Bacterial septic arthritis in adults

Features and outcomes of hospitalized Thai patients with pyogenic arthritis: analysis from the nationwide hospital database

BACKGROUND

Pyogenic arthritis (PA) is still a problematic arthritic disease that requires hospitalization.

OBJECTIVE

To study the epidemiological characteristics and predictors of treatment outcomes for Thai patients hospitalized with PA.

MATERIALS AND METHODS

The nationwide hospital database from the 2010 fiscal year was analyzed. Patients 18 years of age onward, who had primary diagnosis of pyogenic arthritis, were included in this study.

RESULTS

There were a total of 6242 PA admissions during 2010. It was ranked third among hospitalized musculoskeletal patients after osteoarthritis (OA) and gouty arthritis. The estimated prevalence of PA was 13.5 per 100 000 adult population. Geographic distributions of PA was related to the population density of each region; however it seemed more frequent in the northern and northeastern regions of Thailand. The prevalence increased with age, 3.6 and 43.6 per 100 000 in young adults and the elderly, respectively. Among the 2877 co-morbidities coded, diabetes was the most common, followed by crystal-induced arthritis, existing other foci of infections (urinary tract infection, skin and soft tissue infections and pneumonia) and pre-existing chronic joint diseases (OA,rheumatoid arthritis), respectively. Overall hospital mortality rate was 2.6%. Poorer outcomes were found among patients with chronic liver disease and other existing foci of infections.

CONCLUSIONS

The prevalence of hospitalized PA is still modest in Thailand, showing the highest prevalence in the advanced age group. Diabetes was the most commonly co-morbidity found; however, poorer outcomes were noted among patients with chronic liver disease and existing multiple sites of infections.

Serum Procalcitonin is a sensitive and specific marker in the diagnosis of septic arthritis and acute osteomyelitis

BACKGROUND

Early diagnosis of Acute Osteomyelitis (OM) and Septic Arthritis (SA) is of vital importance to avoid devastating complications. There is no single laboratory marker which is sensitive and specific in diagnosing these infections accurately. Total Count, ESR and CRP are not specific as they can also be elevated in non pyogenic causes of inflammation. Pus Culture and sensitivity is not a true gold standard due to its varied positivity rates (40 - 70%). Serum Procalcitonin (PCT), at 0.5 ng/ml is found to be an accurate marker for pyogenic infections. The objectives of this study were to show that PCT is an accurate marker in differentiating Acute Osteomyelitis and Septic Arthritis from viral and non infective inflammatory bone and joint conditions.

METHODS

Patients of all age groups (n = 82) with suspected Acute Osteomyelitis and Septic Arthritis were prospectively included in this study. All patients were subjected to TC, CRP, PCT, IgM Dengue, IgM Chikungunya, pus and blood culture and sensitivity. At the end of the study, patients were classified into 3 groups: Group 1 = Confirmed Pyogenic (n = 27); Group 2 = Presumed Pyogenic (n = 21); Group 3 = Non - infective inflammatory (n = 34).

RESULTS

Group 1 has higher mean PCT levels than Group 2 and 3 (p < 0.05). PCT, at 0.4 ng/ml, was 85.2% sensitive and 87.3% specific in diagnosing Septic Arthritis and Acute Osteomyelitis. In comparison, PCT at conventional cut - off of 0.5 ng/ml is 66.7% sensitive and 91% specific.

CONCLUSION

Serum Procalcitonin, at a cut - off of 0.4 ng/ml, is a sensitive and specific marker in the diagnosis of Septic Arthritis and Acute Osteomyelitis.

Clinical management of septic arthritis

Septic arthritis is a rheumatologic emergency as joint destruction occurs rapidly and can lead to significant morbidity and mortality. Accurate diagnosis can be particularly challenging in patients with underlying inflammatory joint disease. This review outlines the risk factors for septic arthritis and summarizes the causative bacterial organisms. We highlight advances in antibiotic management with a focus on new drugs for methicillin-resistant Staphylococcus aureus (MRSA) and discuss the use of adjunctive therapies for treatment of septic arthritis in adults.

Surgical treatment for septic arthritis of the knee joint in elderly patients: a 10-year retrospective clinical study

Septic arthritis is the most rapidly destructive joint disease, but its early diagnosis remains challenging; delayed or inadequate treatment, even by expert physicians, can lead to irreversible joint destruction. Between 25% and 50% of patients develop irreversible loss of joint function, which is especially concerning in elderly patients. To understand the factors influencing the outcome of septic arthritis, the authors reviewed patients aged older than 50 years who had undergone debridement surgery for primary septic arthritis at their institution between 1998 and 2008. Ninety-two patients (92 knees) were enrolled in the study; 14 did not meet inclusion criteria and were excluded from the final analysis. Of the 78 included patients, 7 underwent arthrodesis, 22 underwent total knee arthroplasty, 19 were indicated for total knee arthroplasty for severe knee joint osteoarthritis but did not undergo surgery by the end of this study, and the remaining 30 had no or mild symptoms of osteoarthrosis and did not receive any surgical procedure. Staphylococcus aureus was the most common pathogenic agent (38%), followed by mixed bacterial infection (10%). Several factors negatively influenced the final clinical outcome, including delayed treatment, advanced macroscopic staging made during debridement surgery, performing multiple debridement surgeries, and a larger Lysholm score difference pre- and posttreatment. More antibiotics administered, longer duration of antibiotic treatment, and more pathogenic agents present were also significantly correlated with poor outcome. These findings shed new light on the management of septic arthritis. Accurate diagnoses and effective treatments are important for the clinical outcome of knee joint bacterial infection in elderly patients.

Polyarticular septic arthritis in an immunocompetent patient

Septic arthritis is an uncommon condition with an incidence of 2-3/100,000. It is clinically notable, however, as it is a rapidly destructive joint disease with significant associated morbidity and mortality. Polyarticular septic arthritis has an estimated incidence of 15% of all cases of infectious arthritis. We report a case of polyarticular septic arthritis with involvement of bilateral shoulders and wrist to highlight the importance of early diagnosis and treatment as well as the high mortality rates associated with this condition. Bilateral septic shoulder arthritis poses a challenge to treat, and its significance should not be underestimated as even with early surgical intervention and aggressive antibiotic and fluid resuscitation death is a sad but perhaps not uncommon outcome. It is therefore imperative that the diagnosis of polyarticular septic arthritis is kept prominent in the physician's mind when confronted with a patient with symptomatic polyarthralgia.

Optimizing combination rifampin therapy for staphylococcal osteoarticular infections

Staphylococcus spp. causes more than half of all osteoarticular infections of native structures or implanted material. The ability of Staphylococcus spp. to persist within infected bone tissue and to produce a bacterial biofilm, most notably in infections of implanted material, can lead to treatment failures and microbiological relapses. Rifampin is a cornerstone of the treatment of staphylococcal osteoarticular infections, particularly those of implanted material. Rifampin is a bactericidal antibiotic that diffuses very well within bone tissue and bacterial biofilms. The mechanism of action is inhibition of bacterial DNA transcription to mRNA independently from bacterial division, which results in activity against even dormant Staphylococcus spp. organisms. However, the high risk of emergence of rifampin-resistant mutants requires the concomitant administration of another antibiotic. Several antibiotics are recommended in the French guidelines issued by the French-Speaking Society for Infectious Diseases (Société de Pathologie Infectieuse de Langue Française [SPILF]). Here, we discuss the results from in vitro, animal, and clinical studies that explain the advantages and drawbacks of each antibiotic used with rifampin to treat osteoarticular infections due to Staphylococcus spp.

MRI findings of treated bacterial septic arthritis

INTRODUCTION

The purpose of this study was to report the MRI findings that can be encountered in successfully treated bacterial septic arthritis.

MATERIALS AND METHODS

The study included 12 patients (8 male and 4 female; mean age 38 years, range 9-85) with 13 proven cases of bacterial septic arthritis. The joints involved were hip (n = 3), knee (n = 3), shoulder (n = 2), sacroiliac (n = 2), ankle (n = 1), wrist (n = 1), and elbow (n = 1). MRI examinations following surgical debridement and at initiation of antibiotic therapy and after successful treatment were compared for changes in effusion, synovium, bone, and periarticular soft tissues. Imaging findings were correlated with microbiological and clinical findings.

RESULTS

Joint effusions were present in all joints at baseline and regressed significantly at follow-up MRI (p = 0.001). Abscesses were present in 5 cases (38 %), and their sizes decreased significantly at follow-up (p = 0.001). Synovial enhancement and thickening were observed in all joints at both baseline and follow-up MRI. Myositis/cellulitis was present in 10 cases (77 %) at baseline and in 8 cases (62 %) at follow-up MRI. Bone marrow edema was present in 10 joints (77 %) at baseline and persisted in 8 joints (62 %). Bone erosions were found in 8 joints (62 %) and persisted at follow-up MRI in all cases.

CONCLUSION

The sizes of joint effusions and abscesses appear to be the factors with the most potential for monitoring therapy for septic arthritis, since both decreased significantly following successful treatment. Synovial thickening and enhancement, periarticular myositis/cellulitis, and bone marrow edema can persist even after resolution of the infection.

Azithromycin in combination with riboflavin decreases the severity of Staphylococcus aureus infection induced septic arthritis by modulating the production of free radicals and endogenous cytokines

OBJECTIVE AND DESIGN

To determine alternate therapeutic measures to combat Staphylococcus aureus induced arthritis. Thus, azithromycin was combined with riboflavin, which may combat the ROS production and inflammation.

METHODS

An in vivo model of S. aureus infection-induced arthritis was set up by infecting mice with 5 × 10⁶ bacterial cell/mouse. S. aureus was administered intravenously. Azithromycin and riboflavin was injected intraperitoneally at a single dose of 100 and 20 mg/kg body, respectively. The mice were sacrificed at 3, 9, 15 days post infection (dpi). TNF-α, IFN-γ, IL-6 and IL-10 from serum and SOD, catalase and reduced glutathione concentration were observed in hepatic, cardiac, renal and splenic tissue.

RESULTS

CFU was found very prominent in spleen and joints and reduced in blood at 3 and 9 dpi. However, treatment with azithromycin and riboflavin completely eradicated the bacteria from blood and spleen. TNF-α, IFN-γ, IL-6, and MCP-1 were induced due to infection which were downregulated by treatment with azithromycin and riboflavin. Infected mice were also found to have altered antioxidant status, measured in terms of reduced glutathione and anti-oxidant enzymes such as SOD and catalase.

CONCLUSION

These changes were found to be ameliorated when the animals were co-treated with azithromycin and riboflavin.

Subtalar joint septic arthritis in a patient with hypogammaglobulinemia

The clinical presentation of a monoarticular, red, hot, and swollen joint has many possible diagnoses, including septic arthritis, which is 1 of the most devastating. The morbidity associated with this pathologic process involves permanent joint damage and the potential for progression to systemic illness and, even, mortality. The common risk factors for joint sepsis include a history of rheumatoid arthritis, previous joint surgery, joint prosthesis, intravenous drug abuse, alcoholism, diabetes, previous intra-articular steroid use, and cutaneous ulceration. The diagnosis is primarily determined from the culture results after arthrocentesis and correlation with direct visualization, imaging, and various serologies, including synovial analysis. In the present report, a case of an insidious presentation of subtalar joint septic arthritis and its association with a unique patient presentation concomitant with primary immunodeficiency and culture-proven Myocplasma hominis infection is discussed. Septic arthritis has a predilection for the lower extremities and typically is isolated to the hip or knee, with less common involvement of the ankle or metatarsophalangeal joints. Owing to the uncommon nature of primary immunodeficiency disorders and the paucity of studies discussing their association with septic arthridites, we aimed to raise awareness of subtalar joint septic arthritis and to provide a brief overview of the pathogenesis as it presented in a 33-year-old male with X-linked hypogammaglobulinemia/agammaglobulinema.

Infection of orthopedic implants with emphasis on bacterial adhesion process and techniques used in studying bacterial-material interactions

Staphylococcus comprises up to two-thirds of all pathogens in orthopedic implant infections and they are the principal causative agents of two major types of infection affecting bone: septic arthritis and osteomyelitis, which involve the inflammatory destruction of joint and bone. Bacterial adhesion is the first and most important step in implant infection. It is a complex process influenced by environmental factors, bacterial properties, material surface properties and by the presence of serum or tissue proteins. Properties of the substrate, such as chemical composition of the material, surface charge, hydrophobicity, surface roughness and the presence of specific proteins at the surface, are all thought to be important in the initial cell attachment process. The biofilm mode of growth of infecting bacteria on an implant surface protects the organisms from the host immune system and antibiotic therapy. The research for novel therapeutic strategies is incited by the emergence of antibiotic-resistant bacteria. This work will provide an overview of the mechanisms and factors involved in bacterial adhesion, the techniques that are currently being used studying bacterial-material interactions as well as provide insight into future directions in the field.

Synovial fluid from patients with early osteoarthritis modulates fibroblast-like synoviocyte responses to toll-like receptor 4 and toll-like receptor 2 ligands via soluble CD14

OBJECTIVE

Synovial inflammation, a feature of both osteoarthritis (OA) and meniscal injury, is hypothesized to be triggered in part via stimulation of Toll-like receptors (TLRs). We undertook this study to test whether a TLR-2- or TLR-4-stimulating factor in synovial fluid (SF) from patients with early knee OA with meniscal injury could lead to inflammatory activation of synoviocytes.

METHODS

SF was obtained from patients with early OA cartilage damage undergoing arthroscopic meniscal procedures. SF was used to stimulate primary cultures of fibroblast-like synoviocytes (FLS) and cell lines transfected with TLR-2 or TLR-4. SF was used either alone or in combination with a TLR-2 stimulus (palmitoyl-3-cysteine-serine-lysine-4 [Pam3CSK4]) or a TLR-4 stimulus (lipopolysaccharide [LPS]). In blocking experiments, SF was preincubated with anti-CD14 antibody.

RESULTS

SF from these patients did not stimulate interleukin-8 (IL-8) release from TLR transfectants. Compared with SF on its own, SF (at concentrations of 0.09-25%) in combination with TLR-2 or TLR-4 ligands resulted in significant augmentation of IL-8 release from both transfectants and primary FLS. Soluble CD14 (sCD14), a coreceptor for TLRs, was measured in SF from patients with early OA at levels comparable to those in patients with advanced OA and patients with rheumatoid arthritis. Blockade with anti-CD14 antibody abolished the ability of SF to augment IL-8 production in response to LPS, and diminished Pam3CSK4 responses.

CONCLUSION

SF augments FLS responses to TLR-2 and TLR-4 ligands. This effect was largely due to sCD14. Our results demonstrate that sCD14 in the setting of OA and meniscal injury sensitizes FLS to respond to inflammatory stimuli such as TLR ligands.

Of bugs and joints: the relationship between infection and joints

The association between microbes and joints has existed since antiquity, and remains complex. Diagnosis is often times difficult to determine despite highly suspicious clinical characteristics for the presence of an underlying infection. Over the several past decades, considerable advances have occurred in diagnostic methodologies and therapy. However, the morbidity and mortality of septic arthritis remains high. Great advances have occurred in the diagnosis, pathogenesis, and therapeutic management of reactive arthritis, and there is evidence that when the responsible microorganism is Chlamydia trachomathis, complete remission and cure is possible. Emergent infections, especially viral, has been recognized, i.e. HIV, hepatitis C, and most recently Chikengunya virus, and in the case of HIV associated articular manifestations, the introduction of HAART has resulted in a decrease in the incidence and development of newer complications such as the immune reconstitution syndrome. The infectious etiology of rheumatoid arthritis is being strongly considered once again, and the exciting association with periodontal disease is at the forefront of intense research. The gut microbiota is also being investigated and new and most interesting data is being gathered of the potential role of commensal gut organisms and the pathogenesis of rheumatoid arthritis.

Bone and joint infections in hospitalized patients in France, 2008: clinical and economic outcomes

BACKGROUND

Adult bone and joint infections (BJIs) often require repeated and prolonged hospitalizations and are considered as a serious public health issue.

AIM

To describe the epidemiology and economical outcomes of BJI in France.

METHODS

BJI hospitalizations with selected demographic, medical, and economic parameters from the French national hospital database for the year 2008 were identified. Overall patient characteristics and hospital stays for BJI underwent univariate analysis. Risk factors for device-associated infections were identified using multiple logistic regression modelling.

FINDINGS

Of all hospitalizations in France, 0.2% were BJI-related, representing 54.6 cases per 100,000 population, with a higher prevalence in males (sex ratio: 1.54). BJIs were more often native (68%) than device-associated (32%). The mean age was 63.1 years. Only 39% of hospital discharges had microbiological information coded; Staphylococcus spp. were isolated in 66% of those cases. Obesity, Staphylococcus spp., male sex and age >64 years were important risk factors for device-associated infections, whereas diabetes and ulcer sores were significantly associated with native infections. The case fatality was 4.6%. Intensive care unit stays were needed in 6% of cases. Readmissions to hospital occurred in 19% of cases, with significantly longer stays for device-associated infections than for native BJIs (18.9 vs 16.8 days). The cost of BJIs was €259 million, or about €7,000 per hospitalization in 2008.

CONCLUSIONS

This is the largest BJI study to date. The high economic burden of BJIs was mostly associated with more frequent and prolonged hospitalizations, high morbidity, and complexity of care.

Rat bite fever as a presenting illness in a patient with AIDS

The etiology of culture-negative septic arthritis is poorly characterised in persons infected with human immunodeficiency virus (HIV). New molecular methods may assist in the investigation of culture-negative infections of sterile sites, including septic arthritis. We describe the first case of septic arthritis due to the cause of rat bite fever (RBF), Streptobacillus moniliformis, confirmed by 16S rRNA sequence analysis, in a patient with newly diagnosed HIV infection.

Chlamydia-induced ReA: immune imbalances and persistent pathogens

Reactive arthritis (ReA), an inflammatory arthritic condition that is commonly associated with Chlamydia infections, represents a significant health burden, yet is poorly understood. The enigma of this disease is reflected in its problematic name and in its ill-defined pathogenesis. The existence of persistent pathogens in the arthritic joint is acknowledged, but their relevance remains elusive. Progress is being made in understanding the underlying mechanisms of ReA, whereby an imbalance between type 1 and type 2 immune responses seems to be critical in determining susceptibility to disease. Such an imbalance occurs prior to the initiation of an adaptive immune response, suggesting that innate cellular and molecular mechanisms in ReA should be prioritized as fruitful areas for investigation.

What's New in the Management of Bacterial Septic Arthritis?

Septic arthritis is a common rheumatological emergency requiring prompt diagnosis and treatment, since delays in management can lead to high morbidity and mortality. In this review article, we discuss the epidemiology and recent advances in knowledge of the pathogenesis of septic arthritis, with a special emphasis on various bacterial and host factors involved in mediating the inflammatory process and the potential for targeted therapy to modulate the immune response. Recent advances in laboratory and imaging techniques are reviewed along with treatment and potential new therapies.

Retrospective investigation of prognostic indicators for adult horses with infection of a synovial structure

OBJECTIVE

To investigate predictors of survival and athletic function in adult horses with infection of a synovial structure.

HYPOTHESES

Increasing duration from contamination to referral, bone or tendon involvement and positive microbial culture decreases short-term survival. Synovitis and/or sepsis at 5 days post-admission and involvement of Staphylococcus spp. decreases long-term athletic function.

DESIGN

Retrospective study.

METHODS

Records over 4 years of adult horses with synovial sepsis were reviewed. A two-tailed Fisher's exact test, Mann-Whitney U test or t-test was used to examine whether variables were predictive of short-term survival and long-term athletic function.

RESULTS

During the study period 75 horses underwent treatment for infection of 93 synovial structures. Short-term survival was 84% (63/75) and 54% (30/56) of horses returned to athletic function. Of the variables measured at admission, duration from contamination to referral did not affect survival, whereas evidence of bone or tendon involvement decreased survival and athletic function. Of the variables available during treatment, abnormal synovial fluid at 4-6 days post-admission and positive microbial culture reduced athletic function. Staphylococcal infection was associated with persistent sepsis.

CONCLUSIONS

Of the variables available at presentation, only evidence of bone or tendon involvement negatively affected survival and athletic function. During treatment of synovial sepsis, analysis of synovial fluid at 4-6 days and bacterial culture results have prognostic value.

Intra-articular therapy to treat septic arthritis in a dog

A 6 yr old female spayed Labrador retriever was examined for severe pain and a nonweight-bearing right forelimb lameness due to swelling and wounds with direct communication into the elbow joint. The medical management of β hemolytic Streptococcus septic arthritis with needle lavage of the joint, systemic and local antibiotic therapy, and analgesic therapy is described. This case provides information on the need to address septic arthritis in the dog as an emergency situation and the treatment with intra-articular medication. Earlier medical management for septic joints could be considered in dogs to help decrease the long-term complications that can result from septic arthritis.

Septic arthritis: monitoring with USPIO-enhanced macrophage MR imaging

PURPOSE

To prospectively evaluate in vivo noninvasive monitoring of antibiotic therapy in experimental infectious arthritis by imaging macrophages by using magnetic resonance (MR) imaging enhanced with ultrasmall superparamagnetic iron oxide (USPIO) particles.

MATERIALS AND METHODS

The institutional review committee on animal care approved the experimental protocol. Unilateral knee infection was induced by intra-articular injection of Staphylococcus aureus in 12 rabbits. Each rabbit underwent MR imaging before and after injection of USPIO particles, as well as before and after injection of gadoterate meglumine. All 12 of the animals were imaged during the acute phase of infection. Half were then sacrificed to obtain histopathologic samples, and the other half were imaged a second time after antibiotic treatment. MR imaging data were analyzed and compared with bacteriologic and histopathologic findings.

RESULTS

In acute infections, intense synovitis with marked signal intensity increase of the synovium on gadoterate dimeglumine-enhanced fat-suppressed T1-weighted images was observed in all animals and was associated with areas of signal intensity loss within the infected synovium on USPIO-enhanced T2*-weighted gradient-echo images, reflecting an intense infiltration of USPIO-loaded macrophages. After antibiotic treatment and histologic evidence of healing infection, less synovial signal intensity loss was seen (P = .03). In contradistinction, the signal intensity increase on gadoterate dimeglumine-enhanced fat-suppressed T1-weighted images remained unchanged.

CONCLUSION

In contrast to conventional MR imaging performed by using extracellular contrast agents, USPIO-enhanced macrophage MR imaging can demonstrate resolution of experimental bacterial joint infection.

Current concepts review: septic arthritis of the knee pathophysiology, diagnostics, and therapy

Treatments for bacterial arthritis of the knee joint are arthroscopic irrigation and debridement with systemic antibiotic medication. This article summarizes the relevant data of pathophysiology, stage of infection, symptoms, and diagnostics as well as stage-dependent treatment of bacterial arthritis of the knee joint. The major treatment principles are joint decompression, elimination of the causative organisms by intensive irrigation of the joint with elimination of proteolytic and lysosomal enzymes. Debridement of necrotic soft tissues with the aim of preserving the synovial membrane as an immune-competent structure, and a natural barrier, is recommended. Good results in treating knee infections have been achieved with arthroscopic joint revision and stage-dependent surgical therapy. The infection staging I-IV suggested by Gächter was used most commonly, which mainly reflects the pathophysiologic infection stages. For stages I-III, arthroscopic joint decompression with joint irrigation and debridement is effective and can be repeated in cases of persisting infection. The incidence of repeated arthroscopic joint irrigation depends on the initial stage of the infection and varies between 0 and 41% of the cases. For stage IV infections, the open revision is needed or in seldom cases of therapy failure under initial or repeated arthroscopic joint revision. The success rate of healing infections by arthroscopic irrigation was high with 90-100%.

What are we doing about septic arthritis? A survey of UK-based rheumatologists and orthopedic surgeons

This study aims to determine the current practices and beliefs of United Kingdom (UK)-based rheumatologists and orthopedic surgeons (OS) in managing septic arthritis (SA) and to determine awareness levels of national guidance. Two-hundred OS and 200 rheumatologists were sent a link to a web-based survey tool via email. Questions posed related to the management of SA, including the respondent's views on antibiotic therapy, joint drainage, which specialty should manage these cases, and also the clinician's evidence base. There were 354 functioning addresses with 182 responses (51%). One hundred fifty-one (77 OS, 74 rheumatologists) (43%) responses were complete and included for analysis. Eighty percent of rheumatologists and 82% of OS recommended 6-weeks total antibiotic therapy. Seventy-three percent in each group recommended 1-2 weeks intravenous therapy initially followed by oral continuation therapy. In patients at risk of methicillin-resistant Staphylococcus aureus (MRSA), 25% rheumatologists and 14% OS would ensure MRSA cover. Seventy-seven percent of rheumatologists and 66% of OS recommended surgical joint drainage; 22% and 27%, respectively, recommended repeated closed needle aspiration as their chosen method of joint drainage. Sixty-six percent of rheumatologists and 65% of OS believed OS should manage SA. Twenty-three percent of rheumatologists and 22% of OS quoted published guidance as their main evidence base in the treatment of SA. Only 24% of rheumatologists and 34% of OS quoted British Society of Rheumatology (BSR) guidance when asked if they were aware of any guidelines. Views of rheumatologists and OS are not that dissimilar in managing SA. Surprisingly, rheumatologists are more aggressive regarding the recommendation for surgical joint drainage. Within both groups, significant variation in management principles exists often discrepant to recommendations laid out by the BSR. There are poor awareness levels of the BSR guidelines.

Gout: epitome of painful arthritis

Arthritic pain and disability are at or near the top of the list of reasons adult patients seek medical attention. At least 47.8 million US residents have arthritis. In Europe, the magnitude of the problem is similar, affecting 8 million in the United Kingdom and 108 million across the continent. Osteoarthritis is by far the most common form of arthritis. In a regional UK study, nearly half of adults 50 years or older reported some form of osteoarthritic knee pain over a 1-year period. Among the arthritides, gout is notable for the agonizing nature and unique pathogenesis of the pain it generates. Gout is the most common cause of inflammatory arthritis among men and postmenopausal women. Because of the atypical nature of some of its clinical manifestations, gout can present serious diagnostic challenges for practicing physicians. In recent years, knowledge about gout's pathogenesis, pathophysiology, and differential diagnosis has advanced on a broad front. Genetic variants within a newly identified transport gene, SLC2A9, have been associated with a low fractional excretion of uric acid and the presence of gout in several population samples. The SLC2A9 gene encodes glucose transporter 9-a unique hexose and high-capacity urate transporter. In addition, human ATP-binding cassette, subfamily G2 (ABCG2), encoded by the ABCG2 gene, has been found to mediate renal urate secretion. Introduction of a mutation encoded in a model system by a common single nucleotide polymorphism, rs2231142, resulted in a 53% reduction in urate transport rates compared with wild-type ABCG2. Based on a large population study, it has been estimated that at least 10% of all gout cases in white persons may be attributable to this single nucleotide polymorphism causal genetic variant. Of the various categories of arthritis, the crystal-induced arthropathies, gout and pseudogout, are manifested by acute inflammation and tissue damage arising from deposition in joints and periarticular tissues of monosodium urate (MSU), calcium pyrophosphate dehydrate, or basic calcium phosphate crystals. The innate immune system rapidly detects invading pathogenic microbes and nonmicrobial "danger signals" such as MSU crystals. When these crystals are deposited in synovial tissues, NLR proteins (NOD-like receptors) form multiprotein complexes known as inflammasomes that trigger secretion of inflammation-producing cytokines like interleukin-1β and interleukin-18. Usually, gout can be diagnosed by medical history, physical examination, and presence of hyperuricemia (urate >416 μmol/L). However, a urate concentration less than 416 does not by itself rule out gout. Confirmation of the diagnosis by identification of typical MSU crystals in aspirated synovial fluid is definitive. Analysis of joint fluid is mandatory to rule out septic arthritis, which can rapidly become lethal. Because of its special ability to identify and quantitate urate deposits in peripheral tissues, dual-energy computed tomography should prove valuable in the differential diagnosis of gout. Gout mimics a variety of illnesses; for example, spinal gout may masquerade as metastatic cancer, epidural abscess, and nerve compression syndrome.

Aspergillus fumigatus joint infection: a review

OBJECTIVES

To describe a case of joint infection by Aspergillus fumigatus in a unusual site (sacroiliac) and perform a systematic review of such cases described in the literature.

METHODS

We performed a Medline search of the cases of fungal joint of Aspergillus fumigatus in the period ranging from 1970 to 2009.

RESULTS

Following PRISMA Guidelines, 15 cases including ours were reported during this period. Stem cell and solid organ transplantation, hematologic malignancy, and intra-articular steroids injection were the medical conditions found in such patients. The knee followed by the shoulder were the joints more affected. In the cases where synovial fluid analyses were reported, elevated cell count numbers could be found with a predominance of polymorphonuclear neutrophils.

CONCLUSIONS

Fungal joint arthritis is a rare clinical disease most frequently present in immuno-incompetent patients. Rheumatologists should be aware of this condition, where early diagnosis can be associated with good prognosis.