnostic tool for periprosthetic joint infection (PJI). However, its diagnostic value for PJI is still uncertain. This systematic review aimed to explore the diagnostic value of NGS for PJI and verify its accuracy for culture‐negative PJI patients. We conducted this systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis (PRISMA) guidelines. Medline, Embase, and Cochrane Library were searched to identify diagnostic technique studies evaluating the accuracy of NGS in the diagnosis of PJI. The diagnostic sensitivity, specificity, and positive and negative predictive values were estimated for each article. The detection rate of NGS for culture‐negative PJI patients or PJI patients with antibiotic administration history was also calculated. Of the 87 identified citations, nine studies met the inclusion criteria. The diagnostic sensitivities and specificities of NGS ranged from 63% to 96% and 73% to 100%, respectively. The positive and negative predictive values ranged from 71% to 100% and 74% to 95%, respectively. The detection rate of NGS for culture‐negative PJI patients in six studies was higher than 50% (range from 82% to 100%), while in three studies it was lower than 50% (range from 9% to 31%). Also, the detection rate of NGS for PJIs with antibiotic administration history ranged from 74.05% to 92.31%. In conclusion, this systematic review suggests that NGS may have the potential to be a new tool for the diagnosis of PJI and should be considered to be added to the portfolio of diagnostic procedures. Furthermore, NGS showed a favorable diagnostic accuracy for culture‐negative PJI patients or PJI patients with antibiotic administration history. However, due to the small sample sizes of studies and substantial heterogeneity among the included studies, more research is needed to confirm or disprove these findings.