Clinical features and outcome of septic arthritis in a single UK Health District 1982-1991

How to manage a native stiff knee

Knee stiffness is a widely known and worrying condition in several postoperative knees. Less is known about native stiff knee. The aim of this manuscript is to summarize the available literature on native stiff knee epidemiology, classification and treatment. In 1989 stiff knee was defined as a knee with less than 50° of total range of motion. If range of motion is <30°, it is defined as an ankylosed knee. Knee stiffness can be divided into three main types: flexion contractures, extension contractures, and combined contractures. Different risk factors have been associated to native stiff knee and grouped into modifiable or not modifiable. Furthermore, risk factors can be divided into patients' related no patients'-related. Different treatment modalities can be indicated to treat knee stiffness, including manipulation under anesthesia (MUA), arthroscopic and open surgical release. When stiffness is associated with articular disruption TKA represent an option. TKA in native stiff knee can be challenging for the surgeon. Implant's choice and knee exposure are the first steps. In some cases, additional release and extensive can be considered. A stepwise approach and careful preoperative planning are mandatory to obtain long-term satisfactory outcomes. Native stiff knee is a rare but invalidating condition. Different treatment modalities have been proposed as treatment. However, considering that it is frequently associated to sever arthritis, TKA can be an option in painful stiff knees. Nature of knee stiffness necessitates a customized approach to ensure successful management and achieve satisfying outcomes.

Orthopedic Articular and Periarticular Joint Infections

Acute nontraumatic joint pain has an extensive differential. Emergency physicians must be adept at identifying limb and potentially life-threatening infection. Chief among these is septic arthritis. In addition to knowing how these joint infections typically present, clinicians need to be aware of host and pathogen factors that can lead to more insidious presentations and how these factors impact the interpretation of diagnostic tests.

Does arthroscopic or open washout in native knee septic arthritis result in superior post-operative function? A systematic review and meta-analysis of randomised controlled trials and observational studies

AIMS

Septic arthritis (SA) of the native knee joint is associated with significant morbidity. This review compared post-operative functional outcomes (patient-reported outcome measures (PROMs) and range of movement (ROM)) following arthroscopic washout (AW) and open washout (OW) amongst adult patients with SA of the native knee. The need for further operative intervention was also considered.

METHODS

Electronic databases of PubMed, MEDLINE, Embase, Cochrane, Web of Science and Scopus were searched between 16 February 2023 and 18 March 2023. Randomised controlled trials (RCTs) and comparative observational analytic studies comparing function (reflected in PROMs or ROM) at latest follow-up following AW and OW were included. A narrative summary was provided concerning post-operative PROMs. Pooled estimates for mean ROM and re-operation rates were conducted using the random-effects model. The risk of bias was assessed using the Cochrane risk-of-bias assessment tool-2 for RCTs and the Risk of Bias in Non-Randomized Studies of Interventions tool for observational analytic studies.

RESULTS

Of 2580 retrieved citations, 7 articles (1 RCT and 6 cohort studies) met the inclusion criteria. Of these, five had some concerns/moderate risk of bias, and two had serious risk. There was a slight tendency for superior mean PROMs following AW compared with OW, but due to small effect sizes, this was unlikely clinically relevant. Additionally, the use of four different PROMs scales made direct comparisons impossible. AW was associated with superior ROM (mean difference 20.18° (95% CI 14.35, 26.02; p < 0.00001)), whilst there was a tendency for lower re-operation requirements following AW (OR 0.64, 95% CI 0.26, 1.57, p = 0.44).

CONCLUSIONS

AW was associated with equivalent to superior post-operative function and lower requirement for further intervention compared with OW. Results need to be interpreted cautiously, taking into consideration the methodological and clinical heterogeneity of the included studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2022, CRD42022364062.

The Septic Elbow Joint: Treatment Approaches for Improved Patient Outcomes

Septic arthritis of the elbow is a serious problem requiring prompt, accurate diagnosis and urgent surgical intervention. Achieving successful patient outcomes depends heavily on early diagnosis and efficient streamlined surgical treatment. Essential tactics for treating the septic elbow joint include immediate joint irrigation and debridement in addition to administration of appropriate antibiotics. This comprehensive review delves into the cause of the septic elbow joint, identifies associated risk factors, and provides a comprehensive approach encompassing the diagnosis and treatment of the septic elbow. The aim of this review is to optimize patient care and outcomes.

Potential value of a rapid syndromic multiplex PCR for the diagnosis of native and prosthetic joint infections: a real-world evidence study

Introduction: The BIOFIRE Joint Infection (JI) Panel is a diagnostic tool that uses multiplex-PCR testing to detect microorganisms in synovial fluid specimens from patients suspected of having septic arthritis (SA) on native joints or prosthetic joint infections (PJIs). Methods: A study was conducted across 34 clinical sites in 19 European and Middle Eastern countries from March 2021 to June 2022 to assess the effectiveness of the BIOFIRE JI Panel. Results: A total of 1527 samples were collected from patients suspected of SA or PJI, with an overall agreement of 88.4 % and 85 % respectively between the JI Panel and synovial fluid cultures (SFCs). The JI Panel detected more positive samples and microorganisms than SFC, with a notable difference on Staphylococcus aureus, Streptococcus species, Enterococcus faecalis, Kingella kingae, Neisseria gonorrhoeae, and anaerobic bacteria. The study found that the BIOFIRE JI Panel has a high utility in the real-world clinical setting for suspected SA and PJI, providing diagnostic results in approximately 1 h. The user experience was positive, implying a potential benefit of rapidity of results' turnover in optimising patient management strategies. Conclusion: The study suggests that the BIOFIRE JI Panel could potentially optimise patient management and antimicrobial therapy, thus highlighting its importance in the clinical setting.

The accuracy and diagnostic value of gram staining joint aspirates in suspected joint infections

BACKGROUND

Septic arthritis is a debilitating condition with prolonged treatment and adverse outcomes. A gram stain is often performed from the joint aspirate sample, followed by a definitive culture. In our study, we assessed the accuracy of gram staining for suspected septic arthritis and explored factors associated with positive culture growth and false negatives in the gram stain.

METHODS

We retrospectively reviewed joint aspirates performed from 2015-2021 at a major trauma centre. Aspirates not cultured for septic arthritis were excluded. Data collected included aspirate site, gram stain and culture result delay, patient demographics, orthopaedic/rheumatological history, and comorbidities. Outcomes measured were gram stain sensitivity and specificity. Factors influencing positive cultures and false negative gram stain results were analysed using logistic regression.

RESULTS

Of 408 joint aspirates meeting the criteria, 37 did not undergo initial gram staining. Gram stain sensitivity was 30.4%, specificity was 97.6%. The delay from aspirate to definitive gram stain and culture results was 1.1 and 5.4 days, respectively Logistic regression identified that prosthetic joint(p = 0.007), past joint infections(p = 0.006), arthritis(p < 0.001), hypertension(p = 0.007), diabetes(p = 0.019) were positively associated with positive cultures. Past joint infections(p = 0.004) were positively associated with false negative gram stain results. Patients on antibiotics during the aspirate had a higher risk of false negative gram stain results (OR = 5.538, 95%CI, 2.802-10.948; p < 0.001).

CONCLUSIONS

In conclusion, the initial gram stain has limited sensitivity and caution should be exercised when interpreting negative results. Vigilance is crucial when the highlighted comorbidities or antibiotic use are present, to assess patients with potential joint infections.

Exploring the role of bacterial virulence factors and host elements in septic arthritis: insights from animal models for innovative therapies

Septic arthritis, characterized as one of the most aggressive joint diseases, is primarily attributed to Staphylococcus aureus (S. aureus) and often results from hematogenous dissemination. Even with prompt treatment, septic arthritis frequently inflicts irreversible joint damage, leading to sustained joint dysfunction in a significant proportion of patients. Despite the unsatisfactory outcomes, current therapeutic approaches for septic arthritis have remained stagnant for decades. In the clinical context, devising innovative strategies to mitigate joint damage necessitates a profound comprehension of the pivotal disease mechanisms. This entails unraveling how bacterial virulence factors interact with host elements to facilitate bacterial invasion into the joint and identifying the principal drivers of joint damage. Leveraging animal models of septic arthritis emerges as a potent tool to achieve these objectives. This review provides a comprehensive overview of the historical evolution and recent advancements in septic arthritis models. Additionally, we address practical considerations regarding experimental protocols. Furthermore, we delve into the utility of these animal models, such as their contribution to the discovery of novel bacterial virulence factors and host elements that play pivotal roles in the initiation and progression of septic arthritis. Finally, we summarize the latest developments in novel therapeutic strategies against septic arthritis, leveraging insights gained from these unique animal models.

Role of ultrasound and inflammatory factors in the management of pediatric hip joint effusion

BACKGROUND

Septic arthritis is an important differential diagnosis of hip joint pain. Joint aspiration analysis is a necessary diagnostic measure for septic arthritis. In order to reduce the need for joint aspiration, we compared the combination of ultrasound findings and laboratory findings to separate septic arthritis from reactive arthritis.

METHODS

Children aged < 14 years who were referred to Akbar pediatric hospital in 2020-2022 with hip pain or limping were included in this longitudinal study. Participants underwent ultrasound examinations of the hip and blood samples were obtained from them. After confirming an effusion, dependent on patient status and clinical diagnosis, one of the following approaches was recommended; the close follow-up, or the ultrasound-guided aspiration of the hip joint effusion, and or arthrotomy. The various ultrasound and laboratory were documented. Data were analyzed and P < 0.001 being considered statistically significant.

RESULTS

Overall, 115 patients with a mean age of 3.43 ± 5.76 years, 46 of whom were girls, were studied. The final diagnosis in 23 cases (20.0%) was septic arthritis and 92 (80.0%) had reactive arthritis. C-reactive protein (CRP) and The erythrocyte sedimentation rate (ESR) unlike aspirate volume, effusion volume measured on ultrasound, capsule thickness, total thickness, and recorded capsule-to-effusion ratio were significantly higher in patients with septic arthritis (P < 0.001). There was a significant agreement between the volume of measured fluid in the anterior recess and the volume of aspirated fluid (2.5 times, P < 0.001). Septic arthritis was not observed in any of the patients with effusion volume in anterior recess less than 0.5 cc and ESR less than 40 mm/hr or CRP less than 15 mg/L.

CONCLUSION

Since septic arthritis was not observed in any of the patients with effusion volume < 0.5 cc and normal inflammatory factors (ESR or CRP), conservative management and close follow-up can be recommended in these patients instead of joint fluid aspiration.

Upper extremity infection: imaging features with focus on magnetic resonance imaging

Upper extremity infections are frequently seen, especially in individuals with weakened immune system, posttraumatic events, and after surgery procedures. If not properly treated, such conditions can lead to serious consequences, such as movement impairment, amputation, and even mortality. These infections have the potential to spread extensively from their initial site of entry, traversing interconnected spaces either intra or extra-compartmental. Understanding the relevant anatomy is crucial to assess location and stage of infection, since surgical intervention and intravenous antibiotics are usually required. In this article, the authors provide a comprehensive review of the imaging findings of upper extremity infection, focusing on magnetic resonance imaging (MRI). Furthermore, this article sheds light on the pivotal role of radiology in managing hand, elbow, and shoulder infections offering an overview of available treatment options. KEY FINDINGS: Various types of infections affecting the upper extremity will be discussed, including infectious tenosynovitis, deep space infections, septic arthritis, and osteomyelitis. Authors also highlight anatomical spaces, common pathogens, spread routes, and key radiological features of these conditions.

Moraxella catarrhalis Septic Arthritis Unveils Undiagnosed Systemic Lupus Erythematous in a Pediatric Patient

Septic arthritis is uncommon in pediatric patients, who are less likely to have major risk factors such as underlying joint disease or prosthetic joints. It only rarely affects the elbow and is usually caused by Gram-positive cocci, with Staphylococcus aureus being the most common bacterial organism. We present the case of a 15-year-old previously healthy female who experienced new-onset monoarticular nontraumatic elbow pain and was found to have a synovial effusion growing from Moraxella catarrhalis. The atypical clinical presentation, coupled with the growth of an unusual organism, raised concern for an underlying immunocompromising or inflammatory joint disorder. Further laboratory workup ultimately revealed a diagnosis of systemic lupus erythematosus (SLE), which more commonly presents with arthralgias that are polyarticular, symmetric, and migratory. This case report should encourage clinicians to maintain a high degree of suspicion for underlying joint disease when septic arthritis presents atypically.

Microbiological Profile and Clinical Features of Septic Arthritis of the Shoulder: A 10-Year Cohort Single-Centre Study

Introduction  Septic arthritis (SA) constitutes a pressing orthopedic emergency characterized by acute, non-traumatic joint pain. Timely diagnosis and intervention are imperative to avert complications such as chondrolysis and systemic sepsis. The etiology is predominantly hematogenous, necessitating an integrated approach involving surgical and microbiological modalities. Shoulder aspiration and microbiological analysis play pivotal roles in guiding treatment, especially when positive findings prompt more aggressive therapeutic strategies. This study aims to elucidate the nuanced clinical and epidemiological characteristics of septic arthritis in both native and prosthetic joints within a singular institutional cohort over a decade. Methods  This retrospective case series analysis spanned a 10-year period, focusing on non-prosthetic shoulder joints from January 2012 to July 2021. In this timeframe, only 183 aspirations were performed and sent to the microbiology department for analysis, including cultures, microscopy, and antibiotic sensitivity tests for positive cultures. The study delved into the microbiological profile of infections, encompassing gram stain, culture positivity rates, identification of microorganisms, and antibiotic susceptibility patterns. Additionally, the incidence of primary joint infections with resistant strains, particularly methicillin-resistant Staphylococcus aureus (MRSA), was scrutinized. Statistical analysis utilized the SPSS program version 20.0 (IBM Inc., Armonk, New York), with a significance level set at 5%. The project, registered with the trust's clinical audit department (Reg #5372), adhered to the Declaration of Helsinki and good clinical practice guidelines. Data collection involved extracting non-identifiable patient modifiers from the laboratory database bank into Excel spreadsheets. Results  The study included 183 patients, with 108 (59%) females and 75 (41%) males. The average age was 76.2±16.5 years. Among them, 138 (75.4%) reported pain, and 15 (8.2%) had a body temperature over 37.8°C. Lab results showed a mean white blood cell count of 11.6±4.5 and an average C-reactive protein level of 121.7±102.1. Leucocytosis (>11,000 WBC) was seen in 82 (44.8%) cases. Elevated C-reactive protein (CRP; >10 mg/dl) was found in 136 (74.3%) patients. Synovial fluid analysis revealed no crystals in 91.3% of cases. Microbial resistance analysis showed 19 strains resistant to co-trimoxazole and 11 to erythromycin. Among co-trimoxazole-resistant strains, 73.7% were Staphylococcus aureus, a statistically significant association (p<0.001). Conclusion The evolving sensitivity patterns of microbes in septic arthritis underscore the necessity to reassess empirical antibiotic therapy. Subsequent joint damage resulting from infection can result in substantial disability.

Administering Antibiotics for Less Than Four Weeks Increases the Risk of Relapse in Culture-Positive Septic Arthritis of Native Joints

(1) Objectives: This study investigated the optimal duration of antibiotic therapy and determined the risk factors associated with relapse in patients with culture-proven septic arthritis of native joints. (2) Methods: A retrospective review was conducted on patients aged ≥18 years diagnosed with native joint septic arthritis, with bacteria isolated from joints and/or blood. The exclusion criteria were prosthetic joint infections and cases with no identified microorganisms. The outcomes were assessed in the remission and relapse groups. (3) Results: Among 479 patients with native joint septic arthritis, 137 met the inclusion criteria, with a median follow-up duration of 2.7 years. The relapse rate was 9.5%, which mainly occurred within 30 days after antibiotic treatment completion. Compared with the remission group, the relapse group showed a significantly higher proportion of cases that received antibiotic therapy for ≤ 4 weeks (4.8% vs. 46.2%, p < 0.001), synovial fluid white blood cell (WBC) counts ≥150 × 103/mm3 (25.3% vs. 60.0%, p = 0.030), acute kidney injury (19.2% vs. 50%, p = 0.024), and extended-spectrum beta-lactamases-producing Enterobacteriaceae (0.8 vs. 15.4%, p = 0.024). Independent risk factors for relapse were determined as antibiotic therapy duration of ≤ 4 weeks (odds ratio (OR), 25.47; 95% confidence interval (CI), 1.57-412.33; p = 0.023) and synovial fluid WBC counts ≥150 × 103/mm3 (OR, 17.46; 95% CI, 1.74-175.62; p = 0.015). (4) Conclusions: Patients with native joint septic arthritis require vigilant monitoring for relapse, particularly when treated with antibiotic regimens administered for less than four weeks or when synovial aspirates exhibit elevated WBC counts at diagnosis.

Re-operation rates of arthroscopic management versus arthrotomy in treatment of septic arthritis of native shoulder joint in adults. A systematic review and meta-analysis

AIMS

Previous studies have reported concern regarding high reoperation rates when septic arthritis of the native shoulder is treated arthroscopically, compared to open arthrotomy. We aimed to compare re-operation rate between the two strategies.

PATIENTS AND METHODS

The review was registered prospectively at PROSPERO, (CRD42021226518). We searched common databases and references lists (8 February 2021). The inclusion criteria included interventional or observational studies of adult patients with a confirmed diagnosis of native shoulder joint septic arthritis and had either arthroscopy or arthrotomy. The exclusion criteria included patients with periprosthetic or post-surgical infections, patients who had atypical infections, and studies that did not report re-operation rate. Cochrane Collaboration's tool for assessing risk of bias (ROBINS-I) was used.

RESULTS

Nine studies (retrospective cohort studies) were included that involved 5,643 patients (5,645 shoulders). Mean age ranged from 55.6 to 75.5 years, and follow-up time ranged from 1-41 months. Mean duration of symptoms prior to presentation ranged from 8.3-23.3 days. Metanalysis observed a higher re-operation rate for reinfection at any time point following initial arthroscopy in comparison to arthrotomy, odds ratio 2.61 (95% confidence interval 1.04, 6.56). There was marked heterogeneity (I2 = 78.8%) among studies including surgical techniques and missing data.

CONCLUSION

This metanalysis observed a higher reoperation rate in arthroscopy in comparison to arthrotomy for the treatment of native shoulder septic arthritis in adults. The quality of the included evidence is low and the heterogeneity among included studies is marked. Higher quality evidence is still needed that address limitations of previous studies.

Performance and Hypothetical Impact on Joint Infection Management of the BioFire Joint Infection Panel: a Retrospective Analysis

Pathogen identification is key in septic arthritis. Culture-based techniques are challenging, especially when patients have been pretreated with antibiotics or when difficult-to-culture bacteria are encountered. The BioFire joint infection assay (BJA) is a multiplex PCR panel which detects 31 of the most prevalent bacterial and fungal pathogens causing septic arthritis. Here, 123 cryoconserved contemporary synovial fluid samples from 120 patients underwent BJA analysis. Results were compared to those of culture-based diagnostics (standard of care [SOC]). Clinical data were collected, and the possible impact of the molecular diagnostic application on patient management was evaluated. Fifteen of 123 synovial fluid cultures grew bacterial pathogens. All on-panel pathogens (9/15) were correctly identified by the BJA. The BJA identified four additional bacterial pathogens in four SOC-negative cases. BJA sensitivity and specificity were 100% (95% confidence interval [CI], 69.2% to 100%) and 100% (95% CI, 96.8% to 100%), respectively. Compared to the SOC, the BJA would have resulted in faster provision of species identification and molecular susceptibility data by 49 h and 99 h, respectively. Clinical data analysis indicates that in BJA-positive cases, faster species ID could have led to timelier optimization of antibiotic therapy. This retrospective study demonstrates high sensitivity and specificity of the BJA to detect on-panel organisms in bacterial arthritis. The usefulness of the BJA in prosthetic-joint infections is limited, as important pathogens (i.e., coagulase negative staphylococci and Cutibacterium acnes) are not covered. Evidence from patient data analysis suggests that the assay might prove valuable for optimizing patient management in acute arthritis related to fastidious organisms or for patients who received antibiotics prior to specimen collection.

Arthroscopic Treatment of the Septic Ankle

Ankle joint sepsis is a relatively rare but potentially devastating pathologic process of the lower extremity that requires expeditious identification and management. Establishing the diagnosis of ankle joint sepsis is often challenging as it may present with concomitant pathologies and often lacks consistency in regard to classic clinical characteristics. Once a diagnosis has been established, prompt management is imperative to minimize the potential for long-term sequelae. The purpose of this chapter is to address the diagnosis and management of the septic ankle with a focus on arthroscopic treatment.

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.

Gene expression of S100a8/a9 predicts Staphylococcus aureus-induced septic arthritis in mice

Septic arthritis is the most aggressive joint disease associated with high morbidity and mortality. The interplay of the host immune system with the invading pathogens impacts the pathophysiology of septic arthritis. Early antibiotic treatment is crucial for a better prognosis to save the patients from severe bone damage and later joint dysfunction. To date, there are no specific predictive biomarkers for septic arthritis. Transcriptome sequencing analysis identified S100a8/a9 genes to be highly expressed in septic arthritis compared to non-septic arthritis at the early course of infection in an Staphylococcus aureus septic arthritis mouse model. Importantly, downregulation of S100a8/a9 mRNA expression at the early course of infection was noticed in mice infected with the S. aureus Sortase A/B mutant strain totally lacking arthritogenic capacity compared with the mice infected with parental S. aureus arthritogenic strain. The mice infected intra-articularly with the S. aureus arthritogenic strain significantly increased S100a8/a9 protein expression levels in joints over time. Intriguingly, the synthetic bacterial lipopeptide Pam2CSK4 was more potent than Pam3CSK4 in inducing S100a8/a9 release upon intra-articular injection of these lipopeptides into the mouse knee joints. Such an effect was dependent on the presence of monocytes/macrophages. In conclusion, S100a8/a9 gene expression may serve as a potential biomarker to predict septic arthritis, enabling the development of more effective treatment strategies.

Deep learning-based assessment of knee septic arthritis using transformer features in sonographic modalities

PURPOSE

Septic arthritis is an infectious disease. Conventionally, the diagnosis of septic arthritis can only be based on the identification of causal pathogens taken from synovial fluid, synovium or blood samples. However, the cultures require several days for the isolation of pathogens. A rapid assessment performed through computer-aided diagnosis (CAD) would bring timely treatment.

METHODS

A total of 214 non-septic arthritis and 64 septic arthritis images generated by gray-scale (GS) and Power Doppler (PD) ultrasound modalities were collected for the experiment. A deep learning-based vision transformer (ViT) with pre-trained parameters were used for image feature extraction. The extracted features were then combined in machine learning classifiers with ten-fold cross validation in order to evaluate the abilities of septic arthritis classification.

RESULTS

Using a support vector machine, GS and PD features can achieve an accuracy rate of 86% and 91%, with the area under the receiver operating characteristic curves (AUCs) being 0.90 and 0.92, respectively. The best accuracy (92%) and best AUC (0.92) was obtained by combining both feature sets.

CONCLUSIONS

This is the first CAD system based on a deep learning approach for the diagnosis of septic arthritis as seen on knee ultrasound images. Using pre-trained ViT, both the accuracy and computation costs improved more than they had through convolutional neural networks. Additionally, automatically combining GS and PD generates a higher accuracy to better assist the physician's observations, thus providing a timely evaluation of septic arthritis.

An update on recent progress of the epidemiology, etiology, diagnosis, and treatment of acute septic arthritis: a review

Acute septic arthritis is on the rise among all patients. Acute septic arthritis must be extensively assessed, identified, and treated to prevent fatal consequences. Antimicrobial therapy administered intravenously has long been considered the gold standard for treating acute osteoarticular infections. According to clinical research, parenteral antibiotics for a few days, followed by oral antibiotics, are safe and effective for treating infections without complications. This article focuses on bringing physicians up-to-date on the most recent findings and discussions about the epidemiology, etiology, diagnosis, and treatment of acute septic arthritis. In recent years, the emergence of antibiotic-resistant, particularly aggressive bacterial species has highlighted the need for more research to enhance treatment approaches and develop innovative diagnosis methods and drugs that might combat better in all patients. This article aims to furnish radiologists, orthopaedic surgeons, and other medical practitioners with contemporary insights on the subject matter and foster collaborative efforts to improve patient outcomes. This review represents the initial comprehensive update encompassing patients across all age groups.

Image-guided synovial biopsy with a focus on infection

Image-guided biopsy of the synovium is a relatively uncommon but safe procedure with a high-diagnostic yield in the correct clinical scenario. Whilst surgical and arthroscopic techniques are still commonly performed and remain the gold standard, they are more invasive, expensive and not widely available. Ultrasound and X-ray-guided synovial biopsy are being increasingly performed by radiologists to diagnose both native and periprosthetic joint infection (PJI) to guide surgical and microbiological management. The purpose of this review article is to present the historical background to synovial biopsy particularly related to potential joint infection, including common and uncommon pathogens encountered, sampling techniques and pitfalls, focusing mainly on its role in PJI and its role in patient pathways and decision-making within a joint infection multi-disciplinary framework.

Clinical prediction rule for bacterial arthritis: Chi-squared automatic interaction detector decision tree analysis model

Objectives:

Differences in demographic factors, symptoms, and laboratory data between bacterial and non-bacterial arthritis have not been defined. We aimed to identify predictors of bacterial arthritis, excluding synovial testing.

Methods:

This retrospective cross-sectional survey was performed at a university hospital. All patients included received arthrocentesis from January 1, 2010, to December 31, 2020. Clinical information was gathered from medical charts from the time of synovial fluid sample collection. Factors potentially predictive of bacterial arthritis were analyzed using the Student’s t-test or chi-squared test, and the chi-squared automatic interaction detector decision tree analysis. The resulting subgroups were divided into three groups according to the risk of bacterial arthritis: low-risk, intermediate-risk, or high-risk groups.

Results:

A total of 460 patients (male/female = 229/231; mean ± standard deviation age, 70.26 ± 17.66 years) were included, of whom 68 patients (14.8%) had bacterial arthritis. The chi-squared automatic interaction detector decision tree analysis revealed that patients with C-reactive protein > 21.09 mg/dL (incidence of septic arthritis: 48.7%) and C-reactive protein ⩽ 21.09 mg/dL plus 27.70 < platelet count ⩽ 30.70 × 10⁴/μL (incidence: 36.1%) were high-risk groups.

Conclusions:

Our results emphasize that patients categorized as high risk of bacterial arthritis, and appropriate treatment could be initiated as soon as possible.

Septic arthritis of the native hip joint: a multi-pattern, multi-outcome disease

PURPOSE

Septic arthritis of the native hip joint (SANH) is an uncommon surgical and medical emergency with few reports. The aim of this study was to determine predictors of return to theatre (RTT), complications and mortality.

METHODS

Patients with SANH were identified from January 2009 to June 2022; 50 patients and three subgroups were identified: Pyogenic (surgical washout without systemic inflammatory disease), Systemic (surgical washout with SIDs) and patients managed non-surgically. Patterns of these groups were assessed with a principal component analysis. The cumulative incidences for death, any complication and RTT for repeat washout were calculated. The predictive variables associated with outcomes were selected with univariable models and then incorporated in multivariable CoxPH regressions.

RESULTS

The 1-year cumulative incidence was 14% for mortality and 48.5% for any complication. Amongst patients managed surgically, 1-year risk of RTT was 46% in Pyogenic subgroup and 21% in Systemic subgroup. Systemic subgroup had lower complications and RTT and higher rate of sterile aspirate, compared to Pyogenic. Charlson comorbidity index (CCI) (HR = 1.41, P value = 0.03), preoperative albumin (HR = 0.81, P value = 0.009) and preoperative haemoglobin (HR = 0.95, P value = 0.02) were significantly associated with 1-year mortality. Time between symptom onset and admission > 7 days (HR = 3.15, P value = 0.042), preoperative Hb (HR = 1.05, P value = 0.016), socioeconomic deprivation (HR = 1.18, P value = 0.04) and Systemic subgroup (HR = 0.25, P value = 0.04) were significantly associated with RTT.

CONCLUSION

Mortality was well predicted by the usual parameters including CCI, albumin, but also low haemoglobin. Patients presenting in a delayed fashion were more likely to have multiple lavages.

A case of septic arthritis of the elbow joint in rheumatoid arthritis diagnosed by arthroscopic synovectomy

We report a case of methicillin-resistant Staphylococcus aureus (MRSA) septic arthritis of the elbow detected by arthroscopic synovectomy in an 81-year-old woman with rheumatoid arthritis (RA) who was initially diagnosed with a rheumatoid arthritis flare-up. The patient was administered abatacept, an antirheumatic biological agent, as the synovial fluid culture was negative. Destruction of the joint progressed despite medication, and the patient underwent arthroscopic synovectomy. MRSA was detected in the culture of the synovium that was collected intraoperatively, and septic arthritis was diagnosed. The infection subsided with anti-MRSA antibiotics, but the patient continued to experience moderate pain and limited motion. In RA patients, it might be difficult to differentiate minor findings from infection. Arthroscopic synovectomy is one of the selectable procedures that should be actively considered when infection is suspected.

Total hip arthroplasty for destructive septic arthritis of the hip using a two-stage protocol without spacer placement

INTRODUCTION

The optimal treatment of patients with a degenerative joint disease secondary to an active or chronic septic arthritis of the hip is unclear. The aim of the present study was to report on our experience with two-stage total hip arthroplasty (THA) using a contemporary treatment protocol without spacer insertion.

MATERIALS AND METHODS

Our prospective institutional database was used to identify all patients with degenerative septic arthritis treated with a non-spacer two-stage protocol between 2011 and 2017. Clinical outcomes included interim revision, periprosthetic infection (PJI) and aseptic revision rates. Restoration of leg-length and offset were assessed radiographically. Modified Harris hip score (mHHS) were obtained. Treatment success was defined using the modified Delphi consensus criteria. Mean follow-up was 62 months (13-110).

RESULTS

A total of 33 patients with a mean age of 60 years (13-85) were included. 55% of the cohort was male and average Charlson Comorbidity Index (CCI) was 3.7 (0-12). 21 patients (64%) had an active/acute infection and 12 patients (36%) were treated for chronic/quiescent septic arthritis. Overall, 11 patients (33%) had treatment failure, including 5 patients who failed to undergo THA, 2 interim re-debridement for persistent infection, and 4 patients who developed PJI after an average of 7 months (0.3-13) following THA. The most common identified pathogen was Staphylococcus aureus (42.4%). No aseptic revision was recorded following THA. Leg-length and offset were successfully restored. Mean mHHS improved from 35.2 points to 73.4 points.

CONCLUSION

Two-stage THA without spacer placement is a viable treatment option for destructive septic arthritis of the hip, demonstrating comparable rates of infection control and functional outcome. However, definitive resection arthroplasty is not uncommon in these often critically ill patients.

Performance of a diagnostic score for gouty arthritis: results from a cohort of acute arthritis suspected of being septic

Septic arthritis (SA) and gout are the main suspected etiologies of acute monoarthritis. Differentiating them is essential because SA is an emergency. The performance of a gout diagnostic score developed by Janssens et al. was investigated in a cohort of patients with acute arthritis suspected of being septic. This was an ancillary study of a single-center cohort of patients with suspected SA. Patients were classified into three groups according to the final diagnosis (gout, SA or other diagnosis). We assessed the performance of the score (sensitivity [Se], specificity [Sp], positive and negative predictive value [PPV, NPV], area under the receiver operating characteristic [ROC] curve) for the diagnosis of gouty arthritis. In total, 138 patients were included: 28 (20.3%) had gout, 42 (30.4%) SA, and 68 (49.3%) another diagnosis. The median diagnostic score was 7.0 [4.5; 8.8] for patients with gout, 3.5 [2.5; 6.0] for those with SA and 3.0 [2.0-5.0] for those with another diagnosis. With a score threshold of ≥ 8, the Se for a diagnosis of gout was 28.6%, Sp 96.4%, PPV 66.7%, and NPV 84.1%. With a threshold of ≤ 4, the Se was 82.1%, Sp 64.5%, PPV 37.1%, and NPV 93.4%. The area under the ROC for the diagnostic score was 0.79. The performance of the clinico-biological score of Janssens et al. for a diagnosis of gout applied to a cohort of patients with acute arthritis and suspected of being septic was poor. Joint aspiration remains necessary to differentiate SA from another etiology.

Concurrent targeting of glycolysis in bacteria and host cell inflammation in septic arthritis

Intracellular infiltration of bacteria into host cells complicates medical and surgical treatment of bacterial joint infections. Unlike soft tissue infections, septic arthritis and infection-associated inflammation destroy cartilage that does not regenerate once damaged. Herein, we show that glycolytic pathways are shared by methicillin-resistant Staphylococcus aureus (MRSA) proliferation and host inflammatory machinery in septic arthritis. MRSA readily penetrates host cells and induces proinflammatory cascades that persist after conventional antibiotic treatment. The glycolysis-targeting drug dimethyl fumarate (DMF) showed both bacteriostatic and anti-inflammatory effects by hindering the proliferation of intracellular MRSA and dampening excessive intraarticular inflammation. Combinatorial treatment with DMF and vancomycin further reduced the proliferation and re-emergence of intracellular MRSA. Combinatorial adjuvant administration of DMF with antibiotics alleviated clinical symptoms of septic arthritis by suppressing bacterial burden and curbing inflammation to protect cartilage and bone. Our results provide mechanistic insight into the regulation of glycolysis in the context of infection and host inflammation toward development of a novel therapeutic paradigm to ameliorate joint bioburden and destruction in septic arthritis.

[Ultrasound-targeted joint puncture in rheumatology]

Joint punctures not only have a long tradition but are also an essential component in the diagnostic differentiation of various joint diseases. In addition, therapeutic injections are an essential component of an individual targeted treatment strategy in a disease-modifying antirheumatic drug (DMARD)-based treat-to-target concept. This article aims to convey to the reader the ultrasound-targeted joint puncture techniques in text and with many video clips that can be downloaded. This article therefore steps away from the conventional two-dimensional demonstration of anatomy-oriented puncture techniques and elucidates the diagnostic and therapeutic potency of ultrasound-targeted techniques in the daily routine. Furthermore, special importance is given to a sterile working technique, puncture material and synovial analysis.

TLR-activated mesenchymal stromal cell therapy and antibiotics to treat multi-drug resistant Staphylococcal septic arthritis in an equine model

BACKGROUND

Rapid development of antibiotic resistance necessitates advancement of novel therapeutic strategies to treat infection. Mesenchymal stromal cells (MSC) possess antimicrobial and immunomodulatory properties, mediated through antimicrobial peptide secretion and recruitment of innate immune cells including neutrophils and monocytes. TLR-3 activation of human, canine and equine MSC has been shown to enhance bacterial killing and clearance in vitro, in rodent Staphylococcal biofilm infection models and dogs with spontaneous multi-drug-resistant infections. The objective of this study was to determine if intra-articular (IA) TLR-3-activated MSC with antibiotics improved clinical parameters and reduced bacterial counts and inflammatory cytokine concentrations in synovial fluid (SF) of horses with induced septic arthritis.

METHODS

Eight horses were inoculated in one tarsocrural joint with multidrug-resistant Staphylococcus aureus (S. aureus). Bone marrow-derived MSC from three unrelated donors were activated with TLR-3 agonist polyinosinic, polycytidylic acid (pIC). Recipient horses received MSC plus vancomycin (TLR-MSC-VAN), or vancomycin (VAN) alone, on days 1, 4, 7 post-inoculation and systemic gentamicin. Pain scores, quantitative bacterial counts (SF, synovium), SF analyses, complete blood counts, cytokine concentrations (SF, plasma), imaging changes (MRI, ultrasound, radiographs), macroscopic joint scores and histologic changes were assessed. Results were reported as mean ± SEM.

RESULTS

Pain scores (d7, P=0.01, 15.2±0.2 vs. 17.9±0.5), ultrasound (d7, P=0.03, 9.0±0.6 vs. 11.8±0.5), quantitative bacterial counts (SF d7, P=0.02, 0±0 vs. 3.4±0.4; synovium P=0.003, 0.4±0.4 vs. 162.7±18.4), systemic neutrophil (d4, P=0.03, 4.6±0.6 vs. 7.8±0.6) and serum amyloid A (SAA) (d4, P=0.01, 1,106.0±659.0 vs. 2,858.8±141.3; d7, P=0.02, 761.8±746.2 vs. 2,357.3±304.3), and SF lactate (d7, P<0.0001, 5.4±0.2 vs. 15.0±0.3), SAA (endterm, P=0.01, 0.0 vs. 2,094.0±601.6), IL-6 (P=0.03, 313.0±119.2 vs. 1,328.2±208.9), and IL-18 (P=0.02, 11.1±0.5 vs. 13.3±3.8) were improved in TLR-MSC-VAN vs. VAN horses. Study limitations include the small horse sample size, short study duration, and lack of additional control groups.

CONCLUSIONS

Combined TLR-activated MSC with antibiotic therapy may be a promising approach to manage joint infections with drug resistant bacteria.

Raised initial total white cell count and lower post-operative decline of C reactive protein increases the risk of secondary surgery in septic arthritis of the native knee

PURPOSE

Septic arthritis is an orthopaedic emergency with high morbidity and mortality. The aim of this study is to determine the risk factors associated with secondary surgery for septic arthritis of the native knee joint.

METHODS

This is a retrospective study reviewing all patients who underwent surgery for septic arthritis of the knee from 2012 to 2019 in a single institution. A total of 117 patients were recruited. Patients were divided into 2 groups: Group I (79/117, 67.5%) underwent one surgery and Group II (38/117, 32.5%) underwent more than one surgery.

RESULTS

Patients with a raised initial total white (TW) cell count of > 20 × 10⁹/L had a significantly higher risk of secondary surgery. (Adjusted hazard ratio 2.42, p < 0.05) A decline of CRP level of less than 20% within 24 h from initial operation was also a risk for secondary surgery. (Adjusted hazard ratio 0.34, p < 0.01) Patients in group II also had significantly higher post-operative median TW cell count and neutrophil count. There was no significant difference in the offending microbe, surgical approach, and duration of operation from initial presentation between the groups.

CONCLUSIONS

Patients with septic arthritis of the native knee joint who present with raised initial total white cell count of > 20 × 10⁹/L and decline of CRP level of less than 20% within 24 h from initial operation are at higher risk of secondary operation. In these patients, more aggressive treatment strategies and appropriate counselling on the risks of repeated surgery are recommended.

LEVEL OF EVIDENCE

Level IV.

Septic arthritis in an in vivo murine model induced by Staphylococcus aureus : a comparison between actions of the haemolysin toxin and the effects of the host immune response

Aims

Staphylococcus aureus is a major cause of septic arthritis, and in vitro studies suggest α haemolysin (Hla) is responsible for chondrocyte death. We used an in vivo murine joint model to compare inoculation with wild type S. aureus 8325-4 with a Hla-deficient strain DU1090 on chondrocyte viability, tissue histology, and joint biomechanics. The aim was to compare the actions of S. aureus Hla alone with those of the animal’s immune response to infection.

Methods

Adult male C57Bl/6 mice (n = 75) were randomized into three groups to receive 1.0 to 1.4 × 10⁷ colony-forming units (CFUs)/ml of 8325-4, DU1090, or saline into the right stifle joint. Chondrocyte death was assessed by confocal microscopy. Histological changes to inoculated joints were graded for inflammatory responses along with gait, weight changes, and limb swelling.

Results

Chondrocyte death was greater with 8325-4 (96.2% (SD 5.5%); p < 0.001) than DU1090 (28.9% (SD 16.0%); p = 0.009) and both were higher than controls (3.8% (SD 1.2%)). Histology revealed cartilage/bone damage with 8325-4 or DU1090 compared to controls (p = 0.010). Both infected groups lost weight (p = 0.006 for both) and experienced limb swelling (p = 0.043 and p = 0.018, respectively). Joints inoculated with bacteria showed significant alterations in gait cycle with a decreased stance phase, increased swing phase, and a corresponding decrease in swing speed.

Conclusion

Murine joints inoculated with Hla-producing 8325-4 experienced significantly more chondrocyte death than those with DU1090, which lack the toxin. This was despite similar immune responses, indicating that Hla was the major cause of chondrocyte death. Hla-deficient DU1090 also elevated chondrocyte death compared to controls, suggesting a smaller additional deleterious role of the immune system on cartilage.

Cite this article: Bone Joint Res 2022;11(9):669–678.

Septic arthritis of the wrist: a retrospective review of 39 cases

LEVEL OF EVIDENCE

III.

Comparison of MR Findings between Patients with Septic Arthritis and Acute Gouty Arthritis of the Knee

Purpose

To compare the MR findings of septic and acute gouty arthritis of the knee joint.

Materials and Methods

This retrospective study included patients who underwent knee MRI for septic or gouty arthritis at our hospital between October 2012 and October 2018. The MR findings were analyzed for the presence of bone marrow edema, soft tissue edema, abscess, pattern of synovial thickening (frondlike, lamellated, diffuse linear), maximum thickness of the synovium, and joint effusion volume. The gouty (n = 5) and septic arthritis (n = 10) groups were compared using the Wilcoxon rank-sum test and Fisher's exact test.

Results

No statistically significant differences were observed for each item. One patient in the gouty arthritis group and seven in the septic arthritis group had bone marrow edema. Soft tissue abscess formation was only observed in the septic group. The incidence of each synovial thickening pattern was as follows: 100% (diffuse linear) in the gouty arthritis group and 20% (frondlike), 50% (lamellated), and 30% (diffuse linear) in the septic arthritis group.

Conclusion

Differentiation of gouty arthritis and septic arthritis based on imaging findings is difficult. However, lamellated synovial thickening patterns, bone marrow edema, and soft tissue abscess formation are more commonly observed in patients with septic arthritis than in those with gouty arthritis.

Mortality of septic knee arthritis in Korea: risk factors analysis of a large national database

This study aimed to analyze the risk factors for mortality of septic knee arthritis in Korea through a large nationwide data research. The National Health Insurance Service-Health Screening database was used to analyze 89,120 hospitalizations for septic knee arthritis between 2005 and 2018. In-hospital, thirty-day, and ninety-day mortality, and their association with patient’s demographic factors, various comorbidities (i.e., cerebrovascular disease, congestive heart failure, and myocardial infarction) and Charlson Comorbidity Index (CCI) were assessed. Secondary outcomes of complications (osteomyelitis, knee arthroplasty, recurrence) were analyzed. The number of hospitalization with septic knee arthritis increased from 1847 cases in 2005 to 8749 cases in 2018. There was no significant difference in mortality after diagnosis of septic knee arthritis between years. The risk of mortality in patients who hospitalized with septic knee arthritis increased in comorbidities like Congestive heart failure, dementia, myocardial infarction, chronic kidney disease. Hazard ratio (HR) decreased in patients who have comorbidities such as rheumatoid arthritis, liver disease, rheumatologic disease. HR for mortality in septic knee arthritis increased in patients with CCI more than 1. The risk factors for mortality in all periods were male sex, old age, high CCI, comorbidities such as congestive heart failure, dementia, myocardial infarction, chronic kidney disease. Efforts to reduce mortality should be concentrate more on patients with these risk factors.

Management and outcome of native joint septic arthritis: a nationwide survey in French rheumatology departments, 2016-2017

OBJECTIVES

To describe current management and outcome of native joint septic arthritis (NJSA) in French rheumatology departments.

METHODS

For this retrospective, nationwide multicentric study, 127 French rheumatology departments were contacted to report up to 12 cases of NJSA that occurred between 1 January 2016 and 31 December 2017. Characteristics, diagnosis procedures, therapeutic management and outcome were recorded.

RESULTS

Overall, 362 patients were included (mean age 64.0±18.6 years, median Charlson comorbidity index 3.5 (0-14)). Knee was the most frequent site (n=160 (38.9%)), and Staphylococcus sp (n=185 (51.4%)), the most frequent pathogen. All patients received antibiotics for a mean duration of 46.8 (±22.0) days, including intravenous route for a mean of 17.2 (±15.4) days. Management was heterogeneous. Surgical procedure was performed in 171 (48.3%), joint immobilisation in 128 (43.8%). During follow-up, 91 (28.3%) patients have had serious complications and 28 (9.2%) of them died. Factors associated with 1-year mortality were age (OR 1.08, 95% CI 1.04 to 1.13; p<0.001), Charlson's index (OR 1.30, 95% CI 1.06 to 1.58; p=0.012), presence of bacteraemia (OR 4.02, 95% CI 1.35 to 11.99; p=0.008), antibiotic use in the previous 3 months (OR 3.32, 95% CI 1.11 to 9.87; p=0.029) and Staphylococcus aureus NJSA compared with Streptococcus sp. NJSA (OR 7.24, 95% CI 1.26 to 41.68, p=0.027). The complete recovery with no adverse joint outcome at 1 year was observed in n=125/278 patients (55.0%).

CONCLUSION

Prognosis of NJSA remained severe with a high rate of morbimortality. Its management was very heterogeneous. This study highlights the importance of the new French recommendations, published after the completion of the study, in order to facilitate NJSA management.

Treating 'Septic' With Enhanced Antibiotics and 'Arthritis' by Mitigation of Excessive Inflammation

Bacterial infection within the synovial joint, commonly known as septic arthritis, remains a clinical challenge as it presents two concurrent therapeutic goals of reducing bacterial burden and preservation of articular cartilage from destructive host inflammation. We hypothesized that mitigation of MRSA-induced inflammatory signaling could diminish destruction of articular cartilage in the setting of septic arthritis when used in conjunction with antibiotics. Herein, we provide evidence which supports a new therapeutic notion that concurrent antimicrobial therapy to address the ‘septic’ component of the disease with inflammation mitigation to manage the destructive ‘arthritis’ component. We established a murine model to mimic septic knee arthritis, as well as a variety of other inflammatory joint conditions. This murine septic arthritis model, in conjunction with in vitro and ex-vivo models, was utilized to characterize the inflammatory profile seen in active septic arthritis, as well as post-antibiotic treatment, via transcriptomic and histologic studies. Finally, we provided the clinical rationale for a novel therapeutic strategy combining enhanced antibiotic treatment with rifampin and adjuvant immunomodulation to inhibit post-infectious, excess chondrolysis and osteolysis. We identified that septic arthritis secondary to MRSA infection in our murine model led to increased articular cartilage damage compared to various types of inflammatory arthritis. The activation of the pERK1/2 signaling pathway, which is implicated with the mounting of an immune response and generation of inflammation, was increased in intracellular MRSA-infected synovial tissue and persisted despite antibiotic treatment. Trametinib, an inhibitor of ERK signaling through suppression of MEK1/2, alleviated the inflammation produced by the addition of intra-articular, heat-killed MRSA. Further, when combined with vancomycin and rifampin, mitigation of inflammation by pERK1/2 targeting improved outcomes for MRSA septic arthritis by conferring chondroprotection to articular cartilage and diminishing inflammatory osteolysis within bone. Our results support a new therapeutic notion that cell/biofilm-penetrating antibiotics alongside adjuvant mitigation of excessive intra-articular inflammation accomplish distinct therapeutic goals: reduction of bacterial burden and preservation of articular cartilage integrity.

Concomitant septic arthritis of the hip joint and femoral head avascular necrosis in patients with recent COVID-19 infection: a cautionary report

Purpose

At present, concomitant avascular necrosis (AVN) of femoral head and septic arthritis (SA) as a sequel of COVID-19 infection has yet not been documented. By large-scale use of life-saving corticosteroids (CS) in COVID-19 cases, our aim is to warn of the occurrence of hip joint infection in these patients.

Methods

We report a series of five cases in which patients developed septic arthritis concomitant with AVN after being treated for COVID-19 infection. The mean dose of prednisolone used in these cases was 1695.2 mg. The time period of onset of hip symptoms in our cases from the beginning of the COVID-19 infection was 56 days in the first case, 43 days in the second case, 30 days in the third case, 29 days in the fourth case and 50 days in the last case, with an average time of 41.6 days. All patients underwent surgery depending on the extent of articular cartilage damage by direct anterior approach.

Results

Clinical and laboratory symptoms improved significantly in all patients. The mean visual analogue pain score of the patients decreased from 9.4 (9–10) before surgery to 2.8 (1–4) after 1 week of operation.

Conclusion

In any patient with the history of COVID-19 infection specially those who have been treated with corticosteroid as one of the medications prescribed during the disease, any joint symptom specially in the hips should draw our attention to the joint infection, and with timely diagnosis and surgery, their hip joint can be saved.

Clinical Efficacy of the Antibiotic-Loaded Collagen Sponge During Arthroscopic Treatment of Acute Septic Arthritis of the Native Knee

Background:

To completely eliminate an infection, the antibiotic concentration must exceed the minimum inhibitory concentration for the causative pathogens. The antibiotic-loaded collagen sponge (ALCS) has been used to manage an infection through a high local concentration of antibiotics.

Purpose:

To evaluate the clinical efficacy of ALCS in the arthroscopic treatment of patients with acute septic arthritis of the native knee.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

The authors retrospectively reviewed the data for 132 consecutive patients with acute septic arthritis of the knee who underwent arthroscopic debridement between 2013 and 2019. Patients with a history of surgery in the affected joint, concomitant osteomyelitis, or accompanying medical infection were excluded. The study patients were divided into 2 groups based on the use of ALCS during surgery. C-reactive protein (CRP) levels were temporally measured to normalization and the duration of intravenous antibiotic administration was recorded, and the mean length of hospital stay was compared between the groups. Independent t test and chi-square test were performed to assess differences between the groups, and univariate analysis was used to analyze factors affecting recurrence of septic arthritis.

Results:

Of the 132 patients, 88 were ultimately included in this study; 51 patients were managed without ALCS and 37 were treated with ALCS. There were statistically significant differences between groups in the mean period for CRP-level normalization (15.2 ± 8.2 days [ALCS] vs 26.2 ± 14.7 days [without ALCS]; P = .004), mean duration of intravenous antibiotic use (18.4 ± 7.3 days [ALCS] vs 26.6 ± 16.1 days [without ALCS]; P = .046), and mean length of hospital stay (21.1 ± 11.6 days [ALCS] vs 30.3 ± 18.3 days [without ALCS]; P = .045). The preoperative CRP level was the only significant risk factor for recurrence or treatment failure after single arthroscopic debridement.

Conclusion:

The results of this study indicated that ALCS was able to reduce the duration of CRP-level normalization, intravenous antibiotic use, and hospitalization in patients who underwent arthroscopic irrigation and debridement for acute septic arthritis of the native knee.

Short- and Mid-Term Survival of Geriatric Patients with Septic Arthritis of the Knee and the Impact of Risk Factors on Survival

Septic arthritis is common in older adults and can be related to joint surgery or hematogenous distribution. To date, the risk factors affecting survival are unknown. This study aimed to evaluate the effects of existing implants, positive synovial microbiological culture results, and the American Society of Anesthesiology Physical Status (ASA) classification on the short- and mid-term survival of older patients with primary septic gonarthritis. This retrospective study included 133 older adults >60 years who underwent surgery for primary septic gonarthritis. Data were collected from medical records and public obituaries. Kaplan–Meier survival curves were used to estimate the probability of survival, as well as log-rank tests to measure and compare survival rates over one- and five-year periods. The mean age was 74.9 years (SD ± 9.2), and the 5-year follow-up rate was 74.3% (the mean follow-up was 3000.5 days; SD ± 1771.6). Mean survival was significantly different in patients with implants and without implants (p = 0.015), and between ASA II, ASA III, and ASA IV (p < 0.001). There was no significant difference in the survival of patients with or without a positive synovial microbiological culture (p = 0.08). Older adults with septic monoarthritis and pre-existing medical implants showed impaired survival. The ASA classification prior to surgery for primary septic monoarthritis can be helpful in identifying patients with poorer mid-term outcomes.

Similar Efficacy of Arthroscopy and Arthrotomy in Infection Eradication in the Treatment of Septic Knee: A Systematic Review and Meta-Analysis

Aim: To compare the arthroscopy vs. arthrotomy for the treatment of native knee septic arthritis.

Methods: Electronic databases of PubMed, Embase and Cochrane Library were searched for eligible studies. Retrospective comparative studies comparing arthroscopy or arthrotomy for patients with septic arthritis of the native knee were eligible for this review. The primary outcome was recurrence of infection after first procedure. The secondary outcomes included hospital length of stay, operative time, range of motion of the involved knee after surgery, overall complications and mortality rate,

Results: Thirteen trials were included in this study. There were a total of 2,162 septic arthritis knees treated with arthroscopic debridement and irrigation, and 1,889 septic arthritis knees treated with open debridement and irrigation. Arthroscopy and arthrotomy management of the knee septic arthritis showed comparable rate of reinfection (OR = 0.85; 95% CI, 0.57–1.27; P = 0.44). No significant difference was observed in hospital length of stay, operative time and mortality rate between arthroscopy and arthrotomy management group, while arthroscopy treatment was associated with significantly higher knee range of motion and lower complication rate when compared with arthrotomy treatment.

Conclusion: Arthroscopy and arthrotomy showed similar efficacy in infection eradication in the treatment of native septic knee. However, arthroscopy treatment was associated with better postoperative functional recovery and lower complication rate.

Management of a Hot Swollen Joint in the Acute Setting

BACKGROUND

The presentation of a hot swollen joint is common in the emergency department, general practice, rheumatology and orthopedic clinics. There is a wide set of differential diagnoses for a hot swollen joint, thus making it difficult to diagnose and manage, especially for junior doctors. Initially, it is pertinent to exclude/diagnose medical and surgical emergencies.

OBJECTIVE

This paper aims to summarize the key indications within the history, examination and investigations in order to quickly and effectively diagnose a hot swollen joint based on the original 2006 management guidelines and the papers discussing other possible indications and management strategies published since.

RESULTS

Currently, the management of crystal and non-infectious arthropathies are well recognized with little disparity. However, the treatment of infectious arthritis is not concrete and there are discrepancies in management between doctors.

CONCLUSION

We have summarized the key indications and provided a diagnostic flow chart to aid with the management.

In vitro antibiotic activity against intraosteoblastic Staphylococcus aureus: a narrative review of the literature

Staphylococcus aureus – a major aetiological agent of bone and joint infection (BJI) – is associated with a high risk of relapse and chronicity, in part due to its ability to invade and persist in non-professional phagocytic bone cells such as osteoblasts. This intracellular reservoir protects S. aureus from the action of the immune system and most antibiotics. To date, the choice of antimicrobial strategies for BJI treatment mostly relies on standard susceptibility testing, bone penetration of antibiotics and their ‘antibiofilm’ activity. Despite the role of intracellular persistent S. aureus in the development of chronic infection, the ability of antibiotics to target the S. aureus intraosteoblastic reservoir is not considered in therapeutic choices but might represent a key determinant of treatment outcome. This review provides an overview of the intracellular pharmacokinetics of antistaphylococcal drugs used in the treatment of BJI and of their ability to target intraosteoblastic S. aureus. Thirteen studies focusing on the intraosteoblastic activity of antibiotics against S. aureus were reviewed, all relying on in vitro models of osteoblast infection. Despite varying incubation times, multiplicities of infection, bacterial strains, and the types of infected cell lines, rifamycins and fluoroquinolones remain the two most potent antimicrobial classes for intraosteoblastic S. aureus eradication, consistent with clinical data showing a superiority of this combination therapy in S. aureus orthopaedic device-related infections.

Serial Surgical Debridement and Fixation of Chronic Pelvis Instability Secondary to Pubic Symphysis and Sacroiliac Osteomyelitis: A Case Report

Introduction

Chronic global pelvic instability can be due to many different etiologies with infection being an uncommon cause. We present a case of chronic global pelvis instability secondary to osteomyelitis involving both the anterior and posterior ring, a rare and challenging problem with no standard treatment.

Case Presentation

A 57-year-old female with a history of intravenous drug use presented with global pelvis instability in the setting of pubic symphysis and posterior sacroiliac osteomyelitis with multiple-associated abscesses. She was managed with serial surgical debridement's X4 and combined anterior and posterior fixation/fusion, with resolution of her infection and instability.

Conclusions

This is the first reported case of chronic pelvis instability secondary to anterior and posterior pelvic ring osteomyelitis that was successfully treated with serial debridement and combined anterior and posterior fixation/fusion.

EULAR recommendations for intra-articular therapies

OBJECTIVES

To establish evidence-based recommendations to guide health professionals using intra-articular therapies (IAT) in adult patients with peripheral arthropathies.

METHODS

A multidisciplinary international task force established the objectives, users and scope and the need for background information, including systematic literature reviews) and two surveys addressed to healthcare providers and patients throughout Europe. The evidence was discussed in a face-to-face meeting, recommendations were formulated and subsequently voted for anonymously in a three-round Delphi process to obtain the final agreement. The level of evidence was assigned to each recommendation with the Oxford levels of evidence.

RESULTS

Recommendations focus on practical aspects to guide health professionals before, during and after IAT in adult patients with peripheral arthropathies. Five overarching principles and 11 recommendations were established, addressing issues related to patient information, procedure and setting, accuracy, routine and special aseptic care, safety issues and precautions to be addressed in special populations, efficacy and safety of repeated joint injections, use of local anaesthetics and aftercare.

CONCLUSION

We have developed the first evidence and expert opinion-based recommendations to guide health professionals using IAT. We hope that these recommendations will be included in different educational programmes, used by patient associations and put into practice via scientific societies to help improve uniformity and quality of care when performing IAT in peripheral adult joints.

Native joint infections in Iceland 2003-2017: an increase in postarthroscopic infections

Objectives

Nationwide study on the epidemiology, clinical characteristics and outcomes among patients with native joint infection (NJI) in Iceland, 2003–2017.

Methods

All positive synovial fluid culture results in Iceland were identified and medical records reviewed.

Results

A total of 299 NJI (40 children and 259 adults) were diagnosed in Iceland in 2003–2017, with a stable incidence of 6.3 cases/100 000/year, but marked gender difference among adults (33% women vs 67% men, p<0.001). The knee joint was most commonly affected, and Staphylococcus aureus was the most common isolate in both adults and children, followed by various streptococcal species in adults and Kingella kingae in children. NJI was iatrogenic in 34% of adults (88/259) but comprised 45% among 18–65 years and a stable incidence. Incidence of infections following arthroscopic procedures in adults increased significantly compared with the previous decade (9/100 000/year in 1990–2002 vs 25/100 000/year in 2003–2017, p<0.01) with no significant increase seen in risk per procedure. The proportion of postarthroscopic NJI was 0.17% overall but 0.24% for knee arthroscopy. Patients with postarthroscopic infection were more likely to undergo subsequent arthroplasty when compared with other patients with NJI (p=0.008).

Conclusions

The incidence of NJI in Iceland has remained stable. The proportion of iatrogenic infections is high, especially among young adults, with an increase seen in postarthroscopic infections when compared with the previous decade. Although rare, NJI following arthroscopy can be a devastating complication, with significant morbidity and these results, therefore, emphasise the need for firm indications when arthroscopic treatment is considered.

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.

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.

Streptococcus Pneumoniae septic arthritis in adults in Bristol and Bath, United Kingdom, 2006-2018: a 13-year retrospective observational cohort study

Few studies on adult pneumococcal septic arthritis are sufficiently large enough to assess both epidemiological trends following routine pneumococcal immunization and clinical disease. With major shifts in serotypes causing invasive pneumococcal disease (IPD), we wanted to determine the clinical phenotype of adult septic arthritis caused by Streptococcus pneumoniae. We conducted a retrospective cohort study of pneumococcal infections in Bristol and Bath, UK, 2006–2018. We defined pneumococcal septic arthritis as adults with clinically-confirmed septic arthritis, with pneumococcus isolated from sterile-site culture or urinary antigen test positivity. Clinical records were reviewed for each patient in the cohort. Septic arthritis accounted for 1.7% of all IPD cases. 45 cases of adult pneumococcal septic arthritis occurred, with disease typically affecting older adults and those with underlying comorbidity. 67% patients had another focus of infection during their illness. 66% patients required increased care on discharge and 43% had reduced range of movement. In-hospital case fatality rate was 6.7%. One-year patient mortality was 31%. Currently most cases of adult pneumococcal septic arthritis are due to non-PCV13 serotypes which are associated with more severe disease. Non-PCV-13 serotypes had higher prevalence of concomitant pneumococcal infection at another site (73.7% versus 36.6%), increased intensive care or high-dependency unit requirement (32.4% versus 0%), and increased inpatient and 1-year case fatality rate (8.8% versus 0%, and 32.4% versus 27.4% respectively) compared to PCV-13 serotypes. Pneumococcal septic arthritis remains a small proportion of IPD. However, there is significant associated morbidity and mortality, and pneumococcal septic arthritis requires monitoring in coming years.