Septic arthritis

Dual neutralization of TGF-β and IL-21 regulates Th17/Treg balance by suppressing inflammatory signalling in the splenic lymphocytes of Staphylococcus aureus infection-induced septic arthritic mice

Septic arthritis (SA) caused by Staphylococcus aureus is a severe inflammatory joint disease, characterized by synovitis accompanied with cartilage destruction and bone erosion. The available antibiotic treatment alone is insufficient to resolve the inflammation that leads to high rates of morbidity and mortality. Among the CD4+ T helper lymphocytes, the Th17 and Tregs are key regulators of immune homeostasis. A high Th17 could lead to autoimmunity, whereas an increase in Tregs indicates immunosuppression. Depending on the external cytokine milieu, naïve CD4+ T cells transform into either Th17 or Treg cell lineage. TGF-β in the presence of IL-21 produces Th17 cells and drives the inflammatory cascade of reactions. We studied the effects of in vivo neutralization of TGF-β and IL-21 in septic arthritic mice to control arthritic inflammation, which has not been studied before. The arthritic index showed maximum severity in the SA group which substantially reduced in the Ab-treated groups. Flow cytometric analyses of peripheral blood collected from mice at 9DPI revealed the highest Th17/Treg ratio in the SA group but least in the combined-antibody-treated group. TGF-β1 and IL-21 cytokine production from serum, spleen, and synovial tissue homogenates was significantly reduced in the dual Ab-treated group than in the untreated SA group. From the Western blot analyses obtained from splenic lymphocytes at 9 DPI, we elucidated the possible underlying mechanism of interplay in downstream signalling involving the interaction between different STAT proteins and SOCS, NF-κB, RANKL, mTOR, iNOS, and COX-2 in regulating inflammation and osteoclastogenesis. On endogenous blockade with TGF-β and IL-21, the Th17/Treg ratio and resultant arthritic inflammation in SA were found to be reduced. Therefore, maintaining the Th17/Treg balance is critical to eradicate infection as well as suppress excessive inflammation and neutralization of TGF-β and IL-21 could provide a novel therapeutic strategy to treat staphylococcal SA.

[Septic musculoskeletal complications under immunomodulating treatment]

Infections are an important cause of morbidity and mortality in patients with inflammatory rheumatic diseases. Among these, musculoskeletal infections represent a relevant proportion as patients with rheumatoid arthritis face an increased risk of developing septic arthritis and prosthesis infections. The causes are multifactorial. In addition to immunosuppressive treatment, risk factors of infection in rheumatoid arthritis (RA) patients include repeated intra-articular joint punctures, an increased rate of joint replacement surgery, damaged joint structure and comorbidities. The use of glucocorticoids and tumor necrosis factor alpha (TNF-alpha) inhibitors, especially in the first 6 months of treatment, increase the risk of septic arthritis and periprosthetic joint infections. In addition, an increased disease activity could also be identified as a risk factor. Under immunosuppressive therapy rare pathogens such as Candida and mycobacteria can cause the infection and should be considered when there is a lack of clinical response to antibiotic treatment.

Pneumococcal Septic Arthritis among Adults, France, 2010-2018

Streptococcus pneumoniae infection is considered an uncommon cause of arthritis in adults. To determine the clinical and microbiological characteristics of pneumococcal septic arthritis, we retrospectively studied a large series of cases among adult patients during the 2010-2018 conjugate vaccine era in France. We identified 110 patients (56 women, 54 men; mean age 65 years), and cases included 82 native joint infections and 28 prosthetic joint infections. Most commonly affected were the knee (50/110) and hip (25/110). Concomitant pneumococcal infections were found in 37.2% (38/102) and bacteremia in 57.3% (55/96) of patients, and underlying conditions were noted for 81.4% (83/102). Mortality rate was 9.4% (8/85). The proportion of strains not susceptible to penicillin was 29.1% (32/110). Of the 55 serotyped strains, 31 (56.4%) were covered by standard pneumococcal vaccines; however, several nonvaccine serotypes (mainly 23B, 24F, and 15A) had emerged, for which susceptibility to β-lactams was low.

Two-stage total joint replacement for hip or knee septic arthritis: post-traumatic etiology and difficult-to-treat infections predict poor outcomes

PURPOSE

Septic arthritis (SA) is a rare but significant clinical challenge in orthopedics that can impact patients' quality of life. This study aims to examine the clinical outcomes of patients undergoing two-stage total joint replacement (TJR) in hip and knee SA and analyze potential predictors of treatment failure.

METHODS

A retrospective analysis was conducted using data from a prospectively collected institutional arthroplasty registry from January 1st, 2012, to January 1st, 2019. Patients with hip or knee SA who underwent a two-stage TJR and had at least two years of follow-up were included. Demographic characteristics, surgical variables, and outcomes were collected and analyzed from clinical and surgical data. Statistical analysis was performed using IBM SPSS Statistics, with statistical significance at p < 0.05.

RESULTS

One hundred and fourteen patients (61 with hip SA, 53 with knee SA) were included in the study. The mean follow-up was 72.8 months. Postoperatively, both clinical and functional outcomes significantly improved, as indicated by the Hip Society Score (HHS) and Knee Society Score (KSS). The overall success rate of the two-stage protocol was 89.5%. Complications that did not require revision occurred in 21% of cases. The most identified pathogen was methicillin-sensitive Staphylococcus aureus (MSSA). Difficult-to-treat (DTT) infections and post-traumatic etiology were identified as predictors of treatment failure in patients undergoing two-stage TJR for hip and knee SA.

CONCLUSIONS

Two-stage TJR in hip and knee SA demonstrated favorable clinical outcomes at mid-term follow-up. The procedure significantly improved functional scores and achieved a high success rate, while DTT infections and post-traumatic etiology were associated with a higher risk of treatment failure.

Glenohumeral joint septic arthritis and osteomyelitis caused by Moraxella catarrhalis after arthroscopic rotator cuff repair: case report and literature review

Moraxella catarrhalis commonly colonizes the upper respiratory tract of humans, but infection caused by M. catarrhalis after orthopedic surgery is rare. Here, we report the first case of septic arthritis of the shoulder caused by an M. catarrhalis infection and outline the diagnosis and treatment steps as well as differences compared with other cases.

Increased Incidence and Clinical Features of Septic Arthritis in Patients Aged 80 Years and above: A Comparative Analysis with Younger Cohorts

BACKGROUND

This study aimed to determine the incidence of septic arthritis across adult age groups in Västra Götaland Region (VGR) of Sweden, while also comparing disease characteristics among different age groups with hematogenous septic arthritis.

METHODS

Using ICD-10 codes for septic arthritis from 2016 to 2019, we identified 955 patients in VGR. We reviewed the medical records of 216 adult patients with hematogenous septic arthritis and compared data across age groups.

RESULTS

The overall incidence of septic arthritis in adults was 4 per 100,000 persons annually, rising to 14 per 100,000 in those ≥80 years. The median age of the 216 patients was 71. The comparison across age groups (18-64, 65-79, and ≥80) showed significantly longer hospital stays and higher mortality rate in the older groups. CRP levels were higher in the middle age group, SF-WBC counts were lower in the youngest age group, and synovial fluid crystals were more common in the oldest. No differences were found in joint involvement or the organisms isolated.

CONCLUSION

The incidence of septic arthritis is 6.5 times higher in patients aged ≥ 80 compared to those under 65, highlighting the need to consider age-related differences in disease management.

Bactericidal behavior of silver nanoparticle decorated nano-sized magnetic hydroxyapatite

Methicillin-resistant Staphylococcus aureus (MRSA) is the most common cause of acute bacterial arthritis. Due to the increase in antibiotic resistance in these bacteria, the discovery of new antibacterial agents has become one of the hot topics in the scientific community. Here, we prepared a nano-sized porous biocompatible magnetic hydroxyapatite through a solvothermal method. Then, we adopted a post-synthesis modification strategy to modify its surface for the stabilization of Ag NPs through a green reduction by the euphorbia plant extract. Moreover, the results show that the prepared composite perfectly prevents the aggregation of Ag NPs. This composite was used as a bactericidal and antibiofilm agent against MRSA bacteria in an in vitro environment, which showed excellent results. Also, the cell viability assay indicates that the prepared composite has low cytotoxicity, making it a perfect antibacterial agent for in vivo experiments.

How to Approach the Imaging Differential Diagnosis of Rheumatic Diseases by Anatomic Location

The purpose of this review is to present an approach to differential diagnosis based on the particular features of involvement of the most common rheumatological conditions focused on anatomic location (by joint). The most common radiological signs and how they are demonstrated in different modalities, as well as the typical patterns of involvement are analyzed, with the aim to facilitate the differential diagnosis. Early and adequate adjustment of treatment has an effect on outcome, and on this basis, early diagnosis and characterization are paramount to appropiately manage patients.

Pathophysiology and Evolving Treatment Options of Septic Arthritis: A Narrative Review

Pyogenic (septic) arthritis is a severe joint infection characterized by the invasion of microorganisms into the synovium, causing inflammation and joint destruction. This review article provides a comprehensive overview of pyogenic arthritis, focusing on etiology, pathogenesis, clinical manifestations, diagnosis, and management strategies. This review explores routes of microbial entry into joints, emphasizing the importance of prompt identification and treatment to prevent irreversible joint damage. Clinical manifestations, such as joint pain, swelling, and limited range of motion, are discussed, along with the challenges in differentiating pyogenic arthritis from other joint disorders. Diagnostic approaches, including joint aspiration and imaging modalities, are critically examined for accuracy in confirming diagnosis. This review also addresses the significance of early intervention through antimicrobial therapy and joint drainage, highlighting the role of multidisciplinary collaboration in optimizing patient outcomes. In summary, the present investigation underscores the complexities of pyogenic arthritis and the need for a comprehensive understanding of pathophysiology for timely and effective management to improve patient prognosis and quality of life.

Application of Nuclear Medicine Techniques in Musculoskeletal Infection: Current Trends and Future Prospects

Nuclear medicine has become an indispensable discipline in the diagnosis and management of musculoskeletal infections. Radionuclide tests serve as a valuable diagnostic tool for patients suspected of having osteomyelitis, spondylodiscitis, or prosthetic joint infections. The choice of the most suitable imaging modality depends on various factors, including the affected area, potential extra osseous involvement, or the impact of previous bone/joint conditions. This review provides an update on the use of conventional radionuclide imaging tests and recent advancements in fusion imaging scans for the differential diagnosis of musculoskeletal infections. Furthermore, it examines the role of radionuclide scans in monitoring treatment responses and explores current trends in their application. We anticipate that this update will be of significant interest to internists, rheumatologists, radiologists, orthopedic surgeons, rehabilitation physicians, and other specialists involved in musculoskeletal pathology.

Developing an antibiogram for empiric antibiotic prescribing for adult non-spinal orthopaedic infections in a developing world setting

PURPOSE

Empiric antibiotic strategies in the treatment of fracture-related infections, chronic osteomyelitis, prosthetic joint infection, and septic arthritis should be based on local microbiological antibiograms. This study aims to describe the microbiology and review the antibiogram profiles of bacterial isolates from patients undergoing surgical treatment for non-spinal orthopaedic infections, to identify the most appropriate empiric antibiotic strategy.

METHODS

A retrospective review was performed of all cases of non-spinal orthopaedic infections treated surgically from 1 January 2018 to 31 December 2018. The National Health Laboratory Service microbiology database was used to identify all intra-operative microbiological specimens obtained from orthopaedic patients, and data were correlated with the orthopaedic surgical database. Cases were divided into fracture-related infections, chronic osteomyelitis, prosthetic joint infection, and septic arthritis. Antibiotic susceptibility data were used to predict the efficacy of different empiric antibiotic regimens.

RESULTS

A total of 107 cases were included in the study; 184 organisms were cultured. Overall, the most common organism cultured was Staphylococcus aureus (25%) followed by Acinetobacter baumannii (9%), Enterococcus faecalis (7%) and Enterobacter cloacae (5%). Across all categories the oral antibiotic combination with the highest effectiveness (81%) would have been a combination of co-trimoxazole, ciprofloxacin and amoxicillin. The most effective intravenous antibiotic combination would have been either piperacillin-tazobactam, amikacin and vancomycin or meropenem and vancomycin; 90% of tested isolates were susceptible to either of these combinations.

CONCLUSION

Antibiogram profiles can serve to guide to empiric antibiotic choice in the management of different categories of non-spinal orthopaedic infections.

Disseminated gonococcal infection of the shoulder mimicking rheumatoid arthritis

Introduction

Gonococcal arthritis is a characteristic of disseminated gonococcal infection (DGI). DGI arthritis is one of the most serious orthopedic emergencies because it can result in rapidly progressive joint damage, but it is often difficult to diagnose. Delayed treatment can result in the development of osteomyelitis in the adjacent bone, similar to other types of bacterial arthritis.

Method

We report a case of gonococcal osteomyelitis associated with DGI that was initially treated as rheumatoid arthritis. The diagnosis was confirmed by DNA testing of synovium collected during arthroscopic debridement.

Results

Seven years after the initial consultation, there was no acute-phase reactant, the arthritic changes had improved over time and the range of motion had increased. DGI may be difficult to confirm, but it is one of the most important entities that should be differentiated in the treatment of arthritis.

Conclusion

Clinicians need to keep in mind that blood and synovial fluid cultures often do not lead to a definitive diagnosis.

The evaluation, classification, and management of septic arthritis of the shoulder: the comprehensive shoulder sepsis system

BACKGROUND

Septic arthritis of the shoulder is distinctly challenging to diagnose and treat. Guidelines for appropriate workup and management are limited and do not account for the variations in clinical presentation. The purpose of this study was to present a comprehensive and anatomically based classification system and treatment algorithm for septic arthritis of the native shoulder joint.

METHODS

A multicenter, retrospective analysis of all patients treated surgically for septic arthritis of the native shoulder joint was performed at 2 tertiary care academic institutions. Preoperative magnetic resonance imaging and operative reports were used to classify patients as having 1 of 3 infection subtypes: type I, confined to the glenohumeral joint; type II, extra-articular extension; or type III, concomitant osteomyelitis. On the basis of these clinical groupings of patients, the comorbidities, types of surgical management, and outcomes were analyzed.

RESULTS

Sixty-five shoulders in 64 patients met the inclusion criteria for the study. Of these infected shoulders, 9.2% had type I infections, 47.7% had type II, and 43.1% had type III. Age and the time between symptom onset and diagnosis were the only significant risk factors for the development of a more severe infection. Fifty-seven percent of shoulder aspirates revealed cell counts below the standard surgical cutoff of 50,000 cells/mL. On average, each patient required 2.2 surgical débridements to eradicate the infection. Infections recurred in 8 shoulders (12.3%). Body mass index was the only risk factor for recurrence of infection. Of the 64 patients, 1 (1.6%) died acutely of sepsis and multiorgan system failure.

CONCLUSION

We propose a comprehensive system for the classification and management of spontaneous shoulder sepsis based on stage and anatomy. Preoperative magnetic resonance imaging can help determine the severity of disease and aid in surgical decision making. A systematic approach to septic arthritis of the shoulder as a unique entity from septic arthritis of other large peripheral joints may lead to more timely diagnosis and treatment and improve the overall prognosis.

Gonococcal septic arthritis of the sternoclavicular joint: A case report

Gonococcal septic arthritis is a rare condition that most frequently involves the interphalangeal joints of the hands, wrists, knees, and ankles. We report a case of monoarticular gonococcal septic arthritis of the sternoclavicular joint in the absence of pharyngeal or genitourinary symptoms in a patient with a history of arthropathy and intravenous drug use. This case report aims to describe the clinical features and management of gonococcal arthritis.

Aspergillus fumigatus Septic Arthritis of the Wrist: A Report of a Rare Case in an Immunocompromised Patient

Aspergillus fumigatus is a saprophytic fungus encountered as a pathogen in airborne lung infections. Although it commonly causes pulmonary infectious diseases, when disseminated, it may cause a systemic infection termed invasive aspergillosis, which is associated with high mortality and morbidity. Virtually, all organ systems may be involved. However, the musculoskeletal system is relatively uncommon. Here, we present a case of invasive aspergillosis in an immunocompromised patient involving the wrist joint, an exceedingly rare site. Our treatment choice is serial open debridement, irrigation, and intravenous antibiotics. This case study exemplifies the potential challenges in the identification and treatment of such an uncommon clinical condition. A thorough clinical and microbiological evaluation is essential for accurate diagnosis of fungal septic arthritis of the wrist. Aggressive early surgical treatment combined with appropriate early intravenous antibiotics is crucial for eradicating joint infection.

Mid- to Long-Term Survival of Geriatric Patients with Primary Septic Arthritis of the Shoulder: A Retrospective Study over a Period of 20 Years

Septic arthritis of the shoulder is an urgent medical emergency that often occurs in elderly patients and is associated with high morbidity and mortality. Retrospectively, 56 patients aged ≥60 years, treated for primary septic monoarthritis of the shoulder at a maximum care hospital between 1 July 2001, and 30 July 2022, were included in this study. The primary aim of the study was analyzing survival rates and different bacteria in these patients. For statistical analysis, Kaplan-Meier curves were used for survival probability and the log-rank test was used to compare a survival probability of 5 years. The mean patient age was 78.7 years and a mean follow-up time of 3011.8 days. The mean survival of the entire study population was 920.3 days or 2.5 years. Significantly impaired 5-year survival was found only with increasing age and higher American Society of Anesthesiologists (ASA) physical status (PS) classification scores. Eight different types of bacteria were detected in the synovial fluid cultures. A total of 42 of 48 overall pathogens was Gram-positive and 6 were Gram-negative bacteria. Staphylococcus aureus was identified as the most frequent variant. We conclude that the mean survival is significantly shortened within the first 5 years with increasing age and ASA PS classification.

No more tears from surgical site infections in interventional pain management

As the field of interventional pain management (IPM) grows, the risk of surgical site infections (SSIs) is increasing. SSI is defined as an infection of the incision or organ/space that occurs within one month after operation or three months after implantation. It is also common to find patients with suspected infection in an outpatient clinic. The most frequent IPM procedures are performed in the spine. Even though primary pyogenic spondylodiscitis via hematogenous spread is the most common type among spinal infections, secondary spinal infections from direct inoculation should be monitored after IPM procedures. Various preventive guidelines for SSI have been published. Cefazolin, followed by vancomycin, is the most commonly used surgical antibiotic prophylaxis in IPM. Diagnosis of SSI is confirmed by purulent discharge, isolation of causative organisms, pain/tenderness, swelling, redness, or heat, or diagnosis by a surgeon or attending physician. Inflammatory markers include traditional (C-reactive protein, erythrocyte sedimentation rate, and white blood cell count) and novel (procalcitonin, serum amyloid A, and presepsin) markers. Empirical antibiotic therapy is defined as the initial administration of antibiotics within at least 24 hours prior to the results of blood culture and antibiotic susceptibility testing. Definitive antibiotic therapy is initiated based on the above culture and testing. Combination antibiotic therapy for multidrug-resistant Gram-negative bacteria infections appears to be superior to monotherapy in mortality with the risk of increasing antibiotic resistance rates. The never-ending war between bacterial resistance and new antibiotics is continuing. This article reviews prevention, diagnosis, and treatment of infection in pain medicine.

Neisseria gonorrhoeae arthritis in a patient with systemic lupus: resistance and virulence profiles

In this study, we describe a case report of gonococcal arthritis in a Systemic Lupus Erythematosus patient. Although several mechanisms favor disseminated gonococcal infection (DGI) in patients immunosuppressed by SLE, this association is rarely reported in literature. We performed whole genome sequencing (WGS) of the etiologic agent involved and molecular analysis using a global collection of Neisseria gonorrhoeae strains. Ours is the only sample derived from synovial fluid identified in this collection, the others being from the usual anatomical sites. Antimicrobial susceptibility was determined by disk diffusion and Etest, and WGS was conducted to determine multilocus sequence typing profiles, group isolates based on core genome single nucleotide polymorphisms (SNP), and identify virulence genes and antimicrobial resistance determinants. The N. gonorrhoeae samples in the global collection were highly heterogeneous. The SNP tree had a total 19,532 SNPs in 320 samples. Our sample displayed resistance to ciprofloxacin (MIC = 2 μg/mL) and tetracycline (zone diameter = 0 mm) belonged to ST 1588 and was not closely related to any isolate in the global collection of N. gonorrhoeae strains. The isolate had genetic features related to beta-lactam, tetracycline and quinolone resistance. Seventy-one virulence genes were identified in our sample, belonging to the following classes: adherence, efflux pump, immune modulator, invasion, iron uptake, protease and stress adaptation. Moreover, no virulence genes for immune evasion and toxin were identified.

Reduced Costs, Complications, and Length of Stay After Arthroscopic Versus Open Irrigation and Débridement for Knee Septic Arthritis

BACKGROUND

In the treatment of native knee bacterial septic arthritis, the optimal irrigation and débridement modality-arthroscopic versus open-is a matter of controversy. We aim to compare revision-free survival, complications, and resource utilization between these approaches.

METHODS

The National Readmission Database was queried from 2016 to 2019 to identify patients using International Classification of Diseases, 10th revision, diagnostic and procedure codes. Days to revision irrigation and débridement (I&D), if any, were calculated for patients during index admission or subsequent readmissions. Multivariate regression was used for healthcare utilization analysis. Survival analysis was done using Kaplan-Meier analysis and Cox proportional hazard regression.

RESULTS

A total of 14,365 patients with native knee septic arthritis undergoing I&D were identified, 8,063 arthroscopic (56.1%) and 6,302 open (43.9%). The mean follow-up was 148 days (interquartile range 53 to 259). A total of 2,156 patients (15.0%) underwent revision I&D. On multivariate analysis, arthroscopic I&D was associated with a reduction in hospital costs of $5,674 and length of stay of 1.46 days (P < 0.001 for both). Arthroscopic I&D was associated with lower overall complications (odds ratio [OR] 0.63, P < 0.001), need for blood transfusion (OR 0.58, P < 0.001), and wound complications (OR 0.32, P < 0.001). Revision-free survival after index I&D was 95.3% at 3 days, 91.0% at 10 days, 88.3% at 30 days, 86.0% at 90 days, and 84.5% at 180 days. No statistically significant difference was observed between surgical approaches on Cox modeling.

DISCUSSION

Risk of revision I&D did not differ between arthroscopic and open I&D; however, arthroscopy was associated with decreased costs, length of stay, and complications. Additional study is necessary to confirm these findings and characterize which patients require an open I&D.

LEVEL OF EVIDENCE

III.

Less Than 1-Year Quiescent Period After Septic Arthritis of the Hip is Associated With High Risk of Periprosthetic Joint Infection Following Total Hip Arthroplasty

BACKGROUND

Approximately 20,000 patients are diagnosed with septic arthritis annually, with 15% specifically affecting the hip joint. These cases exacerbate arthritic changes, often warranting a total hip arthroplasty (THA). Given their prior history of infection, these patients are predisposed to subsequent periprosthetic joint infections (PJIs). Multiple studies suggest delaying THA after a native septic hip, but no study utilizing a large cohort examined the specific timing to mitigate post-THA PJI risk within a short (<1 year) quiescent period after septic arthritis. We sought to compare patients who were diagnosed with septic hip arthritis at time intervals (0-6, or 6-12 months) prior to an ipsilateral primary THA to a cohort of THA patients who never had a septic hip history. Specifically, we assessed: from 90 days to 2 years (1) revisions due to PJI and (2) associated risk factors for PJI at 2-years.

METHODS

A national, all-payer database was queried to identify all patients who underwent a primary THA between 2010 and 2021 and patients who had prior ipsilateral septic hip arthritis were characterized using International Classification of Disease and Current Practice Terminology codes (n = 1,052). A randomized sample of patients who never had a history of septic arthritis prior to undergoing THA was used as a nonseptic group comparison (n = 5,000). The incidences of PJI at 90 days through two years were then identified and compared using bivariate chi-square analyses. Risk factors for post-THA PJIs were then analyzed using multivariate regression models.

RESULTS

The septic arthritis cohorts were more likely to require revisions due to PJIs, as compared to the non-septic group at 90 days, 1 year, and 2 years (all P < .0001). Patients who were diagnosed with septic arthritis between 0 and 6 months prior to THA were at greater PJI risk at both one-year (odds ratio (OR) of 43.1 versus 29.6, P < .0001) and two years (OR of 38.3 versus 22.1, P < .0001) compared to patients who had diagnoses between 6 and 12 months. Diabetes mellitus, obesity, and tobacco use were associated risk factors for PJIs at 2 years in the septic hip cohort in comparison to the cohort without a septic hip history.

CONCLUSION

Less than a 1-year quiescent period after septic arthritis is associated with a 38 times increased risk and a 22 times risk for post-THA PJI, at 0 and 6 months and 6 and 12 months, respectively. Though patients who undergo THA greater than 6 months after their septic arthritis treatment have a decreased risk compared to those between 0 and 6 months the risks are still high. Orthopaedic surgeons should be aware of the increased risks of PJIs when considering performing a THA in patients with a history of septic arthritis.

Therapeutic Effects of Boric Acid in a Septic Arthritis Model Induced by Escherichia coli in Rats

The study aimed to evaluate the therapeutic effect of boric acid (BA) in experimentally induced septic arthritis. A total of 30 rats, 6 rats in each group (5 groups), were used in the study. No treatment was applied to the rats in the control group. Only BA was administered intraperitoneally (IP) to the rats in the bor group. Escherichia coli was administered at a single dose of 25 μL, 1 × 10¹⁰ cfu/rat from the right foot pad of the rats, via intra-articular route, to the mice in the arthritis, arthritis-bor, and arthritis-antb groups. Then, BA at a dose of 50 mg/kg and cefazolin at a dose of 25 mg/kg were administered to the rats in the arthritis-bor and arthritis-antb groups, respectively, for 7 days via the IP route. At the end of the study, all animals were euthanized following the ethical rules. Blood and tissue samples were taken from the rats for biochemical and histopathological analyses. The levels of GSH, MDA, Endoglin, Endocan, and TNF-β markers were measured in the blood samples taken. A significant decrease was observed in MDA and Endoglin levels in the boric acid-administered group compared with the arthritis group, while a significant increase was observed at the GSH level. Histopathologically, it was determined that the reactive surrounding tissue response in the bor group was significantly reduced. As a result, a significant decrease in inflammation was found biochemically and histopathologically in the groups treated with BA.

Simultaneous occurrence of knee septic arthritis and coronavirus disease 2019 (COVID-19): A case report

Background

Coronavirus disease 2019 (COVID-19) pandemic is increasingly recognized as a serious, worldwide public health concern. Most of the patients with COVID-19 are asymptomatic or show mild symptoms. It is important to identify the unusual manifestations and their long-term complication.

Case presentation

A case of COVID-19 in 45 years old man with septic arthritis due to Staphylococcus aureus is presented. COVID-19 was diagnosed using real-time polymerase chain reaction without obvious clinical manifestation. The patient had no history of trauma or inflammatory arthritis and had progressive left knee pain and limitation of movement. Knee X-ray was normal. Aspiration of the knee joint fluid showed a cloudy and purulent appearance. The patient was admitted to hospital and immediately treated with vancomycin 1gr/12 hr. A polymerized chain reaction (PCR) test for COVID-19 was performed, which was positive 24 h after hospitalization. Staphylococcus aureus was reported in synovial fluid culture which was sensitive to vancomycin and ciprofloxacin, thus vancomycin was continued. On the 4th day of hospitalization the patient had cough, therefore underwent CT scan lungs and ground-glass opacities (GGO) characteristic of COVID-19 were noticed. Favipiravir and interferon were started. Patient's knee aspiration was performed for 5 consecutive days. On the 6th day of hospitalization, joint fluid markedly decreased and the patient's oxygen saturation was 96%. One week after hospitalization, the patient was discharged and a month later knee examination was completely normal.

Conclusions

Septic arthritis should be considered in the manifestations or co-morbidity of COVID-19 patients with joint pain, swelling or redness.

Klebsiella pneumoniae and Enterobacter cloacae Induced Septic Arthritis in a Healthy Adolescent: A Rare Case Report

Septic arthritis (SA) is a joint inflammation that develops secondary to infectious causes. SA in children is associated with a high rate of morbidity and mortality; therefore, it is regarded as an orthopedic emergency. Because SA of the hip joint usually mimics other musculoskeletal diseases, diagnosis remains challenging. Although this lesion usually shows a good outcome, treatment at an inappropriate time, neglect, or inadequate treatment could lead to poor outcomes. We report on the case of a healthy adolescent who complained of episodes of fever and chills, weight loss, pain in his left hip, and limping. After performing necessary workups, two differential diagnoses of tumor and SA were made. The results of Gram stain and culture of the synovial fluid after surgical excision showed Klebsiella pneumoniae and Enterobacter cloacae complex. To the best of our knowledge, this is the first report of SA due to co-infection with K. pneumoniae and E. cloacae in a healthy patient.

Elbow Septic Arthritis caused by Klebsiella pneumoniae in a Newborn - Case Report and Literature Review

Septic arthritis is a rare condition in children, especially in neonates. Early recognition and proper treatment are required to avoid serious complications. We present the case of a male newborn diagnosed with septic arthritis of the right elbow who was treated with repeated joint aspiration and i.v. antibiotics (Amikacin and Meropenem). Blood culture and joint cultures were positive for Klebsiella pneumoniae. The final outcome was good, with no apparent local or systemic complications. General considerations regarding this rare condition, etiology and treatment options are also included in the paper.

Septic Arthritis of Neonates: Descriptive Study of a Neonatal Intensive Care Unit Nosocomial Outbreak

Purpose 

This is a retrospective descriptive study of a nosocomial outbreak of septic arthritis in a neonatal intensive care unit with a Pseudomonas species as the predominant organism. There have been no previous reports of the same. The risk factors for this disease were analysed. The different diagnostic modalities that we used are described and the short-term outcomes are reported after antibiotic therapy and surgery.

Methods 

Fourteen patients and 16 joints were included in the study over a three-month period. The risk factors were analysed from the records and included prematurity, birth weight, sex and joint predilection. The causative organisms were also analysed from microbiological profiling. The outcomes after surgery and adjunctive antibiotic therapy were analysed in terms of clinical and laboratory parameters.

Results 

Pseudomonasaeruginosa was found to be the predominant organism in this series. The hip joint was predominantly involved and the majority of the patients were found to be premature. All the neonates affected were found to have low birth weight.

Conclusion 

Prematurity and low birth weight were found to have an association with risk for septic arthritis. In our setting of a nosocomial outbreak, a Pseudomonas species was more common than other organisms. A treatment regimen of arthrotomy surgery and adjunctive antibiotic therapy was found to be effective in all our patients.

Two-Stage Total Hip Arthroplasty for Primary Advanced Septic Arthritis of the Hip in Adults

Background

Comparing the outcomes of debridement and total hip arthroplasty (THA) with antibiotic-loaded spacer implantation and subsequent THA for the treatment of patients affected by primary advanced septic arthritis (SA) of the hip in adults.

Methods

All of the 20 patients (20 hips) underwent two-stage surgery. Nine patients were submitted to surgical debridement first and then THA (group 1), while 11 patients were treated with antibiotic-loaded spacer and subsequent THA (group 2). Patients were evaluated based on the recurrence of infection, Harris hip score, visual analogue scale (VAS) pain score, and leg length discrepancy.

Results

No cases of infection, deep vein thrombosis, death, and loosening of the hip prosthesis were observed during follow-up. The mean follow-up time was 29.09 ± 10.80 months in group 1 and 28.22 ± 14.80 months in group 2. Before the THA surgery, the mean leg length discrepancy was 2.80 ± 2.03 cm in group 1 and 0.50 ± 0.23 cm in group 2 (P < 0.05). In the latest follow-up, the Harris hip scores of patients were 90.33 ± 4.85 in group 1 and 94.36 ± 2.34 in group 2 (P < 0.05), respectively. There was no statistically significant difference in the VAS pain score of the hip between the two groups (P > 0.05).

Conclusions

Debridement and antibiotic-loaded spacer and subsequent THA were effective in eradicating the infection for advanced SA. However, antibiotic-loaded spacer and subsequent THA was superior for effectively maintaining the length of the lower limb and function of the hip.

Microbiological pathogen analysis in native versus periprosthetic joint infections: a retrospective study

BACKGROUND

The presence or absence of an implant has a major impact on the type of joint infection therapy. Thus, the aim of this study was the examination of potential differences in the spectrum of pathogens in patients with periprosthetic joint infections (PJI) as compared to patients with native joint infections (NJI).

METHODS

In this retrospective study, we evaluated culture-positive synovial fluid samples of 192 consecutive patients obtained from January 2018 to January 2020 in a tertiary care university hospital. For metrically distributed parameters, Mann-Whitney U was used for comparison between groups. In case of nominal data, crosstabs and Chi-squared tests were implemented.

RESULTS

Overall, 132 patients suffered from periprosthetic joint infections and 60 patients had infections of native joints. The most commonly isolated bacteria were coagulase-negative Staphylococci (CNS, 28%), followed by Staphylococcus aureus (S. aureus, 26.7%), and other bacteria, such as Streptococci (26.3%). We observed a significant dependence between the types of bacteria and the presence of a joint replacement (p < 0.05). Accordingly, detections of CNS occurred 2.5-fold more frequently in prosthetic as compared to native joint infections (33.9% vs. 13.4% p < 0.05). In contrast, S. aureus was observed 3.2-fold more often in NJIs as compared to PJIs (52.2% vs. 16.4%, p < 0.05).

CONCLUSION

The pathogen spectra of periprosthetic and native joint infections differ considerably. However, CNS and S. aureus are the predominant microorganisms in both, PJIs and NJIs, which may guide antimicrobial therapy until microbiologic specification of the causative pathogen.

[Management of joint empyema]

Joint empyema, also known as septic arthritis, is a severe disease associated with considerable morbidity and mortality. Failing to initiate immediate treatment can result in irreversible joint destruction within a short time. The knee joint is most frequently involved, followed by the shoulder and hip joints. Small joints are rarely affected. Typical risk factors include immunosuppression, renal insufficiency, diabetes mellitus and previous joint interventions. An early targeted diagnostic work-up and initiation of therapeutic steps is crucial to avoid irreversible joint destruction. Joint aspiration for diagnostic purposes is essential and should be performed immediately when a septic arthritis is suspected. An important differential diagnosis is metabolic arthritis (gout and chondrocalcinosis), which typically presents in a similar way. A differentiation from septic arthritis is important as metabolic arthritis requires a completely different treatment. After confirming the diagnosis, treatment consisting of a surgical procedure combined with antibiotics is initiated. In most cases an arthroscopic intervention is sufficient. In severe cases the arthroscopy needs to be repeated. An arthrotomy must be carried out only rarely. A pre-emptive antibiotic treatment is initially administered and is later adjusted according to the resistogram. This article gives an overview on the pathophysiology, diagnostics and general management of joint empyema.

What are the best diagnostic tests for diagnosing bacterial arthritis of a native joint? : a systematic review of 27 studies

AIMS

This study aimed to answer two questions: what are the best diagnostic methods for diagnosing bacterial arthritis of a native joint?; and what are the most commonly used definitions for bacterial arthritis of a native joint?

METHODS

We performed a search of PubMed, Embase, and Cochrane libraries for relevant studies published between January 1980 and April 2020. Of 3,209 identified studies, we included 27 after full screening. Sensitivity, specificity, area under the curve, and Youden index of diagnostic tests were extracted from included studies. We grouped test characteristics per diagnostic modality. We extracted the definitions used to establish a definitive diagnosis of bacterial arthritis of a native joint per study.

RESULTS

Overall, 28 unique diagnostic tests for diagnosing bacterial arthritis of a native joint were identified. The following five tests were deemed most useful: serum ESR (sensitivity: 34% to 100%, specificity: 23% to 93%), serum CRP (sensitivity: 58% to 100%, specificity: 0% to 96%), serum procalcitonin (sensitivity: 0% to 100%, specificity: 68% to 100%), the proportion of synovial polymorphonuclear cells (sensitivity: 42% to 100%, specificity: 54% to 94%), and the gram stain of synovial fluid (sensitivity: 27% to 81%, specificity: 99% to 100%).

CONCLUSION

Diagnostic methods with relatively high sensitivities, such as serum CRP, ESR, and synovial polymorphonuclear cells, are useful for screening. Diagnostic methods with a relatively high specificity, such as serum procalcitonin and synovial fluid gram stain, are useful for establishing a diagnosis of bacterial arthritis. This review helps to interpret the value of various diagnostic tests for diagnosing bacterial arthritis of a native joint in clinical practice. Cite this article: Bone Joint J 2021;103-B(12):1745-1753.

Optimal Synovial Fluid Leukocyte Count Cutoff for Diagnosing Native Joint Septic Arthritis After Antibiotics: A Receiver Operating Characteristic Analysis of Accuracy

INTRODUCTION

Urgent treatment of septic arthritis is key in preventing devastating morbidity or mortality. Accurate diagnosis is critical, and the standard diagnostic cutoff of 50,000 synovial leukocytes may be altered by previous administration of antibiotics. Our objective was to identify and compare a cutoff synovial leukocyte count with a high sensitivity and specificity for diagnosis of septic arthritis in patients who received antibiotics and those who had not. A receiver operating characteristic (ROC) curve was used to provide a discriminate cutoff value for diagnosing septic arthritis.

METHODS

A retrospective chart review of 383 patients was done over a 13-year period including those who had arthrocentesis of any joint. Two groups were created, those who had not been given antibiotics within 2 weeks (control) and those who received intravenous or oral antibiotics within 2 weeks before arthrocentesis. Relevant data included synovial leukocyte count and differential cell count. Additional metrics included temperature, erythrocyte sedimentation rate, and C-reactive protein. A ROC curve determined the optimal synovial white blood cell cutoff for diagnosing septic arthritis in native joints for each group.

RESULTS

The ROC curve determined that patients who received antibiotics had an optimal cutoff of >16,000 cells (sensitivity = 82%, specificity = 76%), and a neutrophil percentage cutoff of >90% (sensitivity = 73%, specificity = 74%). The control group had an optimal synovial leukocyte cutoff of >33,000 cells (sensitivity = 96%, specificity = 95%). The optimal neutrophil percentage cutoff in the control group was >83% neutrophils (sensitivity = 89%, specificity = 79%).

CONCLUSION

When a patient is given antibiotics before arthrocentesis, a diagnostic value of >16,000 synovial leukocytes should be used to guide treatment of septic arthritis. A diagnostic value of >33,000 synovial leukocytes yields the highest accuracy for diagnosis of septic arthritis in patients who have not been given antibiotics before arthrocentesis.

LEVEL OF EVIDENCE

III.

Risk Factors of Coexisting Septic Spondylitis and Arthritis: A Case-Control Study in a Tertiary Referral Hospital

Introduction: In patients under immunosuppression or severe sepsis, it is sometimes manifested as coexisting septic arthritis and spondylitis. The aim of this study is to evaluate and investigate the risk factors of infectious spondylitis associated with septic arthritis. Methods: The study retrospectively reviewed the patients diagnosed with infectious spondylitis between January 2010 and September 2018 for risk factors of coexisting major joint septic arthritis. Results: A total of 10 patients with infectious spondylitis and coexisting septic arthritis comprised the study group. Fifty matched patients with solely infectious spondylitis were selected as the control group. Major risk factors include preoperative C-reactive protein (p = 0.001), hypoalbuminemia (p = 0.011), history of total joint replacement (p < 0.001), duration of preoperative antibiotics treatment (p = 0.038) and psoas muscle abscess (p < 0.001). Conclusion: Infectious spondylitis and septic arthritis are thought of as medical emergencies due to their high mortality and morbidity. Our study evaluated 5 risk factors as significant major findings: hypoalbuminemia (<3.4 g/dL), higher preoperative CRP (>130 mg/L), psoas muscle abscess, longer preoperative antibiotics treatment (>8 days) and history of total joint replacement. Clinicians should pay attention to the patients with those five factors to detect the coexisting infections as early as possible.

A Pain in the Foot: Delayed Diagnosis of Primary Septic Arthritis of Naviculocuneiform and Second/Third Tarsometatarsal Joints

Patient: Male, 65-year-old

Final Diagnosis: Septic arthritis of midfoot

Symptoms: Foot pain

Medication: —

Clinical Procedure: Debridement • drainage

Specialty: Family Medicine • General and Internal Medicine • Orthopedics • Emergency Medicine

Septic arthritis in the end-stage renal disease population

Septic arthritis is important to consider in any patient who presents with joint pain because it is a medical emergency with an 11% fatality rate. Diagnosis and treatment may improve prognosis; however, many patients do not regain full joint function. In patients with end-stage renal disease (ESRD), immune dysfunction due to uremia and chronic vascular access leads to increased risk of infection. We examined the incidence, risk factors and sequelae of septic arthritis in a cohort of hemodialysis patients. The US Renal Data System was queried for diagnoses of septic arthritis and selected sequelae using International Statistical Classification of Diseases and Related Health Problems-9 and Current Procedural Terminology-4 codes in patients who initiated hemodialysis between 2005 and 2010. Multivariable logistic regression was used to determine potential risk factors for septic arthritis and its sequelae. 7009 cases of septic arthritis were identified, an incidence of 514.8 per 100,000 persons per year. Of these patients, 2179 were diagnosed with a documented organism within 30 days prior to or 14 days after the septic arthritis diagnosis, with methicillin-resistant Staphylococcus aureus infections (57.4%) being the most common. Significant risk factors for septic arthritis included history of joint disease, immune compromise (diabetes, HIV, cirrhosis), bacteremia and urinary tract infection. One of the four sequelae examined (joint replacement, amputation, osteomyelitis, Clostridioides difficile infection) occurred in 25% of septic arthritis cases. The high incidence of septic arthritis and the potential for serious sequelae in patients with ESRD suggest that physicians treating individuals with ESRD and joint pain/inflammation should maintain a high clinical suspicion for septic arthritis.

Biosensors for Detection and Monitoring of Joint Infections

The aim of this review is to assess the use of biosensors in the diagnosis and monitoring of joint infection (JI). JI is worldwide considered a significant cause of morbidity and mortality in developed countries. Due to the progressive ageing of the global population, the request for joint replacement increases, with a significant rise in the risk of periprosthetic joint infection (PJI). Nowadays, the diagnosis of JI is based on clinical and radiological findings. Nuclear imaging studies are an option but are not cost-effective. Serum inflammatory markers and the analysis of the aspirated synovial fluid are required to confirm the diagnosis. However, a quick and accurate diagnosis of JI may remain elusive as no rapid and highly accurate diagnostic method was validated. A comprehensive search on Medline, EMBASE, Scopus, CINAH, CENTRAL, Google Scholar, and Web of Science was conducted from the inception to June 2021. The PRISMA guidelines were used to improve the reporting of the review. The MINORS was used for quality assessment. From a total of 155 studies identified, only four articles were eligible for this study. The main advantages of biosensors reported were accuracy and capability to detect bacteria also in negative culture cases. Otherwise, due to the few studies and the low level of evidence of the papers included, it was impossible to find significant results. Therefore, further high-quality studies are required.

Valvular and infection-associated risk factors as criteria to guide the use of echocardiography in patients with native joint infections

BACKGROUND

Native joint and bone infections (NJBI) are associated with infective endocarditis (IE) in 15% of cases. There are no studies analyzing the use of cardiac imaging in cases of NJBI. The objective of this study was to identify factors associated with echocardiography suggestive of IE in patients with NJBI.

METHODS

This medical records review was conducted in patients hospitalized for NJBI between 2007 and 2017 in Rheumatology and Infectious Diseases departments of 2 university hospitals. Patients included had a microbiologically proven NJBI during their hospitalization.

RESULTS

In this cohort of 546 patients, median age 66 years, echocardiography was suggestive of IE in 66 (12%). In multivariate analysis, factors associated with echocardiography suggestive of IE were 2 or more positive blood cultures (OR 11.55 (CI95% 3.24-74.20)), cardiac conditions with a high risk of IE (OR 7.34 (CI95% 2.95-18.61)), unknown heart murmur (OR 4.59 (CI95% 1.79-11.74)), multifocal infection (OR 2.26 (CI95% 1.21-4.23)) and an infection due to S. bovis (OR 3.52 (CI95% 1.26-9.79)). The factor associated with the absence of an echocardiography evocative of IE was infection due to unconventional bacteria for IE (OR 0.13 (CI95% 0.01-0.76)). According to the factors associated with echocardiography evocative of IE, we propose the Normandy score based on three kinds of data: cardiac condition, bacterial strain and NJBI mechanism. Echocardiography should be realized when this score, whose negative predictive value is 100% CI95% (98-100%) for prescription of echocardiography, is more than zero.

CONCLUSIONS

A score based on valvular condition, bacterial strain and NJBI mechanism could guide clinicians in prescribing echocardiography during NJBI with an excellent negative predictive value.

Degenerative Joint Damage Is Not a Risk Factor for Streptococcal Sepsis and Septic Arthritis in Mice

Septic arthritis (SA) is an aggressive joint disorder causing invalidity and mortality. Although epidemiological studies suggest osteoarthritis (OA) as a risk factor for SA, experimental insights into the relatedness of both diseases are lacking. We therefore sought to investigate whether pre-existing OA indeed promotes SA frequency or severity. We used STR/ort mice that spontaneously develop OA and, in addition, induced OA via anterior cruciate ligament transection (ACLT) in C57BL/6J mice. Mice were infected with Group A Streptococcus (GAS) and then were monitored for clinical signs of sepsis and SA. Sepsis was confirmed via elevated inflammatory cytokines in plasma, while bone morphology was assessed by micro-computed tomography. Cartilage integrity was evaluated histologically. Mice with spontaneous OA developed life-threatening SA, with GAS only moderately affecting the femoral bone structure. Surgically induced OA neither impacted on SA incidence nor on mortality when compared to infected mice without the preceding joint disease. Furthermore, only insignificant differences in bone morphology were detected between both groups. Our data indicate that degenerative joint damage due to ACLT, by itself, does not predispose mice to SA. Hence, we propose that other factors such as prosthetic joint replacement or high age, which frequently coincide with OA, pose a risk for SA development.

Pediatric Septic Arthritis of the Knee Due to a Multi-Sensitive Streptococcus pyogenes Strain Responsive to Clindamycin-A Case Report

Septic arthritis is an inflammatory process usually generated by a bacterial infection. The knee is one of the most frequently involved joints. The etiology varies depending on age, and hematogenous spread remains the primary cause in children. Herein, we report a case of a previously healthy three-year-old female who was referred to our institution for acute swelling of her right knee. After a clinical and radiological diagnosis of septic arthritis, an empirical treatment with a combination of cefotaxime and clindamycin was initiated. The isolation of a multi-sensitive Streptococcus pyogenes strain from the joint’s effusion prompted the discontinuation of clindamycin and the usage of cefotaxime alone. One week later, an ultrasound was executed due to worsening in the patient’s clinical conditions, and an organized corpuscular intra-articular effusion with diffuse synovial thickening was revealed. Cefotaxime was therefore replaced with clindamycin, which improved the symptoms. Despite the antibiotic sensitivity test having revealed a microorganism with sensitivity to both cephalosporin and clindamycin, clinical resistance to cefotaxime was encountered and a shift in the antimicrobial treatment was necessary to ensure a full recovery. This case study confirms that an antibiotic regimen based solely on a susceptibility test may be ineffective for such cases.

Ruling out septic arthritis risk in a few minutes using mid-infrared spectroscopy in synovial fluids

OBJECTIVES

The aim of this study was to show the usefulness of a mid-infrared fibre evanescent wave spectroscopy point of care device in the identification of septic arthritis patients in a multicentre cohort, and to apply this technology to clinical practice among physicians.

METHODS

SF samples from 402 patients enrolled in a multicentre cohort were frozen for analysis by mid-infrared fibre evanescent wave spectroscopy. The calibration cohort was divided into two groups of patients (septic arthritis and non-septic arthritis) and relevant spectral variables were used for logistic regression model. Model performances were tested on an independent set of 86 freshly obtained SF samples from patients enrolled in a single-centre acute arthritis cohort and spectroscopic analyses performed at the patient's bedside.

RESULTS

The model set-up, using frozen-thawed SFs, provided good performances, with area under the curve 0.95, sensitivity 0.90, specificity 0.90, positive predictive value 0.41 and negative predictive value 0.99. Performances obtained in the validation cohort were area under the curve 0.90, sensitivity 0.92, specificity 0.81, positive predictive value 0.46 and negative predictive value 0.98. The septic arthritis probability has been translated into a risk score from 0 to 4 according to septic risk. For a risk score of 0, the probability of identifying a septic patient is very low (negative predictive value of 1), whereas a risk score of 4 indicates very high risk of septic arthritis (positive predictive value of 1).

CONCLUSION

Mid-infrared fibre evanescent wave spectroscopy could distinguish septic from non-septic synovial arthritis fluids with good performances, and showed particular usefulness in ruling out septic arthritis. Our data supports the possibility of technology transfer.

TRIAL REGISTRATION

ClinicalTrials.gov, http://clinicaltrials.gov, NCT02860871.

Septic Arthritis Caused by Perirectal Abscess

Septic arthritis is a debilitating, inflammatory condition of joints that can cause patients to experience significant pain and discomfort. An estimated 0.006% of people annually develop the condition; the absence of prompt diagnosis and treatment can lead to long-term joint dysfunction. Septic arthritis is usually caused by hematologic seeding of the joint space by bacteria, however, those who receive intra-joint injections and IV access are also at high risk for developing the condition. In this article, we present the case of a 58-year-old male with no immediately identifiable risk factors for septic arthritis, who was found to have a septic joint as a result of an invading perirectal abscess that was discovered in an imaging study.

Bacteria and Host Interplay in Staphylococcus aureus Septic Arthritis and Sepsis

Staphylococcus aureus (S. aureus) infections are a major healthcare challenge and new treatment alternatives are needed. S. aureus septic arthritis, a debilitating joint disease, causes permanent joint dysfunction in almost 50% of the patients. S. aureus bacteremia is associated with higher mortalities than bacteremia caused by most other microbes and can develop to severe sepsis and death. The key to new therapies is understanding the interplay between bacterial virulence factors and host immune response, which decides the disease outcome. S. aureus produces numerous virulence factors that facilitate bacterial dissemination, invasion into joint cavity, and cause septic arthritis. Monocytes, activated by several components of S. aureus such as lipoproteins, are responsible for bone destructions. In S. aureus sepsis, cytokine storm induced by S. aureus components leads to the hyperinflammatory status, DIC, multiple organ failure, and later death. The immune suppressive therapies at the very early time point might be protective. However, the timing of treatment is crucial, as late treatment may aggravate the immune paralysis and lead to uncontrolled infection and death.

Intracellular Staphylococcus aureus in bone and joint infections: A mechanism of disease recurrence, inflammation, and bone and cartilage destruction

Bone and joint infections are devastating afflictions. Although medical interventions and advents have improved their care, bone and joint infections still portend dismal outcomes. Indeed, bone and joint infections are associated with extremely high mortality and morbidity rates and, generally, occur secondary to the aggressive pathogen Staphylococcus aureus. The consequences of bone and joint infections are further compounded by the fact that although they are aggressively treated, they frequently recur and result in massive bone and articular cartilage loss. Here, we review the literature and chronicle the fact that the fundamental cellular components of the musculoskeletal system can be internally infected with Staphylococcus aureus, which explains the ready recurrence of bone and joint infections even after extensive administration of antibiotic therapy and debridement and offer potential treatment solutions for further study. Moreover, we review the ramifications of intracellular infection and expound that the massive bone and articular cartilage loss is caused by the sustained proinflammatory state induced by infection and offer potential combination therapies for further study to protect bone and cartilage.

First experience with a thermal-sprayed silver oxide-containing hydroxyapatite coating implant in two-stage total hip arthroplasty for the treatment of septic arthritis with hip osteoarthritis: A case report

•

Septic arthritis of the hip joint is relatively uncommon in adults.

•

Ag-HA implants have not been used in two-stage total hip arthroplasty.

•

Ag-HA implants may be used in two-staged total hip arthroplasty.

Introduction

Septic arthritis of the hip joint in adults is a rare and potentially devasting disease. To the best of our knowledge, there have been no reports of two-stage total hip arthroplasty (THA) for the treatment of septic arthritis of the hip joint with a cementless hip implant that has antibacterial properties.

Presentation of case

We present a case of two-stage THA with a thermal-sprayed silver oxide-containing hydroxyapatite coating (Ag-HA) implant to treat septic arthritis of the hip joint with hip osteoarthritis in an 80-year-old woman. There was no complication or recurrence at 28 months follow-up after 2nd-stage operation.

Discussion

Ag-HA implants were found to have antibacterial activity within the subcutaneous tissues and bone, osteoconductive properties, and no adverse reactions in vivo. Moreover, no adverse events due to silver were reported in a clinical or radiographic study.

Conclusion

To further reduce infection after two-staged THA for septic arthritis of the hip joint, antibacterial implants, such as an Ag-HA implant, may be used.

Assessing an alpha-defensin lateral flow device for diagnosing septic arthritis: reporting on a false-negative case and a false-positive case

Alpha-defensin (αD), an antimicrobial peptide released by neutrophils in response to bacterial pathogens, was proposed as a novel diagnostic biomarker in synovial fluid. Several reports have shown that αD can serve as a reliable biomarker in the diagnosis of periprosthetic joint infection (PJI). We assessed whether αD could also serve to diagnosis of septic arthritis, a similarly difficult to diagnose PJI. To our knowledge, besides PJI, few reports exist assessing the utility of αD for septic arthritis. We have attempted to diagnose several cases of suspected septic arthritis using the Synovasure^® αD detection lateral flow device. We report a false-positive case and a false-negative case. The false-negative case we experienced was caused by Staphylococcus capitis, which is coagulase-negative, and possibly represents a low virulence micro-organism infection. The false-positive case was ultimately diagnosed as seronegative rheumatoid arthritis and possessed calcium pyrophosphate depositions. False positives have been suggested to occur in conditions where neutrophils are mobilised. As for PJI, in cases where diagnosis is difficult, αD can be an additional diagnostic indicator. However, making a definitive diagnosis using the αD lateral flow device alone was found to be difficult. The utility of αD in assessing septic arthritis is inconclusive; therefore, larger prospective clinical studies should be considered for a better assessment.

Inflammatory Joint Disease Is a Risk Factor for Streptococcal Sepsis and Septic Arthritis in Mice

Septic arthritis is a medical emergency associated with high morbidity and mortality, yet hardly any novel advances exist for its clinical management. Despite septic arthritis being a global health burden, experimental data uncovering its etiopathogenesis remain scarce. In particular, any interplay between septic arthritis and preceding joint diseases are unknown as is the contribution of the synovial membrane to the onset of inflammation. Using C57BL/6 mice as a model to study sepsis, we discovered that Group A Streptococcus (GAS) – an important pathogen causing septic arthritis - was able to invade the articular microenvironment. Bacterial invasion resulted in the infiltration of immune cells and detrimental inflammation. In vitro infected fibroblast-like synoviocytes induced the expression of chemokines (Ccl2, Cxcl2), inflammatory cytokines (Tnf, Il6), and integrin ligands (ICAM-1, VCAM-1). Apart from orchestrating immune cell attraction and retention, synoviocytes also upregulated mediators impacting on bone remodeling (Rankl) and cartilage integrity (Mmp13). Using collagen-induced arthritis in DBA/1 × B10.Q F1 mice, we could show that an inflammatory joint disease exacerbated subsequent septic arthritis which was associated with an excessive release of cytokines and eicosanoids. Importantly, the severity of joint inflammation controlled the extent of bone erosions during septic arthritis. In order to ameliorate septic arthritis, our results suggest that targeting synoviocytes might be a promising approach when treating patients with inflammatory joint disease for sepsis.

Successful two-stage primary total knee arthroplasty for infective arthritis of the knee - our experience

BACKGROUND

The incidence of septic arthritis is 2-10/100,000. Morbidity is higher with persistent joint dysfunction in up to 30%. Osteoarthritic knee with infection presents a rare challenge, with no established approach for treatment exists. We present our experience of managing infected degenerative joint disease (DJD) with two-stage primary arthroplasty similar to the management of periprosthetic joint infection.

PATIENTS AND METHODS

Four patients presented to us between 2016 and 2018 with advanced DJD associated with coexistent joint sepsis with or without adjacent osteomyelitis. The diagnosis of joint sepsis with periarticular osteomyelitis was made based on clinical presentation, radiographic findings, inflammatory serological markers, and culture of knee joint aspirate. All were operated with primary arthroplasty in two stages of debridement with a static spacer followed by antibiotics and implantation.

DISCUSSION

With no established method of treating DJD superadded with infection, our experience adds valuable information in treating the same. Our 2-staged primary arthroplasty had a short antibiotic duration between stages, a mean of 63.5 days, and stopped within 3 days of 2^ndstage reducing hospital stay, morbidity, and cost.Our approach is a very viable method of treating infected DJD with a minimum drug holiday time of two weeks before implantation with a better outcome, reducing the recurrence rate of infection.Though a small number with a minimum follow-up of 24 months, we believe we provide valuable additional information.

CONCLUSION

All patients had painless return to early activities with no signs of recurrent infection. Our approach is a very viable and could serve as a cost-effective method treatment for an infected arthritic knee.

Thiol/disulfide homeostasis as a novel indicator of oxidative stress during the treatment process of patients with septic arthritis

Objectives

This study aims to investigate dynamic thiol/disulfide homeostasis as a novel indicator of oxidative stress and to find out its association with standard inflammatory markers during the treatment of patients with septic arthritis (SA).

Patients and methods

In this prospective study, a new colorimetric method for measuring thiol/disulfide homeostasis was assessed between May 2013 and October 2014 in 24 patients with SA (14 males, 10 females; mean age 14.5±19.1 years; range, 1 to 80 years) at baseline and the end of the third week of the treatment, and in 24 healthy controls (14 males, 10 females; mean age 12.5±18.7 years; range, 1 to 85 years). Also, standard inflammatory markers such as C-reactive protein (CRP), erythrocyte sedimentation rate, and white blood cell count were evaluated.

Results

At baseline, serum disulfide was higher in SA group compared to the control group, whereas native thiol was lower (p<0.05 for all). At the end of the third week of the treatment, serum disulfide level was lower, whereas the native thiol was higher compared to baseline (p<0.05 for all). In addition, serum disulfide level was positively correlated with CRP (r=0.736, p<0.001) and disulfide/native thiol ratio (r=0.779, p<0.001). Furthermore, in multiple regression analyses, the disulfide level was independently associated with CRP (β=0.226, p=0.005).

Conclusion

Our results suggest that the elevated levels of serum disulfide and standard inflammatory markers at baseline in patients with SA and decreased levels of these parameters are related with oxidative stress. This homeostasis shifted towards disulfide formation due to thiol oxidation. Therefore, thiol/ disulfide homeostasis may be a helpful biomarker for the follow- up in patients with SA.