Periprosthetic Joint Infection in Patients with Inflammatory Joint Disease: Prevention and Diagnosis

Risk factors for metachronous periprosthetic joint infection in patients with multiple prosthetic joints: a systematic review and meta-analysis

OBJECT

Although periprosthetic joint infection (PJI) can affect multiple joints simultaneously, most individuals with multiple joint involvement exhibit PJI in only one joint. Data regarding the metachronous PJI management for these patients are limited. This study aimed to explore the risk factors for metachronous PJI in patients with multiple prosthetic joints, thereby guiding and optimizing clinical practice.

METHODS

The MEDLINE, Web of Science, Cochrane Library, and EMBASE were searched for all clinical studies of metachronous PJI from inception until May 2024. The clinical studies on risk factors for metachronous PJI in patients with multiple prosthetic joints after experiencing a periprosthetic infection were collected, with two authors independently screening the literatures. Newcastle Ottawa scale was used as a quality assessment tool for the included studies, and the meta-analysis was conducted to evaluate the potential risk factors of metachronous PJI.

RESULTS

A total of 1,544 patients with PJI after multiple joint arthroplasties were reported in 9 studies, including 189 with metachronous PJI. The meta-analysis showed that methicillin-resistant staphylococcus aureus (MRSA; OR, 3.43; 95%CI, 1.71-6.88; p = 0.0005), rheumatoid arthritis (RA; OR, 2.38; 95%CI, 1.06-5.38; p = 0.04), history of steroid use (OR, 2.93; 95%CI, 1.58-5.43; p = 0.0007), and previous or ongoing non-periprosthetic infection (OR, 4.47; 95%CI, 1.45-13.82; p = 0.009) were identified as significant risk factors for metachronous PJI in patients with multiple prosthetic joints. However, there was no significant difference between the metachronous PJI group and non-metachronous group in terms of revision, age, diabetes, and gender.

CONCLUSION

Patients with MRSA, RA, history of steroid use, previous or ongoing non-periprosthetic infection are at significantly higher risk for metachronous PJI. Further research is needed to optimize management strategies for preventing metachronous PJI in patients with multiple prostheses after a single joint PJI.

Novel Method for the Rapid Establishment of Antibiotic Susceptibility Profiles in Bacterial Strains Linked to Musculoskeletal Infections Using Scattered Light Integrated Collector Technology

Bacterial antibiotic resistance is an important challenge that the healthcare system is continually battling and a major problem in the treatment of musculoskeletal infections such as periprosthetic joint infections. Current methods to identify infectious microbes and define susceptibility to antibiotics require two to ten days from isolation to the establishment of an antibiogram. This slow process limits advances in antimicrobial drug discovery and, in the clinical context, delays the delivery of targeted treatments, with potentially devastating outcomes for patients. With this in mind, we strived to establish a quicker and more sensitive method to deliver antibiotic susceptibility profiles of clinically relevant microbes using Scattered Light Integrated Collector (SLIC) technology. We established antibiotic panels to obtain an approximate identification of a wide variety of microbes linked to periprosthetic joint infections and determine their susceptibility to antibiotics. We challenged microbes isolated from patients with our tailored antibiotic panels and found that SLIC detects perturbations in bacterial growth accurately and reproducibly within minutes of culture. Indeed, we could show that SLIC can be used to measure the dose-dependent inhibitory or bacteriolytic activity of broad classes of antibiotics. Our panel design enabled us to establish a profile similar to an antibiogram for the tested bacteria within 90 min. Our method can provide information on the class of bacteria tested and potential treatment avenues in parallel. Our proof-of-principle experiments using isolated clinical strains of bacteria demonstrate that SLIC, together with our specifically designed antibiotic panels, could be used to rapidly provide information on the identity of an infecting microbe, such as those associated with periprosthetic joint infections, and guide physicians to prescribe targeted antibiotic treatment early-on. The constant emergence of resistant strains of bacteria pushes the pharmaceutical industry to develop further effective drugs. Our optimized method could significantly accelerate this work by characterizing the efficacy of new classes of compounds against bacterial viability within minutes, a timeframe far shorter than the current standards.

Sterile Inflammatory Synovitis as a Mimic for Prosthetic Joint Infection in Patients With Rheumatoid Arthritis Following Total Knee Arthroplasty: A Report of Two Cases

Patients with rheumatoid arthritis (RA) present with unique challenges following total knee arthroplasty (TKA). Rarely, these patients may present with sterile inflammatory synovitis with a clinical picture that can mimic prosthetic joint infection (PJI). We report on two patients with RA who underwent primary TKA performed by the senior author who presented with sterile inflammatory synovitis following TKA. Both patients presented several years after their index procedure with knee pain and effusion, concerning for PJI. Both patients underwent extensive evaluations for infection. Initial aspirations showed a synovial fluid white blood cell count of more than 3,000 WBC/uL but a differential of less than 80% and no growth on the final culture. Both patients were treated non-operatively without antibiotics with the resolution of their symptoms. Sterile inflammatory synovitis is a rare post-operative complication that can present among patients with RA following TKA. While the initial presentation and evaluation may be concerning for PJI, a thorough laboratory evaluation must be performed to accurately diagnose these patients. The use of next-generation DNA sequencing, Synovasure alpha-defensin, and Synovasure microbial ID panel can aid in diagnoses. These patients may be treated without antibiotics or operative intervention. A thorough evaluation for PJI should be performed to ensure the correct diagnosis and appropriate management.

Synovial fluid dual-biomarker algorithm accurately differentiates osteoarthritis from inflammatory arthritis

Osteoarthritis (OA) prevalence increases as the population ages. Diagnosing osteoarthritis often occurs in the late stages when cartilage degradation is severe, making it difficult to distinguish from other types of arthritis. Accurate differentiation of primary osteoarthritis from other arthritic conditions is crucial for effective treatment planning. A new diagnostic test has been developed that uses a dual-biomarker algorithm to inform osteoarthritis diagnosis. Synovial fluid from patients with confirmed primary osteoarthritis showed elevated levels of cartilage oligomeric matrix protein. However, this biomarker alone could not distinguish primary osteoarthritis from other inflammatory conditions that also cause cartilage deterioration. Therefore, a combinatorial algorithm using cartilage oligomeric matrix protein and Interleukin-8 concentrations was developed to differentiate primary osteoarthritis from inflammatory arthritis. Clinical decision limits for cartilage oligomeric matrix protein concentration and the cartilage oligomeric matrix protein to Interleukin-8 ratio were established and validated using 171 human knee synovial fluid specimens. The osteoarthritis algorithm demonstrated clinical sensitivity and specificity of 87.0% and 88.9%, respectively. This is the first report of a biomarker test that can differentiate primary osteoarthritis from inflammatory arthritis with a high degree of accuracy.

Periprosthetic joint infections in patients with rheumatoid arthritis are associated with higher complication and mortality rates

INTRODUCTION

Periprosthetic joint infection (PJI) remains the most devasting complication after total joint arthroplasty (TJA). There has been a significant focus on this topic in recently-published medical literature. However, relatively little has been published about PJI in patients with rheumatoid arthritis (RA), which are often physiologically frail and immunocompromised. A better understanding of PJI in this patient population is therefore crucial. The main aims of this paper are to (1) report complication and mortality rates in a cohort of PJI-RA patients; and (2) clinically characterize them.

METHODS

Medical and surgical records of all RA PJI patients treated surgically from 2003 to 2020 were retrospectively reviewed. Medical history, physical examination, reactive protein (CRP) level, procalcitonin, white blood cell (WBC) count, joint aspiration results, and cultures were used to determine PJI.

RESULTS

54PJIs, 49 of them chronic, were treated in 53RA patients. Mean patient age was 65 yrs. (range = 32-88); 33females and 20 males (one bilateral hip). The overall mortality rate was 18.9%(n = 10), with five deaths directly attributed to PJI. Staphylococci accounted for 34 infections (63%), while 11(20.4%) had multiorganism infections and six culture-negative PJI. At the end of treatment 79.6%(n = 43) still had an implanted TJR, 7.4% (n = 4) had spacers, 5.6%(n = 3) had undergone resection arthroplasty, 3.7%(n = 2) arthrodesis, and one each amputation and exarticulation.

CONCLUSIONS

Mortality and specially complication rates were (are) high in this RA patients group presenting PJI. Delays to diagnosis and treatment may explain some of these poor outcomes.

LEVEL OF EVIDENCE

A cohort level III retrospective study.

Development of a multiplex Loop-Mediated Isothermal Amplification (LAMP) for the diagnosis of bacterial periprosthetic joint infection

BACKGROUND

Periprosthetic joint infection (PJI) is one of the most serious and debilitating complications that can occur after total joint arthroplasty. Therefore, early diagnosis and appropriate treatment are important for a good prognosis. Recently, molecular diagnostic methods have been widely used to detect the causative microorganisms of PJI sensitively and rapidly. The Multiplex Loop-Mediated Isothermal Amplification (LAMP) method eliminates the complex temperature cycling and delays caused by temperature transitions seen in polymerase chain reaction (PCR) methods, making it faster and easier to perform compared to PCR-based assays. Therefore, this study developed a multiplex LAMP assay for diagnosing bacterial PJI using LAMP technology and evaluated its analytical and clinical performance.

METHODS

We developed a multiplex LAMP assay for the detection of five bacteria: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae, Pseudomonas aeruginosa, and Escherichia coli, frequently observed to be the causative agents of PJI. The method of analytical sensitivity and cross-reactivity were determined by spiking standard strains into the joint synovial fluid. The analytical sensitivity of the multiplex LAMP assay was compared with that of a quantitative real-time PCR (qPCR) assay. Clinical performance was evaluated using 20 joint synovial fluid samples collected from patients suspected of having bacterial PJI.

RESULTS

The analytical sensitivity of the gram-positive bacterial multiplex LAMP assay and qPCR were 105/104 CFU/mL, 103/103 CFU/mL, and 105/104 CFU/mL against S. agalactiae, S. epidermidis, and S. aureus, respectively. For P. aeruginosa and E. coli, the analytical sensitivity of the multiplex LAMP and qPCR assays were 105/104 and 106/104 CFU/mL, respectively. The multiplex LAMP assay detects target bacteria without cross-reacting with other bacteria, and exhibited 100% sensitivity and specificity in clinical performance evaluation.

CONCLUSIONS

This multiplex LAMP assay can rapidly detect five high-prevalence bacterial species causing bacterial PJI, with excellent sensitivity and specificity, in less than 1 h, and it may be useful for the early diagnosis of PJI.

The Microbial Revolution in the World of Joint Replacement Surgery

Background

The prevalence of revision surgery due to aseptic loosening and periprosthetic joint infection (PJI) following total hip and knee arthroplasty is growing. Strategies to prevent the need for revision surgery and its associated health-care costs and patient morbidity are needed. Therapies that modulate the gut microbiota to influence bone health and systemic inflammation are a novel area of research.

Methods

A literature review of preclinical and clinical peer-reviewed articles relating to the role of the gut microbiota in bone health and PJI was performed.

Results

There is evidence that the gut microbiota plays a role in maintaining bone mineral density, which can contribute to osseointegration, osteolysis, aseptic loosening, and periprosthetic fractures. Similarly, the gut microbiota influences gut permeability and the potential for bacterial translocation to the bloodstream, increasing susceptibility to PJI.

Conclusions

Emerging evidence supports the role of the gut microbiota in the development of complications such as aseptic loosening and PJI after total hip or knee arthroplasty. There is a potential for microbial therapies such as probiotics or fecal microbial transplantation to moderate the risk of developing these complications. However, further investigation is required.

Clinical Relevance

Modulation of the gut microbiota may influence patient outcomes following total joint arthroplasty.

Influence of Janus kinase inhibitors on early postoperative complications in patients with rheumatoid arthritis undergoing orthopaedic surgeries

OBJECTIVE

We retrospectively reviewed the records of rheumatoid arthritis (RA) patients who underwent orthopaedic surgery to examine the influence of the perioperative use of Janus kinase (JAK) inhibitors on early postoperative complications.

PATIENTS AND METHODS

Thirty-two patients with RA under disease control with JAK inhibitors who underwent 49 orthopaedic procedures were included in the study. Patient records after surgery were investigated for surgical site infection (SSI), delayed wound healing (DWH), a flare-up of the disease, preoperative and postoperative absolute lymphocyte counts (ALCs), venous thromboembolism, and other postoperative complications.

RESULTS

JAK inhibitors were continued during the perioperative period in 31 procedures. In the remaining 18 procedures, JAK inhibitors were discontinued perioperatively with a mean discontinuation period of 2.4 days. No instances of SSI were identified in any patient during at least 90 days' follow-up, while DWH was seen in one patient. Disease flare-up was noted in two patients after 3 and 9 days of discontinuation of JAK inhibitors, respectively. The ALCs significantly decreased on postoperative Day 1 (P < .0001), and there was a significant correlation between pre- and post-one-day ALCs (r = 0.75, P < .0001).

CONCLUSION

JAK inhibitors seem to be safe during the perioperative period of orthopaedic surgery.

What Is the Most Effective Treatment for Periprosthetic Joint Infection After Total Joint Arthroplasty in Patients with Rheumatoid Arthritis?: A Systematic Review

BACKGROUND

Rheumatoid arthritis (RA) is a risk factor for periprosthetic joint infection (PJI) after total joint arthroplasty (TJA). The purpose of this study was to perform a systematic review comparing the failure rates of debridement, antibiotics, and implant retention (DAIR), one-stage exchange arthroplasty/revision (OSR), and 2-stage exchange arthroplasty/revision (TSR) for RA patients with PJI and identify risk factors in the RA population associated with increased treatment failure rate.

METHODS

PubMed, Ovid MEDLINE, and Ovid Embase databases were screened with the terms "rheumatoid arthritis," "total joint arthroplasty," "prosthetic joint infection," and "treatment for PJI" on August 29, 2021. Four hundred ninety-one studies were screened, of which 86 were evaluated. The primary outcome evaluated was failure of surgical treatment for PJI.

RESULTS

Ten retrospective cohort studies were included after full-text screening, yielding 401 patients with RA. Additional demographic and PJI management data were obtained for 149 patients. Patients with RA who underwent TSR demonstrated a lower failure rate (26.8%) than both DAIR (60.1%) and OSR (39.2%) (χ2 = 37.463, p < 0.00001). Patients with RA who underwent DAIR had a 2.27 (95% CI, 1.66-3.10) times higher risk of experiencing treatment failure than those who underwent TSR. Among risk factors, there was a significant difference in the C-reactive protein of patients who did vs. did not experience treatment failure (p = 0.02).

CONCLUSION

TSR has a higher rate of success in the management of PJI patients with RA compared with DAIR and OSR. The complete removal of the infected prosthesis and delayed reimplantation may lower the treatment failure rate.

LEVEL OF EVIDENCE

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

Periprosthetic joint infection and immunity: Current understanding of host-microbe interplay

Periprosthetic joint infection (PJI) is a major complication of total joint arthroplasty. Even with current treatments, failure rates are unacceptably high with a 5-year mortality rate of 26%. Majority of the literature in the field has focused on development of better biomarkers for diagnostics and treatment strategies including innovate antibiotic delivery systems, antibiofilm agents, and bacteriophages. Nevertheless, the role of the immune system, our first line of defense during PJI, is not well understood. Evidence of infection in PJI patients is found within circulation, synovial fluid, and tissue and include numerous cytokines, metabolites, antimicrobial peptides, and soluble receptors that are part of the PJI diagnosis workup. Macrophages, neutrophils, and myeloid-derived suppressor cells (MDSCs) are initially recruited into the joint by chemokines and cytokines produced by immune cells and bacteria and are activated by pathogen-associated molecular patterns. While these cells are efficient killers of planktonic bacteria by phagocytosis, opsonization, degranulation, and recruitment of adaptive immune cells, biofilm-associated bacteria are troublesome. Biofilm is not only a physical barrier for the immune system but also elicits effector functions. Additionally, bacteria have developed mechanisms to evade the immune system by inactivating effector molecules, promoting killing or anti-inflammatory effector cell phenotypes, and intracellular persistence and dissemination. Understanding these shortcomings and the mechanisms by which bacteria can subvert the immune system may open new approaches to better prepare our own immune system to combat PJI. Furthermore, preoperative immune system assessment and screening for dysregulation may aid in developing preventative interventions to decrease PJI incidence.

Achieving High Accuracy in Predicting the Probability of Periprosthetic Joint Infection From Synovial Fluid in Patients Undergoing Hip or Knee Arthroplasty: The Development and Validation of a Multivariable Machine Learning Algorithm

Background and objective The current periprosthetic joint infection (PJI) diagnostic guidelines require clinicians to interpret and integrate multiple criteria into a complex scoring system. Also, PJI classifications are often inconclusive, failing to provide a clinical diagnosis. Machine learning (ML) models could be leveraged to reduce reliance on these complex systems and thereby reduce diagnostic uncertainty. This study aimed to develop an ML algorithm using synovial fluid (SF) test results to establish a PJI probability score. Methods We used a large clinical laboratory's dataset of SF samples, aspirated from patients with hip or knee arthroplasty as part of a PJI evaluation. Patient age and SF biomarkers [white blood cell count, neutrophil percentage (%PMN), red blood cell count, absorbance at 280 nm wavelength, C-reactive protein (CRP), alpha-defensin (AD), neutrophil elastase, and microbial antigen (MID) tests] were used for model development. Data preprocessing, principal component analysis, and unsupervised clustering (K-means) revealed four clusters of samples that naturally aggregated based on biomarker results. Analysis of the characteristics of each of these four clusters revealed three clusters (n=13,133) with samples having biomarker results typical of a PJI-negative classification and one cluster (n=4,032) with samples having biomarker results typical of a PJI-positive classification. A decision tree model, trained and tested independently of external diagnostic rules, was then developed to match the classification determined by the unsupervised clustering. The performance of the model was assessed versus a modified 2018 International Consensus Meeting (ICM) criteria, in both the test cohort and an independent unlabeled validation set of 5,601 samples. The SHAP (SHapley Additive exPlanations) method was used to explore feature importance. Results The ML model showed an area under the curve of 0.993, with a sensitivity of 98.8%, specificity of 97.3%, positive predictive value (PPV) of 92.9%, and negative predictive value (NPV) of 99.8% in predicting the modified 2018 ICM diagnosis among test set samples. The model maintained its diagnostic accuracy in the validation cohort, yielding 99.1% sensitivity, 97.1% specificity, 91.9% PPV, and 99.9% NPV. The model's inconclusive rate (diagnostic probability between 20-80%) in the validation cohort was only 1.3%, lower than that observed with the modified 2018 ICM PJI classification (7.4%; p<0.001). The SHAP analysis found that AD was the most important feature in the model, exhibiting dominance among >95% of "infected" and "not infected" diagnoses. Other important features were the sum of the MID test panel, %PMN, and SF-CRP. Conclusions Although defined methods and tools for diagnosis of PJI using multiple biomarker criteria are available, they are not consistently applied or widely implemented. There is a need for algorithmic interpretation of these biomarkers to enable consistent interpretation of the results to drive treatment decisions. The new model, using clinical parameters measured from a patient's SF sample, renders a preoperative probability score for PJI which performs well compared to a modified 2018 ICM definition. Taken together with other clinical signs, this model has the potential to increase the accuracy of clinical evaluations and reduce the rate of inconclusive classification, thereby enabling more appropriate and expedited downstream treatment decisions.

Diagnosis of periprosthetic joint infections in patients who have rheumatoid arthritis

Aims

To investigate the optimal thresholds and diagnostic efficacy of commonly used serological and synovial fluid detection indexes for diagnosing periprosthetic joint infection (PJI) in patients who have rheumatoid arthritis (RA).

Methods

The data from 348 patients who had RA or osteoarthritis (OA) and had previously undergone a total knee (TKA) and/or a total hip arthroplasty (THA) (including RA-PJI: 60 cases, RA-non-PJI: 80 cases; OA-PJI: 104 cases, OA-non-PJI: 104 cases) were retrospectively analyzed. A receiver operating characteristic curve was used to determine the optimal thresholds of the CRP, ESR, synovial fluid white blood cell count (WBC), and polymorphonuclear neutrophil percentage (PMN%) for diagnosing RA-PJI and OA-PJI. The diagnostic efficacy was evaluated by comparing the area under the curve (AUC) of each index and applying the results of the combined index diagnostic test.

Results

For PJI prediction, the results of serological and synovial fluid indexes were different between the RA-PJI and OA-PJI groups. The optimal cutoff value of CRP for diagnosing RA-PJI was 12.5 mg/l, ESR was 39 mm/hour, synovial fluid WBC was 3,654/μl, and PMN% was 65.9%; and those of OA-PJI were 8.2 mg/l, 31 mm/hour, 2,673/μl, and 62.0%, respectively. In the RA-PJI group, the specificity (94.4%), positive predictive value (97.1%), and AUC (0.916) of synovial fluid WBC were higher than those of the other indexes. The optimal cutoff values of synovial fluid WBC and PMN% for diagnosing RA-PJI after THA were significantly higher than those of TKA. The specificity and positive predictive value of the combined index were 100%.

Conclusion

Serum inflammatory and synovial fluid indexes can be used for diagnosing RA-PJI, for which synovial fluid WBC is the best detection index. Combining multiple detection indexes can provide a reference basis for the early and accurate diagnosis of RA-PJI.

Extensive subcutaneous emphysema of the thigh as a rare complication following total knee arthroplasty: A case report

INTRODUCTION AND IMPORTANCE OF THE CASE

This is the first report of subcutaneous emphysema of the thigh as a complication after total knee arthroplasty (TKA).

PRESENTATION OF CASE

A 78-year-old female patient with valgus knee arthropathy underwent TKA. Two days postoperatively, the patient experienced left thigh swelling and pain, and subcutaneous emphysema was detected upon palpation. Although the skin tone was comparable to the other side, the left thigh was tender and firm. The surgical wound did not exhibit erythema. Computed tomography imaging revealed emphysema in the subcutaneous and intermuscular regions of the left thigh. Gram stain and culture tests from arthrocentesis were negative, and blood culture results were also negative. As there was no fever or disturbance of consciousness, and the LRINEC score was 1, supportive care was provided to the patient. At 5 days postoperatively, there was an observable improvement in the emphysema, and by day 9 postoperatively, the emphysema had fully resolved.

CLINICAL DISCUSSION

There is a lack of documented cases reporting extensive subcutaneous emphysema of the thigh following TKA, suggesting it to be an exceedingly rare complication. In this case, we conducted a thorough investigation to assess the potential association of infection. Subsequently, the symptoms were successfully alleviated with supportive care without antibiotics.

CONCLUSION

The occurrence of subcutaneous emphysema in the thigh was identified as a postoperative complication following TKA. Blood tests, culture tests and LRINEC score can be valuable tools for differentiation.

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.

Perioperative management of patients with inflammatory rheumatic diseases : Updated recommendations of the German Society for Rheumatology

BACKGROUND

Prior to surgical interventions physicians and patients with inflammatory rheumatic diseases remain concerned about interrupting or continuing anti-inflammatory medication. For this reason, the German Society for Rheumatology has updated its recommendations from 2014.

METHODS

After a systematic literature search including publications up to 31 August 2021, the recommendations on the use of of glucocorticoids, conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and biologics (bDMARDs) were revised and recommendations on newer drugs and targeted synthetic (ts)DMARDs were added.

RESULTS

The glucocorticoid dose should be reduced to as low as possible 2-3 months before elective surgery (in any case <10 mg/day) but should be kept stable 1-2 weeks before and on the day of surgery. In many cases csDMARDs can be continued, exceptions being a reduction of high methotrexate doses to ≤15 mg/week and wash-out of leflunomide if there is a high risk of infection. Azathioprine, mycophenolate and ciclosporin should be paused 1-2 days prior to surgery. Under bDMARDs surgery can be scheduled for the end of each treatment interval. For major interventions Janus kinase (JAK) inhibitors should be paused for 3-4 days. Apremilast can be continued. If interruption is necessary, treatment should be restarted as soon as possible for all substances, depending on wound healing.

CONCLUSION

Whether bDMARDs increase the perioperative risk of infection and the benefits and risks of discontinuation remain unclear based on the currently available evidence. To minimize the risk of a disease relapse under longer treatment pauses, in the updated recommendations the perioperative interruption of bDMARDs was reduced from at least two half-lives to one treatment interval.

Role of Biomarkers in Periprosthetic Joint Infections

Periprosthetic joint infection (PJI) is one of the most serious complications after joint arthroplasty. The incidence rate of PJI after total joint replacement is 1-3%. Although there are different guidelines and diagnostic criteria used to diagnose PJI, diagnosing PJI is a highly difficult process for orthopedists. The current Musculoskeletal Infection Society (MSIS) criteria are widely used for the diagnosis of PJI. These criteria include results from blood/synovial fluid tests, physical examination, and histological and microbiological analyses of intra-operative samples. However, there is currently no blood or synovial test that can definitively diagnose PJI. To make a more effective diagnosis of PJI, a large number of studies have explored and continue to investigate biomarkers. This review aims to provide general information about serum and synovial markers used for the diagnosis of PJI that may be used to create a database to guide researchers in new studies.

Molecular Approach for the Laboratory Diagnosis of Periprosthetic Joint Infections

The incidence of total joint arthroplasty is increasing over time since the last decade and expected to be more than 4 million by 2030. As a consequence, the detection of infections associated with surgical interventions is increasing and prosthetic joint infections are representing both a clinically and economically challenging problem. Many pathogens, from bacteria to fungi, elicit the immune system response and produce a polymeric matrix, the biofilm, that serves as their protection. In the last years, the implementation of diagnostic methodologies reduced the error rate and the turn-around time: polymerase chain reaction, targeted or broad-spectrum, and next-generation sequencing have been introduced and they represent a robust approach nowadays that frees laboratories from the unique approach based on culture-based techniques.

[Continue or interrupt? Antirheumatic treatment in elective surgery]

In patients with inflammatory rheumatic diseases, a decision is needed prior to elective surgery on whether the medicinal treatment can be continued or whether the dose needs to be changed or interrupted. The German Society for Rheumatology (DGRh) has developed updated recommendations that specify a course of action for disease-modifying antirheumatic drugs (DMARD) and glucocorticoids. The recommendations for action can be adapted to the individual situation and coordinated with the interdisciplinary treating physicians and the patient. Depending on the dose, glucocorticoids have a high risk of infection and should be set as low as possible in the preoperative period. Most of the conventional synthetic (cs)DMARDs can be continued. Under biologic (b)DMARDs treatment surgery can be scheduled for the end of each treatment interval. It is recommended that Janus kinase (JAK) inhibitors should be interrupted for 3-4 days before major interventions. Treatment should be restarted as soon as possible, depending on the wound healing.

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

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

The accuracy of D-dimer in the diagnosis of periprosthetic infections: a systematic review and meta-analysis

Background

Periprosthetic joint infection (PJI) is a devastating complication after total hip arthroplasty (THA) or total knee arthroplasty (TKA). It is scarce and contradicting evidence supporting the use of serum D-dimer to diagnose PJI in revision THA and TKA. This systematic review and meta-analysis aimed to investigate the accuracy of D-dimer in the diagnosis of periprosthetic infections.

Methods

The PubMed, Embase, Web of Science were systematically searched from the inception dates to August 15, 2020. We included all diagnostic studies of D-dimer in the diagnosis of periprosthetic infections. The literature's quality was evaluated by the QUADAS-2 tool, and Stata16 and Revman5.3 software carried out the meta-analysis.

Results

Of 115 citations identified by the search strategy, 10 studies (comprising 1756 participants) met the inclusion criteria. The literature quality assessment results show that most of the literature is low-risk bias literature. The combined sensitivity of D-dimer in diagnosing periprosthetic infections was 0.81 (95% confidence interval [CI] 0.71–0.88), combined specificity was 0.74 (95% CI 0.61–0.84), combined positive likelihood ratio was 3.1 (95% CI 2.0–5.0), combined negative likelihood ratio 0.26 (95% CI 0.16–0.41), combined diagnosis odds ratio 12 (95% CI 5–27), area under the Summary Receiver Operator Characteristic Curve (SROC) is 0.85 (95% CI 0.81–0.88). The data are statistically significant.

Conclusion

D-dimer has a high diagnostic value in diagnosing PJI and has clinical significance in diagnosing periprosthetic infection. In addition, there are relatively few studies on the threshold of D-dimer, different sampling types, different laboratory detection methods, and different races, so more prospective trials with large samples, multi-centers, and scientific design should be carried out in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03001-y.

[Perioperative management of treatment of patients with inflammatory rheumatic diseases : Updated recommendations of the German Society of Rheumatology]

BACKGROUND

Prior to surgical interventions physicians and patients with inflammatory rheumatic diseases remain concerned about interrupting or continuing anti-inflammatory medication. For this reason, the German Society for Rheumatology has updated its recommendations from 2014.

METHODS

After a systematic literature search including publications up to 31 August 2021, the recommendations on the use of of glucocorticoids, conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and biologics (bDMARDs) were revised and recommendations on newer drugs and targeted synthetic (ts)DMARDs were added.

RESULTS

The glucocorticoid dose should be reduced to as low as possible 2-3 months before elective surgery (in any case <10 mg/day) but should be kept stable 1-2 weeks before and on the day of surgery. In many cases csDMARDs can be continued, exceptions being a reduction of high methotrexate doses to ≤15 mg/week and wash-out of leflunomide if there is a high risk of infection. Azathioprine, mycophenolate and ciclosporin should be paused 1-2 days prior to surgery. Under bDMARDs surgery can be scheduled for the end of each treatment interval. For major interventions Janus kinase (JAK) inhibitors should be paused for 3-4 days. Apremilast can be continued. If interruption is necessary, treatment should be restarted as soon as possible for all substances, depending on wound healing.

CONCLUSION

Whether bDMARDs increase the perioperative risk of infection and the benefits and risks of discontinuation remain unclear based on the currently available evidence. To minimize the risk of a disease relapse under longer treatment pauses, in the updated recommendations the perioperative interruption of bDMARDs was reduced from at least two half-lives to one treatment interval.

Postoperative Infection Risk in Total Joint Arthroplasty After Perioperative IV Corticosteroid Administration: A Systematic Review and Meta-Analysis of Comparative Studies

BACKGROUND

Perioperative corticosteroid administration is associated with reduced postoperative nausea, pain, and enhanced recovery after surgery. However, potential complications including wound and periprosthetic joint infections remain a concern for surgeons after total joint arthroplasty (TJA).

METHODS

A systematic review of the search databases PubMed, Google Scholar, and EMBASE was made in January 2021 to identify comparative studies evaluating infection risk after perioperative corticosteroid administration in TJA. PRISMA guidelines were used for this review. Meta-analysis was used to assess infection risk in accordance with joint and corticosteroid dosing regimen used.

RESULTS

201 studies were returned after initial search strategy, with 29 included for review after application of inclusion and exclusion criteria. Studies were categorized as using low- or high-dose corticosteroid with single or repeat dosing regimens. Single low-dose corticosteroid administration was not associated with an increased risk of infection (P = .4; CI = 0.00-0.00). Single high-dose corticosteroid was not associated with an increased infection risk (P = .3; CI = 0.00-0.01) nor did repeat low-dose regimens result in increased risk of infection (P = .8; CI = -0.02-0.02). Studies assessing repeat high-dosing regimens reported no increased infection, with small numbers of participants included. No significant risk difference in infection risk was noted in hip (P = .59; CI = -0.03-0.02) or knee (P = .2; CI = 0.00-0.01) arthroplasty. Heterogeneity in patient profiles included in studies to date was noted.

CONCLUSION

Use of perioperative corticosteroid in TJA does not appear to be associated with increased risk of postoperative infection in patients with limited comorbidities. Further research is warranted to evaluate postoperative complications after TJA in these at-risk patient populations.

Failure to Medically Optimize Before Total Hip Arthroplasty: Which Modifiable Risk Factor Is the Most Dangerous?

Background

There is mounting evidence that smoking, abnormal body mass index (BMI), uncontrolled diabetes, and poor nutritional status are associated with complications after total hip arthroplasty (THA). The goal of the present study was to evaluate the consequences of failure to medically optimize Medicare-eligible patients with respect to these key modifiable health targets by assessing complications in the early postoperative period after THA.

Methods

The National Surgical Quality Improvement Program database was queried for all primary THAs performed in 2018. Data were collected on preoperative serum albumin, BMI, diabetes, and tobacco use as well as postoperative infections, readmissions, complications, and mortality. We identified 47,924 THA patients with a median BMI of 29 kg/m² and age of 72 years, and 60% of whom were female.

Results

We found that preoperative albumin <3.5 g/dL, BMI ≥40 kg/m², tobacco use, and diabetes were all individually associated with increased risk of postoperative complications. Serum albumin <3.5 g/dL was the greatest overall risk factor for infection (odds ratio [OR]: 3.1, 95% confidence interval [CI]: 2.3-4.4, P < .0001), readmission (OR: 2.2, 95% CI: 1.9-2.5, P < .0001), any complication (OR: 4.2, 95% CI: 3.8-4.6, P < .0001), and mortality (OR: 7.5, 95% CI: 5.3-10.6, P < .0001).

Conclusions

Low albumin, elevated BMI, tobacco use, and diabetes are associated with increased risk of postoperative infection, readmission, any complication, and mortality after primary THA. Low albumin poses the greatest risk of these. Preoperative optimization should be obtained in all patients before elective surgery, and the final decision for surgery should be individually made between a surgeon and patient.

Level of Evidence

IV.

Preoperative optimization to prevent periprosthetic joint infection in at-risk patients

Periprosthetic joint infection (PJI) remains an important complication with devastating consequences after total joint arthroplasties. With the increasing number of arthroplasties worldwide, the number of PJI will increase correspondingly with a significant economic burden to our healthcare system. It is likely impossible to completely eradicate PJI; hence, assessment and optimization of its risk factors to preventing such a disastrous complication will be the key. There are many strategies to prevent PJI in the preoperative, intraoperative, or postoperative phases. The preoperative assessment provides a unique opportunity to screen and diagnose underlying comorbidities and optimize modifiable risk factors before elective surgeries. In this review, we will focus on current literature in preoperative assessment of various modifiable risk factors and share the experience and practical approach in our institution in preoperative optimization to reduce PJI in total joint arthroplasties.

Gout in primary total knee arthroplasty: Prevalent but not independently associated with complications

BACKGROUND

Gout is a common synovial pathology, but its prevalence in patients undergoing total knee arthroplasty (TKA) and potential association with complications such as periprosthetic infection (PJI) and revision are unknown.

METHODS

Medicare data from 2009 to 2013 was retrospectively reviewed using PearlDiver. All patients 65 years of age or older and undergoing primary TKA with at least 3 years of pre-TKA records were included. The prevalence of gout was based on ICD-9 codes. Univariable associations of gout with PJI and revision at 1 year were assessed using odds ratios with 95% confidence intrervals (C.I.). To control for potential confounding, patients with a history of gout were matched on age, gender, smoking history, and Elixhauser Comorbidity Index (ECI) to patients without gout and associations reassessed.

RESULTS

The prevalence of gout in Medicare patients undergoing primary TKA was 5.7%. On univariable analysis, patients with a history of gout were more likely to develop PJI (O.R., 1.58; 95% C.I., 1.45-1.72) and undergo revision (O.R., 1.33; 95% C.I., 1.25-1.41) at 1 year. After matching for confounders, a history of gout was no longer associated with developing PJI (O.R., 0.98; 95% C.I., 0.90-1.06) or undergoing revision (O.R., 0.94; 95% C.I., 0.89-1.00) at 1 year.

CONCLUSIONS

Gout is a relatively common pathology in patients undergoing TKA. While gout is associated with increased complications, this appears to be driven by confounding through its association with other medical comorbidities. Gout does not appear to be an independent risk factor for complications following TKA.

Reliability of d-Dimer Determination in Diagnosis of Peri-Prosthetic Joint Infection: A Systematic Review and Meta-Analysis

Background: Surgeons continue to seek indicators for the diagnosis of peri-prosthetic joint infection (PJI), which is a serious complication after total joint arthroplasty (TJA). Many recent studies have assessed the value of d-dimer in diagnosing PJI because of the close relation between the d-dimer value and inflammation. However, the conclusions from different studies are still disputed. Methods: We searched for studies published from 2011 to March 2020 using online databases and screened studies based on the inclusion criteria. Diagnostic parameters of d-dimer, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were calculated, including the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and the area under the curve (AUC). In addition, univariate meta-regression and subgroup analyses were performed to identify sources of heterogeneity. Results: A total of nine studies with 431 Patients with PJI were included. The pooled sensitivity, specificity, DOR, and AUC of d-dimer were 0.82 (95% confidence interval [CI], 0.73-0.89), 0.73 (95% CI, 0.58-0.83), 12 (95% CI, 5-30), and 0.85 (95% CI, 0.82-0.88), respectively. In addition, the sensitivity, specificity, and AUC of CRP were 0.78 (95% CI, 0.73-0.83), 0.80 (95% CI, 0.73-0.86) and 0.85 (95% CI, 0.81-0.87), respectively, whereas those of ESR were 0.68 (95% CI, 0.60-0.74), 0.83 (95% CI, 0.75-0.88), and 0.80 (95% CI, 0.76-0.83), respectively. Conclusions: d-dimer determination had similar performance to CRP and ESR in the diagnosis of PJI and may be a good addition to the current diagnostic criteria.

The global state of clinical research and trends in periprosthetic joint infection: A bibliometric analysis

OBJECTIVES

The purpose of this study was to estimate the trends and state of research in periprosthetic joint infection (PJI).

METHODS

Publications on PJI published between 1998 and 2018 were searched in the Web of Science database and analyzed using bibliometrics. The Altmetric score and Research Interest score were combined to provide a weighted count. The scope of the Altmetric score includes >16 weighted composite scores from websites such as Twitter, Facebook, and YouTube, whereas the Research Interest score is calculated from information derived from ResearchGate.

RESULTS

Total of 3245 published documents were identified. The largest contribution was made by the United States, with the institution contributing most being the Rothman Institute. The most relative articles were published by the Journal of Arthroplasty, whereas the highest citation frequency journal was Clinical Orthopaedics and Related Research. There was a positive correlation between citation counts and Research Interest scores, while the Altmetric Attention score showed a negative value for highly cited articles.

CONCLUSIONS

Based on the current trends of globalization, there is a rising trend in publications on PJI, with the largest annual contributions made by the United States. The most influential contributors are researchers from the United States and Europe. Twitter is used as a platform to communicate knowledge by most PJI researchers. The most recent research has focused on the diagnosis and risk factors of PJI.

Identification of high-risk groups for complication after arthroplasty: predictive value of patient's related risk factors

BACKGROUND

Total joint arthroplasty (TJA) benefit patients with osteoarthritis (OA) and rheumatoid arthritis (RA). However, a specific approach to detect patients at higher risk of prosthetic joint infection (PJI) and mechanical complications is absent. The aim of this study is to identify groups at higher risk for infections and mechanical complications after TJA in patients with RA and OA based on their most significant predictors.

METHODS

This is a hospital-based cohort study with 1150 recipients of TJA. Risk factors and comorbidities were assessed prior to the index surgery. Multivariate logistic and hazard regression were used to determine the relationship between risk factors and occurrence of complications after TJA. Odds ratios (OR), hazard ratios (HR), 95% confidence intervals (CI), and comparison between areas under the curve (AUC) using DeLong's method are presented.

RESULTS

Complications were more frequent in subjects with RA, use of corticosteroids, and previous comorbidities: respiratory disease, infections, diabetes, anemia, mental and musculoskeletal comorbidities than in subjects without these risk factors, and these factors were predictors of infections and mechanical complications (P < 0.05). A model including these factors was superior to a model with only type of joint disease (OA/RA) or age and gender to detect infections or mechanical complications after TJA (P < 0.05 for difference between models). Complication risk proportionally increased with the presence of two or more comorbidities (P < 0.001).

CONCLUSIONS

There are two groups at higher risk for infections after TJA: patients with OA with at least two risk factors and patients with RA, who usually present at least one of the risk factors for infection.