Diagnostic accuracy of arthroscopic biopsy in periprosthetic infections of the hip

The role of biopsy in diagnosing infection after hip and knee arthroplasty: a meta-analysis

INTRODUCTION

Early diagnosis of periprosthetic hip and knee infection still represents a major challenge, as no single test can achieve ideal results. Currently, multiple preoperative indicators were performed to diagnose periprosthetic joint infection (PJI) to confirm or exclude infection in the early stage. However, the diagnostic value of biopsy-related tests in diagnosing periprosthetic hip and knee infection remains unclear.

MATERIALS AND METHODS

Publications in PubMed, Embase, and the Web of Science databases were searched systematically until October 2020. Inclusion and exclusion criteria were used for screening biopsy-related studies of the diagnosis of periprosthetic hip and knee infection.

RESULTS

Three biopsy-related tests were identified in 14 articles and further analyzed in the present meta-analysis. The combined method had the highest value for the area under the curve (0.9805), followed by histology (0.9425) and microbiological tests (0.9292). In the subgroup, statistical differences were identified in sensitivity and specificity for PJI diagnosis between the synovial fluid culture and biopsy culture group, as well as in the biopsy-related combined method and serum C-reactive protein.

CONCLUSIONS

Biopsy culture does not appear to be advantageous compared to synovial fluid culture in the preoperative diagnosis of periprosthetic hip and knee infection. In contrast, combined biopsy microbial culture with histology analysis shows great potential in improving the preoperative diagnosis of PJI. The standard procedure of biopsy needs to be further explored. Further research is required to verify our results.

Diagnostic utility of open biopsy in patients with two culture-negative aspirations in the diagnostic work-up of periprosthetic joint infection

INTRODUCTION

Different approaches have been proposed for bacterial identification in patients with a suspected periprosthetic joint infection (PJI). If a one-stage procedure is considered, a higher rate of preoperative bacterial identification can be achieved if biopsy is included in the diagnostic work-up. The performance of open biopsy (OB) in the context of PJI has not been clearly determined yet. The purpose of this study was to determine the value of an OB added to two consecutive culture-negative joint aspirations during PJI workup.

MATERIALS AND METHODS

We retrospectively analyzed the OB data from a single institution. Patients under PJI work-up of the hip or knee with two culture-negative periprosthetic aspirations who underwent OB were included. Sensitivity and specificity were calculated using the musculoskeletal infection society (MSIS) criteria as gold standard. Patients undergoing urgent irrigation and debridement and patients with history of surgery to the affected joint in the prior 6 weeks were excluded.

RESULTS

126 patients were included in this study. 62 (49.2%) patients had prior revisions, 48 of them due to PJI. The sensitivity and specificity of OB was 69.4% and 89.1%, respectively. The OB procedure led to the identification of the causative germ in 50 out of 126 (40%) cases so they could undergo one-stage (septic) exchange.

CONCLUSION

The OB is a valuable resource if preoperative synovial fluid cultures are negative, a high suspicion of infection persists and a one-stage procedure is preferred. It intends bacteria identification and allows surgeons to evaluate prosthetic complications for further surgical procedures.

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.

Diagnostic value of open incisional biopsies in suspected, difficult-to-diagnose periprosthetic hip joint infection prior to revision surgery

INTRODUCTION

Prior to revision of total hip arthroplasty (THA), low-grade chronic periprosthetic joint infection (PJI) is often difficult to diagnose. We aimed to determine the diagnostic accuracy of open incisional tissue biopsy for the prediction of PJI prior to THA revision in cases with culture-negative or dry tap joint aspirates.

MATERIALS AND METHODS

This retrospective single-center study includes 32 consecutive THA revision cases with high clinical suspicion of low-grade chronic PJI of the hip with culture-negative or dry tap joint aspirates and without systemic signs of infection. Open incisional biopsy (OIB) was performed prior to revision surgery. Periprosthetic tissue samples were analyzed by microbiology and histopathology for PJI. During definitive revision arthroplasty, identical diagnostics were repeated. Results from both procedures were compared and sensitivity, specificity, positive and negative predictive values of OIB for the final diagnosis were calculated.

RESULTS

Average age at revision was 69.3 ± 13.5 years. The sensitivity of the OIB procedure was 80% (microbiology), 69% (histology) and 82% for combined analyses (microbiology and histology). Specificity of OIB was 80% (microbiology), 94% (histology) and 60% for combined analyses.

CONCLUSIONS

Open tissue biopsy performed in cases with culture-negative or inconclusive synovial fluid aspirates prior to revision of THA has limited diagnostic accuracy for the prediction of PJI. The procedure does not reliably close the diagnostic gap in a substantial number of cases. In this difficult patient population, risk of an open procedure may outweigh benefits and alternative less invasive methods should be considered for the preoperative diagnosis of PJI.

Reliable Diagnostic Tests and Thresholds for Preoperative Diagnosis of Non-Inflammatory Arthritis Periprosthetic Joint Infection: A Meta-analysis and Systematic Review

Objective

The current diagnostic criteria for periprosthetic joint infection (PJI) are diverse and controversial, leading to delayed diagnosis. This study aimed to evaluate and unify their diagnostic accuracy and the threshold selection of serum and synovial routine tests for PJI at an early stage.

Methods

We searched the MEDLINE and Embase databases for retrospective or prospective studies which reported preoperative‐available assays (serum, synovial, or culture tests) for the diagnosis of chronic PJI among inflammatory arthritis (IA) or non‐IA populations from January 1, 2000 to June 30, 2022. Threshold effective analysis was performed on synovial polymorphonuclear neutrophils (PMN%), synovial white blood cell (WBC), serum C‐reactive protein (CRP), and erythrocyte sedimentation rate (ESR) to find the relevant cut‐offs.

Results

Two hundred and sixteen studies and information from 45,316 individuals were included in the final analysis. Synovial laboratory‐based α‐defensin and calprotectin had the best comprehensive sensitivity (0.91 [0.86–0.94], 0.95 [0.88–0.98]) and specificity (0.96 [0.94‐0.97], 0.95 [0.89–0.98]) values. According to the threshold effect analysis, the recommended cut‐offs are 70% (sensitivity 0.89 [0.85–0.92], specificity 0.90 [0.87–0.93]), 4100/μL (sensitivity 0.90 [0.87–0.93], specificity 0.97 [0.93–0.98]), 13.5 mg/L (sensitivity 0.84 [0.78–0.89], specificity 0.83 [0.73–0.89]), and 30 mm/h (sensitivity 0.79 [0.74–0.83], specificity 0.78 [0.72–0.83]) for synovial PMN%, synovial WBC, serum CRP, and ESR, respectively, and tests seem to be more reliable among non‐IA patients.

Conclusions

The laboratory‐based synovial α‐defensin and synovial calprotectin are the two best independent preoperative diagnostic tests for PJI. A cut off of 70% for synovial PMN% and tighter cut‐offs for synovial WBC and serum CRP could have a better diagnostic accuracy for non‐IA patients with chronic PJI.

The significance of synovial biopsy in the diagnostic workup of the low-grade periprosthetic joint infection of shoulder arthroplasty

INTRODUCTION

A common reason for painful shoulder arthroplasties and revision surgery is a low-grade periprosthetic joint infection (PJI). Diagnosing a low-grade infection is, however, a major diagnostic challenge. This applies even more to the shoulder, which differs from other large joints in terms of clinical features and microbiological spectrum. Aim of this study was to evaluate the diagnostic value of the synovial biopsy in the diagnostic workup of low-grade PJI of the shoulder.

MATERIALS AND METHODS

A retrospective evaluation was conducted on 56 patients receiving revision surgery on their shoulder arthroplasty. A standardized preoperative workup was performed comprising CRP value, leukocyte blood count, synovial fluid microbiological analyses and leukocyte count from joint aspiration, and five synovial biopsy samples for bacteriologic and histologic analysis obtained through an arthroscopic approach. During revision surgery, five samples of periprosthetic tissue were harvested for bacteriologic and histologic analyses. The MSIS-Criteria 2014 were used to evaluate the diagnostic results.

RESULTS

In total, 15 of 56 revised prostheses turned out as PJI (27%). When applying our diagnostic workup, we obtained a sensitivity of 67% with a specificity of 95%. When performing a subgroup analysis on those patients that had received diagnostic biopsy, a sensitivity of 100% and a specificity of 83% could be achieved. With a sensitivity and specificity of 90% and 83%, respectively, the biopsy is the single method with the highest diagnostic value.

CONCLUSIONS

The sensitivity of only 67% of our standard workup emphasizes the difficulty to adequately diagnose low-grade infections after shoulder arthroplasty. The excellent specificity of 95% ensures, however, that non-infected prostheses are not incorrectly explanted. This study highlights that synovial biopsy has a high diagnostic value and should be done prior to complex revision surgeries to raise sensitivity in diagnosing a PJI.

[Septic revision arthroplasty: how to confirm diagnosis, plan surgery and manage follow-up treatment]

BACKGROUND

Septic revision arthroplasty represents an interdisciplinary challenge in terms of diagnosis as well as surgical and follow-up treatment.

DIAGNOSIS

The implementation of a standardized diagnostic algorithm including anamnesis, clinic, imaging, blood sampling and joint aspiration is essential. Depending on the duration of the symptoms acute (< 3 weeks) and chronic (> 3 weeks) infections are distinguished.

THERAPY

While acute infections show an immature biofilm and can usually be addressed surgically via debridement and changing the mobile parts, chronic infections almost always require a complete change of the implant. This can be done in one or two stages, depending on the general condition of the patient, the pathogen, its resistances as well as the wound conditions. The surgical revision is always followed by a resistance-based antibiotic treatment.

Diagnostic value of routine pre-operative investigations used in combination in the diagnosis of periprosthetic joint infection

The primary aim of this study was to assess the diagnostic accuracy of joint aspiration culture, serum C-reactive protein (CRP) and serum erythrocyte sedimentation rate (ESR), individually, and in combination for the diagnosis of periprosthetic joint infection (PJI). A consecutive patient series with pre-operative inflammatory marker levels, an aspiration culture of either hip or knee arthroplasty and intra-operative culture samples from subsequent revision surgery was compiled. This retrospective patient cohort analysis included 128 aspiration. The data were analysed to compare pre-operative aspiration cultures, serum ESR and CRP levels to the chosen gold standard for PJI diagnosis of intra-operative culture samples. A diagnostic algorithm was created using the above tests combined with clinical suspicion index. The values that had the highest sensitivity and specificity of predicting PJI were >5 for CRP and >16 for ESR. CRP used individually had the highest sensitivity and negative predictive value (NPV) of any test (75.0% and 75.9%, respectively). ESR + aspirate had the highest specificity and positive predictive value (PPV), of 100% for both. Using all three tests together the specificity and PPV were higher than the test individual values (95.3% and 85.0% respectively). Based on subgroup analyses the combination of ESR or CRP plus joint aspiration has superior PPV compared to individual tests. ESR and CRP had the highest NPV when used in isolation. An algorithm has been developed to guide clinical diagnosis.

[Diagnosis of periprosthetic joint infection : Development of an evidence-based algorithm by the work group of implant-associated infection of the AE-(German Society for Arthroplasty)]

Hintergrund

Die Behandlung periprothetischer Infektionen (PPI) ist eine der größten Herausforderungen im Bereich der Endoprothetik. Der möglichst sichere Ausschluss oder die Bestätigung einer periprothetischen Infektion ist die Voraussetzung für jede Revisionsoperation und kann für den behandelnden Orthopäden und Unfallchirurgen eine große Herausforderung darstellen. Eine sichere evidenzbasierte präoperative Diagnostik ist im Sinne des Patienten notwendig, um einerseits eine periprothetische Infektion zu erkennen sowie die entsprechende chirurgische und antibiotische Therapie zu planen und andererseits unnötige zweizeitige Wechsel zu vermeiden.

Ziel der Arbeit

Ziel ist es, ein evidenzbasiertes problem- und prioritätenbasiertes Vorgehen zu entwickeln und dies in einem transparenten und standardisierten Algorithmus zusammenzufassen.

Methode

Durch systematische Literaturrecherche wurden relevante Arbeiten identifiziert und im Rahmen von Expertenrunden bewertet. Nach Extraktion der Daten erfolgte die Berechnung von Sensitivität, Spezifität, positiver und negativer Likelihood-Ratio sowie positiver und negativer prädiktiver Werte. Im Rahmen von 4 Treffen wurden die entsprechenden Studien der Arbeitsgruppe für implantatassoziierte Infektionen präsentiert und analog zu Standard-Delphi-Runden durch die einzelnen Experten bearbeitet und bewertet. Gemäß der Prioritätenliste der Expertenrunde erfolgte die Entwicklung eines zur ISO (International Organization for Standardisation) konformen Algorithmus.

Ergebnisse

Der entwickelte Algorithmus ist eine Abfolge von evidenzbasierten Prozessen gemäß der verwendeten ISO-Norm. Gemäß der durch die Expertenrunde priorisierten Haupt- und Nebenkriterien erfolgte die Entwicklung logisch strukturiert und problemorientiert.

Schlussfolgerung

Der Ausschluss einer periprothetischen Infektion ist von enormer Bedeutung vor einer Revisionsoperation und entscheidet in vielen Fällen über den Erfolg und die Invasivität der Operation. Die Diagnose „periprothetische Infektion“ erfordert eine substanzielle Veränderung der therapeutischen Strategie. Der durch die Arbeitsgruppe entwickelte Algorithmus fasst Positionen aus der aktuellen Literatur und spezielle Expertenmeinungen zusammen, dies ermöglicht einen transparenten diagnostischen Ansatz im Sinne einer Standard Operation Procedure.

Hip arthroscopy in France: An epidemiological study of postoperative care and outcomes involving 3699 patients

BACKGROUND

Hip arthroscopy is a surgical procedure that is becoming more and more prevalent in France. Even though indications are now well-established little is still known about patient outcomes. Therefore, the purpose of our retrospective study was to: (1) describe the circumstances in which hip arthroscopies are being performed; (2) study arthroscopy and arthroplasty reoperation rates; (3) assess the incidence of readmissions for complications.

HYPOTHESIS

Hip arthroscopy in France produced similar results to those observed in other countries.

MATERIALS AND METHODS

We conducted a cohort study from January 2008 to December 2014 in the French population using the national hospital discharge database called "Programme de médicalisation des systèmes d'information (PMSI)." We included all admissions that had a hip arthroscopy code and analyzed readmissions for conversion to hip arthroplasty, revision hip arthroscopy and complications (without being able to provide detailed descriptions). Risk factors associated with conversion, revision and readmission for complications were studied after performing a population analysis.

RESULTS

A total of 3,699 patients were included over a period of seven years. The mean age was 40 years, with women being significantly older (mean age of 43 years) than men (38 years) (p<0.05). The number of procedures increased from 240 in 2008 to 702 in 2014. Synovectomies (67.9%; 2514/3699) and surgical bone procedures (acetabuloplasty or femoroplasty) (47.3%; 1751/3699) were the main procedures performed during the primary arthroscopy. In total, 410 patients underwent a conversion to arthroplasty, 231 patients had a revision arthroscopy, and 126 patients suffered a complication. Five years after the index procedure, the conversion rate was 16.3%, revision rate was 8.2%, and readmission rate for a postoperative complication was 5%. The main risk factor associated with conversions was [Hazard ratio (HR) and 95% Confidence Index (CI)] an age between 40 and 79 years during the first arthroscopy [3.04 (2.40; 3.87) compared with the reference class of 25-39 years]. Patients between ages 16 to 24 years during the first arthroscopy (0.35 [0.20; 0.61] compared with the reference class of 25-39 years) had a decreased risk of conversion (HR and 95% CI). The main risk factors associated with revisions were: synovectomies [1.90 (1.34; 2.70)] and surgical bone procedures on the femoral neck and/or the acetabulum [1.82 (1.36; 2.4)]. The risk factor associated with complication-related readmissions was an age greater than 40 years [2.23 (1.43; 3.49)].

CONCLUSION

Unlike the international literature, our study population was largely male. The rates of revision (8.2% after five years) and conversion to arthroplasty (16.3% after five years) were relatively low and comparable to the different international studies. This procedure, which is not widely performed, is growing in popularity, has low morbidity and remains an interesting approach given the revision and conversion rates after five years. The implementation of specific coding for arthroscopic hip procedures and the pathologies to be treated seems warranted.

LEVEL OF EVIDENCE

IV; descriptive epidemiological study.

Combination Tests in the Diagnosis of Chronic Periprosthetic Joint Infection: Systematic Review and Development of a Stepwise Clinical Decision-Making Tool

BACKGROUND

Our objective was to identify combination tests used to diagnose chronic periprosthetic joint infection (PJI) and develop a stepwise decision-making tool to facilitate diagnosis.

METHODS

We conducted a systematic review of existing combinations of serum, synovial, and tissue-based tests for diagnosing chronic PJI after hip or knee replacement. This work is an extension of our systematic review of single tests, from which we chose eligible studies that also described the diagnostic performance of combination tests.

RESULTS

Thirty-seven eligible articles described the performance of 56 combination tests, of which 8 combinations had at least 2 studies informing both sensitivity and specificity. We also identified 5 types of combination tests: (1) a type-I Boolean combination, which uses Boolean logic (AND, OR) and usually increases specificity at the cost of sensitivity; (2) a type-II Boolean combination, which usually increases sensitivity at the cost of specificity; (3) a triage-conditional rule, in which the value of 1 test serves to triage the use of another test; (4) an arithmetic operation on the values of 2 tests; and (5) a model-based prediction rule based on a fitted model applied to biomarker values.

CONCLUSIONS

Clinicians can initiate their diagnostic process with a type-II Boolean combination of serum C-reactive protein (CRP) and interleukin-6 (IL-6). False negatives of the combination can be minimized when the threshold is chosen to reach 90% to 95% sensitivity for each test. Once a joint infection is suspected on the basis of serum testing, joint aspiration should be performed. If joint aspiration yields a wet tap, a leukocyte esterase (LER) strip is highly recommended for point-of-care testing, with a reading of ++ or greater indicating PJI; a reading below ++ should be followed by one of the laboratory-based synovial tests. If joint aspiration yields a dry tap, clinicians should rely on preoperative tissue culture and histological analysis for diagnosis. Combinations based on triage-conditional, arithmetic, and model-based prediction rules require further research.

LEVEL OF EVIDENCE

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

Is combining serum interleukin-6 and C-reactive protein a reliable diagnostic tool in periprosthetic joint infections?

BACKGROUND

Because there is no single gold standard method for the diagnosis of periprosthetic joint infection (PJI), the combination of valuable methods to evaluate infection appears to achieve a better diagnostic result. The objective of the present study was to evaluate the diagnostic value of serum interleukin (IL)-6 and C-reactive protein (CRP) for the diagnosis of PJI.

METHODS

PubMed, Embase, and the Web of Science databases were searched for articles describing PJI diagnosis using serum IL-6 and CRP published between January 1990 and December 2019.

RESULTS

Eight studies were included in the meta-analysis. The pooled sensitivity was 0.84 (95% confidence interval [CI], 0.80-0.88) for the combined method (serum IL-6 and CRP) in series and parallel approaches, 0.87 (95% CI, 0.82-0.90) for IL-6, and 0.84 (95% CI, 0.79-0.88) for CRP. The pooled specificity was 0.85 (95% CI, 0.82-0.88) for the combined method, 0.83 (95% CI, 0.79-0.87) for IL-6, and 0.83 (95% CI, 0.79-0.87) for CRP. The combined method had the highest value for the area under the curve (0.9453), followed by IL-6 (0.9237) and CRP (0.9074). Subgroup analyses showed that the sensitivity of the combined method in parallel tests was higher than that in IL-6 or CRP (94% vs. 89% and 84%, respectively). Serial testing of the combined method showed increased specificity compared to a single indicator (96% vs. 83% and 80%).

CONCLUSION

The combination of serum IL-6 and CRP was a reliable tool for the diagnosis of periprosthetic hip and knee infection, demonstrating a better diagnostic accuracy than single marker analysis.

The diagnostic value of routine preliminary biopsy in diagnosing late prosthetic joint infection after hip and knee arthroplasty

AIMS

Biopsy of the periprosthetic tissue is an important diagnostic tool for prosthetic joint infection (PJI) as it enables the detection of the responsible microorganism with its sensitivity to antibiotics. We aimed to investigate how often the bacteria identified in the tissue analysis differed between samples obtained from preoperative biopsy and intraoperative revision surgery in cases of late PJI; and whether there was a therapeutic consequence.

METHODS

A total of 508 patients who required revision surgery of total hip arthroplasty (THA) (n = 231) or total knee arthroplasty (TKA) (n = 277) because of component loosening underwent biopsy before revision surgery. The tissue samples collected at biopsy and during revision surgery were analyzed according to the criteria of the Musculoskeletal Infection Society (MSIS).

RESULTS

In total, 178 (113 THA, 65 TKA) were classified as infected. The biopsy procedure had a sensitivity of 93.8%, a specificity of 97.3%, a positive predictive value (PPV) of 94.9%, a negative predictive value (NPV) of 96.7%, and an accuracy of 96.1%. Of the 178 infected patients, 26 showed a difference in the detected bacteria from the biopsy and the revision surgery (14.6%). This difference required a change to antibiotic therapy in only two cases (1.1%).

CONCLUSION

Biopsy is a useful tool to diagnose PJI, but there may be a difference in the detected bacteria between the biopsy and revision surgery. However, this did not affect the choice of antibiotic therapy in most cases, rendering the clinical relevance of this phenomenon as low. Cite this article: Bone Joint J 2020;102-B(3):329-335.

Twenty common errors in the diagnosis and treatment of periprosthetic joint infection

Background

Misconceptions and errors in the management of periprosthetic joint infection (PJI) can compromise the treatment success. The goal of this paper is to systematically describe twenty common mistakes in the diagnosis and management of PJI, to help surgeons avoid these pitfalls.

Materials and methods

Common diagnostic and treatment errors are described, analyzed and interpreted.

Results

Diagnostic errors include the use of serum inflammatory biomarkers (such as C-reactive protein) to rule out PJI, incomplete evaluation of joint aspirate, and suboptimal microbiological procedures (such as using swabs or collection of insufficient number of periprosthetic samples). Further errors are missing possible sources of distant infection in hematogenous PJI or overreliance on suboptimal diagnostic criteria which can hinder or delay the diagnosis of PJI or mislabel infections as aseptic failure. Insufficient surgical treatment or inadequate antibiotic treatment are further reasons for treatment failure and emergence of antimicrobial resistance. Finally, wrong surgical indication, both underdebridement and overdebridement or failure to individualize treatment can jeopardize surgical results.

Conclusion

Multidisciplinary teamwork with infectious disease specialists and microbiologists in collaboration with orthopedic surgeons have a synergistic effect on the management of PJI. An awareness of the possible pitfalls can improve diagnosis and treatment results.

Culture of periprosthetic tissue in blood culture bottles for diagnosing periprosthetic joint infection

BACKGROUND

The purpose of this meta-analysis was to evaluate the diagnostic accuracy of periprosthetic tissue culture in blood culture bottles (BCB) for periprosthetic joint infection (PJI).

METHODS

PubMed, Web of Science, and Embase were systematically searched for eligible studies evaluating the diagnostic performance of periprosthetic tissue culture in BCB for the diagnosis of PJI. The pooled data were analysed by Meta-Disc software.

RESULTS

Four studies with a total of 1071 patients were included in this meta-analysis. The summarized estimates showed that periprosthetic tissue culture in BCB may be of great value in PJI diagnosis with a pooled sensitivity of 0.70 (95% confidence interval [CI]; 0.66-0.75), specificity of 0.97 (95% CI: 0.95-0.98); positive likelihood ratio (PLR) of 20.98 (95% CI: 11.52-38.2); negative likelihood ratio (NLR) of 0.28 (95% CI: 0.20-0.40); and diagnostic odds ratio (DOR) of 92.26 (95% CI: 43.93-193.78).

CONCLUSIONS

The present meta-analysis showed that periprosthetic tissue in BCB improves the results of microorganism cultures, with a sensitivity of 70% and a specificity of 97%. However, more large-scale, well-performed studies are needed to verify our findings.

Diagnostic Accuracy of Serum, Synovial, and Tissue Testing for Chronic Periprosthetic Joint Infection After Hip and Knee Replacements: A Systematic Review

BACKGROUND

Chronic periprosthetic joint infection (PJI) is a devastating complication that can occur following total joint replacement. Patients with chronic PJI report a substantially lower quality of life and face a higher risk of short-term mortality. Establishing a diagnosis of chronic PJI is challenging because of conflicting guidelines, numerous tests, and limited evidence. Delays in diagnosing PJI are associated with poorer outcomes and morbid revision surgery. The purpose of this systematic review was to compare the diagnostic accuracy of serum, synovial, and tissue-based tests for chronic PJI.

METHODS

This review adheres to the Cochrane Collaboration's diagnostic test accuracy methods for evidence searching and syntheses. A detailed search of MEDLINE, Embase, the Cochrane Library, and the grey literature was performed to identify studies involving the diagnosis of chronic PJI in patients with hip or knee replacement. Eligible studies were assessed for quality and bias using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Meta-analyses were performed on tests with sufficient data points. Summary estimates and hierarchical summary receiver operating characteristic (HSROC) curves were obtained using a bivariate model.

RESULTS

A total of 12,616 citations were identified, and 203 studies met the inclusion criteria. Of these 203 studies, 170 had a high risk of bias. Eighty-three unique PJI diagnostic tests were identified, and 17 underwent meta-analyses. Laboratory-based synovial alpha-defensin tests and leukocyte esterase reagent (LER) strips (2+) had the best performance, followed by white blood-cell (WBC) count, measurement of synovial C-reactive protein (CRP) level, measurement of the polymorphonuclear neutrophil percentage (PMN%), and the alpha-defensin lateral flow test kit (Youden index ranging from 0.78 to 0.94). Tissue-based tests and 3 serum tests (measurement of interleukin-6 [IL-6] level, CRP level, and erythrocyte sedimentation rate [ESR]) had a Youden index between 0.61 to 0.75 but exhibited poorer performance compared with the synovial tests mentioned above.

CONCLUSIONS

The quality of the literature pertaining to chronic PJI diagnostic tests is heterogeneous, and the studies are at a high risk for bias. We believe that greater transparency and more complete reporting in studies of diagnostic test results should be mandated by peer-reviewed journals. The available literature suggests that several synovial fluid-based tests perform well for diagnosing chronic PJI and their use is recommended in the work-up of any suspected case of chronic PJI.

LEVEL OF EVIDENCE

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

Arthroscopic treatment of total knee arthroplasty complications

The most frequent indications for arthroscopy in patients with total knee arthroplasty (TKA) are soft-tissue impingement, arthrofibrosis (knee stiffness), periprosthetic infection and removal of free bodies or cement fragments.

When performing a knee arthroscopy in a patient with a symptomatic TKA, look for possible free/retained bone or cement fragments, which can be anywhere in the joint.

Patellar tracking should be evaluated and soft-tissue impingement under the patella or between the femoral and tibial prosthetic components should be ruled out.

Current data suggest that knee arthroscopy is an effective procedure for the treatment of some patients with symptomatic TKA.

The approximate rates of therapeutic success vary according to the problem in question: 85% in soft-tissue impingement; 90% in arthrofibrosis; and 55% in periprosthetic infections.

More clinical studies are needed to determine which patients with symptomatic TKA can be the best candidates for knee arthroscopy.

Cite this article: EFORT Open Rev 2019;4:33-43. DOI: 10.1302/2058-5241.4.180035.

The terminal complement pathway is activated in septic but not in aseptic shoulder revision arthroplasties

BACKGROUND

The early diagnosis of suspected periprosthetic low-grade infections in shoulder arthroplasties is important for the outcome of the revision surgical procedures. The aim of this study was to investigate new biomarkers of infection in revision shoulder arthroplasties, taking into account the implant design, patient age, and comorbidities.

METHODS

The study included 33 patients with shoulder arthroplasties undergoing revision surgical procedures. Microbiological diagnostic testing was performed in all cases. C-reactive protein serum levels and white blood cell counts were evaluated, and the periprosthetic tissue was stained immunohistologically for the terminal complement pathway components (C3, C5, and C9) and for CD68 and α-defensin.

RESULTS

Microbiological diagnostic testing detected a periprosthetic infection in 10 reverse shoulder arthroplasties and in 4 anatomic shoulder arthroplasties, while the remaining 19 shoulder arthroplasties were classified as aseptic. We observed more Staphylococcus epidermidis infections in reverse shoulder arthroplasties and more Staphylococcus aureus infections in anatomic shoulder arthroplasties. The revision rate correlated with pre-existing comorbidities and number of previous surgical procedures. The C-reactive protein values and the incidence of specific periprosthetic radiolucent lines were significantly increased in septic revision cases. We found increased staining for all tested complement factors (C3, C5, and C9) but not for α-defensin and CD68 in septic tissue. The most interesting finding was that C9 separated septic from aseptic tissue with a predictive specificity of 100% and a sensitivity of 88.89%.

CONCLUSION

We observed a strong correlation between C9 expressions in septic revision tissue. We propose that the terminal complement pathway, especially C9 deposition, may be a potential biomarker to identify septic complications using tissue biopsy specimens.

Diagnosing periprosthetic hip joint low-grade infection via arthroscopic neo synovium biopsies

BACKGROUND

There is currently a lack of consensus regarding the most effective diagnostic algorithm for cases of supposed low-grade infection after total hip arthoplasty (THA).

OBJECTIVE

The aim of this study was to assess reliability in the use of biopsies, obtained by hip arthroscopy, to detect a periprosthetic hip joint infection (PJI).

METHODS

From 2012 to 2016, diagnostic arthroscopy of the hip joint was performed in 20 patients with a supposed PJI following THA. In 10 of these patients, the THA was revised for various reasons after diagnostic arthroscopy. The microbiological and histological findings of the biopsies obtained by arthroscopy were compared to findings from intraoperative samples of the revision arthroplasty.

RESULTS

For arthroscopic biopsies, we detected a sensitivity of 1.00 (95% confidence interval [CI] 0.40-1.00), a specificity of 0.83 (95% CI 0.36-1.00), a positive predictive value of 0.80 (95% CI 0.28-1.00), and a negative predictive value of 1.00 (95% CI 0.48-1.00). The accuracy was 0.90.

CONCLUSIONS

The analysis of arthroscopic biopsies represents a helpful tool to verify or rule out a PJI in selected patients. Nevertheless, minimally invasive diagnostic tools (e.g., laboratory analysis and aspiration) should be utilized beforehand.

Puncture Protocol in the Diagnostic Work-Up of a Suspected Chronic Prosthetic Joint Infection of the Hip

BACKGROUND

Diagnosing a chronic prosthetic joint infection (PJI) can be challenging. We hypothesized that obtaining preoperative tissue samples for culture in hip arthroplasty will increase the likelihood of diagnosing an infection before revision surgery. The aim of this cohort study was to determine the diagnostic accuracy of 2 tissue acquiring biopsy strategies to diagnose a PJI.

METHODS

Patients with a painful hip arthroplasty, in which a chronic PJI was suspected, were included. Tissue samples were obtained either by ultrasound guidance with a 16-Gauge needle (2012-2013) or in the operating room with a thick-bore needle (2013-2016). Revision surgery tissue biopsies were used as the gold standard. Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were calculated.

RESULTS

A total of 16 patients in the ultrasound cohort and 29 patients in the surgical cohort were included. Thirty-one percent (n = 14) were finally diagnosed with a PJI. The addition of thick bore needle tissue biopsies resulted in 9% more diagnosed PJIs compared with synovial fluid alone. The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio was 33%, 85%, 33%, 85%, 2.2, and 0.8, respectively, for the ultrasound-guided biopsy cohort and 82%, 100%, 100%, 90%, infinite, and 0.2, respectively, for the surgical biopsy cohort.

CONCLUSION

Obtaining multiple good quality tissue biopsies in a sterile environment will contribute to the diagnosis of a chronic PJI of the hip, with a higher diagnostic accuracy compared with ultrasound-guided thin needle biopsies and compared with synovial fluid culture alone.

Two-stage revision for the culture-negative infected total hip arthroplasty : A comparative study

Aims

Periprosthetic joint infection (PJI) remains a challenging complication following total hip arthroplasty (THA). It is associated with high levels of morbidity, mortality and expense. Guidelines and protocols exist for the management of culture-positive patients. Managing culture-negative patients with a PJI poses a greater challenge to surgeons and the wider multidisciplinary team as clear guidance is lacking.

Patients and Methods

We aimed to compare the outcomes of treatment for 50 consecutive culture-negative and 50 consecutive culture-positive patients who underwent two-stage revision THA for chronic infection with a minimum follow-up of five years.

Results

There was no significant difference in the outcomes between the two groups of patients, with a similar rate of re-infection of 6%, five years post-operatively. Culture-negative PJIs were associated with older age, smoking, referral from elsewhere and pre-operative antibiotic treatment. The samples in the culture-negative patients were negative before the first stage (aspiration), during the first-stage (implant removal) and second-stage procedures (re-implantation).

Conclusion

Adherence to strict protocols for selecting and treating culture-negative patients with a PJI using the same two-stage revision approach that we employ for complex culture-positive PJIs is important in order to achieve control of the infection in this difficult group of patients.

Cite this article: Bone Joint J 2018;(1 Supple A)100-B:3–8.