Bacterial arthritis

Polyarticular Septic Arthritis with Bilateral Psoas Abscesses following Acupuncture

We report a case of polyarticular septic arthritis with bilateral psoas abscesses. A 50-year-old woman was admitted with fever, multiple joint swelling and pain. She had a clinical history of acupuncture therapy for treatment of her chronic lower back pain two days before the appearance of her symptoms. Methicillin-sensitive Staphylococcus aureus was isolated from blood culture, knee joint fluids and psoas abscess. After a long course of antibiotics for 70 days together with drainage of the abscess, the condition completely resolved. The acupuncture is the probable cause of the infection, and this case report reveals the importance of asking about a clinical history of acupuncture treatment and of making repeated bacterial examinations in undiagnosed polyarthritis patients.

A case of brucellosis with abscess of the iliacus muscle, olecranon bursitis, and sacroiliitis

Brucellosis is a systemic infection involving many organs and tissues. The musculoskeletal system is one of the most commonly affected. The disease can present with sacroiliitis, peripheral arthritis, spondylitis, paraspinal abscess, bursitis, and osteomyelitis. A 25-year-old male patient was admitted with fever of 20-day duration, right-sided hip pain, and night sweating. A Brucella standard tube agglutination test was positive at a titer of 1/160. Magnetic resonance imaging (MRI) of the hip joint showed right sacroiliitis and a hyperintense, nodular, lobulated mass within the right iliacus muscle, consistent with abscess. The patient was started on intramuscular streptomycin at a dose of 1 g/day, oral rifampin 600 mg/day, and doxycycline 200 mg/day. On day 20 of treatment, the patient was admitted with swelling and pain over the left elbow for the past week. MRI of the left elbow was performed, which showed fluid edema suggestive of olecranon bursitis. Taking the patient's complaints into consideration, rifampin and doxycycline treatment were maintained for a year. Pain at the hip joint and elbow resolved and MRI findings disappeared. Abscess of the iliacus muscle, which has not been reported before, and the olecranon bursitis that developed during treatment make this case worth presenting.

Bilateral periprosthetic joint infection caused by Salmonella enterica serotype Enteritidis, and identification of Salmonella sp using molecular techniques

Salmonella septic arthritis is rare. Our objective was to identify bacterial species from joint fluid using a broad-range real-time PCR and pyrosequencing technique. We describe a case of bilateral Salmonella enterica serotype Enteritidis infection of right and left total knee arthroplasties. DNA was extracted from the joint fluid of the left knee, amplified by PCR, and the amplicons were evaluated by pyrosequencing. The patient was treated with ciprofloxacin, and the polyethylene liners were replaced in both knees. The results of pyrosequencing detected a Salmonella species. To the best of our knowledge, this is the first report describing the detection of Salmonella in joint fluid by universal PCR followed by pyrosequencing.

Septic arthritis: an extensive variety of pathology

Septic arthritis typically presents as a hot, swollen joint. Rapid recognition and treatment of this condition is essential to prevent permanent joint damage. However, septic arthritis does not always present in a textbook manner. The case presented here concerns septic arthritis affecting the right sternoclavicular joint. The patient did not have any risk factors for septic arthritis and presented with a swollen tender joint that was not hot. He was treated with penicillin and then amoxicillin for a total of 12 weeks and made a full recovery. The organism isolated from his right sternoclavicular joint was Neisseria elongata, which is the first ever documented case of this organism causing septic arthritis. This case emphasises that the suspicion of septic arthritis should remain high when unexplained monoarthritis occurs and there should be a low threshold in treating monoarthritis as septic arthritis even in the absence of risk factors.

Septic arthritis in patients with rheumatoid arthritis

There is an increasing number of rheumatoid patients who get septic arthritis. Chronic use of steroids is one of the important predisposing factors. The clinical picture of septic arthritis is different in immunocompromised patients like patients with rheumatoid arthritis. The diagnosis and management are discussed in this review article.

Hematogenous septic ankle arthritis

Ankle infection is a serious problem with limited published information on microbiology and associated morbidities. We describe the laboratory findings, microbiology, and occurrence of adjacent osteomyelitis in patients with hematogenous septic ankle arthritis. We retrospectively reviewed 30 patients with hematogenous septic arthritis of the ankle admitted over a 10-year period. Twenty-two patients were male and eight female. The mean age was 46 years (range, 23-67 years). C-reactive protein and erythrocyte sedimentation rate were elevated in all patients, but the peripheral white blood cell count was elevated in only 47% of patients. Staphylococcus aureus (S. aureus) was the most common pathogen, isolated in 13 (54%) of the 24 patients with positive cultures; four of these isolates (four of 24; 17% of positive cultures) were oxacillin-resistant. Four (17%) of the 24 patients with positive cultures had a mycobacterial infection. We identified adjacent osteomyelitis in 30% of patients, which was considerably associated with the presence of patient comorbidities. S. aureus is the most common pathogen in septic ankle arthritis and empiric antibiotic therapy is recommended. Adjacent osteomyelitis may be present and a high index of suspicion is necessary in patients with comorbidities.

LEVEL OF EVIDENCE

Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Streptococcus pneumoniae septic arthritis complicating hip osteonecrosis in adults: case report and review of the literature

A 42-year-old patient presented acutely with bacteremic pneumococcal pneumonia along with metastatic pneumococcal infection of the hip joint. Diagnostic evaluation revealed evidence of a pre-existing bilateral hip osteonecrosis. The osteonecrotic changes were attributed to chronic alcohol abuse and/or an old motor vehicle accident. Appropriate therapy was promptly instituted and the septic arthritis responded well, necessitating hip aspiration only once. A few months later, the patient had no permanent sequelae of the infection.

Septic arthritis in Western and sub-Saharan African children - a review

This article reviews what is known about the incidence, aetiology, presentation, bacteriology and management of septic arthritis in children. It compares where possible the different presentations and characteristics of this condition in the Western and sub-Saharan African regions.

TLR-2-mediated induction of vascular endothelial growth factor (VEGF) in cartilage in septic joint disease

Bacterial arthritis is a progressive joint disease which includes rapid destruction of articular cartilage even after clearance of the causal factor. The resulting post-infectious arthropathy is mainly characterized by self-perpetuating joint destruction and extensive angiogenesis in the emerging pannus-like synovial membrane, but the underlying molecular mechanisms of the bacteria-initiated process remain incompletely understood. This study was conducted to elucidate the expression and regulation of angiogenic and cartilage-destructive vascular endothelial growth factor (VEGF) in septic arthritis. For that purpose, aspirates of synovial fluid from patients with pyogenic arthritis were examined for VEGF levels by ELISA. In vitro studies with primary and immortalized chondrocytes were performed to determine whether Gram-positive and Gram-negative bacteria induce VEGF expression, by using real-time RT-PCR, ELISA, and immunohistochemistry. Activation of the transcription factor AP-1 was assessed by EMSA experiments. The necessity of the Toll-like receptor-2 (TLR-2), ERK-1/-2, and AP-1 pathway for infectious VEGF induction in chondrocytes was examined by using specific blocking reagents. ELISA experiments revealed that aspirates of synovial fluid from patients with pyogenic arthritis contain elevated levels of VEGF. The in vitro results confirmed the transcriptional induction of VEGF in chondrocytes after bacterial challenge by real-time RT-PCR, ELISA, and immunohistochemistry. This activation was mediated by a TLR-2-, ERK-1/-2-, and AP-1-dependent pathway. The findings demonstrate the expression of Toll-like receptors on mesenchymal articular chondrocytes and reveal TLR-2-mediated VEGF induction in human chondrocytes after Gram-positive bacterial sensing. Since VEGF is a potent angiogenic and tissue remodelling factor, evidence that Toll-like receptors contribute to destructive arthropathy after microbial joint infection is provided. VEGF may be a therapeutic target in the future for the prevention of post-infectious cartilage degradation in articular joints.

Advances in the Management of Septic Arthritis

Septic arthritis still continues to be a common and serious problem at major urban medical centers and is one of the most rapidly destructive forms of acute arthritis. The yearly incidence of bacterial arthritis varies from 2 to 10 per 100,000 in the general population to 30 to 70 per 100,000 in patients with rheumatoid arthritis and in patients with joint prostheses. Irreversible loss of joint function may develop in up to 50% of the patients. Despite better antimicrobial agents and improved hospital care, the fatality rate for this medical problem has not changed substantially during the past 30 years. An understanding of the risk factors and the pathogenesis of nongonoccocal bacterial arthritis and other forms of infectious arthritis, primarily in the context of a differential diagnosis and treatment, are important to avoid the delay in making a correct diagnosis and to improve the prognosis.

Septic arthritis of the temporomandibular joint successfully treated with arthroscopic lysis and lavage: case report and review of the literature

Septic arthritis of the temporomandibular joint (TMJ) is infrequently reported. We present a case of septic arthritis of the TMJ following the extraction of the left upper second molar that occurred 1 week before beginning of symptoms. No evident predisposing factors were detected. Arthroscopic diagnosis of septic arthritis, lysis and lavage, and capsular stretch were performed. Cultures taken from the TMJ space grew Streptococcus sp. After 1 month of antimicrobial therapy the patient was asymptomatic and mandibular function was normal. Literature related to septic arthritis of TMJ and its treatment was reviewed. Different surgical procedures are available to treat this condition. Arthroscopy should be preferred as initial treatment on account of the possibility of drainage and accurate lavage under direct visualization of joint space, at the same time allowing confirmation of diagnostic hypotheses. Improving joint mobility with lysis of adhesions and capsular stretch in an early stage of disease may be helpful in stopping the fibrosis process.

Acute Monarthritis: Diagnosis and Management

The diagnosis for an acute monarthritis may still be elusive, even after an extensive initial evaluation. For example, what should be done for a patient who has a paucity of extra-articular findings on physical examination and an inflammatory synovial fluid with negative Gram's stain, cultures, and crystals? Conservative management is always prudent. Assume the joint is infected and treat as such until proven otherwise, because infection carries the highest morbidity and mortality of all the common acute monarthopathies.

Septic arthritis in patients with systemic lupus erythematosus: salmonella and nonsalmonella infections compared

OBJECTIVES

To assess the clinical characteristics and outcome of systemic lupus erythematosus (SLE) with septic arthritis.

METHODS

In this 20-year retrospective study, we reviewed the charts of SLE patients with septic arthritis confirmed by synovial fluid analysis and culture. To identify risk factors for septic arthritis, data of SLE patients with septic arthritis were compared with data of 100 hospitalized SLE patients without septic arthritis.

RESULTS

There were 10,732 inpatient records of 3,127 SLE patients; 29 SLE patients had septic arthritis. Their ages ranged from 14 to 68 years (mean, 35.1 +/- 14.1 years). The mean SLE duration before septic arthritis onset was 30.6 months. All patients received corticosteroids; 93% had active disease (SLEDAI > or = 4). Compared with controls, avascular necrosis (AVN) of the femoral head was the most common predisposing articular disease (Odds ratio, 3.799;CI, 1.59 to 9.05). Of the 29 patients, 17 (59%) had salmonella infections and 12 (41%) had other infections. Salmonella-infected patients were younger (28.7 +/- 10.4 years) than those with nonsalmonella infections (44.1 +/- 14.0 years; P = 0.002). The hip was the most commonly affected joint, especially in the salmonella group, followed by the knees and ankles. Salmonella-infected patients were more prone to oligo-articular septic arthritis. The overall mortality rate was 10%.

CONCLUSIONS

Salmonella enteritidis B is the most common pathogen causing septic arthritis in younger SLE patients. Septic arthritis tended to be oligo-articular and involve the hip joint. AVN of the femoral head was the most common predisposing articular disease. Once septic arthritis is suspected, culture specimens should be collected and appropriate antibiotics given immediately.

Atraumatic Joint and Limb Pain in the Elderly

Patients who visit the emergency department often have complaints of joint and limb pain. The differential diagnosis, clinical presentation, and treatment choices can be vastly different in the young- or middle-aged population compared with the elderly population, and the concerns of each group must be addressed. The emergency physician is in a unique position in that they are frequently the first to see these individuals and have the opportunity to intervene before permanent disability ensues. Some of the more common etiologies of atraumatic joint and limb pain, including crystal deposition diseases such as gout and pseudogout, osteoarthritis, septic arthritis, and inflammatory arthritides such as rheumatoid arthritis will be addressed in this article. In addition,several arthritides specific to the elderly population such as poly-myalgia rheumatica and associated giant cell arteritis will be covered. Finally a discussion of cervical and lumbar disc disease, as well as gait disorders, and their impact on the elderly, will be presented.

Synovial fluid analysis

AsA prompt and accurate diagnosis of a painful, swollen joint is imperative, primarily in the case of a septic joint, as delayed therapy may result in progression of disease or permanent loss of function. Procurement and analysis of synovial fluid (SF) are paramount in helping the clinician to determine a patient's clinical condition and further course of treatment. Measurement of white blood cell (WBC) counts, crystal analysis by polarized microscopy, and microbiologic studies including Gram stain and culture are the SF parameters that are collectively most important in the ultimate determination by a clinician of the presence or absence of an infectious or inflammatory joint. It is important for the clinician to understand and recognize the limitations of various SF parameters to minimize under-treating patients with potentially serious joint pathology.

Septic Arthritis

Septic arthritis has increased in incidence in the United States in the past two decades, and increasingly affects an older population with a greater burden of chronic illness and a higher risk for drug-resistant organisms. Successful management depends on a high diagnostic suspicion, empiric antibiotic treatment, and joint drainage. A bacteriologic diagnosis is more likely with inoculation into blood culture bottles than plating on solid media. As MRSA increases in prevalence in the community, empiric anti-biotic regimens increasingly need to be active against MRSA.

Septic arthritis in patients aged 80 and older: a comparison with younger adults

OBJECTIVES

To compare the frequency and characteristics of septic arthritis in patients younger than 80 and aged 80 and older.

DESIGN

Retrospective.

SETTING

Single hospital center.

PARTICIPANTS

Patients admitted between 1979 and 2002 for septic arthritis.

MEASUREMENTS

Age, sex, time to diagnosis, predisposing factors, joint, temperature, white blood cell count, microorganism, and short-term outcome.

RESULTS

Of 335 patients, 206 (61.4%) were aged 60 and older, and 42 (12.5%) were 80 and older. The latter had an average age of 84 (range 80-97) and were mainly women (72%). Eighteen of the 42 had at least one risk factor. The mean time to diagnosis was 21 days (range 1 day to 3 months). Twenty patients (47%) had knee involvement, six (14%) shoulder involvement, ten (23.8%) a prosthetic infection, and five (12%) polyarticular infection. Ten (23%) were afebrile. In half of the cases, there was no increase in white blood cell count. The microorganisms isolated were Staphylococcus aureus (n=16, 38%), coagulase negative staphylococci (n=8, 19%), streptococci (n=12, 28%), and gram-negative bacilli (n=6, 14%). The mortality rate increased with age: 0.7% of patients younger than 60, 4.8% of those aged 60 to 79, and 9.5% of those aged 80 and older.

CONCLUSION

Advanced age is a risk factor for septic arthritis and poor outcome.

Persistence of zinc-binding bacterial superantigens at the surface of antigen-presenting cells contributes to the extreme potency of these superantigens as T-cell activators

Bacterial superantigen intoxication causes massive overactivation of T cells, which can result in potentially lethal toxic shock. Superantigens fall into two groups: superantigens such as staphylococcal enterotoxin B (SEB) that contain a single generic binding site for major histocompatibility complex class II (MHC-II) and more potent superantigens such as SEA with a second, zinc-dependent MHC-II binding site that enables them to cross-link adjacent MHC-II molecules. We found that although all superantigens bound rapidly to the surface of human B cells, zinc-binding superantigens largely remained at the cell surface for at least 40 h. In contrast, single-binding-site superantigens were greatly depleted from the surface by 4 h. Subcellular fractionation and confocal microscopy revealed that some SEB entered lysosomal compartments, but SEA remained almost undetectable inside cells at 20 h. SEA and SEB mutants that do not bind MHC-II were trafficked rapidly to lysosomal compartments. Our findings suggest that the persistence of SEA and other zinc-dependent, cross-linking superantigens on the surface of antigen-presenting cells contributes to their potency as T-cell activators.

Abnormal gait in a child with fever: diagnosing septic arthritis of the hip

The diagnosis of septic arthritis should be considered in all children with hip pain. We review the evaluation of children who present with fever and hip pain, emphasizing features that may assist in distinguishing septic arthritis of the hip from transient synovitis. We also discuss the impact of the increased prevalence of methicillin-resistant Staphylococcus aureus on the management of septic arthritis of the hip.

Arthroscopic Treatment of Temporomandibular Joint Sepsis in a Horse

OBJECTIVE

To report arthroscopic debridement and lavage of a septic temporomandibular joint (TMJ) in a horse.

DESIGN

Clinical case report.

ANIMALS

A 12-year-old Thoroughbred mare.

METHODS

Arthroscopic investigation of the dorsal joint pouch of the right TMJ was made through a stab incision into the dorsocaudal compartment. Mechanized resection of synovium and fibrinous debris combined with copious lavage, and intra-articular and systemic antibiotic administration was used to treat the septic TMJ.

RESULTS

Arthroscopic debridement and lavage of the TMJ, in combination with intra-articular and systemic antimicrobials resulted in resolution of sepsis. Eight months post-operatively, there was no clinical evidence of degenerative joint disease or ankylosis of the TMJ.

CONCLUSION

TMJ sepsis is rare in horses, however, standard arthroscopic equipment can be used in the management of this condition with minimal complications.

CLINICAL RELEVANCE

Arthroscopic debridement and lavage should be considered for evaluation and initial treatment of TMJ sepsis in horses.

Glucuronoxylomannan, the major capsular polysaccharide of Cryptococcus neoformans, inhibits the progression of group B streptococcal arthritis

Glucuronoxylomannan (GXM), the principal constituent of the Cryptococcus neoformans capsule, modulates the inflammatory response of human monocytes in vitro. Here we examine the efficacy of GXM as a novel anti-inflammatory compound for use against experimental septic arthritis. Arthritis was induced in mice by the intravenous injection of 8 x 10(6) CFU of type IV group B streptococcus (GBS). GXM was administered intravenously in different doses (50, 100, or 200 microg/mouse) 1 day before and 1 day after bacterial inoculation. GXM treatment markedly decreased the incidence and severity of articular lesions. Histological findings showed limited periarticular inflammation in the joints of GXM-treated mice, confirming the clinical observations. The amelioration of arthritis was associated with a significant reduction in the local production of interleukin-6 (IL-6), IL-1beta, macrophage inflammatory protein 1alpha (MIP-1alpha), and MIP-2 and an increase in systemic IL-10 levels. Moreover, peritoneal macrophages derived from GXM-treated mice and stimulated in vitro with heat-inactivated GBS showed a similar pattern of cytokine production. The present study provides evidence for the modulation of the inflammatory response by GXM in vivo and suggests a potential therapeutic use for this compound in pathologies involving inflammatory processes.

Streptococcus pneumoniae septic arthritis in adults

Streptococcus pneumoniae septic arthritis is an uncommon infection. The classic clinical picture is that of concomitant pulmonary and/or meningeal and joint infections in the presence of predisposing local and systemic factors. Initial laboratory tests are usually inconclusive, and joint aspiration is required for a definitive diagnosis. Treatment options include antibiotic therapy (usually with penicillin) combined with closed or open joint drainage. Increasing reports of infections involving penicillin-resistant strains are a concern. The prognosis is usually favourable, but early recognition and aggressive management are essential to reduce the likelihood of significant joint injury.

Traitement des arthrites septiques de hanche chez l’adulte drépanocytaire par prothèse totale de hanche

PURPOSE OF THE STUDY

Septic hip arthritis is a recognized complication of sickle-cell disease. The incidence is difficult to assess but is significant since certain authors estimate that 11% of children with sickle-cell disease develop orthopedic complications. We report our experience with hip joint infection in adults with sickle-cell disease.

MATERIAL AND METHODS

We diagnosed ten cases of hip joint infection in seven adults with sickle-cell disease. The characteristic feature of the septic arthritis was the development of a septic focus in a zone of osteonecrosis of the femoral head. Diagnosis was difficult due to the presence of prior hip disease and also the circumstances of development: other infectious foci, septicemia, distant osteomyelitis. The diagnosis was confirmed by joint puncture and isolation of the causal germ. Despite adapted antibiotics and immobilization with traction-suspension, hip joint destruction could not be prevented and all patients became bedridden. Surgery was therefore undertaken to remove the head and neck and institute local antibiotic treatment. A total hip prosthesis was implanted in all patients.

RESULTS

At 2 to 12 years follow-up, all seven patients had nearly normal hip function (all 10 hips). Recurrent infection nevertheless developed in 2 hips, demonstrating the limitations of this technique.

Bacterial and lyme arthritis

Septic arthritis is an infectious disease emergency, requiring aggressive joint drainage and prompt antibiotic therapy. Because age and joint damage are major risk factors, septic arthritis may become more common as the baby-boom generation reaches senescence. Bacteremic joint infections have a high mortality, and long-term disability from joint damage is common. Lyme arthritis has a negligible mortality and low morbidity but causes disproportionate popular anxiety. Most patients with Lyme arthritis respond well to oral antibiotic regimens and recover completely. A few patients develop antibiotic-resistant Lyme arthritis, which is probably autoimmune in nature and responds to immunosuppressive therapy. This paper reviews the presentation, diagnosis, and management of bacterial and Lyme arthritis. Septic arthritis caused by Streptococcus pneumoniae and group B streptococci may be increasing in prevalence. Prospective studies are required to determine whether there is any benefit of surgical or arthroscopic joint drainage in septic arthritis, compared with serial arthrocentesis, and to determine the role of corticosteroid therapy in septic arthritis in adults, if any.

Role of interleukin-18 in experimental group B streptococcal arthritis

OBJECTIVE

To assess the role of interleukin-18 (IL-18) in the evolution of septic arthritis induced by group B streptococci (GBS) in mice.

METHODS

CD1 mice were inoculated intravenously with 8 x 10(6) colony-forming units (CFU) of type IV GBS (strain 1/82), and administered intraperitoneally 1 hour before infection with anti-IL-18 monoclonal antibodies (0.25 mg/mouse). In a subsequent set of experiments, mice infected with a suboptimal arthritogenic dose of GBS (4 x 10(6) CFU/mouse) were administered different doses of recombinant IL-18 for 4 days, starting 1 hour after infection. Mortality, evolution of arthritis, bacterial clearance, joint histopathology, and cytokine production were examined in infected mice that did or did not receive treatment with anti-IL-18 antibodies or IL-18.

RESULTS

IL-18 was produced during GBS infection. Neutralization of IL-18 resulted in a decrease in mortality rates, and in the incidence and severity of arthritis. Amelioration of arthritis was accompanied by a dramatic reduction in local IL-1 beta, IL-6, macrophage inflammatory protein 1 alpha (MIP-1 alpha) and MIP-2 production, and reduced bacterial burden. Administration of exogenous IL-18 resulted in increased mortality rates and increased incidence and severity of GBS arthritis, concomitant with a higher number of GBS and increased levels of IL-6, IL-1 beta, MIP-1 beta, and MIP-2 production in the joints.

CONCLUSION

The present study indicated some involvement of IL-18 in the pathogenesis of GBS-induced arthritis. The role of IL-18 in joint pathology is shown by a regulatory effect on inflammatory mediator levels and local cell influx. Thus, IL-18 should be regarded as a potential therapeutic target in GBS infection and arthritis.

Pyogenic Arthritis in Qatar

A retrospective study of patients diagnosed with pyogenic arthritis at Hamad Medical Corporation over the fiveyear period January 1st 1996 to December 312000 showed that only 24 patients out of 63 fulfilled the criteria for bacterial arthritis. Staph. aureus was the main organism isolated from the synovial fluid (72%). The mean duration between the onset of symptoms and admission was 11 days. Nearly half the patients (45%) were under 12 years of age. Earlier diagnosis and treatment gives a better outcome.

Treatment of postoperative anterior cruciate ligament infections with graft removal and early reimplantation

BACKGROUND

Septic arthritis after arthroscopic anterior cruciate ligament reconstruction is rare, and the most appropriate treatment is unclear. Current recommendations are that, if the graft is removed, reimplantation should be delayed for 6 to 9 months.

HYPOTHESIS

Early removal of the graft with appropriate infection management followed by early reimplantation can lead to good results.

STUDY DESIGN

Uncontrolled retrospective review.

METHODS

Records of all patients who developed postoperative infection after anterior cruciate ligament reconstruction were reviewed. Four patients had early graft removal and appropriate infection management including 6 weeks of intravenous antibiotics followed by anterior cruciate ligament graft reimplantation within 6 weeks of completion of antibiotic therapy.

RESULTS

Follow-up at an average of 21 months (range, 14 to 31) showed that the patients treated with early reimplantation had full symmetric knee range of motion and no effusion. The average modified Lysholm score was 92.5. Radiographs demonstrated no joint-space narrowing or osteophyte formation. The 30-pound KT-1000 arthrometer side-to-side difference averaged 3 mm.

CONCLUSION

Graft removal after confirmed anterior cruciate ligament graft infection and intravenous antibiotic administration followed by early graft reimplantation can give excellent results.

A swollen joint: why all the fuss?

Acute arthritis may be a potential medical emergency. An infected joint causes rapid cartilaginous destruction and risk of future osteoarthritis. Prompt attention to the historical clues and potential causative organisms ensures appropriate therapy. Numerous microbes have been identified as the causative agent in septic arthritis, and various populations have distinct susceptibilities to these specific organisms. One broad classification of septic arthritis is differentiating gonococcal and nongonococcal organisms. This classification is important, as not only do the organisms differ, but the age of the patient and the portal of entry also differ. Aspiration of synovial fluid is paramount for proper diagnosis and management of septic arthritis. In addition, the timely administration of properly chosen antibiotic agents is essential for reducing morbidity and mortality.

Pneumococcal septic arthritis: review of 190 cases

This article reports 13 cases of pneumococcal septic arthritis and reviews another 177 cases reported since 1965. Of 2407 cases of septic arthritis from large series, 156 (6%) were caused by Streptococcus pneumoniae. Mortality was 19% among adults and 0% among children. Pneumococcal bacteremia was the strongest predictor of mortality. At least 1 knee was involved in 56% of adults. Polyarticular disease (36%) and bacteremia (72%) were more common among adults with septic arthritis caused by S. pneumoniae than among adults with other causative organisms. Only 50% of adults with pneumococcal septic arthritis had another focus of pneumococcal infection, such as pneumonia. Functional outcomes were good in 95% of patients. Uncomplicated pneumococcal septic arthritis can be managed with arthrocentesis and 4 weeks of antibiotic therapy; most cases of pneumococcal prosthetic joint infection can be managed without prosthesis removal. A fatal case of septic arthritis caused by a beta-lactam-resistant strain of S. pneumoniae is also presented.

Infection by Streptococcus pyogenes induces the receptor activator of NF-kappaB ligand expression in mouse osteoblastic cells

Group A Streptococcus pyogenes is known to induce nongonococcal septic arthritis in addition to pharyngitis, scarlet fever, and poststreptococcal sequelae. However, little is known about the interaction between S. pyogenes and bone cells. We report here that S. pyogenes strain JRS4 (M6) attached to and invaded mouse primary osteoblasts. Reverse transcription-PCR demonstrated that S. pyogenes infection of osteoblasts stimulated expression of mRNA for the receptor activator of NF-kappaB ligand (RANKL). Western blot analysis followed by ligand precipitation with the receptor activator of NF-kappaB receptor showed that there was an increase in RANKL protein in infected osteoblasts. Production of interleukin-6 was also stimulated, but no production of interleukin-1beta or tumor necrosis factor alpha was observed. Stimulation of RANKL production was not observed in osteoblasts stimulated with heat-inactivated S. pyogenes, suggesting that an active interaction of S. pyogenes with osteoblasts is essential for this phenomenon. A Western blot analysis performed with antibodies specific for phosphorylated signal transduction proteins demonstrated that S. pyogenes infection induces phosphorylation of p38 mitogen-activated protein kinase. A specific inhibitor of this kinase, SB203580, inhibited RANKL production by infected osteoblasts. These results suggest that infection of osteoblasts by S. pyogenes stimulates RANKL production and may trigger bone destruction in infected bone tissue.

Advances in the management of septic arthritis

Bacterial arthritis still is a common and serious problem at mayor urban medical centers and is one of the most rapidly destructive forms of acute arthritis. The yearly incidence of bacterial arthritis varies from 2 to 10 per 100,000 in the general population to 30 to 70 per 100,000 in patients with rheumatoid arthritis and in patients with joint prostheses. Irreversible loss of joint function may develop in up to 50% of the patients. Despite better antimicrobial agents and improved hospital care, the fatality rate for this medical problem has not changed substantially during the past 25 years. An understanding of the risk factors and the pathogenesis of nongonoccocal bacterial arthritis and other forms of infectious arthritis, primarily in the context of a differential diagnosis and treatment, are important in order to avoid the delay in making a correct diagnosis and to improve the prognosis.

Sternoclavicular infectious arthritis in previously healthy adults

OBJECTIVE

To define characteristics of sternoclavicular infection (SCI) in previously healthy patients.

METHODS

SCI in a previously healthy man is reported along with 4 similar cases found by surveying the hospital's database; 22 previously reported cases were culled from the literature and summarized.

RESULTS

The frequency of SCI in healthy adults was 0.5% of all bone and joint infections admitted to the hospital. The clinical and bacteriologic features were similar to previous reports in nonselected SCI patients. Computerized tomography (CT) scan, arthrocenthesis, and biopsy were required for diagnosis. Complications included abscess formation, mediastinitis, and sepsis. The majority of patients were treated by surgical drainage and antibiotics. The final outcome was good, without mortality or long-term morbidity.

CONCLUSIONS

Although SCI is a rare infection in healthy adults, it should be considered in the differential diagnosis of a painful sternoclavicular joint. Prompt diagnosis and appropriate treatment of SCI results in excellent outcome in most cases.

Acute septic arthritis

Acute septic arthritis may develop as a result of hematogenous seeding, direct introduction, or extension from a contiguous focus of infection. The pathogenesis of acute septic arthritis is multifactorial and depends on the interaction of the host immune response and the adherence factors, toxins, and immunoavoidance strategies of the invading pathogen. Neisseria gonorrhoeae and Staphylococcus aureus are used in discussing the host-pathogen interaction in the pathogenesis of acute septic arthritis. While diagnosis rests on isolation of the bacterial species from synovial fluid samples, patient history, clinical presentation, laboratory findings, and imaging studies are also important. Acute nongonococcal septic arthritis is a medical emergency that can lead to significant morbidity and mortality. Therefore, prompt recognition, rapid and aggressive antimicrobial therapy, and surgical treatment are critical to ensuring a good prognosis. Even with prompt diagnosis and treatment, high mortality and morbidity rates still occur. In contrast, gonococcal arthritis is often successfully treated with antimicrobial therapy alone and demonstrates a very low rate of complications and an excellent prognosis for full return of normal joint function. In the case of prosthetic joint infections, the hardware must be eventually removed by a two-stage revision in order to cure the infection.

Arthritis in the intensive care unit

Acute arthritis in critically ill patients may be caused by local or systemic infection, by a flare of chronic joint disease such as rheumatoid or crystal-associated arthritis, or by less common entities such as hemarthrosis. Diagnosis requires analysis of synovial fluid, and appropriate treatment is based on its findings. Prompt diagnosis and treatment are usually necessary to prevent the significant morbidity associated with these conditions.

Role of macrophages in experimental group B streptococcal arthritis

Septic arthritis is a clinical manifestation of group B Streptococcus (GBS) infection in both neonates and adults. Because macrophages are known to participate in tissue injury, the role of this cell population in GBS-induced arthritis was investigated. Mice were rendered monocytopenic by administration of etoposide, a drug that selectively depletes the monocyte/macrophage population and then injected with GBS (1 x 10(7) colony-forming units per mouse). Appearance of arthritis, mortality, GBS growth in the organs, and local and systemic cytokine production were examined. Etoposide-treated mice had a significantly less severe arthritis than control animals. Histopathological analysis of the joints confirmed clinical observations. Decreased joint levels of the proinflammatory cytokines interleukin 1 (IL-1) beta and IL-6 accompanied the less severe development of arthritis in monocytopenic mice. In contrast, mortality was increased in the etoposide-treated mice compared with controls. Monocytopenic mice exhibited elevated bacterial load in the blood and kidneys at all time points examined. These results indicate that lack of macrophages leads to less severe joint lesions, but also results in impaired clearance of bacteria, and consequent enhancement of mortality rates.

Polymicrobial polyarticular septic arthritis: a rare clinical entity

Polymicrobial polyarticular septic arthritis is a rare clinical entity, with only a few cases having been reported to date. We report a case due to Streptococcus pyogenes and Staphylococcus aureus in an IVDU, complicated by fatal streptococcal toxic-shock syndrome, and review the current literature. We conclude that whenever polymicrobial polyarticular septic arthritis is diagnosed, a high index of suspicion should be maintained for the detection of locally destructive infectious processes as well as systemic complications, and that a high mortality rate should be expected.

Combined antibiotic and free radical trap treatment is effective at combating Staphylococcus-aureus-induced septic arthritis

Although early antibiotic treatment of patients with septic arthritis eradicates bacteria, joint destruction commonly results from the unregulated host inflammatory responses to infection. The spin trap compound phenyl-N-tert-butyl nitrone (PBN) has been shown to have both anti-inflammatory and antioxidant effects. The aim of this study was to assess the effect of combined systemic administration of PBN and cloxacillin on the development of Staphylococcus aureus arthritis.Three days after Naval Medical Research Institute (NMRI) mice were infected intravenously with S. aureus LS-1, daily treatment was started with cloxacillin alone, PBN alone, or cloxacillin and PBN. Arthritis, weight loss and general condition were evaluated for each mouse, and joints were analyzed histopathologically. Systemic administration of PBN in conjunction with cloxacillin ameliorated the course of experimental S. aureus arthritis, as evidenced by an increased cure rate. Thus, combinatorial antioxidant plus antibiotic anti-inflammatory therapies represent a potentially efficacious approach to the management of septic arthritis.