Bacterial septic arthritis in adults

Secondary purulent infections of the elbow joint: a retrospective, single-center study

Background

Septic arthritis of the elbow joint is a rare condition. Limited data is available on infections of the elbow joint following trauma or prior surgery on this joint. The aim of this study was to describe the etiology, comorbidities, bacterial spectrum and therapy of secondary purulent elbow infections.

Methods

Patients treated in our hospital were selected through retrospective chart review between 2006 and 2015. We included all patients with an empyema of the elbow after a trauma or surgical intervention on this joint. 30 patients between 26 and 82 years (mean: 52.47) were included.

Results

Seven patients (23.3%) were female, 23 (76.7%) male. 22 patients (73.3%) had a history of trauma, eight (26.7%) had prior elective surgeries on their elbow. Between one and 25 surgeries (mean: 5.77) were necessary for treatment. In nine patients, debridement and synovectomy were sufficient, eight patients (26.7%) received resection of the elbow joint. One patient was treated with a chronic fistula. In 18 patients (60%), cultures of aspiration/intraoperative swabs were positive for Staphylococcus aureus, four of these were methicillin-resistant. Four patients (13.3%) had positive cultures for Staphylococcus epidermidis, in five patients (16.7%) no bacteria could be cultured.

Conclusions

Secondary infections of the elbow joint are a rare disease with potentially severe courses, requiring aggressive surgical treatment and possibly severely impacting elbow function. Staphylococcus aureus was the most common bacteria in secondary infections and should be addressed by empiric antibiotic treatment when no suspicion for other participating organisms is present.

Influence of inflammatory arthritis on leukocyte esterase strip results in the diagnosis of periprosthetic joint infection

Background

The leukocyte esterase (LE) strip is considered as a helpful method to detect infection, which might be influenced by other inflammatory diseases. This study aims to explore whether the centrifugation of synovial fluid could influence the positive result of LE strip caused by inflammatory arthritis during the diagnosis of periprosthetic joint infection (PJI).

Methods

From March 2016 to December 2018, 64 patients who were diagnosed as PJI or aseptic arthritis and another 20 patients with inflammatory arthritis were enrolled in our study. After synovial fluid samples were obtained, the LE strip test was performed with and without centrifugation. Then clinicians read the color changes 3 min after the samples were dropped and classify the results based on the instruction of strip. The differences between septic and aseptic arthritis patients and septic and inflammatory arthritis patients were analyzed.

Results

Among the included 21 PJI samples, 19 of them showed positive results (++) of LE strip before centrifugation. After centrifugation, two samples changed from two-positive (++) to one-positive (+), which is also considered as positive. Before centrifugation, 29 of the LE strip tests in the aseptic arthritis group (43 samples included) were ++ or +. After centrifugation, 16 of the samples yielded negative results. Among 20 samples with inflammatory arthritis, LE strip of 18 samples were positive (++ or +) before centrifugation, among which only 3 samples remained as positive after centrifugation.

Conclusion

LE strip test results could be influenced by inflammatory arthritis during the diagnosis of PJI. Centrifugation should be performed for LE strip tests to determine whether the result is a true positive or a false positive influenced by inflammatory arthritis.

Bone and joint infections of the hand

BACKGROUND

Little guidance is currently available for standardized diagnostic protocols and therapeutic recommendations for bone and joint infections (BJIs) of the hand.

OBJECTIVES

To summarize the available data in the scientific English-language literature on the diagnosis and treatment of native BJIs of the hand. To illustrate these concepts from a narrative point of view in areas where there is lack of evidence.

SOURCES

We performed a systematic PubMed and Internet search of studies that investigated hand BJIs in adult patients.

CONTENT

Few studies have systematically investigated and validated diagnostic concepts, classifications or surgical treatment protocols. Most concepts derive from traditional intra-institutional experience, expert opinions and extrapolations from infections in large joints and long bones. Similarly, there is no uniformly accepted infection definition of BJIs of the hand. The best-documented literature is available for microbiological findings and antibiotic treatment duration in uncomplicated native joint arthritis of the fingers. Retrospective studies and one prospective randomized trial suggest that post-surgical targeted antibiotic therapy of 2 weeks results in a microbiological cure rate of ≥88%.

IMPLICATIONS

Studies on diagnostic workup and infection definition and classification are urgently needed to compare inter-institutional outcome results and generate guidelines for the best patient care. For uncomplicated pyogenic arthritis of native joints, current evidence suggests that a 2-week course of antibiotic therapy following surgery cures the infection.

Acromioclavicular Septic Arthritis Caused by Veillonella parvula

We hereby report the case of a primary acromioclavicular septic arthritis caused by Veillonella parvula. This bacteria is rare as a pathogen but is well known as a commensal of the lungs, vagina, mouth, and gastrointestinal tract of humans. However, it may turn as an opportunistic pathogen. It was isolated in blood culture and confirmed in biopsy specimen. The patient had complete recovery after surgical washout with second look at postoperative day two and targeted antibiotic treatment.

Factors Related to Surgical Treatment and Outcomes of Thai Patients With Septic Arthritis

OBJECTIVE

The aim of this study was to identify factors associated with the surgical treatment of Thai patients with septic arthritis.

METHODS

This cohort study used a university hospital database in Thailand to identify 450 adult patients with confirmed septic arthritis. Data related to baseline characteristics, clinical and laboratory findings, treatment, and outcomes were collected. A multivariate analysis identified the factors related to surgical treatment.

RESULTS

The patients had a mean age (±SD) of 53.6 (±17.8) years, and 51% were male. Surgical drainage was performed on 332 patients (74%). The factors identifed as relating to the need for surgical drainage included preexisting joint disease (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.3-4.9), hip involvement (OR, 36.3; 95% CI, 4.1-320.5), abscess formation (OR, 5.6; 95% CI, 1.1-27.1), osteomyelitis (OR, 4; 95% CI, 1.1-14.9), and positive synovial fluid culture (OR, 3.8; 95% CI, 2-7.2). In contrast, patients who were treated with steroids (OR, 0.2; 95% CI, 0.1-0.4) or had septic shock (OR, 0.31; 95% CI, 0.13-0.83) were less likely to undergo surgery. This model correctly predicted 35% of cases. Patients treated with surgical drainage had a significant longer length of stay (median [interquartile range], 21 [11-34] days vs 14 [7-24] days; p < 0.0001) and were less likely to achieve complete recovery (26% vs 53%, p < 0.0001). However, the mortality rate was lower (2.4% vs 10.2%).

CONCLUSIONS

Patients with septic arthritis who had underlying joint disease, hip involvement, abscess formation, osteomyelitis, and organisms in their synovial fluid were more likely to undergo surgical intervention with a significantly prolonged length of stay but had a lower mortality rate.

Benefits of Polymerase Chain Reaction Combined With Culture for the Diagnosis of Bone and Joint Infections: A Prospective Test Performance Study

Background

The microbiological diagnosis of bone and joint infections (BJI) currently relies on cultures, and the relevance of molecular methods is still debated. The aim of this study was to determine whether polymerase chain reaction (PCR) could improve the etiological diagnosis of BJI.

Methods

A prospective study was conducted during a 4-year period at Lariboisiere University Hospital (Paris, France), including patients with suspicion of infectious spondylodiscitis, septic arthritis, prosthetic joint infections, and respective noninfected groups. Clinical and radiological data were collected at inclusion and during follow-up. All samples were analyzed by conventional cultures and 16S ribosomal deoxyribonucleic acid (rDNA) gene (16S-PCR). Specific cultures and PCR targeting Mycobacterium tuberculosis were also performed for spondylodiscitis samples. Case records were subsequently analyzed by an independent expert committee to confirm or invalidate the suspicion of infection and definitively classify the patients in a case or control group. The sensitivity of the combination of culture and PCR was compared with culture alone.

Results

After expert committee analysis, 105 cases of BJI cases and 111 control patients were analyzed. The most common pathogens of BJI were staphylococci (30%), M tuberculosis (19%), and streptococci (14%). Adding PCR enhanced the sensitivity compared with culture alone (1) for the diagnosis of M tuberculosis spondylodiscitis (64.4% vs 42.2%; P < .01) and (2) for nonstaphylococci BJI (81.6% vs 71.3%; P < .01). It is interesting to note that 16S-PCR could detect BJI due to uncommon bacteria such as Mycoplasma and fastidious bacteria.

Conclusions

Our study showed the benefit of 16S-PCR and PCR targeting M tuberculosis as add-on tests in cases of suspected BJI.

A Case Report of Pneumococcal Septic Arthritis Following a Respiratory and Gastrointestinal Prodrome with Accompanying Literature Review

We report an uncommon case of septic arthritis of the ankle from a Streptococcus pneumoniae infection and provide an update of the literature reported since 2002. A 58-year-old female presented to the hospital with right ankle pain and an inability to bear weight. She reported a history of productive cough, vomiting, diarrhea, and subjective fevers 4 days earlier. Streptococcus pneumonia was identified in her ankle aspirate, and she was treated urgently with operative incision and debridement, followed by postoperative intravenous antibiotics. At her 7-week follow-up, she demonstrated complete resolution of symptoms and near-complete recovery of range of motion. This case demonstrates the importance of early identification, as the majority of patients recover fully with prompt treatment. The literature review included 44 cases of pneumococcal septic arthritis and found that the knee was the most commonly affected joint, followed by the shoulder and ankle. Blood cultures were positive for S. pneumoniae in 27 of 38 adults (71%) and 4 of 6 children (67%). Comorbid conditions were present in 32 of 38 adults (84%) and 4 of 7 children (57%), the most frequent of which were alcoholism and osteoarthritis in adults and malignancy or immunosuppression in children. Additionally, roughly half of included adults had an extra-articular focus of pneumococcal disease, most frequently pneumonia. Operative treatment was undertaken in 32 of 38 adults (84%) and all 7 children. Of adults with data available, 24 of 33 (73%) recovered with complete joint function, compared with 5 of 7 children (71%).

Native Joint Septic Arthritis: Comparison of Outcomes with Medical and Surgical Management

OBJECTIVE

To determine whether there are differences in the outcomes of native joint septic arthritis (SA) in adults, based on medical versus surgical management.

METHODS

A 10-year retrospective single-center study was conducted of patients admitted to a tertiary care hospital between January 1, 2006 and December 31, 2015 with a diagnosis of SA to compare outcomes based on the management approach taken: medical (bedside closed-needle joint aspiration) versus surgical (arthrotomy/arthroscopy). Evaluated outcomes included joint recovery, time to recovery, length of stay, disposition to home versus rehabilitation unit, recurrence of SA in the same joint, and mortality.

RESULTS

Of 118 confirmed cases of SA, 48 were in prosthetic joints and 70 were in native joints, and 61 met our inclusion criteria. Forty-one (67%) patients received surgery, and 20 (33%) received closed-needle aspiration. There was no statistically significant difference in long-term outcomes between the two groups at 12 months. Patients managed medically were more likely to experience full recovery at 3 months and were less likely to need short-term rehabilitation.

CONCLUSIONS

Medical management with closed-needle aspiration may be an adequate approach to the treatment of native joint infections.

Knee septic arthritis caused by α-hemolytic Streptococcus in a patient with a recent history of knee arthroscopy: a case report

Background

Arthroscopic partial meniscectomy is a common procedure in orthopedic practice. Infections are uncommon complications of this procedure with an incidence rate of 0,01% - 3,4%. Staphylococcus spp are the predominant causative agents in such cases. We present a case of knee septic arthritis caused by α-hemolytic Streptococcus.

Case presentation

A 22-year-old woman diagnosed with obesity (body mass index [BMI] 35 kg/m²) but with no other major comorbidities underwent an arthroscopic selective meniscectomy with administration of intravenous cefazolin for antibiotic prophylaxis. After an uneventful period of 2 months, the patient returned with pain, fever and a discharging sinus at the site of anterolateral arthroscopic portal. Blood tests and magnetic resonance imaging revealed osteomyelitis involving the tibial plate. Cultures of synovial fluid obtained from the knee and a pharyngeal swab yielded α-hemolytic Streptococcus. Five days later, the patient underwent arthroscopic debridement with partial synovectomy. Intraoperative specimens yielded α-hemolytic Streptococcus. The patient received intravenous piperacillin/tazobactam, followed by an associative regimen of amoxicillin and clindamycin with clinical, laboratory and instrumental evidence of symptom resolution.

Conclusion

The incidence of knee septic arthritis after arthroscopic partial meniscectomy is 0.01–3.4%. This infection is usually caused by Staphylococcus spp. and in rare cases by commensal bacteria, such as α-hemolytic streptococci, secondary to transient bacteremia. Screening of the colonized area is important to prevent possible transient bacteremia. Diagnosis is based on isolation of the causative organisms from synovial fluid cultures, and treatment comprises arthroscopic debridement with individualized systemic antibiotic therapy based on the results of an antibiogram.

Septic arthritis of the hip joint due to Bacteroides fragilis in a paraplegic patient

Septic arthritis of native joints is a potentially life-threatening disease. The most frequently isolated pathogens are Gram-positive cocci. Bacteroides fragilis is a rare pathogen in joint infections and is usually associated with immunocompromised and debilitated patients. Most cases of B. fragilis joint infection are related to skin or local perineal infections or are secondary to B. fragilis bacteraemia from another source, for example from the gastrointestinal tract. We present a clinical case of B. fragilis septic arthritis involving a native hip joint in a previously healthy paraplegic patient.

Group B streptococcal empyema necessitatis with pleural fistula after blunt trauma: A case report

INTRODUCTION

We report the first case of empyema necessitatis (EN) with pleural fistula and septic arthritis caused by Streptococcus agalactiae following blunt trauma.

PRESENTATION OF THE CASE

A 46-year-old man with diabetes mellitus and a history of recent right rib fracture and right knee bruising presented with dyspnea and right knee pain. He was diagnosed with EN and underwent chest drainage, followed by open-window thoracotomy. Septic arthritis occurred on day 8 after thoracotomy. The chest wall wound healed after 3 months.

DISCUSSION

EN is a rare complication of empyema. In this patient, infection was invasive, causing necrotizing pneumonia with a pleural fistula. To our knowledge, there are no reports of group B streptococcal EN with a pleural fistula resulting from blunt chest trauma.

CONCLUSION

Group B streptococcal infection might become invasive in immunocompromised patients, so careful follow-up for those patients is important.

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 of the temporomandibular joint: Case series and literature review

Background: Septic arthritis of the temporomandibular joint (SATMJ) is a relatively uncommon condition in the adult population and can result in significant morbidity. This study reviewed seven cases of SATMJ, including their management and complications.Clinical Presentation: A retrospective study was performed on seven cases that developed SATMJ documented from 2011 to 2017. Seven cases demonstrated SATMJ that resulted in joint destruction and complications, such as mandibular osteomyelitis, vertebral osteomyelitis, bone erosion, ankylosis, and death. The management of these seven cases was presented, as well as the treatment outcomes.Clinical Relevance: SATMJ should be treated aggressively, as it may cause severe damage to the TMJs and adjacent tissues, which could lead to loss of function, malocclusion, and potentially fatal complications.

Equine or porcine synovial fluid as a novel ex vivo model for the study of bacterial free-floating biofilms that form in human joint infections

Bacterial invasion of synovial joints, as in infectious or septic arthritis, can be difficult to treat in both veterinary and human clinical practice. Biofilms, in the form of free-floating clumps or aggregates, are involved with the pathogenesis of infectious arthritis and periprosthetic joint infection (PJI). Infection of a joint containing an orthopedic implant can additionally complicate these infections due to the presence of adherent biofilms. Because of these biofilm phenotypes, bacteria within these infected joints show increased antimicrobial tolerance even at high antibiotic concentrations. To date, animal models of PJI or infectious arthritis have been limited to small animals such as rodents or rabbits. Small animal models, however, yield limited quantities of synovial fluid making them impractical for in vitro research. Herein, we describe the use of ex vivo equine and porcine models for the study of synovial fluid induced biofilm aggregate formation and antimicrobial tolerance. We observed Staphylococcus aureus and other bacterial pathogens adapt the same biofilm aggregate phenotype with significant antimicrobial tolerance in both equine and porcine synovial fluid, analogous to human synovial fluid. We also demonstrate that enzymatic dispersal of synovial fluid aggregates restores the activity of antimicrobials. Future studies investigating the interaction of bacterial cell surface proteins with host synovial fluid proteins can be readily carried out in equine or porcine ex vivo models to identify novel drug targets for treatment of prevention of these difficult to treat infectious diseases.

Erwinia billingiae as Unusual Cause of Septic Arthritis, France, 2017

In 2017 in France, we treated a patient with knee septic arthritis caused by Erwinia billingiae after trauma involving a palm tree. This rare pathogen could only be identified through 16S rRNA gene sequencing. For bacterial infections after injuries with plants, 16S rRNA gene sequencing might be required for species identification.

The Use of Ultrasonography in Expediting Septic Joint Identification and Treatment: A Case Report

This case report describes the use of ultrasonography in the identification of a joint effusion to guide diagnosis and management of septic arthritis. Our patient presented with pain, swelling, and erythema of the right thumb after having punctured her thumb with a cactus thorn. Results of physical examination demonstrated tenderness and restricted range of motion. Initial imaging with plain films was unrevealing, without bony and soft tissue abnormalities; however, ultrasound imaging of the interphalangeal joint revealed a focal effusion, and the patient was started on empiric Keflex. Because a focal effusion was visualized with ultrasonography, despite negative x-ray imaging, our patient underwent expedited surgical incision and drainage, foregoing joint aspiration. Intraoperative cultures grew Enterobacter 3 days after surgery, and the empiric antibiotic was adjusted to reflect sensitivities. At 2-wk follow-up, our patient showed near-complete resolution of her symptoms. This case report demonstrates the utility of ultrasonography in the early diagnosis of septic arthritis with the presence of a joint effusion that expedited successful treatment by foregoing joint aspiration in lieu of surgical intervention.

Clinical suspicion is key: an unusual presentation of septic arthritis after distal pancreatectomy

Septic arthritis is the result of an infectious agent gaining access a sterile joint. This results in a devastating inflammatory response that leads to rapid destruction of intra-articular cartilage and with it significant morbidity. This case study reports an unusual presentation of septic arthritis following abdominal surgery; specifically, a distal pancreatectomy performed for an enlarged, mid-body pancreas mass involving the splenic artery. This is the first reported case of septic arthritis following abdominal surgery, though the exact etiology is unknown.

Concomitant orbital subperiosteal abscess, sinusitis, and septic arthritis of the hip in a normal healthy adolescent patient

Septic arthritis is a surgical emergency that can result in substantial morbidity and mortality, especially when diagnosis is delayed. We report a case of an otherwise healthy 12-year old boy, who developed an orbital subperiosteal abscess and paranasal sinusitis with concomitant septic arthritis of the left hip and osteomyelitis. We highlight the importance of repeat assessment of affected sites of infection, despite an overt, local infection of a primary site in an immunocompetent host. This is the first report of concurrent orbital subperiosteal abscess and left hip septic arthritis in literature.

Low frequency of septic arthritis after arthrocentesis and intra-articular glucocorticoid injection

Objective: The aim of this study was to evaluate the risk of septic arthritis (SA) in patients who received an intra-articular (IA) glucocorticoid (GC) injection and to describe the characteristics of these patients. Methods: All patients undergoing IA procedures at the orthopaedic and rheumatological departments on the Danish island of Funen from January 2006 to December 2013 were identified in the central database and included by register extraction. Patients who developed a clinically inflamed joint and positive synovial fluid culture within 14 days after IA GC injection were considered as having SA. Retrospectively, data on age, gender, affected joint location, bacterial agent, pre-existing inflammatory disorder, and death within 30 days were extracted from the patient files. According to local recommendations, a non-touch sterile technique was used for IA procedures. Patients were informed about the risk of SA and advised to seek medical attention on suspicion of infection or lack of improvement. Results: In total, 22 370 IA procedures were performed. Among these, 14 118 GC injections and 8252 arthrocenteses were undertaken. Only 11 patients were diagnosed with SA (0.08%, 95% confidence interval 0.03-0.12). Risk factors for SA were male gender, age, and pre-existing joint disease. Conclusion: We found a low frequency of SA subsequent to IA GC injections. Older patients with pre-existing joint disease are at higher risk of developing SA.

Clinical features of patients with septic arthritis and echocardiographic findings of infective endocarditis

PURPOSE

Patients with septic arthritis (SA) often undergo echocardiographic evaluation to identify concomitant infective endocarditis (IE). The purpose of this study is to identify distinguishing features of patients with SA and IE by comparing them to patients with SA alone.

METHODS

We conducted a retrospective study of all patients 18 and older admitted to a single tertiary hospital between 1998 and 2015 with culture-positive SA. Patients were stratified by echocardiogram status and the presence of vegetations: those who had echocardiographic evaluation with no evidence of infective endocarditis (ECHO + IE-) or with a vegetation present (ECHO + IE+) and those who had no echocardiographic evaluation (ECHO-). Demographic data, clinical characteristics, microbiology data, treatment strategies, and patient outcomes were recorded and compared.

RESULTS

We identified 513 patients with SA. Transthoracic echocardiogram and/or transesophageal echocardiogram were performed in 263 patients (51.2%) and demonstrated evidence for IE in 19 patients (3.7%). While most demographic features, comorbidities, and clinical characteristics did not differ significantly between those with and without IE, those with IE had higher rates of sepsis and septic shock. In addition, patients with SA and IE had higher rates of positive blood cultures and Methicillin-sensitive staphylococcus aureus (MSSA) infection when compared to those with SA without IE. Patients with IE had higher rates of intensive care unit admission and increased 30-day mortality.

CONCLUSIONS

IE is uncommon among patients with SA. Echocardiography may be overutilized and may be more useful among patients presenting with sepsis, shock, or positive blood cultures, especially when MSSA is isolated.

Clinical characteristics of patients with polymicrobial septic arthritis

Little is known about the incidence, risk factors, clinical characteristics, and outcomes of patients with polymicrobial SA (PMSA). We aimed to determine the unique characteristics of patients with PMSA by comparing them to patients with monomicrobial SA (MMSA). We conducted a retrospective cohort study of patients 18 years and older admitted to a single tertiary care medical center, between 1998 and 2015, with surgically treated culture-positive SA affecting one or more joints. Patients were separated into two groups by the presence of one (MMSA) or more organisms (PMSA). A total of 441 patients with MMSA and 47 with PMSA were identified. Prior history of SA was more common among the PMSA group (31.9% vs. 18.6%; p = 0.03) as well as higher rates of prosthetic joint involvement (48.9% vs. 36.1%; p = 0.06). Patients with PMSA were sicker with higher rates of shock at presentation (14.9% vs. 5.5%; p = 0.02), intensive care unit admissions (39.1% vs. 18%; p < 0.001), and longer mean length of stay (16.1 vs. 10.9 days; p < 0.001). The most prevalent pathogens in the PMSA group were coagulase-negative Staphylococcus (31%), followed by methicillin-sensitive Staphylococcus aureus (29%), and Enterococcus (24%). To our knowledge, this is the first study to determine the clinical and microbiologic profiles of patients with PMSA. Important differences were noted such as more frequent involvement of atypical and prosthetic joints in PMSA. PMSA should be suspected in patients with these clinical features, and broad-spectrum antibiotics should be considered as these patients appear to be sicker and have worse outcomes.

Epidemiology, Management, and Outcomes of Large and Small Native Joint Septic Arthritis in Adults

Background

Native joint septic arthritis (NJSA) is poorly studied. We describe the epidemiology, treatment, and outcomes of large joint NJSA (LNJSA) and small joint NJSA (SNJSA) in adults at Middlemore Hospital, Auckland, New Zealand.

Methods

This was a coding-based retrospective study of patients ≥16 years old admitted between 2009 and 2014. Prosthetic joint infections were excluded.

Results

Five hundred forty-three NJSA episodes were included (302 LNJSA, 250 SNJSA). Only 40% had positive synovial fluid culture. Compared to SNJSA, LNJSA has higher incidence (13 vs 8/100 000 person-years [PY]), occurs in older, more comorbid patients, and is associated with greater rates of treatment failure (23% vs 12%) and mortality, despite longer antibiotic treatment. Total incidence is higher than previously reported (21/100 000 PY), with marked interethnic variation. Incidence rises with age (LNJSA only) and socioeconomic deprivation (LNJSA and SNJSA). Tobacco smokers and males are overrepresented. The most commonly involved joints were knee (21%) and hand interphalangeal (20%). Staphylococcus aureus was the most common pathogen (53%). Mean antibiotic duration was 25 days for SNJSA and 40 days for LNJSA, and the mean number of surgical procedures was 1.5 and 1.6, respectively. Treatment failure was independently associated with LNJSA, age, intra-articular nonarthroplasty prosthesis, and number of surgical procedures.

Conclusions

This is the largest contemporary series of adult NJSA. SNJSA has better outcomes than LNJSA and may be able to be safely treated with shorter antimicrobial courses. Incidence is high, with significant ethnic and socioeconomic variation. Microbiological NJSA case ascertainment underestimates case numbers as it frequently excludes SNJSA.

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.

Early Detection of Inflammation and Joint Destruction Revealed by Ultrasound in a Patient with Sternoclavicular Septic Arthritis

A 53-year-old Japanese man experienced fever/neck pain, and neck magnetic resonance imaging revealed a spinal epidural abscess. The following day, he developed a palpable mass with evident inflammatory signs in the right sternoclavicular joint (SCJ) with severe pain. Ultrasound revealed synovitis with remarkable power Doppler signals in the right SCJ. Blood cultures yielded Streptococcus agalactiae growth. After 12 days, ultrasound showed right distal clavicle bone erosion. His symptoms improved with long-term parenteral antibiotic treatment, but the right SCJ joint destruction progressed for several months. We diagnosed him with sternoclavicular septic arthritis complicated with a spinal epidural abscess and bacteremia.

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.

Performance of automated multiplex polymerase chain reaction (mPCR) using synovial fluid in the diagnosis of native joint septic arthritis in adults

AIMS

This study aimed to assess the performance of an automated multiplex polymerase chain reaction (mPCR) technique for rapid diagnosis of native joint septic arthritis.

PATIENTS AND METHODS

Consecutive patients with suspected septic arthritis undergoing aseptic diagnostic joint aspiration were included. The aspirate was used for analysis by mPCR and conventional microbiological analysis. A joint was classed as septic according to modified Newman criteria. Based on receiver operating characteristic (ROC) analysis, the area under the ROC curve (AUC) values of the mPCR and the synovial fluid culture were compared using the z-test. A total of 72 out of 76 consecutive patients (33 women, 39 men; mean age 64 years (22 to 92)) with suspected septic arthritis were included in this study.

RESULTS

Of 72 patients, 42 (58%) were deemed to have septic joints. The sensitivity of mPCR and synovial fluid culture was 38% and 29%, respectively. No significant differences were found between the AUCs of both techniques (p = 0.138). A strong concordance of 89% (Cohen's kappa: 0.65) was shown. The mPCR failed to detect Staphylococcus aureus (n = 1) and Streptococcus pneumoniae (n = 1; no primer included in the mPCR), whereas the synovial fluid culture missed six microorganisms (positive mPCR: S. aureus (n = 2), Cutibacterium acnes (n = 3), coagulase-negative staphylococci (n = 2)).

CONCLUSION

The automated mPCR showed at least a similar performance to the synovial fluid culture (the current benchmark) in diagnosing septic arthritis, having the great advantage of a shorter turnaround time (within five hours). Cite this article: Bone Joint J 2019;101-B:288-296.

Bone and Joint Tissue Penetration of the Staphylococcus-Selective Antibiotic Afabicin in Patients Undergoing Elective Hip Replacement Surgery

Afabicin (formerly Debio 1450, AFN-1720) is a prodrug of afabicin desphosphono (Debio 1452, AFN-1252), a novel antibiotic in development which targets the staphylococcal enoyl-acyl carrier protein reductase (FabI) and exhibits selective potent antibacterial activity against staphylococcal species, including methicillin-resistant Staphylococcus aureus. As part of clinical development in bone and joint infections, a distribution study in bone was performed in 17 patients who underwent elective hip replacement surgery.

Afabicin (formerly Debio 1450, AFN-1720) is a prodrug of afabicin desphosphono (Debio 1452, AFN-1252), a novel antibiotic in development which targets the staphylococcal enoyl-acyl carrier protein reductase (FabI) and exhibits selective potent antibacterial activity against staphylococcal species, including methicillin-resistant Staphylococcus aureus. As part of clinical development in bone and joint infections, a distribution study in bone was performed in 17 patients who underwent elective hip replacement surgery. Patients received 3 doses of 240 mg afabicin orally (every 12 h) at various time points before surgery. Afabicin desphosphono concentrations were measured by liquid chromatography-tandem mass spectrometry in plasma, cortical bone, cancellous bone, bone marrow, soft tissue, and synovial fluid collected during surgery at 2, 4, 6, or 12 h after the third afabicin dose. The study showed good penetration of afabicin desphosphono into bone tissues, with mean area under the curve ratios for cortical bone-, cancellous bone-, bone marrow-, soft tissue-, and synovial fluid-to-total plasma concentrations of 0.21, 0.40, 0.32, 0.35, and 0.61, respectively. When accounting for the free fraction in plasma (2%) and synovial fluid (9.4%), the mean ratio was 2.88, which is indicative of excellent penetration and which showed that the afabicin desphosphono concentration was beyond the MIC₉₀ of S. aureus over the complete dosing interval. These findings, along with preclinical efficacy data, clinical efficacy data for skin and soft tissue staphylococcal infection, the availability of both intravenous and oral formulations, and potential advantages over broad-spectrum antibiotics for the treatment of staphylococcal bone or joint infections, support the clinical development of afabicin for bone and joint infections. (This study has been registered at ClinicalTrials.gov under identifier NCT02726438.)

Native joint septic arthritis due to Clostridium tarantellae

Clostridium is a diverse genus including more than 200 species involved in varied clinical presentations in infectious diseases. Septic arthritis caused by Clostridium sp. are however uncommon. We report here the first septic arthritis due to Clostridium tarantellae, formerly called Eubacterium tarantellae, in a patient under anti-TNF therapy.

Moraxella nonliquefaciens septic arthritis in a hematopoietic stem cell transplant patient a case report and review of the literature

BACKGROUND

Septic arthritis is a common rheumatologic condition with myriad microbiological causative agents. Moraxella is one of the very rare causes of septic arthritis. We hereby present the third case of Moraxella nonliquefaciens septic arthritis and the first case in a hematopoietic stem cell transplant patient (HSCT) along with a brief review of the literature.

METHODS

We used PubMed with google search engine to search the literature for reported cases of moraxella septic arthritis.

RESULTS

Information on 19 other cases of moraxella infectious arthritis was found. M. catarrhalis was the most common species isolated. Only 2 reports on M. nonliquefaciens were found; the first one in a multiple myeloma patient and the second one in a diabetic patient on hemodialysis. Predisposing conditions included inflammatory arthritis, prosthetic joints, diabetes, Human Immunodeficiency Virus (HIV) infection, Hepatitis C, hemodialysis, esophageal cancer, valve replacements, alcoholism and Intravenous (IV) drug use. The age group of the reported cases ranged from 3 months to 78 years.

CONCLUSION

Infectious arthritis with Moraxella spp. is a very rare entity which can occur in any age group and in the setting of various underlying medical conditions.

A comparison of Streptococcus agalactiae septic arthritis and non-Streptococcus agalactiae septic arthritis

INTRODUCTION

Streptococcus agalactiae (Group B Streptococcus, GBS) is an uncommon cause of septic arthritis in the adult population. In recent years, there has been an increase in the incidence of GBS septic arthritis. This study aims to compare the clinical presentation, investigations, microbiology and outcome of management in patients with GBS and non-GBS septic arthritis.

METHODS

Retrospective review of hospital surgical records was done to identify all patients treated surgically at our institution from January 2011 to January 2016 for primary septic arthritis. Patients were categorised into two groups: those with culture-proven GBS septic arthritis and those with causative pathogens that were not GBS. Patients who were medically unfit for surgical intervention as well as those who declined interventional procedures were excluded from the study.

RESULTS

A total of 83 patients were included in the study: 62 (74.7%) had non-GBS septic arthritis and 21 (25.3%) had GBS septic arthritis. Patients with GBS septic arthritis were more likely to have polyarticular involvement (p < 0.001) and involvement of less common sites such as the elbow joint. They were also more likely to have elevated inflammatory markers (C-reactive protein > 150 mg/L; p = 0.017) and positive blood cultures (p = 0.02), and were typically healthy adults with no medical comorbidities (p = 0.012).

CONCLUSION

Patients with GBS septic arthritis were more likely to present with polyarticular involvement, positive blood cultures and higher levels of C-reactive protein on admission, and tended to be healthier individuals with no medical comorbidities.

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.].

Microbiological profile of septic arthritis in adults: Lessons learnt and treatment strategies

OBJECTIVE

The aim of this study is to characterise the clinical and microbiological profile of adult patients treated at our orthopaedic unit with septic arthritic between 2006 and 2017.

MATERIALS AND METHODS

A total of 70 patients who were admitted with a diagnosis of septic arthritis between 2006 and 2017 were included in the study. The patients' clinical and epidemiological characteristics were surveyed; microbiological profile and the complications relating to the patients' treatment were identified.

RESULTS

Septic arthritis was more common among males (83%). About 75% of the patients presented with a history of fever. The knee was the most commonly affected joint (71%), followed by the hip. While C-reactive protein was found to be consistently >75, total blood white blood cell (WBC) counts were found not to be reflective of the presence of infection with a mean WBC count of only 13,561/cu.mm, and Gram stain examination had a poor sensitivity of 47%. Among the co-morbidities, the most prevalent association was with diabetes mellitus. The infectious agent most frequently isolated was Staphylococcus aureus(42.85%). The antibiotic sensitivity pattern has evolved since the early years, with resistant strains becoming increasingly prevalent. Unusually, high incidence of streptococci was noted (30%), contrary to the published literature. One-third of the patients had multi-resistant organisms. Septic arthritis left 70% of the patients with a significant residual disability at 6 months follow-up and had 4.25% mortality.

CONCLUSION

Changing sensitivity patterns of microbes in septic arthritis point to a need for reconsidering empirical antibiotic therapy. Joint damage following infection can lead to significant disability.

Utility of point-of-care synovial lactate to identify septic arthritis in the emergency department

BACKGROUND

Synovial lactate is a promising biomarker to distinguish septic from aseptic arthritis. If available as a point-of care test, synovial lactate would be rapidly available to aid the emergency provider in clinical decision making. This study assesses the test characteristics of synovial lactate obtained using an EPOC© point-of-care (POC) analyzer to rapidly distinguish septic from aseptic arthritis in the emergency department.

METHODS

We enrolled a convenience sample of patients with possible septic arthritis presenting to the emergency department at a large urban academic center between October 2016 and April 2018. Enrolled patients underwent arthrocentesis based on the clinical judgment of the treating provider. We obtained synovial lactate levels (SLL) from the POC device. Standard laboratory analysis, synovial fluid culture, emergency and hospital course, operative procedures, antibiotics, and discharge diagnosis were abstracted from the electronic medical record.

RESULTS

Thirty-nine patients undergoing forty separate arthrocentesis procedures were enrolled in this study over the two-year period. The sensitivity and specificity of SLL ≥ 5 mmol/L was 0.55 and 0.76 respectively, with +LR 2.3 and -LR 0.6. The sensitivity and specificity of SLL ≥ 10 mmol/L was 0.27 and 0.97 respectively, with +LR 7.9 and -LR 0.8; SLL ≥ 10 mmol/L performed similarly to overall synovial WBC ≥ 50,000/μL by conventional laboratory testing.

CONCLUSION

It is feasible to obtain a synovial lactate level using the EPOC© POC device. In our study, POC SLL performs similarly to other markers used to diagnose septic arthritis. Further study with larger sample sizes is warranted.

Impact of setting up a bone and joint infection referral center on arthroscopic treatment of septic arthritis of the knee and shoulder: Retrospective study

INTRODUCTION

Referral Centers for Bone and Joint Infection (BJI) were set up to optimize BJI management thanks to multidisciplinary teamwork. The main aim of the present study was to assess the impact of setting up the Western France Bone and Joint Infection Referral Center on arthroscopic treatment of septic arthritis of the shoulder and knee. The secondary aim was to identify other risk factors for failure of this treatment. The null hypothesis was that there was no difference between the "success group" and the "failure group".

MATERIAL AND METHODS

This single-center retrospective study included 52 patients treated for septic arthritis between January 1, 2000 and December 31, 2013 by arthroscopic joint lavage associated to at least 4 weeks' antibiotic therapy. Exclusion criteria comprised: retrospective diagnosis of rheumatoid arthritis after negative bacteriological analysis, early cessation of antibiotic treatment, and follow-up less than 4 weeks. Failure was defined as non-healing after first-line treatment. The primary endpoint was date of treatment compared to the launch date of the Center in the first quarter of 2010. The influence of pre- and intraoperative criteria related to patient, treatment and microorganism was assessed.

RESULTS

At follow-up, 17 patients (32.9%) showed failure of first-line treatment and 5 (9.6%) were non-healed at end of treatment, whatever the re-intervention. The failure rate significantly decreased after setting up the Center, from 42.9% to 11.8% (p=0.03). In the failure group, 70.6% of patients showed immunosuppression, versus 37.2% in the success group (p=0.01). Neither time to surgery (p=1), type of microorganism, or performance of antiseptic lavage (p=0.25) or synovectomy (p=0.62) influenced outcome.

CONCLUSION

Multidisciplinary management of septic arthritis improved treatment success.

LEVEL OF EVIDENCE

III, Retrospective comparative study.

Corticosteroids for septic arthritis in children

BACKGROUND

Septic arthritis is an acute infection of the joints characterised by erosive disruption of the articular space. It is the most common non-degenerative articular disease in developing countries. The most vulnerable population for septic arthritis includes infants and preschoolers, especially boys. Septic arthritis disproportionately affects populations of low socioeconomic status. Systemic corticosteroids and antibiotic therapy may be beneficial for treatment of septic arthritis. Even if the joint infection is eradicated by antibiotic treatment, the inflammatory process may produce residual joint damage and sequelae.

OBJECTIVES

To determine the benefits and harms of corticosteroids as adjunctive therapy in children with a diagnosis of septic arthritis.

SEARCH METHODS

We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library, Latin American Caribbean Health Sciences Literature (LILACS), the World Health Organization (WHO) trials portal (www.who.int/ictrp/en/), ClinicalTrials.gov (www.ClinicalTrials.gov), and Google Scholar. We searched all databases from their inception to 17 April 2018, with no restrictions on language of publication.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with patients from two months to 18 years of age with a diagnosis of septic arthritis who were receiving corticosteroids in addition to antibiotic therapy or as an adjuvant to other therapies such as surgical drainage, intra-articular puncture, arthroscopic irrigation, or debridement.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility, data extraction, and evaluation of risk of bias. We considered as major outcomes the presence of pain, activities of daily living, normal physical joint function, days of antibiotic treatment, length of hospital stay, and numbers of total and serious adverse events. We used standard methodological procedures expected by Cochrane. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created a 'Summary of findings' table.

MAIN RESULTS

We included two RCTs involving a total of 149 children between three months and 18 years of age who were receiving antibiotics for septic arthritis. The most commonly affected joints were hips and knees. These studies were performed in Costa Rica and Israel. In both studies, dexamethasone administered intravenously (ranging from 0.15 to 0.2 mg/kg/dose every six to eight hours) during four days was the corticosteroid, and the comparator was placebo. Trials excluded patients with any degree of immunodeficiency or immunosuppression. The longest follow-up was one year. Trials did not report activities of daily living nor length of hospital stay. Both studies used adequate processes for randomisation, allocation concealment, and blinding, and review authors judged them to have low risk of selection and performance bias. Losses to follow-up were substantive in both studies, and we judged them to have high risk of attrition bias and of selective outcome reporting. We graded all outcomes as low quality due to concerns about study limitations and imprecision.The risk ratio (RR) for absence of pain at 12 months of follow-up was 1.33, favouring corticosteroids (95% confidence interval (CI) 1.03 to 1.72; P = 0.03; number needed to treat for an additional beneficial outcome (NNTB) = 13, 95% CI 6 to 139; absolute risk difference 24%, 95% CI 5% to 43%).The RR for normal function of the affected joint at 12 months of follow-up was 1.32, favouring corticosteroids (95% CI 1.12 to 1.57; P = 0.001; NNTB = 13, 95% CI 7 to 33; absolute risk difference 24%, 95% CI 11% to 37%).We found a reduction in the number of days of intravenous antibiotic treatment favouring corticosteroids (mean difference (MD) -2.77, 95% CI -4.16 to -1.39) based on two trials with 149 participants.Researchers did not report length of hospital stay. One trial (49 participants) reported that treatment with dexamethasone was associated with a shorter duration of IV antibiotic treatment, leading to a shorter hospital stay, and although duration of hospitalisation was a primary outcome of the study, study authors did not provide data on the duration of hospitalisation. We downgraded the quality by one level for concerns about study limitations (high risk of attrition bias and selective reporting), and by another level for imprecision.In one trial of 49 participants, researchers followed 29 children for 12 months, and parents reported that no children demonstrated adverse effects of the intervention.

AUTHORS' CONCLUSIONS

Evidence for corticosteroids as adjunctive therapy in children with a diagnosis of septic arthritis is of low quality and is derived from the findings of two trials (N = 149). Corticosteroids may increase the proportion of patients without pain and the proportion of patients with normal function of the affected joint at 12 months, and may also reduce the number of days of antibiotic treatment. However, we cannot draw strong conclusions based upon these trial results. Additional randomised clinical trials in children with relevant outcomes are needed.

Autoimmunity Mimics: Infection and Malignancy

Musculoskeletal rheumatic syndromes are commonly encountered in the primary care setting. A plethora of commonly encountered and rare infectious agents can produce osteoarticular and soft tissue manifestations. Likewise, malignancies may manifest rheumatic symptoms via direct tumor invasion or paraneoplastic effects. Awareness of these diseases and their clinical risk factors should result in improved screening and earlier recognition and intervention, leading to improved long-term outcomes and overall patient care.

Management of Polyarthritis Affecting Sea Turtles at Kélonia, the Reunion Island Sea Turtle Observatory (2013-17)

All sea turtle species are listed on the Red List of the International Union for the Conservation of Nature due to multiple threats. Among these, disease is a frequent cause of stranded sea turtles encountered in rehabilitation centers. Since 2013, we found joint swelling in 13 sea turtles belonging to all four sea turtle species submitted to the Kélonia Sea Turtle Observatory of Reunion Island, France. Affected sea turtles presented with lameness, anorexia, and lethargy. Polyarthritis was radiographically confirmed and lesions were characterized by progressive osteolysis of bones surrounding joints. Anterior flippers were affected in all cases and posterior flippers were also involved in some cases. We isolated several bacterial agents from blood and synovial fluid. We attempted a collective treatment with injectable florfenicol, based on sensitivity results, which was continued for 4 wk and then as needed based on radiographic evolution of the lesions. Radiographic stabilization of the lesions occurred in nine of 13 cases. We reviewed environmental conditions and optimized them to minimize stress that could predispose these rehabilitated sea turtles to opportunistic infections. Handling techniques used to move sea turtles were also improved. While we can make no conclusion regarding the cause of polyarthritis in this population of sea turtles, we successfully managed this poorly described problem in a rehabilitation setting.

Procalcitonin may not be a differential diagnostic marker for bacterial infection in febrile patients with chronic gouty arthritis

Objective This study aimed to examine the diagnostic value of serum procalcitonin (PCT) levels for identifying bacterial infection in febrile patients with chronic gouty arthritis. Methods Sixty-six febrile patients with chronic gouty arthritis were divided into non-bacterial infection (n = 45) and bacterial infection groups (n = 21). PCT levels were measured by an immunoassay. Other laboratory parameters, including the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cells (WBCs), and the neutrophil ratio were extracted from medical records. Receiver-operating characteristic curves were used to evaluate diagnostic values and accuracy. Results Serum PCT levels, the ESR, CRP levels, WBC count, and neutrophil ratio were not different between the groups. To assess the ability of PCT to discriminate bacterial infection in febrile patients with chronic gouty arthritis (cut-off value: 0.5 ng/mL), the sensitivity and specificity of PCT were 22.2% and 61.5%, respectively. The area under the curve (AUC) of serum PCT levels was 0.526. The AUCs of related inflammatory indicators were 0.530 for the ESR, 0.635 for CRP, 0.577 for the WBC count, and 0.712 for the neutrophil ratio. Conclusion Serum PCT levels may not be a good biomarker for bacterial infection in febrile patients with chronic gouty arthritis.

Multiplex Polymerase Chain Reaction and Microcalorimetry in Synovial Fluid: Can Pathogen-based Detection Assays Improve the Diagnosis of Septic Arthritis?

OBJECTIVE

To prospectively evaluate automated multiplex PCR and isothermal microcalorimetry tests for rapid and accurate diagnosis of septic arthritis.

METHODS

Patients with acute arthritis were prospectively included from October 2014 to September 2015. In synovial fluid (SF), leukocyte count and differential, culture, PCR, and microcalorimetry were determined. Septic arthritis was diagnosed by positive SF culture or (1) local clinical signs and symptoms, (2) increased SF leukocyte count, and (3) exclusion of noninfectious causes of inflammatory arthropathy. The performance of individual tests was compared with McNemar's test.

RESULTS

Among 57 patients, 22 (39%) were diagnosed with septic arthritis. SF culture grew a pathogen in 10 patients (46%), PCR was positive in 5 (23%), and microcalorimetry in 10 (46%). Compared to SF culture, 49 concordant pairs were found for both methods (PCR and microcalorimetry; 86% agreement). In SF, PCR failed to detect Staphylococcus aureus (2 patients), Streptococcus pneumoniae (1 patient), Streptococcus dysgalactiae (1 patient), and Clostridium clostridioforme (1 patient). Microcalorimetry failed to detect S. dysgalactiae (1 patient), Streptococcus agalactiae (1 patient), and C. clostridioforme (1 patient). No statistical differences between the performance of SF culture, and PCR and microcalorimetry, respectively, were found. The processing time for PCR was 5 h and for microcalorimetry a median of 8.8 h (range, 2.3-64 h), whereas cultures required a median of 4.5 days (range, 3-14 days).

CONCLUSION

Performance of SF PCR was inferior while microcalorimetry was similar to culture but provided results considerably faster. [Clinical trial registration number (https://www.clinicaltrials.gov): NCT02530229].

Bacteriophage ZCKP1: A Potential Treatment for Klebsiella pneumoniae Isolated From Diabetic Foot Patients

The recorded growth in infection by multidrug resistant bacteria necessitates prompt efforts toward developing alternatives to antibiotics, such as bacteriophage therapy. Immuno-compromised patients with diabetes mellitus are particularly prone to foot infections by multidrug resistant Klebsiella pneumoniae, which may be compounded by chronic osteomyelitis. Bacteriophage ZCKP1, isolated from freshwater in Giza, Egypt, was tested in vitro to evaluate its lytic activity against a multidrug resistant K. pneumoniae KP/01, isolated from foot wound of a diabetic patient in Egypt. Characterization of ZCKP1 phage indicated that it belonged to the Myoviridae family of bacteriophages with a ds-DNA genome size of 150.9 kb. Bacteriophage ZCKP1 lysed a range of osteomyelitis pathogenic agents including Klebsiella spp., Proteus spp. and E. coli isolates. The bacteriophage reduced the bacterial counts of host bacteria by ≥2 log₁₀ CFU/ml at 25°C, and demonstrated the ability to reduce bacterial counts and biofilm biomass (>50%) when applied at high multiplicity of infection (50 PFU/CFU). These characteristics make ZCKP1 phage of potential therapeutic value to treat K. pneumoniae and associated bacteria present in diabetic foot patients.

Musculoskeletal Infections in the Emergency Department

Bone and joint infections are potentially limb-threatening or even life-threatening diseases. Emergency physicians must consider infection when evaluating musculoskeletal complaints, as misdiagnosis can have significant consequences. Patients with bone and joint infections can have heterogeneous presentations with nonspecific signs and symptoms. Staphylococcus aureus is the most commonly implicated microorganism. Although diagnosis may be suggested by physical examination, laboratory testing, and imaging, tissue sampling for Gram stain and microbiologic culture is preferable, as pathogen identification and susceptibility testing help optimize long-term antibiotic therapy. A combination of medical and surgical interventions is often necessary to effectively manage these challenging infections.

Bilateral knee septic arthritis: Was it from sternal wound?

Polyarticular septic arthritis is a rare but life-threatening condition and should not be underestimated. Clinicians should look for potential source of infection, either local spread or hematogenous distribution. However, this should not delay the main treatment for septic arthritis.

Sustained Delivery of Analgesic and Antimicrobial Agents to Knee Joint by Direct Injections of Electrosprayed Multipharmaceutical-Loaded Nano/Microparticles

In this study, we developed biodegradable lidocaine–/vancomycin–/ceftazidime–eluting poly(d,l–lactide–co–glycolide) (PLGA) nano/microparticulate carriers using an electrospraying process, and we evaluated the release behaviors of the carriers in knee joints. To prepare the particles, predetermined weight percentages of PLGA, vancomycin, ceftazidime, and lidocaine were dissolved in solvents. The PLGA/antibiotic/lidocaine solutions were then fed into a syringe for electrospraying. After electrospraying, the morphology of the sprayed nano/microparticles was elucidated by scanning electron microscopy (SEM). The in vitro antibiotic/analgesic release characteristics of the nano/microparticles were studied using high-performance liquid chromatography (HPLC). In addition, drug release to the synovial tissues and fluids was studied in vivo by injecting drug-loaded nano/microparticles into the knee joints of rabbits. The biodegradable electrosprayed nano/microparticles released high concentrations of vancomycin/ceftazidime (well above the minimum inhibition concentration) and lidocaine into the knee joints for more than 2 weeks and for over 3 days, respectively. Such results suggest that electrosprayed biodegradable nano/microcarriers could be used for the long-term local delivery of various pharmaceuticals.

A potential key role for alpha-haemolysin of Staphylococcus aureus in mediating chondrocyte death in septic arthritis

Objectives

Staphylococcus aureus (S. aureus) is the most commonly implicated organism in septic arthritis, a condition that may be highly destructive to articular cartilage. Previous studies investigating laboratory and clinical strains of S. aureus have demonstrated that potent toxins induced significant chondrocyte death, although the precise toxin or toxins that were involved was unknown. In this study, we used isogenic S. aureus mutants to assess the influence of alpha (Hla)-, beta (Hlb)-, and gamma (Hlg)-haemolysins, toxins considered important for the destruction of host tissue, on in situ bovine chondrocyte viability.

Methods

Bovine cartilage explants were cultured with isogenic S. aureus mutants and/or their culture supernatants. Chondrocyte viability was then assessed within defined regions of interest in the axial and coronal plane following live- and dead-cell imaging using the fluorescent probes 5-chloromethylfluorescein diacetate and propidium iodide, respectively, and confocal laser-scanning microscopy.

Results

Hla-producing mutants caused substantial chondrocyte death compared with the toxin-deficient control (Hla-Hlb-Hlg-), whilst mutants producing Hlb and Hlg in the absence of Hla induced minimal chondrocyte death. Coronal studies established that Hla-induced chondrocyte death started in the superficial zone of cartilage and spread to deeper layers, whereas Hlb and Hlg toxins were without significant effect.

Conclusion

This study identified Hla as a highly potent S. aureus toxin that caused rapid chondrocyte death in bovine cartilage, with other toxins or metabolic products produced by the bacteria playing a minor role. The identification of Hla in mediating chondrocyte death may assist in the development of therapeutic strategies aimed at reducing the extent of cartilage damage during and after an episode of septic arthritis.

Cite this article: I. D. M. Smith, K. M. Milto, C. J. Doherty, S. G. B. Amyes, A. H. R. W. Simpson, A. C. Hall. A potential key role for alpha-haemolysin of Staphylococcus aureus in mediating chondrocyte death in septic arthritis. Bone Joint Res 2018;7:457–467. DOI: 10.1302/2046-3758.77.BJR-2017-0165.R1.