Multi-centre evaluation of Gram stain in the diagnosis of septic arthritis

Introduction: Gram stain of synovial fluid is a rapid test for the diagnosis of native joint septic arthritis. Single-centre studies have suggested Gram stain will miss a considerable proportion of patients who are subsequently synovial-fluid-culture-positive or polymerase chain reaction (PCR)-positive. The object of this study was to reassess Gram stain in a large, multi-centre cohort of patients from the United Kingdom (UK) and Ireland. Methods: The study was a retrospective analysis combining two large datasets. We defined septic arthritis microbiologically as at least one positive joint aspirate culture and/or PCR test. "Best case" and "worst case" definitions were applied depending on the likelihood organisms were true infecting pathogens. Results: Gram stain missed a high proportion of culture-/PCR-positive patients using both the best (74 % missed) and worst (81 % missed) case definitions. Using the best case definition, the sensitivity of Gram stain was 0.26, specificity 0.99, positive predictive value 0.84, negative predictive value 0.87, accuracy 0.87, and area under the receiver operator curve 0.62 (95 % CI 0.57 to 0.68, p < 0.001 ). False positive Gram stains were infrequent (1 %). Age, joint involved, and other synovial fluid characteristics were less predictive of a positive culture/PCR than Gram stain. Conclusions: While a positive synovial fluid Gram stain should always be considered to indicate potential septic arthritis, a negative Gram stain, regardless of synovial fluid crystals or white cell count, should not be used to rule out septic arthritis. The value of Gram stain as an urgent out-of-hours test for septic arthritis is open to considerable debate.

Knowledge, Attitudes, and Practices of Moroccan Rheumatologists in the Management of Acute Septic Arthritis: Results of a National Cross-Sectional Survey

Objective To assess the level of knowledge of Moroccan rheumatologists regarding the management of acute septic arthritis and analyze their attitudes and clinical practices toward this condition. Methods A descriptive cross-sectional study was conducted among Moroccan rheumatologists through a Google Forms questionnaire distributed via email. The data collected included sociodemographic characteristics of Moroccan rheumatologists, their level of knowledge, as well as their attitudes and clinical practices, assessed on a Likert scale (1 to 5). Results Out of the 440 questionnaires sent, 131 rheumatologists replied, corresponding to a response rate of 131 (33.58%). The average age of participants was 42.9±12.7 years, with a predominance of females (103 (84.8%)) and an average of 13.8 ± 11.3 years of experience in rheumatology. The diagnosis of septic arthritis was systematically considered in the case of acute monoarthritis, even in the absence of fever, by 122 (93.1%) rheumatologists. However, only 68 (51.9%) were aware of the association between a quick Sequential Organ Failure Assessment (qSOFA) score ≥2 and a high risk of mortality. Regarding therapeutic management, 115 (87.8%) rheumatologists preferred a third-generation cephalosporin, often combined with an aminoglycoside (110 (84%)). However, only 18 (13.7%) prescribed short-course antibiotics for small joints, and 13 (9.9%) associated this with joint lavage and/or surgical synovectomy. Furthermore, in cases of unfavorable evolution, only 19 (14.5%) routinely referred the patient to an orthopedic surgeon for surgical lavage. The main challenges identified were delayed diagnosis (90 (68.7%)) and the management of complicated cases (91 (69.5%)). To address these issues, a large majority of rheumatologists recommended the development of standardized protocols (118 (90.1%)), raising awareness among healthcare professionals about early diagnosis (116 (88.5%)), and strengthening collaboration with orthopedic surgeons (111 (84.7%)). Conclusion This study highlights gaps in the management of acute septic arthritis and emphasizes the need for better awareness, standardization of practices, and improved coordination with other specialties to optimize patient care.

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.

Evaluating the Confidence of Non-specialty Doctors Working in Trauma and Orthopedics in Performing Knee Arthrocentesis Through Simulation-Based Teaching

Introduction Acute monoarthropathies that present in emergency settings include septic arthritis, where urgent joint arthrocentesis is the diagnostic gold standard. Literature indicates low confidence among trainee doctors in performing knee aspirations. Simulation-based teaching can be used to supplement procedural skills training and improve their confidence in performing such procedures. Methods This study aimed to assess the self-rated confidence of non-specialty doctors (N=8) in Trauma and Orthopedics in conducting knee aspirations using simulation-based teaching with an anatomically accurate knee model. Pre- and post-intervention questionnaires investigated self-reported confidence using a 10-point Likert-type scale and participant experience using a 7-point Likert scale. Pre- and post-intervention surveys further qualitatively explored attitudes toward conducting the skill. Results Pre-intervention mean confidence was rated 3.9 (SD=2.70) out of 10, with a noted increase to 8.1 (SD=1.25) out of 10, providing a mean difference of 4.2 (SD=2.82) out of 10 with p=0.007. All attendees agreed or strongly agreed on the usefulness and satisfaction of the activity. Qualitative analysis indicated themes of nervousness and lack of confidence pre-intervention and attitudes of increased confidence in the skill post-intervention. Conclusions Overall, increased statistically significant confidence was concluded among non-specialty doctors in conducting knee arthrocentesis following simulation-based teaching, with perceived usefulness and satisfaction of the activity. Nonetheless, we must consider potential limitations of clinical accuracy and realism through such procedural skills training.

Native Joint Septic Arthritis

Native joint septic arthritis (NJSA) is a severe and rapidly progressing joint infection, predominantly bacterial but also potentially fungal or viral, characterized by synovial membrane inflammation and joint damage, necessitating urgent and multidisciplinary management to prevent permanent joint damage and systemic sepsis. Common in large joints like knees, hips, shoulders, and elbows, NJSA's incidence is elevated in individuals with conditions like rheumatoid arthritis, diabetes, immunosuppression, joint replacement history, or intravenous drug use. This review provides a comprehensive overview of NJSA, encompassing its diagnosis, treatment, antibiotic therapy duration, and surgical interventions, as well as the comparison between arthroscopic and open debridement approaches. Additionally, it explores the unique challenges of managing NJSA in patients who have undergone graft anterior cruciate ligament (ACL) reconstruction. The epidemiology, risk factors, pathogenesis, microbiology, clinical manifestations, diagnosis, differential diagnosis, antibiotic treatment, surgical intervention, prevention, and prophylaxis of NJSA are discussed, highlighting the need for prompt diagnosis, aggressive treatment, and ongoing research to enhance patient outcomes.

Septic arthritis of the native hip joint and septic pulmonary embolism in an adult with sickle cell trait after a complicated dental extraction

Septic arthritis (SA) is a serious infection of the joint which can lead to irreversible destruction of the joint.We report a case of right hip SA with septic pulmonary embolism following a complicated dental extraction in a woman in her early 40s with sickle cell trait (SCT).The patient presented with severe right thigh pain and left jaw pain.Initial workup revealed raised C reactive protein and positive blood cultures. Right hip joint SA was confirmed following intraoperative joint aspiration. The patient had right hip debridement with long-term intravenous antibiotics.The incidence of SA in adults with sickle cell disease is low: 0.3% in a study in France and Brazil and 10.3% incidence of haematogenous osteoarticular infection in children with SCT in West Africa.

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.

A case of otogenic septic arthritis of the knee

Septic arthritis is a serious condition resulting in rapid destruction of articular cartilage and potential sepsis. Bacterial invasion of a joint occurs most commonly as a result of haematogenous spread from a distant infection. However, an otogenic source of this transient bacteraemia and resultant septic arthritis has not yet been reported in the literature. We report a case of acute septic arthritis of the knee with Streptococcus pyogenes, secondary to acute otitis media of the ear.

Substrate-derived Sortase A inhibitors: targeting an essential virulence factor of Gram-positive pathogenic bacteria

The bacterial transpeptidase Sortase A (SrtA) is a surface enzyme of Gram-positive pathogenic bacteria. It has been shown to be an essential virulence factor for the establishment of various bacterial infections, including septic arthritis. However, the development of potent Sortase A inhibitors remains an unmet challenge. Sortase A relies on a five amino acid sorting signal (LPXTG), by which it recognizes its natural target. We report the synthesis of a series of peptidomimetic inhibitors of Sortase A based on the sorting signal, supported by computational binding analysis. By employing a FRET-compatible substrate, our inhibitors were assayed in vitro. Among our panel, we identified several promising inhibitors with IC50 values below 200 μM, with our strongest inhibitor - LPRDSar - having an IC50 of 18.9 μM. Furthermore, it was discovered that three of our compounds show an effect on growth and biofilm inhibition of pathogenic Staphylococcus aureus, with the inclusion of a phenyl ring seemingly key to this effect. The most promising compound in our panel, BzLPRDSar, could inhibit biofilm formation at concentrations as low as 32 μg mL-1, manifesting it as a potential future drug lead. This could lead to treatments for MRSA infections in clinics and diseases such as septic arthritis, which has been directly linked with SrtA.

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.

Early postoperative laboratory parameters are predictive of initial treatment failure in acute septic arthritis of the knee and shoulder joint

Septic arthritis is an orthopedic emergency potentially causing irreversible joint damage. However, the predictive value of potential risk factors such as early postoperative laboratory parameters remains uncertain. We investigated risk factors for initial surgical treatment failure using data from 249 patients (194 knees, 55 shoulders) treated for acute septic arthritis between 2003 and 2018. Necessity for further surgical intervention was defined as primary outcome. Demographic data, medical history, initial and postoperative laboratory parameters, Charlson Comorbidity Index (CCI), and Kellgren and Lawrence classification were collected. Two scoring systems were developed as tools for failure risk estimation after initial surgical irrigation and debridement. More than one intervention was necessary in 26.1% of cases. Treatment failure occurred significantly more often for those with longer symptom duration (p = 0.003), higher CCI grades (p = 0.027), Kellgren-Lawrence grade IV (p = 0.013), shoulder arthroscopy (p = 0.010), positive bacterial culture results (p < 0.001), slow postoperative CRP decline until day three (p = 0.032) and five (p = 0.015), reduced WBC-decline (p = 0.008), and lower hemoglobin (p < 0.001). Scores for third and fifth postoperative day achieved AUCs of 0.80 and 0.85, respectively. This study identified risk factors for treatment failure in patients with septic arthritis, suggesting that early postoperative laboratory parameters can guide further treatment.

A multicentre evaluation and expert recommendations of use of the newly developed BioFire Joint Infection polymerase chain reaction panel

Septic arthritis is a serious condition with significant morbidity and mortality, routinely diagnosed using culture. The FDA has recently approved the rapid molecular BioFire® Joint Infection Panel (BJIP) for synovial fluid. We aimed to evaluate the BJIP compared to culture and its potential use in patient management. A multicentre retrospective evaluation of BJIP was conducted in the UK and Ireland. Positive percent agreement (PPA) and negative percent agreement (NPA) were calculated between the BJIP and routine culture. A multidisciplinary team (MDT) discussion addressing the optimal or potential case use of the assay practice was facilitated. Three hundred ninety-nine surplus synovial fluid samples (~ 70% from native joints) from eight centres were processed using BJIP in addition to routine culture. An increased yield of positive results was detected using BJIP compared to routine culture (98 vs 83), giving an overall PPA of 91.6% and overall NPA of 93% for the BJIP compared to culture results. The BJIP detected resistant markers and additional organisms that could influence antibiotic choices including Neisseria gonorrhoeae and Kingella kingae. The MDT agreed that the assay could be used, in addition to standard methods, in adult and children patients with specialist advice use based on local needs. Rapid results from BJIP were assessed as having potential clinical impact on patient management. Organisms not included in the panel may be clinically significant and may limit the value of this test for PJI.

Case Report: Septic arthritis in children caused by Streptococcus pyogenes-rational use of antibiotics

To investigate the clinical characteristics and treatment of septic arthritis caused by Streptococcus pyogenes(S. pyogenes) in children, we retrospectively analyzed the clinical data, laboratory results, treatments and outcomes of three pediatric cases of septic arthritis caused by S. pyogenes occurring from 2016-2018. The three cases of septic arthritis included 1 boy and 2 girls, aged from 2-7 years. Two patients experienced fever, and in all three cases, the affected joints showed redness, swelling, an increased local skin temperature, tenderness and restricted limb movement. At the first visit, all three cases showed a significantly increased white blood cell count [(27.68-32.02)×10⁹/mL] and a significantly increased erythrocyte sedimentation rate (113-134 mm/h). The C-reactive protein level was significantly increased in two cases (67 mg/L, 147.7 mg/L) and normal in one case. The procalcitonin level was normal in 1 case, elevated in 1 case, and undetected in 1 case. S. pyogenes isolated from cases 1 and 2 were emm1/ST28 and from case 3 was emm12/ST36. All patients were treated by abscess incision and drainage, and S. pyogenes was cultured in the abscess puncture fluid. All patients were treated with intravenous antibiotics after admission, and all patients were cured and discharged. The patients were followed up for 2 months, and their condition was improved and stable. No sequelae such as heart and kidney damage were detected. In conclusion, for children with septic arthritis, early diagnosis and timely treatment with incision and drainage followed by culture of the abscess puncture fluid are important. Once S. pyogenes infection is confirmed, β-lactam antibiotics provide effective treatment, avoiding use of broad-spectrum antibiotics.

Epidemiology and outcomes of bone and joint infections in solid organ transplant recipients

Bone and joint infection (BJI) epidemiology and outcomes in solid organ transplant recipients (SOTr) remain largely unknown. We aim to describe BJI in a multi-center cohort of SOTr (Swiss Transplant Cohort Study). All consecutive SOTr with BJI (01.05.2008-31.12.2019) were included. A nested case-control study to identify risk factors for BJI was performed. Among 4482 patients, 61 SOTr with 82 BJI were included, at an incidence of 1.4% (95% CI 1.1-1.7), higher in heart and kidney-pancreas SOTr (Gray's test p < .01). Although BJI were predominately late events (median of 18.5 months post-SOT), most infections occurred during the first year post-transplant in thoracic SOTr. Diabetic foot osteomyelitis was the most frequent infection (38/82, 46.3%), followed by non-vertebral osteomyelitis (26/82, 31.7%). Pathogens included Gram-positive cocci (70/131, 53.4%), Gram-negative bacilli (34/131, 26.0%), and fungi (9/131, 6.9%). BJI predictors included male gender (OR 2.94, 95% CI 1.26-6.89) and diabetes (OR 2.97, 95% CI 1.34-6.56). Treatment failure was observed in 25.9% (21/81) patients and 1-year mortality post-BJI diagnosis was 14.8% (9/61). BJI remain a rare event in SOTr, associated with subtle clinical presentations, high morbidity and relapses, requiring additional studies in the future.

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.

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.

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.

The profile of the causative organisms which lead to septic arthritis of native joints over the last two decades in a single tertiary medical center in the east coast of the United States

BACKGROUND

Septic arthritis (SA) is associated with significant morbidity and mortality. Delayed or inadequate treatment may result in joint destruction, osteomyelitis and sepsis. Like other types of infection, the causative agents of SA may have changed over time. Early targeted intervention is important in cases of SA and can be achieved only by understanding the current trends in the microbiology of SA.

OBJECTIVES

To determine the trends in the microbiology of SA over the last two decades.

METHODS

We conducted a retrospective study including all patients 18 and older with culture positive, surgically treated, native joint septic arthritis (NJSA), admitted to a single tertiary medical centre in Boston between the years of 1997 and 2015. We excluded cases of osteomyelitis and septic bursitis. We focused our analysis on the microbiology data which included synovial fluid gram stain and culture, blood cultures and synovial biopsy cultures.

RESULTS

Among 260 cases, the most common bacteria isolated were Methicillin Sensitive Staphylococcus aureus (MSSA, 36%), Methicillin Resistant Staphylococcus aureus (MRSA, 17.6%), Coagulase Negative Staphylococci (CoNS, 13%) and Group B Streptococcus (GBS, 7.3%). Trends in the rates of these bacteria demonstrated no significant variation. The knee was the most common joint affected, followed by the shoulder and hip. Shoulder SA was most commonly caused by MRSA while MSSA was the leading causative organism in other joints. GBS was a causative bacterium in shoulder SA significantly more often than in knee or hip infections.

CONCLUSIONS

Although no significant trends were noted in the microbiology of SA over nearly 2 decades, we observed meaningful findings regarding shoulder SA as MRSA was the most common bacterial because of SA in this joint. Prompt joint aspiration, microbiologic testing of synovial fluid and empiric antibiotic therapy that covers MRSA may improve outcomes in SA.

Non-gonococcal septic arthritis of native joints in Western Australia. A longitudinal population-based study of frequency, risk factors and outcome

OBJECTIVE

To describe the incidence and long-term outcome of non-gonococcal septic arthritis (SA) in Western Australia (WA).

METHODS

Newman criteria were applied to define culture-positive SA and suspected SA cases in the state-wide West Australian Rheumatic Diseases Epidemiological Registry with longitudinally linked health data for patients >16 years with a first diagnostic code of pyogenic arthritis (711.xx [ICD-9-CM] and M00.xx [ICD-10-AM]) between 1990-2010. Annual incidence rates/100 000 (AIR) and standardized (against WA population) mortality rates/1000 person-years (SMR) and outcomes during 10.1 years follow-up are reported.

RESULTS

Among 2633 SA patients (68.6% male, age 47.4 years), 1146 (43.5%) had culture-positive SA. The overall AIR for culture-positive (1.6-6.3) and total SA cases (4.3-12.9) increased between 1990 and 2010 as did age at onset (39.5-54 years) and proportion of females (23-35.6%). Knees (33.6.%) were most frequently affected and 37.1% of cultures showed microorganisms other than Gram-positive cocci. Thirty-day rates for readmission and mortality were 25.4% and 3.2.%. During follow-up rates for serious infections (56.4%), osteoarthrosis (5.2%) and osteomyelitis (2.7%) were higher in culture-positive SA. SMR was increased for all SA patients but especially in those 17-40 years of age with culture-positive SA (24.2; 95% CI 2.3-261).

CONCLUSIONS

The incidence of SA in WA has risen steeply over 20 years. SA now occurs at higher age, affects females more often with over a third of cases caused by Gram-negative microorganisms. Not only culture-positive, but also suspected SA led to increased bone/joint complications, in-hospital and late mortality.

Cost of off-label antibiotic therapy for bone and joint infections: a 6-year prospective monocentric observational cohort study in a referral centre for management of complex osteo-articular infections

Introduction: Costs related to bone and joint infection (BJI) management are increasing worldwide, particularly due to the growing use of off-label antibiotics that are expensive treatments (ETs), in conjunction with increasing incidence of multi-drug-resistant pathogens. The aim of this study was to evaluate the whole costs related to these treatments during the patient route, including those attributed to the rehabilitation centre (RC) stay in one regional referral centre in France. The total annual cost of ETs for managing complex BJIs in France was then estimated.

Material and methods: A prospective monocentric observational study was conducted from 2014 to 2019 in a referral centre for BJI management (CRIOAc – Centre de Référence des Infections OstéoArticulaires complexes). Costs related to expensive treatments (“old” ETs, i.e. ceftaroline, ertapenem, daptomycin, colistin, tigecycline, and linezolid and “new” ETs, defined as those used since 2017, including ceftobiprole, ceftazidime-avibactam, ceftolozane-tazobactam, tedizolid, and dalbavancin) were prospectively recorded. In all cases, the use of these ETs was validated during multidisciplinary meetings.

Results: Of the 3219 patients treated, 1682 (52.3 %) received at least one ET, and 21.5 % of patients who received ET were managed in RCs. The overall cost of ETs remained high but stable (EUR 1 033 610 in 2014; EUR 1 129 862 in 2019), despite the increase of patients treated by ETs (from 182 in 2014 to 512 in 2019) and in the cumulative days of treatment (9739 to 16 191 d).

Daptomycin was the most prescribed molecule (46.2 % of patients in 2014 and 56.8 % in 2019, with 53.8 % overall), but its cost has decreased since this molecule was genericized in 2018; the same trend was observed for linezolid. Thus, costs for old ETs decreased overall, from EUR 1 033 610 in 2014 to EUR 604 997 in 2019, but global costs remained stable due to new ET utilization accounting for 46.5 % of overall costs in 2019. Tedizolid, used as suppressive antimicrobial therapy, represented 77.5 % of total new ET costs. In our centre, dalbavancin was never used.

The cost paid by RCs for ETs and the duration of ET remained stable overall between 2016 and 2019.

Conclusions: A high consumption of off-label ET is required to treat patients with BJIs in a CRIOAc, and the consequence is a high cost of antimicrobial therapy for these patients, estimated to be almost EUR 10 million in France annually. Costs associated with ET utilization remained stable over the years. On the one hand, the introduction of the generic drugs of daptomycin and linezolid has significantly decreased the share of old ETs, but, on the other hand, the need for new ETs to treat infections associated with more resistant pathogens has not led to decrease in the overall costs. A drastic price reduction of generic drugs is essential to limit the costs associated with more complex BJIs.

Septic Arthritis in Children: A Longitudinal Population-Based Study in Western Australia

Objective

To describe the incidence, risk factors and long-term outcomes in children hospitalised with septic arthritis (SA) in Western Australia (WA).

Methods

We extracted state-wide longitudinally linked administrative health data for patients aged < 16 years with a first diagnostic code of 711.X (ICD9-CM) and M00.X (ICD10-AM) in WA in the period 1990–2010. Annual incidence rates (AIR) per 100,000 with 95% confidence intervals (CIs), prior conditions during a median lookback period of 63.2 [interquartile range (IQR) 19.8–117.1] months and outcomes, including standardised mortality rates (SMR), during a median follow-up of 10 years are reported.

Results

A total of 891 patients [62% male, median age 6.4 (IQR 1.9–10.6) years with 34% aged < 3 years] were admitted for SA during the observation period. The overall AIR (per 100,000) was 9.85 (95% CI 4.79–14.41), and was higher in Indigenous Australians [34.9 vs. 5.5 (non-Indigenous), p < 0.001] and in males [11.9 vs. 7 (females), p < 0.01]; AIR showed no temporal or seasonal variation. Knees (43.9%), hips (34.6%) and ankles (13.3%) were most frequently affected, with Staphylococci predominant (49%) in patients with positive cultures (41.5%). Prior infection(s) (40.4%) and respiratory disease (7%) were the main pre-existing morbidities. Median hospital stay was 4.0 (IQR 2–8) days, with 1.9% requiring admission to the intensive care unit and 10.4% requiring readmission within 30 days. During follow-up, 26 patients (3.1%) developed osteomyelitis, nine patients were diagnosed with osteoarthrosis (1.1%) and five patients (0.6%) underwent joint replacement. Female patients developed other serious infections more often than male patients (40.5 vs. 27.1%, p < 0.01), as well as other comorbidities (Charlson Comorbidity Index > 0: 34.6 vs. 27.2%, p = 0.02), including diabetes (4.2 vs. 0%; p = 0.001), cardiovascular events (4.2 vs 1.4%, p = 0.002) and chronic arthritis (1 vs. 0%, p = 0.05). The crude mortality rate was low (0.3%), with 99.4% survival at 180 months and no increase in the SMR.

Conclusions

The incidence of SA in children in WA did not change over the 20-year observation period. SA did not lead to excess mortality, but bone and joint complications developed in 5% of patients. The high propensity to comorbid conditions in this young cohort suggests an underlying role of comorbidity in SA development.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00307-x.

As more children are living with complex and chronic conditions, we investigated whether children in Western Australia (WA) have become more prone to joint infections. During a 20-year observation period we collected health data for all children admitted to any hospital in the state with an infected joint and recorded their health outcomes. We found that joint infection occurs in nearly ten out of 100,000 children each year, but we saw no change in the frequency over time. We did observe higher rates in Indigenous children (35/100,000) than in non-indigenous children (6/100,000) but found no noticeable influence of the seasons on the frequency of joint infections. Knees, hips and ankles were most often affected, and 15% had additional bone infection. Children needed to be treated in hospital for 4–5 days, and only a small minority (1.2%) were so ill they needed intensive care. Joint infections led to chronic, long-term complications in about 5% of patients, but we found no evidence that joint infections increased the risk of death compared to children in the general population.

Utilisation of musculoskeletal ultrasonography for the evaluation of septic arthritis in a patient presenting to the emergency department with fever during the era of COVID-19

Prompt recognition and treatment of septic arthritis are crucial to prevent significant morbidity and mortality in affected patients. During the current COVID-19 pandemic, anchoring bias may make an already challenging diagnosis like septic arthritis more difficult to diagnose quickly and efficiently. Musculoskeletal (MSK) point of care ultrasonography (POCUS) is an imaging modality that can be used to quickly and efficiently obtain objective findings that may help a clinician establish the diagnosis of septic arthritis. We report a case where MSK POCUS was a key element in establishing the diagnosis of glenohumeral joint septic arthritis and subdeltoid septic bursitis for a patient that presented to the emergency department with a fever during the era of the COVID-19 pandemic.

Utility of bedside leucocyte esterase testing to rule out septic arthritis

INTRODUCTION

Suspected septic arthritis is a common presentation to EDs. The underlying diagnosis is often non-infective pathology. Differentiating between aetiologies is difficult. A bedside test with high negative predictive value (NPV) may allow safe discharge of patients, reduce the time in the ED, hospital admission and associated costs. This study aims to evaluate the NPV of bedside leucocyte esterase (LE) in the assessment of these patients.

METHODS

A prospective multicentre observational study of ED adult patients referred to orthopaedics with suspected native joint septic arthritis between October 2015 and April 2016. At three hospital sites in the Bristol region, the results of the LE test exposed to aspirated synovial fluid were recorded along with Gram stain, culture, haematinics and length of stay. A positive LE test was considered 2+ or 3+ leucocytes based on the test strip colour. Data were analysed to establish sensitivity, specificity, NPV and positive predictive value (PPV) against the gold standard 48-hour culture. We determined the potential number of inpatient bed-days that might be avoided using this bedside test.

RESULTS

Eighty patients underwent joint aspiration. Five cases had positive 48-hour culture. All (5/5) infected cases showed ≥2+ LE, sensitivity of 100% (95% CI 47.8% to 100%) while the Gram stain was positive in only one case (sensitivity 20%, 95% CI 0.51% to 71.6%). Twenty-three LE were read negative or 1+, all with negative 48-hour culture results, resulting in an NPV of 100% (95% CI 82.1% to 1.00%) for a negative LE test. Specificity of a positive LE test was 30.7% (95% CI 20.5% to 42.45%) with PPV of 8.77% (95% CI 7.64% to 10.1%). It was calculated that 57 orthopaedic bed-days could have potentially been saved by immediately discharging those with a negative LE test.

CONCLUSIONS

LE point-of-care testing for suspected septic arthritis of native joints has a high NPV. Implementation of LE may facilitate more rapid discharge of patients with negative results. This test has the potential to reduce diagnostic uncertainty and costs to the healthcare system.

Site-specific mortality in native joint septic arthritis: a national population study

OBJECTIVE

This national cohort study investigated the incidence, site-specific mortality and prognostic factors of native septic arthritis (SA).

METHODS

Tapping Taiwan's National Health Insurance Research Database, we identified inpatients with newly diagnosed SA between 1998 and 2012. They were categorized by site of infection and followed to calculate 30-day, 90-day and 1-year mortality. Predictors of mortality were calculated using Cox models.

RESULTS

A total of 31 491 patients were identified as having SA, the most common site of infection being the knee (50.1%), followed by the hip (14.4%), other sites (26.8%), the shoulder (5.5%) and multiple sites (1.2%). Knee joint involvement was the most common site for all subgroups. Incidence increased from 9.8/105 in 1998 to 13.3/105 in 2012. The 30-day, 90-day and 1-year mortality rates were 4.3, 8.6 and 16.4% respectively. Predictors for mortality were hip infection, shoulder infection, multiple-site infection, being male, age ≥65 years old and comorbidities. We derived a mortality scoring model over age/SA site/comorbidity, and age ≥65 years old had the greatest risk contribution to mortality. No matter whether 1-month, 3-month or 1-year mortality was being considered, patients with the higher risk scores had the higher mortality rates (P < 0.0001).

CONCLUSION

SA is an emerging infectious disease with a rising incidence, long duration of hospital stay and high mortality rate. The most common affected joint was knee for all subgroups. Patients aged ≥65 years old had a high SA incidence and the greatest risk contribution.

Measuring complications of serious pediatric emergencies using ICD-10

OBJECTIVE

To create definitions for complications for 16 serious pediatric conditions using the International Classification of Diseases, 10th Revision, Clinical Modification or Procedure Coding System (ICD-10-CM/PCS), and to assess whether complication rates are similar to those measured with ICD-9-CM/PCS.

DATA SOURCES

The Healthcare Cost and Utilization Project State Emergency Department and Inpatient Databases from five states between 2014 and 2017 were used to identify cases and assess complication rates. Incidences were calculated using population counts from the 5-year American Community Survey.

DATA COLLECTION/EXTRACTION METHODS

Patients were identified by the presence of a diagnosis code for one of the 16 serious conditions. Only the first encounter for a given condition by a patient was included. Encounters resulting in transfer were excluded as the presence of complications was unknown.

STUDY DESIGN

We defined complications using data elements routinely available in administrative databases including ICD-10-CM/PCS codes. The definitions were adapted from ICD-9-CM/PCS using general equivalence mappings and refined using consensus opinion. We included 16 serious conditions: appendicitis, bacterial meningitis, compartment syndrome, new-onset diabetic ketoacidosis (DKA), ectopic pregnancy, empyema, encephalitis, intussusception, mastoiditis, myocarditis, orbital cellulitis, ovarian torsion, sepsis, septic arthritis, stroke, and testicular torsion. Using data from children under 18 years, we compared incidences and complication rates across the ICD-10-CM/PCS transition for each condition using interrupted time series.

PRINCIPAL FINDINGS

There were 61 314 ED visits for a serious condition; the most common was appendicitis (n = 37 493). Incidence rates for each condition were not significantly different across the ICD-10-CM/PCS transition for 13/16 conditions. Three differed: empyema (increased 42%), orbital cellulitis (increased 60%), and sepsis (increased 26%). Complication rates were not significantly different for each condition across the ICD-10-CM/PCS transition, except appendicitis (odds ratio 0.62, 95% CI 0.57-0.68), DKA (OR 3.79, 95% CI 1.92-7.50), and orbital cellulitis (OR 0.53, 95% CI 0.30-0.95).

CONCLUSIONS

For most conditions, incidences and complication rates were similar before and after the transition to ICD-10-CM/PCS codes, suggesting our system identifies complications of conditions in administrative data similarly using ICD-9-CM/PCS and ICD-10-CM/PCS codes. This system may be applied to screen for cases with complications and in health services research.

Evaluating the effectiveness of concurrent opioid agonist treatment and physician-based mental health services for patients with mental disorders in Ontario, Canada

Objective

The objective of this study was to evaluate the relationship between concurrent physician-based mental health services, all-cause mortality, and acute health service use for individuals enrolled in Opioid Agonist Treatment in Ontario, Canada.

Methods

A cohort study of patients enrolled in opioid agonist treatment in Ontario was conducted between January 1, 2011, and December 31, 2015, in Ontario with an inverse probability of treatment weights using the propensity score to estimate the effect of physician-based mental health services. Treatment groups were created based on opioid agonist treatment patients’ utilization of physician-based mental health services. Propensity score weighted odds ratios were calculated to assess the relationship between the treatment groups and the outcomes of interest. The outcomes included all-cause mortality using data from the Registered Persons Database, Emergency Department visits from the National Ambulatory Care Database, and hospitalizations using data from the Discharge Abstract Database. Encrypted patient identifiers were used to link across databases.

Results

A total of 48,679 individuals in OAT with mental disorders. Opioid agonist treatment alone was associated with reduced odds of all-cause mortality (odds ratio (OR) 0.4, 95% confidence interval (CI) 0.3–0.4). Patients who received mental health services from a psychiatrist and primary care physician while engaged in OAT, the estimated rate of ED visits per year was higher (OR = 1.3, 95% CI 1.2–1.4) and the rate of hospitalizations (OR = 0.5, 95% CI 0.4–0.6) than in the control group.

Conclusion

Our findings support the view that opioid agonist treatment and concurrent mental health services can improve clinical outcomes for complex patients, and is associated with enhanced use of acute care services.

The Epidemiology and Outcomes of Septic Arthritis in the Maltese Islands: A Hospital-Based Retrospective Cohort Study

Objective/Aim:

Septic arthritis is an uncommon but important disease with significant morbidity and mortality, especially if inadequately managed. The aim of this epidemiological study was to identify the characteristics and outcomes of patients treated for septic arthritis at Mater Dei Hospital, Malta, over a 10-year period.

Methods:

This was a retrospective observational study. Patients diagnosed with septic arthritis between 2008 and 2018 were recruited. Cases were identified by reviewing all inhospital episodes of patients diagnosed with septic arthritis according to Newman criteria.

Results:

There were 124 cases of native joint septic arthritis and 138 of prosthetic joint infection. Cases were present amongst all age groups, with the highest incidence amongst those aged 61–70 years for both native and prosthetic infections. Fever was present in around 40% of cases. Raised white cell count was prevalent in 66.9% of native joint infections and 52.9% of prosthetic joints. Elevated C-reactive protein was overwhelmingly seen in most cases, present in 93.5% (median=159.5 mg/L; IQR=85.8–291) of native joints and 92.0% of prosthetic joint infections (median=68.7 mg/L; IQR=20.5–186). Over 55% of patients had one or more risk factors for joint sepsis, diabetes mellitus being the most prevalent clinical comorbidity (22.6% and 24.6% for native and prosthetic joint infections respectively). Synovial cultures were positive in 66% and 82% of native and prosthetic joint aspirates respectively. Staphylococcus aureus was the most commonly isolated organism from both native and prosthetic joint infection, followed by streptococcal infections in native joints and coagulase negative staphylococci and gram-negative infections in prosthetic joints. Fifteen deaths were directly attributed to joint sepsis.

Conclusion:

Absence of fever and elevated white cell count does not exclude the diagnosis. The mortality rate due to septic arthritis in this cohort of patients was found to be 5.7%. All deaths occurred in elderly patients with clinical comorbidities suggesting that this group is at highest risk.

A retrospective cohort study evaluating correlates of deep tissue infections among patients enrolled in opioid agonist treatment using administrative data in Ontario, Canada

Objective

The objective of this study was to evaluate the relationship between individual characteristics and deep tissue infections in patients enrolled in opioid agonist treatment in Ontario, Canada.

Methods

A retrospective cohort study was conducted on patients in opioid agonist treatment between January 1, 2011, and December 31, 2015 in Ontario, Canada. Patients were identified using data from the Ontario Health Insurance Plan Database, and the Ontario Drug Benefit Plan Database. We identified other study variables including all-cause mortality using data from the Registered Persons Database. Encrypted patient identifiers were used to link across databases. Logistic regression models were used to measure potential correlates of deep tissue infections.

Results

An increase in the incidence of deep tissue infections was observed between 2011 and 2016 for patients on opioid agonist treatment. Additionally, age, sex, positive HIV diagnosis, and all-cause mortality was correlated with deep tissue infection in our study population.

Conclusion

The study indicates factors that are associated with deep tissue infections in the opioid use disorder population and can be used to identify opportunities to reduce the incidence of new infections.

Calprotectin discriminates septic arthritis from pseudogout and rheumatoid arthritis

OBJECTIVE

We aimed to determine whether calprotectin and α-defensins could discriminate septic from other inflammatory arthritides.

METHODS

Synovial fluids with a predominance of neutrophils from patients with septic arthritis, pseudogout and RA were prospectively collected. Neutrophil-related proteins calprotectin and human neutrophil α-defensins levels were assessed in synovial fluids. Demographic parameters and biomarkers with P-value ⩽0.05 for differentiating septic from non-septic arthritis were included in a multivariable model. Multivariable logistic regression with stepwise selection was performed to build the final combined model.

RESULTS

A total of 74 patients were included: septic arthritis (n = 26), pseudogout (n = 28) and RA (n = 20). Patients with septic arthritis were more likely to be male and young, and to display higher synovial neutrophil count. Calprotectin was significantly increased in patients with septic arthritis. The multivariable model included calprotectin, synovial fluid neutrophil count and gender. Calprotectin was the only biomarker that discriminated septic arthritis from non-septic inflammatory arthritides, with 76% sensitivity, 94% specificity and a positive likelihood ratio = 12.2 at the threshold for calprotectin of 150 mg/l.

CONCLUSION

Synovial fluid calprotectin is a relevant biomarker to discriminate septic arthritis from other inflammatory arthritides. This biomarker should be tested in an independent cohort.

[Native joint infections]

Joint infections are a great challenge for the treating physicians. Infection of a native joint can result in the rapid destruction of the joint if treatment is inadequate or delayed and is associated with severe life-threatening diseases, such as sepsis. This article presents a detailed overview of the treatment of joint infections of native joints with a focus on the diagnostic approach and treatment decisions. Infections in native joints are caused either endogenously by hematogenic spreading or are caused by exogenous factors. A relevant proportion of joint infections in native joints occur in connection with iatrogenic measures, such as operations, synovial punctures and joint infiltrations. Fundamentally, acute infections represent an orthopedic surgical emergency, which is associated with the necessity for immediate operative measures. The best possible success can only be achieved by an interaction between early diagnosis, an adequate surgical approach and a tailor-made anti-infectious treatment. This is also the case with periprosthetic infections, which will be dealt with in detail in a second article.

How well does synovial fluid gram staining correlate with cultures in native joint infections?

To evaluate the sensitivity and specificity of Gram staining of synovial fluid aspirated from native joints suspected to be infected, we reviewed results of synovial fluid Gram stain and cultures. The sensitivity and specificity of the synovial Gram stain were then calculated. From the 1067 consecutive synovial fluid samples evaluated, 830 samples fulfilled the set criteria. From these 830 synovial fluid samples, organisms were detected by culture technique in only 100 samples; most of which were Gram-positive bacteria (78%). The other 22% comprised Gram-negative bacteria, Fungi and a mixture of growth. Of these, concomitant Gram stain test revealed sensitivity and specificity of 17.0% and 99.7% respectively. Our study demonstrates that the Gram stain technique has low sensitivity in detecting organisms in presumed native joint infections. Our findings demonstrate that the Gram stain test is an unreliable investigation in diagnosing native joint infections.

Group B streptococcus is the most common pathogen for septic arthritis with unique clinical characteristics: data from 12 years retrospective cohort study

Background

Group B Streptococcus (GBS) emerged as the frequent pathogen for septic arthritis. There was no study comparing risks, clinical presentations and outcomes between GBS septic arthritis and other bacterial septic arthritis.

The aim of this study is to evaluate the differences in risks, clinical presentations, and outcomes of GBS septic arthritis and other bacterial septic arthritis, and identify independent risks and clinical presentations suggesting GBS septic arthritis.

Method

Medical records of patients diagnosed with non-gonococcal bacterial arthritis admitted in Phramongkutklao Hospital during 2006–2018 were reviewed. Associated risks, clinical presentations and outcomes were compared between GBS septic arthritis (GBS group) and other bacterial septic arthritis (other bacterial group).

Result

Two hundred and thirty one cases of non-gonococcal bacterial arthritis confirmed by positive joint fluid cultures and/or hemocultures were included. The three most common pathogens were GBS (37.7%), Staphylococcus aureus (23.4%) and Streptococcus viridans (7.4%). GBS group was more commonly found in rainy season than other bacterial group. Patients in GBS group were less likely to have underlying diseases and had more number of involved joints than those in other bacterial group. The clinical presentations more commonly found in GBS group than other bacterial group were oligo-polyarthritis, upper extremities joint involvement, axial joint involvement, tenosynovitis and central nervous system involvement.

Multivariate analysis found the independent associated factors of GBS arthritis are tenosynovitis, oligo-polyarthritis and rainy season.

Conclusions

GBS is now the most common pathogen for bacterial septic arthritis. The independent associated factors of GBS arthritis were oligo-polyarthritis, tenosynovitis and rainy season.

Electronic supplementary material

The online version of this article (10.1186/s41927-019-0084-5) contains supplementary material, which is available to authorized users.

Septic arthritis due to streptococci and enterococci in native joints: a 13 year retrospective study

OBJECTIVES

Streptococcal species are the second most common cause of native joint septic arthritis (SA). However, there are few systematic data about streptococcal SA.

METHODS

The medical records of adults with SA caused by streptococci, pneumococci, and enterococci at our tertiary care centre between 2003 and 2015 were reviewed.

RESULTS

71 patients (34% female) with 83 affected joints were included. Median age was 62 years. A single joint was involved in 62 patients (87%). One or more comorbidities were present in 58 patients (82%). 16 patients (23%) had a concomitant soft-tissue infection overlying the affected joint. The hematogenous route was the dominating pathogenesis (42/71, 59%). 9 (13%) patients were diagnosed with endocarditis. The knee was the most commonly affected joint (27/83, 33%) followed by shoulder (13/83, 16%). ß-haemolytic streptococci were most commonly identified (37/71, 52%) followed by polymicrobial infections (12/71, 17%). Surgical interventions included arthroscopic irrigation and debridement in 31 (44%), arthrotomy in 23 (32%), and amputation in five patients (7%). Median duration of antimicrobial therapy was 42 days. Antibiotic treatment without any surgical intervention was performed in 5 (7%) patients. Outcome was good in 55 (89%) patients; mortality was 13% with four of nine deaths attributed to joint infection. Age and pathogen group independently predicted poor outcome in recursive partitioning analysis.

CONCLUSIONS

Streptococcal SA was mostly due to ß-haemolytic streptococci in older and polymorbid patients. Old age, anginosus group streptococci, enterococci, and polymicrobial infections predicted poor outcome, while antibiotic treatment duration can likely be shortened.

Broad-range 16 s rDNA PCR in synovial fluid does not improve the diagnostic performance of septic arthritis in native joints in adults: cross-sectional single-center study in 95 patients

OBJECTIVE

To evaluate the diagnostic performance of bacterial identification by broad-range polymerase chain reaction (PCR) of ribosomal DNA (rDNA) 16 s (16S rDNA PCR) for the diagnosis of septic arthritis on native joints.

METHODS

Patients with acute mono or oligoarthritis who underwent synovial fluid puncture and prospective follow-up allowing definitive diagnosis (septic arthritis, crystal related disease, chronic inflammatory arthritis, undifferentiated arthritis) were recruited in this single-center study. Systematic analysis of synovial fluid included leukocytes count, search for urate and pyrophosphate crystals with polarized light microscopy, direct bacteriological examination (gram staining), bacteriological culture, and 16S rDNA PCR.

RESULTS

Ninety-five patients were included, 34 of which (35.8%) had septic arthritis. Nineteen (20.0%) patients had received probabilistic antibiotic therapy prior to joint puncture. Gram + cocci infection accounted for 79.4% of septic arthritis, of which nearly half (47.1%) was caused by Staphylococcus aureus. Eight (23.5%) septic arthritis patients had a 16S rDNA PCR positive in the synovial fluid with an AUC of 0.618 (95% CI, 0.493-0.742), a sensitivity of 0.24 (95% CI, 0.12-0.40), and a specificity of 1.00 (95% CI 0.94-1.00). The diagnostic performance of 16S rDNA PCR was lower than that of direct examination (AUC at 0.691, CI 95%, 0.570-0.812), blood cultures (AUC at 0.727, CI 95%, 0.610-0.844), and culture (0.925, CI 95%, 0.856-0.994) for the diagnosis of septic arthritis. There was no difference in the positivity of 16S rDNA PCR according to previous exposure to antibiotics.

CONCLUSIONS

16 s rDNA PCR in the synovial fluid does not improve the diagnostic performance of septic arthritis on native adult joints, particularly for Gram-positive cocci infections.

Clinical Characteristics and Long-term Outcomes After Septic Arthritis of the Native Glenohumeral Joint: A 20-Year Retrospective Review

Septic arthritis of the native glenohumeral joint is rare, and there is little information available regarding the natural progression and long-term joint outcomes of this pathology. The authors performed a retrospective analysis of 97 patients with culture-positive glenohumeral septic arthritis between 1995 and 2015 at their institution with a mean clinical follow-up of 83.1 months. Patient records were reviewed to document demographic and laboratory data, clinical presentation, postoperative complications, recurrences, and subsequent shoulder arthroplasty. Common comorbidities uncovered included 20 immunocompromised patients (20.6%), intravenous drug use among 27 patients (27.8%), diabetes mellitus among 40 patients (41.2%), and 18 patients (18.5%) receiving hemodialysis. Staphylococcus aureus was the most common pathogen identified (61 patients; 62.8%), followed by streptococcal species (17 patients; 17.2%). Hematogenous spread of infection was the most common etiology of shoulder sepsis (40.2%). Seven patients (7.2%) developed shoulder sepsis of undetermined etiology in the absence of established risk factors, and 16 patients (16.4%) developed recurrent glenohumeral septic arthritis at a mean of 40 months following initial eradication of infection. Three patients (3.0%) eventually underwent same-side shoulder arthroplasty at a mean of 18 months following septic arthritis, with none experiencing a periprosthetic joint infection. Glenohumeral septic arthritis is highly unlikely in the absence of medical risk factors. Long-term recurrence after clinically successful treatment is low (16.5%), and few patients undergo elective arthroplasty following shoulder septic arthritis. However, orthopedic surgeons can expect 30% to 40% of patients to require multiple trips to the operating room to successfully treat the initial joint infection, regardless of treatment method. [Orthopedics. 2019; 42(1):e118-e123.].

Septic Arthritis in Emergency Departments in the US: A National Study of Health Care Utilization and Time Trends

OBJECTIVE

To assess the health care utilization and emergency department (ED) charges for septic arthritis.

METHODS

We performed a retrospective cohort study of ED visits with septic arthritis as the primary diagnosis using the US Nationwide Emergency Department Sample data from 2009-2012. We examined ED charges, hospitalization, and associated time trends. Multivariable models were adjusted for demographics (age, sex, insurance status, residence, and household income), comorbidity, and hospital characteristics to assess factors associated with ED charges and hospitalization.

RESULTS

Septic arthritis was responsible for 16,382 ED visits in 2012 in the US, which constituted 0.01% of all ED visits. The number of ED visits was stable from 2009-2012. Total ED charges were $34.6, $30.6, and $36.9 million in 2009, 2010, and 2012, respectively, and mean ED charges were $2,149, $1,866, and $2,257, respectively. The majority of the patients with an ED visit for septic arthritis were hospitalized: 82%, 83%, and 84% in 2009, 2010, and 2012, respectively. Metropolitan residence and western US location were associated with higher ED charges, and the highest income quartile, renal failure, or osteoarthritis were associated with lower ED charges. Female sex, metropolitan residence, metropolitan teaching hospital status, and medical comorbidity (diabetes mellitus, hyperlipidemia, hypertension, chronic obstructive pulmonary disease, coronary heart disease, gout, osteoarthritis, renal failure, and heart failure) were associated with a higher risk of hospitalization.

CONCLUSION

Comorbidities were associated with a higher risk of hospitalization after an ED visit for septic arthritis, but not higher ED charges. No time trends in ED visit incidence, ED charges, or hospitalization rate for septic arthritis from 2009-2012 were noted.