A new perspective on current prosthetic joint infection classifications: introducing topography as a key factor affecting treatment strategy

Application of the New Irrigation Protocol to Reduce Recurrence Rate in the Management Of Periprosthetic Joint Infection

OBJECTIVE

Irrigation is a conventional treatment for acute and chronic periprosthetic joint infections (PJI). However, there has been no unified standard for irrigation during surgery for PJI in the past, and the efficacy is uncertain. The purpose of this study is to create a new irrigation protocol to enhance the infection control rate and reduce the postoperative recurrence rate of PJI patients.

METHODS

We conducted a single-institution retrospective review with a total of 56 patients who underwent revision total hip or knee arthroplasties due to PJI from January 2011 to January 2022. Conventional irrigation (CI) was used in 32 cases, and standard operating procedure of irrigation (SOPI) was used in 24. The CI protocol carries out an empirical irrigation after debridement, which is quite random. Our SOPI protocol clearly stipulates the soaking concentration and time of hydrogen peroxide and povidone-iodine. The irrigation is carried out three times, and tissue samples are taken from multiple parts before and after irrigation, which are sent for microbial culture. The important statistical indicators were the rate of positive microbiological culture and postoperative recurrence rate with an average follow-up of 24 average months.

RESULTS

The drainage volume was lower in the SOPI group than in the CI group on postoperative day 3 (p < 0.01) and 7 (p = 0.016). In addition, the percentage of positive microbiological cultures after the third irrigation was less than that before (p < 0.01) and after (p < 0.01) the first irrigation. The most common causative organism was Staphylococcus aureus, which was detected in 25.0% and 12.5% of the SOPI and CI groups, respectively. The failure rate at the final follow-up was 8.3% and 31.3% (p = 0.039) for the SOPI and CI groups, respectively.

CONCLUSION

Compared with the traditional CI method, SOPI standardized the soaking time of hydrogen peroxide and povidone-iodine, increased the frequency of and irrigation, and proved that microorganisms were almost completely removed through the microbial culture of multiple tissues. SOPI has the potential to become a standardized irrigation process worthy of promotion, effectively reducing the postoperative recurrence rate of PJI patients.

Diagnostic value of magnetic resonance imaging for patients with periprosthetic joint infection: a systematic review

PURPOSE

The purpose of this study was to provide a critical systematic review of the role of magnetic resonance imaging (MRI) as a noninvasive method to assess periprosthetic joint infections (PJIs).

METHODS

The electronic databases PubMed and EMBASE were searched, since their inception up to March 27, 2022. The included studies evaluated the reproducibility and accuracy of MRI features to diagnose PJIs. The article quality assessment was conducted by the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) and Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2).

RESULTS

Among 1909 studies identified in the initial search, 8 studies were eligible for final systematic review. The included studies evaluated the reproducibility and accuracy of MRI features to diagnose PJIs. Seven of 8 studies showed good to excellent reliability, but only one article among them in which accuracy was evaluated had a low risk of bias. The intraclass correlation coefficient (ICC) and Cohen coefficient (κ) varied between 0.44 and 1.00. The accuracy varied between 63.9% and 94.4%. Potential MRI features, such as lamellated hyperintense synovitis, edema, fluid collection, or lymphadenopathy, might be valuable for diagnosing PJIs.

CONCLUSION

The quality of the evidence regarding the role of MRI for PJIs diagnosis was low. There is preliminary evidence that MRI has a noteworthy value of distinguishing suspected periprosthetic joint infection in patients with total knee arthroplasty or total hip arthroplasty, but the definition of specific MRI features related to PJIs diagnosis lacks consensus and standardization. Large-scale studies with robust quality were required to help make better clinical decisions in the future.

The Challenge of Periprosthetic Joint Infection Diagnosis: From Current Methods to Emerging Biomarkers

Due to the increase in the life span and mobility at older ages, the number of implanted prosthetic joints is constantly increasing. However, the number of periprosthetic joint infections (PJIs), one of the most severe complications after total joint arthroplasty, also shows an increasing trend. PJI has an incidence of 1-2% in the case of primary arthroplasties and up to 4% in the case of revision operations. The development of efficient protocols for managing periprosthetic infections can lead to the establishment of preventive measures and effective diagnostic methods based on the results obtained after the laboratory tests. In this review, we will briefly present the current methods used in PJI diagnosis and the current and emerging synovial biomarkers used for the prognosis, prophylaxis, and early diagnosis of periprosthetic infections. We will discuss treatment failure that may result from patient factors, microbiological factors, or factors related to errors during diagnosis.

C-reactive protein during the first 6 postoperative days after total hip arthroplasty cannot predict early periprosthetic infection

INTRODUCTION

Periprosthetic joint infection (PJI) after total hip arthroplasty (THA) remains a serious complication in orthopaedic surgery. C-reactive protein (CRP) is widely used as a marker to screen for inflammatory complications. The early postoperative course is well known, but knowledge about the predictive value of CRP in the first 6 postoperative days for detecting an acute postoperative PJI is lacking.

METHODS

We retrospectively analyzed the inpatient course of CRP of all primary THA and THA with acute PJI within 28 days in our hospital from 2013 to 2021. A receiver-operating curve (ROC) analysis was performed and the best CRP threshold for detecting an acute PJI based on Youden's-index was calculated and an area-under-the curve (AUC) analysis of the threshold was performed.

RESULTS

33 of 7042 patients included had an acute PJI within 28 days. Patients with acute PJI were older, had a higher BMI and longer operation time and suffered more often from diabetes mellitus. A preoperatively elevated CRP was a risk factor for PJI. CRP was significantly higher in the PJI group on postoperative days 3 and 5. Threshold values were calculated to be 152 mg/l on day 3 and 73 mg/l on day 5. However, these values had a low sensitivity (75%, 76%) and specificity (67%, 61%).

CONCLUSION

Especially considering the decreasing length of stay after THA, the question of the usefulness of regular inpatient CRP checks arises. AUC analysis of the ROC showed a poor diagnostic accuracy in almost all cases. Only the dynamic analysis of the maximum CRP value to the lowest CRP value with a decrease of 102.7 mg/l showed a fair accuracy. This calls into question the clinical relevance of CRP in the first postoperative week for detection of acute postoperative PJI.

Classification and management options for prosthetic joint infection

Periprosthetic joint infection (PJI) is one of the major complications following arthroplasty implantation. Management of PJIs is a challenge for surgeons and various classification systems have been introduced, which consider variables such as onset of symptoms, pathogenesis and clinical manifestation. In an attempt to overcome the shortcomings which may limit their usefulness in borderline cases, a new classification system focusing on the topography of the infectious process has been proposed. This theory relies on the identification of the exact location of the bacterial colonization thus allowing to decide between a conservative or a more radical intervention irrespectively of the timing. The use of nuclear medicine device like radiolabelled white blood cells (WBC) scan could lead the path in identifying pathogenetic processes and their exact location thus guiding orthopaedic surgeons to the most appropriate diagnosis and treatment options. Currently management relies on debridement, antibiotics and implant retention (DAIR), which is traditionally performed at early stages, 1- or 2-stage revision arthroplasty which is commonly limited to chronic cases. Reports have demonstrated similar rates of infection recurrence following one and two-stage revisions, and the use of one-stage revision surgery is gaining popularity. More recently, satisfying results following partial implant retention during revision total arthroplasty for septic failures have been reported. In addition, in severe cases, definitive articulating antibiotic spacer, excision arthroplasty, arthrodesis or amputation can be performed.

Changes in Invasiveness and Latent Infection Rate Associated with Switching the Approach in Total Hip Replacement

Purpose:

Muscle-sparing approaches for total hip replacement (THR) involve learning curves. This study aimed to clarify changes in invasiveness and infection rate with changes in approach.

Methods:

One surgeon changed the approach of THR from Dall’s approach (Dall) to anterolateral modified Watson-Jones approach (OCM). Another changed from Dall to a direct anterior approach (DAA). Another 3 surgeons changed from posterolateral approach (PL) to OCM. Subjects were 150 cases, comprising the last 25 cases with conventional approaches and the first 25 cases with new approaches (Dall to OCM: 25 + 25; Dall to DAA: 25 + 25; PL to OCM: 25 + 25 cases). Differences in operative time, bleeding volume, hospital stay, haemoglobin (Hb), white blood cell count, lymphocyte count, creatine kinase (CK) and C-reactive protein (CRP) were investigated.

Results:

In the change from Dall to OCM, only hospital stay decreased. In the change from Dall to DAA, hospital stay and CRP decreased, but bleeding volume increased. In the change from PL to OCM, operative time, CRP and CK decreased, but Hb also decreased. Cases with lymphocyte count <1000/μL or lymphocytes comprising <10% of total white blood cells at around day 4 after surgery were defined as latent infection cases. In these cases, operative time was longer, Hb was lower and CK was higher.

Conclusion:

Introducing muscle-sparing approaches improved many markers of invasiveness, but some items deteriorated. In the early stages of introducing a new approach, choosing cases without obesity and without high muscle volume may reduce the risk of infection.

Intra-Articular Injections Prior to Total Knee Arthroplasty Do Not Increase the Risk of Periprosthetic Joint Infection: A Prospective Cohort Study

Periprosthetic joint infections (PJI) occur in 0.5 to 2.8% of total knee arthroplasties (TKA) and expose them to an increase of morbidity and mortality. TKA are mainly performed after failure of non-surgical management of knee osteoarthritis, which frequently includes intra-articular injections of corticosteroids or hyaluronic acid. Concerning the potential impact of intra-articular injections on TKA infection, literature provides a low level of evidence because of the retrospective design of the studies and their contradictory results. In this prospective cohort study, we included patients after a total knee arthroplasty, at the time of their admission in a rehabilitation center, and we excluded patients with any prior knee surgery. 304 patients were included. Mean follow-up was 24.9 months, and incidence proportion of PJI was 2.6%. After multivariate logistic regression, male was the only significant risk factor of PJI (OR = 19.6; p = 0.006). The incidence of PJI did not differ between patients who received prior intra-articular injections and others, especially regarding injections in the last 6 months before surgery. The use of intra-articular injection remains a valid therapeutic option in the management of knee osteoarthritis, and a TKA could still be discussed.

[PJI-TNM as new classification system for periprosthetic joint infections : An evaluation of 20 cases]

Hintergrund

Bisherige Klassifikationen für Protheseninfektionen beurteilen die Heterogenität der Infektion nur unzureichend. Die PJI-TNM-Klassifikation berücksichtigt auf Basis der onkologischen TNM-Klassifikation folgende entscheidende Kriterien bei Protheseninfektionen: Implantatart und -stabilität, Weichteilverhältnisse, Biofilmreife, Erregerart, Komorbiditäten des Patienten und Infektrezidive. Ziel dieser Arbeit ist es, die neue PJI-TNM-Klassifikation auf deren Anwendbarkeit in der klinischen Praxis zu überprüfen.

Methoden

Im Rahmen einer Konzeptionsstudie wurde die PJI-TNM-Klassifikation bei 20 Patienten mit periprothetischen Schulter‑, Hüfte- oder Kniegelenksinfektion angewandt. Anhand der Patientenakte wurde die PJI-TNM-Klassifikation mit den übergeordneten Parametern T („tissue and implants“), N („non-eucaryotic cells and fungi“), M („morbidity“) und r („reinfection“), klassifiziert.

Ergebnisse

Alle 20 Fälle (12 männlich, 8 weiblich, mittleres Alter 72,2 [40–88 Jahre]), darunter 13 Hüft-, 6 Knie- und eine Schulterprotheseninfektion, konnten mit der PJI-TNM-Klassifikation klassifiziert werden. Insgesamt zeigte sich eine große Heterogenität der Fälle: 12 Prothesen waren fest (T0), 6 gelockert (T1) und bei zwei Prothesen ein Weichteildefekt (T2) vorhanden. Bei 7 Prothesen wurde von unreifem Biofilm (N0) ausgegangen. 13 Prothesen wurden entsprechend eines reifen Biofilms klassifiziert (N1+N2). 9 Patienten waren nur geringgradig (M0), 7 Patienten mäßig (M1) und 3 Patienten schwer vorerkrankt (M2). Ein Patient lehnte die chirurgische Therapie ab (M3a). Bei 3 Fällen handelte es sich um eine Reinfektion (r).

Schlussfolgerungen

Die aus der Onkologie stammenden Prinzipien der TNM-Klassifikation lassen sich auch bei periprothetischen Infektionen anwenden. Schon bei einer geringen Fallzahl ist eine deutliche Heterogenität periprothetischer Infektionen, wie sie auch im klinischen Alltag generell beobachtet wird, feststellbar. Diese wird durch die PJI-TNM-Klassifikation gut abgebildet und kann dadurch zukünftig eventuell zur Verbesserung bei der Therapieentscheidung beitragen.

Long-Term Patient-Related Quality of Life after Knee Periprosthetic Joint Infection

BACKGROUND

We aimed to evaluate the impact of knee periprosthetic joint infection (PJI) by assessing the patients' long-term quality of life and explicitly their psychological wellbeing after successful treatment.

METHODS

Thirty-six patients with achieved eradication of infection after knee PJI were included. Quality of life was evaluated with the EQ-5D and SF-36 outcome instruments as well as with an ICD-10 based symptom rating (ISR) and compared to normative data.

RESULTS

At a follow-up of 4.9 ± 3.5 years the mean SF-36 score was 24.82 ± 10.0 regarding the physical health component and 46.16 ± 13.3 regarding the mental health component compared to German normative values of 48.36 ± 9.4 (p < 0.001) and 50.87 ± 8.8 (p = 0.003). The mean EQ-5D index reached 0.55 ± 0.33 with an EQ-5D VAS rating of 52.14 ± 19.9 compared to reference scores of 0.891 (p < 0.001) and 68.6 ± 1.1 (p < 0.001). Mean scores of the ISR revealed the psychological symptom burden on the depression scale.

CONCLUSION

PJI patients still suffer from significantly lower quality of life compared to normative data, even years after surgically successful treatment. Future clinical studies should focus on patient-related outcome measures. Newly emerging treatment strategies, prevention methods, and interdisciplinary approaches should be implemented to improve the quality of life of PJI patients.

High rate of infection eradication following cementless one-stage revision hip arthroplasty with an antibacterial hydrogel coating

PURPOSE

We conducted a retrospective study to evaluate the outcomes of one-stage revision total hip arthroplasty (THA) following periprosthetic joint infection (PJI) in terms of eradication of the infection, improvement of pain and joint function. We hypothesized that this treatment strategy could lead to satisfying results in selected patients after preoperative microorganism isolation.

METHODS

Ten patients underwent cementless one-stage revision hip arthroplasty with antibacterial hydrogel coating for the treatment of an infected THA. Inclusion criteria were: the presence of a known organism with known sensitivity, patients non-immunocompromised with healthy soft tissues with minimal or moderate bone loss. Mean age at surgery was 69.4 years. Assessment included objective examination, Harris hip score, visual analog scale pain score, standard X-rays.

RESULTS

At a mean follow-up of 3.1 years (range, 2-5 years), none of the patients had clinical or radiographic signs suggesting recurrent infection. Follow-up examination showed significant improvement of all variables compared to pre-operative values (p < 0.05). Radiographs did not show progressive radiolucent lines or change in the position of the implant.

CONCLUSIONS

One-stage revision THA with antibacterial hydrogel coated implants represents a safe and effective procedure providing infection eradication and satisfying subjective functional outcomes in selected patients.

One-stage revision surgery provides infection eradication and satisfying outcomes for infected knee arthroplasty in selected patients

OBJECTIVES

We conducted a retrospective study to evaluate the outcomes of one-stage revision total knee arthroplasty (TKA) in terms of eradication of the infection, improvement of pain, and knee function.

METHODS

Between 2009 and 2016, 20 patients underwent one-stage revision TKA for the treatment of a prosthetic joint infection (PJI). Inclusion criteria were: patients nonimmunocompromised with minimal or moderate bone loss, known organisms with known sensitivity. Assessment included clinical signs of infection eradication, range of motion, Knee Society clinical rating score, visual analog scale pain score, and radiographic assessment.

RESULTS

After a mean follow-up of 6.2 years (range, 2-10 years), none of the patients had signs suggesting recurrent infection. Follow-up examination showed significant improvement of all variables compared to preoperative values (p < 0.001).

CONCLUSIONS

One-stage revision surgery provides infection eradication and satisfying subjective functional outcomes for infected knee arthroplasty in selected patients.

EXPERT OPINION

One-stage revision knee arthroplasty is a valuable resource to approach PJIs in selected patients whose infecting micro-organism and sensitivity are determined before surgery. In order to succeed strict inclusion criteria should be applied, as only non-immunocompromised patients with healthy soft tissues with minimal or moderate bone loss are eligible for this procedure.

Selective Component Retainment in the Treatment of Chronic Periprosthetic Infection After Total Hip Arthroplasty: A Systematic Review

INTRODUCTION

Chronic infections after a total hip arthroplasty (THA) are a devastating complication and are usually treated by a complete revision of components. Selective revision, with preservation of well-fixed components, has been previously reported. We did a systematic review to report on success rates of selective revision in chronic infections after THA.

METHODS

PubMed, Web of Science, and the Cochrane Database were systematically searched for studies reporting on partial-retaining revision for chronically infected THA. These were reviewed to determine success rates based on component revised, as well as infectious organism.

RESULTS

Nine studies reported on 134 patients. The majority of the patients underwent femoral-retaining procedures (118), and the rest of the patients underwent acetabular-retaining procedures (16). Average follow-up was 60.56 months, and the success rates were 80% for femoral revision, 90.43% for acetabular revision, and overall success rate was 89.41%.

DISCUSSION

In select patients, retainment of well-fixed components in chronically infected THA may be considered. Although reported success rates are high, and comparable with complete revision arthroplasty in cases of chronic infections, the quality of the studies included is poor. The studies lacked sufficient internal validity, sample size, methodological consistency, and standardization of protocols and outcomes.

LEVEL OF EVIDENCE

Systematic review of level IV studies.

[Periprosthetic joint infections : Latest developments, strategies and treatment algorithms]

BACKGROUND

Due to their multidimensional consequences, periprosthetic joint infections are a serious complication in arthroplasty. There are disagreements in the literature regarding their classification. At the same time, a consequence for the practical procedure cannot always be derived.

THERAPEUTIC PROCEDURES

In addition to debridement with antibiotics and implant retention, there are options for a one or two-stage change in the therapeutic procedure. Although the preservation of implants is only possible in the case of acute infections with a short duration of symptoms, prosthesis changes are indicated with a longer symptom duration. For both procedures, there are interinstitutional deviating indication criteria, weighing pros and cons. Both have specific problems, such as, in particular, the duration of the antibiotics course, the question of anchoring the prosthesis and, in the case of a two-stage procedure, the shape of the spacer.

Prosthetic joint infections: diagnosis, management, and complications of the two-stage replacement arthroplasty

Despite improved strategies to prevent prosthetic joint infection, as the total number of joint replacements increases, so does the absolute number of infections. Radiography serves as the first-line imaging modality for the assessment of a suspected prosthetic joint infection. Additionally, serial radiographs acquired after a surgery to eradicate a prosthetic joint infection are an important clinical tool. Prosthetic joint infections are often treated with a 2-stage replacement arthroplasty utilizing a prosthesis with antibiotic-loaded acrylic cement. While complications are uncommon with this procedure, imaging may demonstrate periprosthetic fractures, as well as spacer migration, joint dislocation, and spacer fracture. We describe the classification of prosthetic joint infections, the clinical and imaging diagnosis, and treatment strategies. Familiarity with the hardware utilized in the management of the prosthetic joint infection, and its potential complications is fundamental to accurate imaging interpretation.

Can the oncology classification system be used for prosthetic joint infection?: The PJI-TNM system

Cite this article:Bone Joint Res. 2020;9(2):79–81.

Debridement, Antibiotics, and Implant Retention for Acute Periprosthetic Joint Infection

Objective

To report on our clinical outcomes and on the experience of managing acute periprosthetic joint infection (PJI) with debridement, antibiotics, and implant retention (DAIR).

Methods

We performed a retrospective review of all patients who were diagnosed with acute PJI after primary hip or knee replacement surgeries and who were managed with DAIR in our prospective joint replacement registry from 2008 to 2019. The diagnosis of PJI was made according to the 2011 Musculoskeletal Infection Society (MSIS) criteria. The symptom onset duration, inflammatory marker levels (i.e. C‐reactive protein [CRP], erythrocyte sedimentation rate [ESR], white cell count [WBC], and synovial WBC count), functional scores including the Knee Society Score (KSS), the KSS functional score and the Harris Hip Score (HHS), bacteriology, and surgical outcomes of the patients were tracked and recorded. A paired sample of joint fluid and tissues was also sent for a metagenomic next‐generation sequencing (mNGS) test. A paired‐samples t‐test was used to compare the differences in the inflammatory markers and functional scores before and after surgery.

Results

A total of 24 patients with 7 infections after hip replacements and 17 infections after knee replacements were included. A total of 21 patients exhibited early postoperative infections, and 3 exhibited late acute hematogenous infections. During a mean follow‐up time of 29.2 ± 15.1 months, 22 patients were successfully treated, whereas 2 patients were unsuccessfully treated and required repeated DAIR. The overall success rate of DAIR was 91.7%. For staphylococcal infections, DAIR had a 100% success rate. Five patients who presented with symptoms between 4 and 8 weeks also achieved a 100% success rate. At the last follow‐up, the mean CRP level decreased from 52.6 ± 34.0 to 5.4 ± 3.5 (P < 0.001), and the mean ESR level decreased from 72.3 ± 34.3 to 20.2 ± 12.1 (P < 0.001). The mean KSS score increased from 44.8 ± 12.2 to 81.4 ± 9.2 (P < 0.001), and the mean KSS functional score increased from 38.1 ± 3.5 to 73.9 ± 23.0 (P < 0.001), and the mean HHS score increased from 34.4 ± 6.9 to 84.1 ± 15.1 (P < 0.001). The overall pathogen identification rate was 91.7% (22/24 cases). The success rates for Staphylococcus, Streptococcus, and the other pathogens were 100% (9/9 cases), 71.4% (5/7 cases), and 100% (6/6 cases), respectively.

Conclusion

Debridement, antibiotics, and implant retention has a high success rate for the treatment of acute PJI and may be performed in selected patients whose symptoms have been sustained for over 4 weeks. A high rate of success for staphylococcal infections was reported with the use of DAIR.