Bacterial septic arthritis in adults

Peripheral Bacterial Septic Arthritis: Review of Diagnosis and Management

Septic arthritis refers to an infection in a joint due to a bacterial, mycobacterial, or fungal cause. Joint infections are a serious cause of morbidity and mortality and constitute a true musculoskeletal emergency. The estimated incidence of septic arthritis in the general population is between 2 and 6 cases per 100,000 people per year. The most common presentation is an acute monoarthritis. Identification of organisms in the synovial fluid is the criterion standard for diagnosis. Synovial fluid aspiration should be performed prior to initiating antibiotics. While no diagnostic cutoff exists for synovial fluid white blood cell count, increasing leukocytosis is associated with a higher likelihood of an infectious cause of arthritis, and patients commonly present with values greater than 50,000/μL. The cornerstones of treating septic bacterial arthritis are adequate drainage and antimicrobials. Joint drainage is always recommended in septic arthritis; however, no clear guidelines or strong evidence exist to guide the preferred method of drainage. Options for joint drainage include daily needle aspiration, arthroscopy, or open surgical drainage via arthrotomy.

[11C]Para-Aminobenzoic Acid: A Positron Emission Tomography Tracer Targeting Bacteria-Specific Metabolism

Imaging studies are frequently used to support the clinical diagnosis of infection. These techniques include computed tomography (CT) and magnetic resonance imaging (MRI) for structural information and single photon emission computed tomography (SPECT) or positron emission tomography (PET) for metabolic data. However, frequently, there is significant overlap in the imaging appearance of infectious and noninfectious entities using these tools. To address this concern, recent approaches have targeted bacteria-specific metabolic pathways. For example, radiolabeled sugars derived from sorbitol and maltose have been investigated as PET radiotracers, since these are efficiently incorporated into bacteria but are poor substrates for mammalian cells. We have previously shown that para-aminobenzoic acid (PABA) is an excellent candidate for development as a bacteria-specific imaging tracer as it is rapidly accumulated by a wide range of pathogenic bacteria, including metabolically quiescent bacteria and clinical strains, but not by mammalian cells. Therefore, in this study, we developed an efficient radiosynthesis for [11C]PABA, investigated its accumulation into Escherichia coli and Staphylococcus aureus laboratory strains in vitro, and showed that it can distinguish between infection and sterile inflammation in a murine model of acute bacterial infection.

Risk factors and clinical characteristics of deep knee infection in patients with intra-articular injections: A matched retrospective cohort analysis

BACKGROUND

Deep knee infection (DKI), consisting of sepsis arthritis (SA) and chronic low-grade infection (CLGI), is a rare but catastrophic adverse event that can result from intra-articular (IA) injections. The purpose of this study was to assess the risk factors for DKI and describe the clinical characteristics of DKI in patients who received IA injections.

METHODS

Fifty patients with IA injection-induced DKI who underwent surgical treatment between January 2010 and May 2016 served as cases and were matched with non-infected controls who received IA injections in a proportion of 1:5 based on age, gender, and date of admission. All IA injections (both cases and controls) were performed within 6 months of admission at our institution or at a referring institution. Risk factors for injection-induced DKI were analyzed, and the clinical characteristics between SA and CLGI were compared.

RESULTS

The final multivariate logistic regression analysis demonstrated that body mass index ≥25kg/m2 [odds ratio (OR) = 2.3; 95% confidence interval (CI): 1.1-4.7], corticosteroid injections (OR = 3.21; 95% CI: 1.63-6.31), rheumatoid arthritis (OR = 2.61; 95% CI: 1.20-5.68) and injections performed by general practitioners (OR = 5.23; 95% CI: 2.00-13.67) increased the risk of DKI following IA injections. Of 50 cases, there were 21 SA cases and 29 CLGI cases. SA cases had significantly higher metrics in the categories of fever, local warmth, swelling, rest pain, night pain, limited motion, serum WBC, and CRP levels than CLGI cases.

CONCLUSIONS

We identified risk factors and clinical characteristics of injection-induced DKI, which may offer improved guidance on IA injections and knowledge of DKI in patients with IA injections, especially in CLGI patients.

Sensitivity of the Saline Load Test for Traumatic Arthrotomy of the Ankle With Ankle Arthroscopy Simulation

BACKGROUND

The saline load test has been used to evaluate for traumatic arthrotomy in orthopedics. The purpose of this study was to determine the volume of saline required to detect traumatic arthrotomy of the ankle.

METHODS

Forty-two patients undergoing elective ankle arthroscopy were prospectively enrolled. For each patient, a standard 4-mm anteromedial portal was established. Next, an 18-gauge needle was inserted at the site of the anterolateral portal. Sterile saline was slowly injected through the needle until saline extravasated from the anteromedial portal. Saline volumes at the time of extravasation were recorded and analyzed.

RESULTS

The saline volume required to achieve extravasation ranged from 0.2 to 60.0 mL. The median saline volume required to achieve extravasation was 9.7 mL (interquartile range, 3.8-29.6 mL); however, 5 of 42 patients required volumes between 50.0 and 60.0 mL. A total of 50.0 mL was required to achieve 90% sensitivity, 55.0 mL to achieve 95% sensitivity, and 60.0 mL to achieve 99% sensitivity.

CONCLUSIONS

The previously recommended 30 mL of saline required to reliably detect traumatic arthrotomy of the ankle may be too small a volume.

CLINICAL RELEVANCE

The present study suggests that clinicians should attempt to inject 60 mL of saline to effectively rule out a traumatic arthrotomy injury. Because of the study's methods involving an anteromedial arthrotomy with anterolateral saline injection, these findings may be most valid for arthrotomies on the medial side of the ankle.

Septic Arthritis and Prosthetic Joint Infections in Older Adults

Older adults are at increased risk for septic arthritis and prosthetic joint infections (PJI), owing at least in part to comorbid conditions and frailty. An increasing number of older adults undergo total joint arthroplasty to improve their quality of life. Infections in older adults differ from younger populations by the causative organisms, a great proportion of which are Staphylococcal infections. Targeting important modifiable and nonmodifiable risk factors may prevent or reduce the burden of joint infections in older adults. This review summarizes the epidemiology, pathogenesis, clinical manifestations, diagnosis, management, and prevention of septic arthritis and PJI in older adults.

LyeTxI-b, a Synthetic Peptide Derived From Lycosa erythrognatha Spider Venom, Shows Potent Antibiotic Activity in Vitro and in Vivo

The antimicrobial peptide LyeTxI isolated from the venom of the spider Lycosa erythrognatha is a potential model to develop new antibiotics against bacteria and fungi. In this work, we studied a peptide derived from LyeTxI, named LyeTxI-b, and characterized its structural profile and its in vitro and in vivo antimicrobial activities. Compared to LyeTxI, LyeTxI-b has an acetylated N-terminal and a deletion of a His residue, as structural modifications. The secondary structure of LyeTxI-b is a well-defined helical segment, from the second amino acid to the amidated C-terminal, with no clear partition between hydrophobic and hydrophilic faces. Moreover, LyeTxI-b shows a potent antimicrobial activity against Gram-positive and Gram-negative planktonic bacteria, being 10-fold more active than the native peptide against Escherichia coli. LyeTxI-b was also active in an in vivo model of septic arthritis, reducing the number of bacteria load, the migration of immune cells, the level of IL-1β cytokine and CXCL1 chemokine, as well as preventing cartilage damage. Our results show that LyeTxI-b is a potential therapeutic model for the development of new antibiotics against Gram-positive and Gram-negative bacteria.

Septic Arthritis of the Wrist

Septic arthritis of the wrist is an uncommon condition, but one that can result in substantial morbidity. Timely identification and treatment is critical to patient care. No serum laboratory values have been shown to consistently confirm wrist joint infection. Thus, diagnosis is made based mainly on a thorough patient history, physical examination, and joint aspiration. When infection is suspected, aspiration of the wrist should be performed to confirm the diagnosis. Broad-spectrum antibiotics and joint aspiration or surgery are required to manage the infection and prevent sequelae.

[Infections of non-prosthetically treated joints]

BACKGROUND

Septic arthritis is a common orthopedic emergency. Immediate establishment of the diagnosis and administration of an adequate therapy is paramount in minimizing morbidity and mortality in this severe condition.

OBJECTIVE

The aim of the present review was to evaluate the existing evidence in order to give an overview on current best practice in diagnostics and treatment of septic arthritis in adults and children.

RESULTS

Joint infections result from either hematogenous spread or direct inoculation of bacteria into the joint, mostly iatrogenically. Predisposing risk factors include recent orthopedic joint surgery, i. v. drug abuse, pre-existing inflammatory and degenerative joint diseases and old age. Although pathogens differ in different populations and age groups Staphylococcus aureus is the single most frequently isolated causative organism, followed by streptococci. Although diagnosis is based on an integration of medical patient history, clinical and laboratory findings and imaging studies, joint fluid analysis remains the mainstay in establishing a valid diagnosis. The range of differential diagnostics is broad and includes non-infectious inflammatory joint diseases, such as gout or reactive arthritis. Once a diagnosis has been established treatment should be started immediately. Treatment is based on adequate antibiotic therapy and joint drainage until dryness. There is a paucity of studies on the optimal antibiotic regimen, route of application and duration of therapy. Moreover, no high-quality studies exist on the optimal mode of joint drainage. While superiority has yet to be shown, operative treatment in terms of arthroscopic lavage must be considered the standard of care in Germany. Finally, despite promising results in children, the role of corticosteroids as an adjunct to antibiotic treatment in adults has yet to be clarified.

Neutrophils: Beneficial and Harmful Cells in Septic Arthritis

Septic arthritis is an inflammatory joint disease that is induced by pathogens such as Staphylococcus aureus. Infection of the joint triggers an acute inflammatory response directed by inflammatory mediators including microbial danger signals and cytokines and is accompanied by an influx of leukocytes. The recruitment of these inflammatory cells depends on gradients of chemoattractants including formylated peptides from the infectious agent or dying cells, host-derived leukotrienes, complement proteins and chemokines. Neutrophils are of major importance and play a dual role in the pathogenesis of septic arthritis. On the one hand, these leukocytes are indispensable in the first-line defense to kill invading pathogens in the early stage of disease. However, on the other hand, neutrophils act as mediators of tissue destruction. Since the elimination of inflammatory neutrophils from the site of inflammation is a prerequisite for resolution of the acute inflammatory response, the prolonged stay of these leukocytes at the inflammatory site can lead to irreversible damage to the infected joint, which is known as an important complication in septic arthritis patients. Thus, timely reduction of the recruitment of inflammatory neutrophils to infected joints may be an efficient therapy to reduce tissue damage in septic arthritis.

Analysis of mortality in a cohort of 650 cases of bacteremic osteoarticular infections

OBJECTIVES

The mortality of patients with bacteremic osteoarticular infections (B-OAIs) is poorly understood. Whether certain types of OAIs carry higher mortality or interventions like surgical debridement can improve prognosis, are unclarified questions.

METHODS

Retrospective analysis of a prospective cohort of patients with B-OAIs treated at a teaching hospital in Barcelona (1985-2014), analyzing mortality (30-day case-fatality rate). B-OAIs were categorized as peripheral septic arthritis or other OAIs. Factors influencing mortality were analyzed using logistic regression models. The association of surgical debridement with mortality in patients with peripheral septic arthritis was evaluated with a multivariate logistic regression model and a propensity score matching analysis.

RESULTS

Among 650 cases of B-OAIs, mortality was 12.2% (41.8% of deaths within 7 days). Compared with other B-OAI, cases of peripheral septic arthritis were associated with higher mortality (18.6% vs 8.3%, p < 0.001). In a multiple logistic regression model, peripheral septic arthritis was an independent predictor of mortality (adjusted odds ratio [OR] 2.12; 95% CI: 1.22-3.69; p = 0.008). Cases with peripheral septic arthritis managed with surgical debridement had lower mortality than those managed without surgery (14.7% vs 33.3%; p = 0.003). Surgical debridement was associated with reduced mortality after adjusting for covariates (adjusted OR 0.23; 95% CI: 0.09-0.57; p = 0.002) and in the propensity score matching analysis (OR 0.81; 95% CI: 0.68-0.96; p = 0.014).

CONCLUSIONS

Among patients with B-OAIs, mortality was greater in those with peripheral septic arthritis. Surgical debridement was associated with decreased mortality in cases of peripheral septic arthritis.

A Real Pain: Diagnostic Quandaries and Septic Arthritis

Rapid diagnosis and treatment of an infected joint are paramount in preserving orthopedic function. Here, we present a brief review of the many challenges associated with the diagnosis of both septic arthritis and prosthetic joint infections. We also discuss the many laboratory tests currently available to aid in the accurate diagnosis of joint infection, as well as emerging diagnostics that may have future utility in the diagnosis of these challenging clinical entities.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

CXCR2 is critical for bacterial control and development of joint damage and pain in Staphylococcus aureus-induced septic arthritis in mouse

Staphylococcus aureus is the main pathogen associated with septic arthritis. Upon infection, neutrophils are quickly recruited to the joint by different chemoattractants, especially CXCR1/2 binding chemokines. Although their excessive accumulation is associated with intense pain and permanent articular damage, neutrophils have an important function in controlling bacterial burden. This work aimed to study the role of CXCR2 in the control of infection, hypernociception and tissue damage in S. aureus-induced septic arthritis in mice. The kinetics of neutrophil recruitment correlated with the bacterial load recovered from inflamed joint after intra-articular injection of S. aureus. Treatment of mice from the start of infection with the non-competitive antagonist of CXCR1/2, DF2156A, reduced neutrophil accumulation, cytokine production in the tissue, joint hypernociception and articular damage. However, early DF2156A treatment increased the bacterial load locally. CXCR2 was important for neutrophil activation and clearance of bacteria in vitro and in vivo. Start of treatment with DF2156A 3 days after infection prevented increase in bacterial load and reduced the hypernociception in the following days, but did not improve tissue damage. In conclusion, treatment with DF2156A seems be effective in controlling tissue inflammation and dysfunction but its effects are highly dependent on the timing of the treatment start.

Clinical Epidemiology of Septic Arthritis Caused by Burkholderia pseudomallei and Other Bacterial Pathogens in Northeast Thailand

Septic arthritis is a medical emergency, and if not treated appropriately, it can be associated with high morbidity and mortality. Melioidosis, a serious infectious disease caused by the Gram-negative bacillus Burkholderia pseudomallei, is highly endemic in South and Southeast Asia and northern Australia. We reviewed the medical charts of adult patients admitted with bacterial septic arthritis at Sunpasitthiprasong Hospital, Ubon Ratchathani, northeast Thailand from January 2012 to December 2014. Bacterial septic arthritis was defined as one or more hot swollen joints with isolation of a pathogenic organism from an affected joint or from blood. A total of 154 patients with septic arthritis were retrospectively evaluated. The most common causes were B. pseudomallei (48%, N = 74), Streptococcus spp. (29%, N = 44), and Staphylococcus aureus (10%, N = 16). Prevalence of diabetes, bacteremia, and pneumonia was higher in B. pseudomallei septic arthritis than in septic arthritis caused by the other bacteria (all P < 0.01). Seventy three percent (54/74) of patients infected with B. pseudomallei and 69% (55/80) of patients with the other bacteria received effective antimicrobials on the first day of admission (P = 0.60), but in-hospital mortality of the former group was considerably higher (34% versus 14%, P = 0.004). In conclusion, B. pseudomallei septic arthritis is common and associated with high mortality in northeast Thailand. Emergence of Streptococcus arthritis is observed. Difficulty in diagnosing melioidosis and identifying B. pseudomallei in areas where health care workers are not familiar with the disease is discussed. In melioidosis-endemic regions, parenteral ceftazidime could be considered as empirical antimicrobial therapy for patients with septic arthritis and underlying diseases.

Procalcitonin and Pancreatic Stone Protein Function as Biomarkers in Early Diagnosis of Pediatric Acute Osteomyelitis

Background

High plasma levels of procalcitonin (PCT) are typically seen in children with severe bacterial infection, particularly in cases of septic shock or bacteremia. Similarly, pancreatic stone protein (PSP) is associated with inflammation, infection, and other disease-related stimuli. However, the prognostic value of PSP in critically ill pediatric patients is unknown. This study investigated the early diagnostic value of PCT and PSP in pediatric acute osteomyelitis.

Material/Methods

A total of 187 patients with suspected acute osteomyelitis and 80 healthy control children were enrolled. The serum expression of PTC and PSP was measured. Pearson correlation analysis was conducted to correlate PTC with PSP. ROC analysis was used to test the value of PTC and PSP in early diagnosis of pediatric acute osteomyelitis.

Results

Acute osteomyelitis was diagnosed in 49.2% of the patients (n=92) based on the layered bone puncture. The serum levels of PTC and PSP in pediatric acute osteomyelitis were higher than in the non-acute osteomyelitis group (P<0.01). Serum PTC concentrations showed a significantly positive correlation with PSP levels (P<0.001). ROC analysis showed that the AUC values of PTC and PSP were 0.767 (95% CI, 0.700–0.826), and 0.796 (95% CI, 0.731–0.855), respectively. The AUC value of PTC & PSP was 0.903 (95% CI: 0.851–0.941), which was markedly increased compared with PTC or PSP (P<0.01).

Conclusions

Serum levels of PCT and PSP are promising biomarkers for early diagnosis of pediatric acute osteomyelitis.

Surgical treatment of shoulder infections: a comparison between arthroscopy and arthrotomy

BACKGROUND

Management of bacterial shoulder infections includes antibiotic therapy and surgical joint decompression. Arthroscopy and open arthrotomy are recommended treatment options. Whether 1 of the 2 surgical options is superior remains unclear. The present study aimed (1) to compare the reinfection rates after arthroscopy and open arthrotomy and (2) to identify risk factors of reinfection after surgical intervention.

MATERIALS AND METHODS

The data of 59 consecutive patients were available for final analysis. All patients received arthroscopy or open arthrotomy at our institution between 2001 and 2015. The reinfection rates between the 2 distinct interventions were compared. We also evaluated the influence of potential confounders, such as age, sex, comorbidities, microbiological findings, duration of symptoms, osteoarthritis, Gächter score, and preoperative inflammatory parameters, on the recurrence of infections and compared the functional outcome between the 2 surgery groups.

RESULTS

From 59 included patients, 38 (64.4%) underwent open arthrotomy, and 21 (35.6%) were treated arthroscopically. Reinfection was documented in 18 patients (30.5%). The reinfection rate was significantly higher in arthroscopically treated patients (11 [52.4%]) than in patients who underwent open arthrotomy (7 [18.4%]; P = .007). An infection with Staphylococcus aureus negatively influenced the treatment success (P = .034).

CONCLUSION

According to our data, open arthrotomy is the more effective treatment method in septic arthritis of the shoulder, with lower reinfection rates and a comparable functional outcome. Furthermore, we could identify Staphylococcus aureus as an independent risk factor for the recurrence of infections.

Pharmacokinetics of Cefuroxime in Synovial Fluid

Cefuroxime is frequently used as preoperative antibiotic prophylaxis and may be used for the treatment of septic arthritis. A prerequisite for successful treatment of septic arthritis is the ability of an antibiotic agent to penetrate into the target site. Therefore, the concentration of cefuroxime in synovial fluid was evaluated. Ten patients who underwent elective knee arthroscopy were included in this study. Patients were treated with a single dose of 1,500 mg cefuroxime intravenously, and subsequently, the concentrations in plasma, the interstitial fluid of muscle tissue, and synovial fluid were measured by using microdialysis. Pharmacokinetic/pharmacodynamic calculations to predict bacterial killing were performed using the epidemiologically defined MIC₉₀ for clinical isolates and CLSI breakpoints. Cefuroxime penetrated excellently into muscle tissue (ratio of the area under the concentration-time curve [AUC] for muscle tissue/AUC for free plasma, 1.79) and synovial fluid (ratio of the AUC for synovial fluid/AUC for free plasma, 1.94). The cefuroxime concentration was greater than the MIC₉₀ for Staphylococcus aureus and S. epidermidis strains (≤2 mg/liter) over the complete dosing interval (the percentage of the dosing interval during which the free cefuroxime concentration exceeded the MIC for the pathogen [fT_MIC]). CLSI defines staphylococci with MICs of ≤8 mg/liter to be susceptible to cefuroxime. For staphylococci with MICs of ≤8 mg/liter, the fT_MIC in plasma was 52.5%, while the fT_MIC in muscle tissue and synovial fluid was 93.6% and 96.3%, respectively. Cefuroxime may be used to treat septic arthritis caused by susceptible bacterial strains (MIC ≤ 8 mg/liter). The activity of cefuroxime in septic arthritis might be underestimated when relying exclusively on plasma concentrations.

The burden of septic arthritis on the U.S. inpatient care: A national study

OBJECTIVE

To assess the health care burden of septic arthritis in the U.S. and examine the associated factors.

METHODS

We used the U.S. Nationwide Emergency Department Sample (NEDS) data of patients hospitalized with septic arthritis as the primary diagnosis from 2009-12 to assess time-trends. Multivariable-adjusted models assessed demographics, comorbidity and hospital characteristics as potential predictors of duration of hospitalization, total hospital (inpatient and ED) charges and discharge to home.

RESULTS

In 2009, 2010 and 2012 in the U.S., respectively, there were 13,087, 13,662 and 13,714 hospitalizations with septic arthritis as the primary diagnosis. Respective average hospital stay was 7.4 vs. 7.4 vs. 7.2 days; total hospital charges were $601 vs. $674 vs. $759 million; and proportion discharged home were 43% vs. 43% vs. 44%. Almost 25% each were discharged to a skilled facility or with home health. Age >50 years, Medicaid and self-pay as primary payer, Northeast U.S. hospital location, teaching hospital status, heart failure and diabetes were associated with longer hospitalization; hyperlipidemia, hypertension or gout were associated with a shorter hospital stay. Similar associations were noted for higher hospital charges. Age >50 years, higher income, Medicare insurance, heart failure, diabetes and longer hospital stay were associated with lower odds, and Western U.S. hospital location and gout with higher odds, of discharge to home.

CONCLUSIONS

We noted an increase in hospital charges from 2009-12, but no time trends in duration or outcomes of hospitalization for septic arthritis. Comorbidity associations with outcomes indicate the potential for developing interventions to improve outcomes.

The Immunomodulatory Effect of Trichophyton Rubrum Exoantigens in the Treatment of Experimental Septic Arthritis

Background:

Understanding the nature and function of fungal exoantigens might lead to novel approaches in the treatment and prophylaxis of some infectious diseases. Septic arthritis represents a serious problem for medicine due to the high incidence rate and severe complications.

Objective:

The present study aimed at assessing the immunomodulatory effects of Trichophyton rubrum culture filtrate as a novel compound in experimental septic arthritis.

Method:

The septic arthritis was haematogenously induced in Sprague-Dawley rats by a single intravenous injection of 10⁹ colony forming units of the human clinical isolate Staphylococcus aureus producing toxic shock syndrome toxin-1. Trichophyton rubrum culture filtrate at two different doses 20 and 40 mg/kg was administered intraperituneally two days after bacterial inoculation in the treatment groups and concurrently with the appearance of clinical signs in the patient groups. The administration of Trichophyton rubrum solution was continued every other day for 10 injections.

Results:

The clinical evaluation showed that Trichophyton rubrum-treated rats were significantly protected from disease development compared with untreated controls. This finding was correlated with results of radiological evaluation of the involved joints. Although, the inflammatory cell infiltration, cartilage/bone destruction and synovial hypertrophy had been decreased in the treatment groups in comparison with arthritic controls however, the histological changes were not significant in these two groups.

Conclusion:

It is possible that Trichophyton rubrum antigens may play a role in modulating the immune responses and would be efficient in septic arthritis treatment.

[Septic arthritis and spondylodiscitis : Rare but feared diseases]

Septic arthritis and spondylodiscitis are relatively rare but severe diseases with increasing incidence. Septic arthritis is an emergency situation with high morbidity (40 %) and fatality rates (11 %). The infection occurs via a hematogenous route by direct inoculation or per continuitatem. Patients with pre-existing destructive joint diseases or under immunosuppressive treatment are particularly at risk. It is mandatory to sample synovial fluid for isolation of the relevant pathogen and quantification of leucocytes before starting antibiotic therapy. In order to preserve the joint, early evacuation of the infected synovial space is necessary. Spondylodiscitis is characterized by infection of the vertebra and neighboring discs mainly via a hematogenous route. Immunosuppressed and older patients are primarily at risk of infection. Back pain represents the main symptom but due to its unspecific character and the frequent absence of fever, diagnosis is often delayed. In Europe Staphylococcus aureus is the most prevalent pathogen, whereas tuberculosis is the most frequent causal agent worldwide. Magnetic resonance imaging (MRI) respresents the method of choice for the radiological diagnostics. In stable patients isolation of the pathogen should be achieved before starting antimicrobial therapy (e.g. blood cultures or tissue samples by computed tomography guided puncture or biopsy). The recommended duration of pathogen-specific antibiotic therapy for native spondylodiscitis is normally 6 weeks.

Monoarticular Arthritis

Monoarticular arthritis is inflammation characterized by joint pain, swelling, and sometimes periarticular erythema. Although chronic causes are seen, the onset is often acute. An infected joint can quickly lead to permanent damage, making it a medical emergency. However, acute gout presenting as monoarticular arthritis is often so uncomfortable it requires urgent attention. Monoarticular crystalline arthritis is common and a septic joint is a medical emergency so it is no surprise that these diagnoses come to mind with complaint of inflammation in 1 joint. However, there are many causes of monoarticular arthritis that clinicians must consider.

Septic Arthritis of the Wrist: Incidence, Risk Factors, and Predictors of Infection

Septic arthritis of the wrist can result in permanent damage to the joint, making timely diagnosis crucial to initiate empiric antibiotics and surgical intervention. Although septic arthritis is routinely included in the differential diagnosis of atraumatic wrist pain, the incidence is unknown. Unlike large joints, there is no consensus on cell count values considered pathognomonic for wrist septic arthritis. The goal of this retrospective study was to determine the incidence of wrist septic arthritis and to identify the clinical, serum, and joint fluid values that predict infection. The records of patients who presented to a single urban hospital with a swollen, painful wrist without trauma during a 10-year period were reviewed. For patients who had a joint fluid analysis, the records were examined for history as well as demographic and laboratory data. Joint fluid analysis consisted of cell count, Gram stain, and cultures. Of 892 patients who met the inclusion criteria, 1.5% had wrist septic arthritis. Variables associated with septic arthritis included serum white blood cell count above 11,000/µL, core temperature above 100.4°F within 24 hours of aspiration, history of intravenous drug abuse, and smoking. No joint cell count analysis predicted septic arthritis, although patients with septic wrists had an elevated joint white blood cell count above 97,000/µL. Wrist septic arthritis is uncommon; however, objective factors can help identify patients at risk. Because joint cell count analysis cannot reliably predict a septic wrist, priority for joint aspirations with limited fluid should be given instead to Gram stain, culture, and crystal analysis. [Orthopedics. 2017; 40(3):e526-e531.].

Posttraumatic Reconstruction of the Foot and Ankle in the Face of Active Infection

Posttraumatic infection of the foot and ankle is a challenging issue for orthopedic surgeons. Making the diagnosis often requires combining laboratory and radiologic testing, patient examination, and history. Patient comorbidities should be identified and optimized whenever possible. Treatment must combine effective antibiotic therapy with thorough debridement of the infected zone. Reconstruction often requires a 2-staged approach using antibiotic spacers and temporary external fixation, with the goal of obtaining a functional, pain-free limb that is free of infection.

Renal failure after placement of an articulating, antibiotic impregnated polymethylmethacrlyate hip spacer

A 58-year-old male presented with native joint septic arthritis of the hip and osteomyelitis. After treatment with an articulating antibiotic spacer, he developed acute renal failure requiring dialysis. He continued to have elevated serum tobramycin levels exclusively from the antibiotic spacer elution as no intravenous tobramycin was used. Subsequent explantation was required to correct his renal failure. Although renal failure after antibiotic impregnated cement placement is rare, the risk of this potential complication should be considered preoperatively and in the postoperative management of these patients.

Pyogenic Arthritis of the Fingers and the Wrist: Can We Shorten Antimicrobial Treatment Duration?

Background

Pyogenic arthritis of the small joints of the hand and wrist is a known but poorly described entity. The objective of this work was to characterize the clinical presentation, antimicrobial treatment, and surgical interventions of native small joint arthritis (SJA) treated in our tertiary center.

Methods

According to predefined variables, medical records of adult patients with SJA treated in a Swiss university hospital between 2005 and 2013 were retrospectively analyzed.

Results

The median age of 97 patients (101 joints) was 52 years (interquartile range [IQR], 38–68 years); 52% had no comorbidity. Small joint arthritis of the second and third fingers accounted for 53% of infections, with metacarpal-phalangeal and proximal interphalangeal joints most commonly involved. Of 86 (89%) episodes with an exogenous source, 63 (65%) followed a trauma. The most commonly isolated microorganism was Staphylococcus aureus (38%), followed by β-hemolytic streptococci (13%) and Pasteurella spp (11%). Eighty-seven episodes (89 joints) in patients with follow-up examinations were included in treatment and outcome analyses. Up to 2 surgical interventions were required to cure infection in 74 (83%) joints. Median antimicrobial treatment duration was 14 days (IQR, 12–28 days), with amoxicillin/clavulanate administered in 74 (85%) episodes. At follow up, cure of infection was noted in all episodes and good functional outcome in 79% of episodes.

Conclusions

Small joint arthritis shows considerable differences from clinical patterns reported for larger joints. In our series, the outcome was good with no more than 2 surgical interventions and median treatment duration of 14 days in 79% of episodes.

Neisseria meningitidis serogroup C sepsis and septic arthritis in an HIV-positive man

A patient with well-controlled HIV-1 infection presented with fever and rigors, a widespread maculopapular rash, and severe generalised arthralgia. Sepsis of unknown aetiology was diagnosed, and treatment with broad-spectrum antimicrobials commenced. Following initial clinical improvement, a right knee septic arthritis developed. Microscopy and culture of the joint aspirate were negative for organisms but 16S rDNA PCR identified Neisseria meningitidis DNA, subsequently verified as capsular genogroup C, thus confirming a diagnosis of disseminated meningococcal sepsis with secondary septic arthritis.

The Hip Restoration Algorithm

BACKGROUND

Despite the rapid advancement of imaging and arthroscopic techniques about the hip joint, missed diagnoses are still common. As a deep joint and compared to the shoulder and knee joints, localization of hip symptoms is difficult. Hip pathology is not easily isolated and is often related to intra and extra-articular abnormalities. In light of these diagnostic challenges, we recommend an algorithmic approach to effectively diagnoses and treat hip pain.

METHODS

In this review, hip pain is evaluated from diagnosis to treatment in a clear decision model. First we discuss emergency hip situations followed by the differentiation of intra and extra-articular causes of the hip pain. We differentiate the intra-articular hip as arthritic and non-arthritic and extra-articular pain as surrounding or remote tissue generated. Further, extra-articular hip pain is evaluated according to pain location. Finally we summarize the surgical treatment approach with an algorithmic diagram.

CONCLUSION

Diagnosis of hip pathology is difficult because the etiologies of pain may be various. An algorithmic approach to hip restoration from diagnosis to rehabilitation is crucial to successfully identify and manage hip pathologies. Level of evidence: V.

Total wrist arthrodesis for septic wrist arthritis and loss of the bony carpus following percutaneous pinning of the fifth carpometacarpal joint: a case report

We report on a patient who developed septic wrist arthritis with destruction of the entire carpus due to osteomyelitis following percutaneous pinning of a fifth metacarpal base fracture. Arthrodesis was performed using a 6 cm vascularized iliac bone graft. This case report may sharpen the surgeon's awareness of risks in orthopedic surgeries, even though the procedure seems to be rather simple and the patient is young and seems to be healthy.

Staphylococcus aureus-dependent septic arthritis in murine knee joints: local immune response and beneficial effects of vaccination

Staphylococcus aureus is the major cause of human septic arthritis and osteomyelitis, which deserve special attention due to their rapid evolution and resistance to treatment. The progression of the disease depends on both bacterial presence in situ and uncontrolled disruptive immune response, which is responsible for chronic disease. Articular and bone infections are often the result of blood bacteremia, with the knees and hips being the most frequently infected joints showing the worst clinical outcome. We report the development of a hematogenous model of septic arthritis in murine knees, which progresses from an acute to a chronic phase, similarly to what occurs in humans. Characterization of the local and systemic inflammatory and immune responses following bacterial infection brought to light specific signatures of disease. Immunization of mice with the vaccine formulation we have recently described (4C-Staph), induced a strong antibody response and specific CD4+ effector memory T cells, and resulted in reduced bacterial load in the knee joints, a milder general inflammatory state and protection against bacterial-mediated cellular toxicity. Possible correlates of protection are finally proposed, which might contribute to the development of an effective vaccine for human use.

Polymerase Chain Reaction-Electrospray-Time-of-Flight Mass Spectrometry Versus Culture for Bacterial Detection in Septic Arthritis and Osteoarthritis

Background: Preliminary studies have identified known bacterial pathogens in the knees of patients with osteoarthritis (OA) before arthroplasty. Aims: The current study was designed to determine the incidence and types of bacteria present in the synovial fluid of native knee joints from adult patients with diagnoses of septic arthritis and OA. Patients and Methods: Patients were enrolled between October 2010 and January 2013. Synovial fluid samples from the affected knee were collected and evaluated with both traditional microbial culture and polymerase chain reaction–electrospray ionization–time-of-flight mass spectrometry (molecular diagnostics [MDx]) to prospectively characterize the microbial content. Patients were grouped by diagnosis into one of two cohorts, those with clinical suspicion of septic arthritis (n = 44) and those undergoing primary arthroplasty of the knee for OA (n = 21). In all cases where discrepant culture and MDx results were obtained, we performed species-specific 16S rRNA fluorescence in situ hybridization (FISH) as a confirmatory test. Results: MDx testing identified bacteria in 50% of the suspected septic arthritis cases and 29% of the arthroplasty cases, whereas culture detected bacteria in only 16% of the former and 0% of the latter group. The overall difference in detection rates for culture and MDx was very highly significant, p-value = 2.384 × 10⁻⁷. All of the culture-positive cases were typed as Staphylococcus aureus. Two of the septic arthritis cases were polymicrobial as was one of the OA cases by MDx. FISH testing of the specimens with discordant results supported the MDx findings in 91% (19/21) of the cases, including one case where culture detected S. aureus and MDx detected Streptococcus agalactiae.Conclusions: MDx were more sensitive than culture, as confirmed by FISH. FISH only identifies bacteria that are embedded or infiltrated within the tissue and is thus not susceptible to contamination. Not all suspected cases of septic arthritis contain bacteria, but a significant percent of patients with OA, and no signs of infection, have FISH-confirmed bacterial biofilms present in the knee.

Short-interval two-stage approach to primary total knee arthroplasty for acutely septic osteoarthritic knees

Treatment strategies for advanced knee osteoarthritis with coexistent joint infection are not well established. While in periprosthetic joint infection the two-stage approach has been studied extensively, only few case reports on two-stage total knee arthroplasty (TKA) for knee osteoarthritis with coexistent joint infection have been published. The purpose of this paper was to report on our method of implementing a two-stage TKA with intervening antibiotic-loaded articulating cement spacers and a short interval between first- and second-stage procedures to treat two patients with Staphylococcus aureus-infected end-stage knee osteoarthritis. Consistent infection eradication was found at a 1-year follow-up with postoperative range of motion and knee scores comparing favourably with those of other case series. Level of evidence V.

Treatment of septic arthritis of the knee: a comparison between arthroscopy and arthrotomy

PURPOSE

The aim of this study was to compare the efficacy of arthroscopy and arthrotomy in patients with septic monarthritis of the knee.

METHODS

Seventy consecutive patients who underwent surgery because of a bacterial monarthritis were evaluated. Patients were either treated with arthroscopy or with arthrotomy. Our primary outcome was the early recurrence of infection (>3 months after surgery), which made a second surgical procedure necessary. Furthermore, the influence of potential confounders on treatment outcome was analysed.

RESULTS

Of the 70 patients, 41 were treated arthroscopically and 29 with arthrotomy. Eight patients (11.4 %) had to undergo a second surgical procedure because of early re-infection. The rate was significantly higher in patients treated with arthrotomy (n = 6; 20.7 %) compared with those treated by arthroscopy (n = 2) (p = 0.041). Range of motion was significantly better in patients who underwent arthroscopy (p < 0.001). Male sex had negative influence on the treatment success (p = 0.03).

CONCLUSIONS

Patients with bacterial monarthritis of the knee who were treated with arthroscopy had a significantly lower re-infection rate and a better functional outcome than those treated with arthrotomy. As arthroscopy is the less invasive method, it should be considered the routine treatment, according to our data.

LEVEL OF EVIDENCE

Therapeutic study, Level III.

Predictors of Septic Arthritis in the Adult Population

Septic arthritis is a devastating condition; well-established criteria for diagnosis exist in the pediatric population, but not for adults. This study evaluated patient factors and laboratory parameters that may be associated with the diagnosis of septic arthritis in adults. A total of 458 knee aspirates for suspected septic arthritis were evaluated with serum and synovial leukocyte counts and differentials as well as Kocher criteria for pediatric septic arthritis. Twenty-two patients (4.8%) had septic arthritis confirmed by a positive synovial fluid culture. Erythrocyte sedimentation rate (ESR) and serum white blood cell (WBC) counts were not statistically different between the 2 groups, with 64% of septic arthritis patients having a normal serum WBC count and 77% being afebrile. Mean synovial fluid WBC count was 26,758 cells/µL and 70,581 cells/µL in the nonseptic and septic groups, respectively. The likelihood ratio for a synovial fluid WBC count greater than 65,000 cells/µL was 2.8 (95% confidence interval, 1.2-6.7). Evaluation receiver operating characteristic curves using synovial WBC counts resulted in a significant area under the curve of 0.66 (P=.02). To achieve 90% specificity, a WBC cutoff of 64,000 cells/µL was required with a corresponding sensitivity of 40%. There was no significant difference in the synovial cell differential of 80% vs 90% in diagnosing infection. Synovial fluid WBC count greater than 64,000 cells/µL yielded the optimal combination of sensitivity and specificity. Polymorphonuclear leukocytes, ESR, serum WBC count, fever, and weight-bearing status were not significant predictors of septic arthritis. This study demonstrates the limited utility of Kocher criteria in the adult population and the importance of synovial leukocyte counts. [Orthopedics. 2016; 39(4):e657-e663.].

Identification of streptococcus dysgalactiae subsp. equisimilis from septic knee by 16S rRNA gene sequencing

Septic arthritis is the infection of a joint by an infectious agent, leading to arthritis. It is therefore important to identify and treat the correct bacteria in septic arthritis. However, accurate identification of bacteria by conventional methods is difficult because of the distinct biochemical characteristics of individual bacteria. This case report aims at assessing septic arthritis caused by Streptococcus dysgalactiaesubsp. equisimilis(SDSE) using nucleotide sequences and discusses the associated treatment. Here, Streptococcus agalactiaewas determined to be the causative bacteria for septic arthritis in a 77 year-old woman using the conventional method of hemolysis pattern interpretation and morphology. However, nucleotide sequence analysis of 16S ribosomal RNA revealed that SDSE was the causative strain. 16S rRNA gene sequencing can correctly identify bacteria strains that are difficult to be identified by traditional method, and this correct identification can provide patients with the opportunity for adequate treatment using the proper antibiotics.

Pyogenic arthritis of native joints due to Bacteroides fragilis: Case report and review of the literature

Pyogenic arthritis of native joints due to Bacteroides fragilis seems to be an infrequent disease. We analyzed the cases diagnosed in a tertiary hospital during a 22-year period and reviewed the literature to summarize the experience with this infectious entity.In our institution, of 308 patients with pyogenic arthritis of native joints, B fragilis was the causative organism in 2 (0.6%) cases. A MEDLINE search (1981-2015) identified 19 additional cases.Of the 21 patients available for review (13 men and 8 women, with a mean age, of 54.4 ± 17 years), 19 (90%) presented a systemic predisposing factor for infection; the most common associated illness was rheumatoid arthritis (8 patients). Bacteremia was documented in 65% (13/20) of cases. In 5 patients (24%), 1 or more concomitant infectious process was found. Metronidazole was the most frequently used antibiotic. Surgical drainage was performed in 11 cases (52%). The overall mortality rate was 5%.Pyogenic arthritis of native joints due to B fragilis is an infrequent disease that mainly affects elderly patients with underlying medical illnesses and in whom bacteremia and the presence of a concomitant infectious process are frequent conditions.

Morbimortality in adult patients with septic arthritis: a three-year hospital-based study

Background

The objective of this ambispective study was to determine outcomes and associated factors for adult patients with confirmed septic arthritis (SA).

Methods

All adult patients admitted to Amiens University Hospital between November 2010 and December 2013 with confirmed SA were included in the study. Patients with prosthetic joint infections were excluded. A statistical analysis was performed in order to identify risk factors associated with a poor outcome (including mortality directly attributable to SA).

Results

A total of 109 patients (mean ± SD age: 60.1 ± 20.1; 74 male/35 females) were diagnosed with SA during the study period. The most commonly involved sites were the small joints (n = 34, 31.2 %) and the knee (n = 25, 22.9 %). The most frequent concomitant conditions were cardiovascular disease (n = 45, 41.3 %) and rheumatic disease (n = 39, 35.8 %). One hundred patients (91.7 %) had a positive microbiological culture test, with Staphylococcus aureus as the most commonly detected pathogen (n = 59, 54.1 %). Mortality directly attributable to SA was relatively infrequent (n = 6, 5.6 %) and occurred soon after the onset of SA (median [range]: 24 days [1–42]). Major risk factors associated with death directly attributable to SA were older age (p = 0.023), high C-reactive protein levels (p = 0.002), diabetes mellitus (p = 0.028), rheumatoid arthritis and other inflammatory rheumatic diseases (p = 0.021), confusion on admission (p = 0.012), bacteraemia (p = 0.015), a low creatinine clearance rate (p = 0.009) and the presence of leg ulcers/eschars (p = 0.003). The median duration of follow-up (in patients who survived for more than 6 months) was 17 months [6–43]. The proportion of poor functional outcomes was high (31.8 %). Major risk factors associated with a poor functional outcome were older age (0.049), hip joint involvement (p = 0.003), the presence of leg ulcers/eschars (p = 0.012), longer time to presentation (0.034) and a low creatinine clearance rate (p = 0.013).

Conclusions

In a university hospital setting, SA is still associated with high morbidity and mortality rates.

Rapid exclusion of bacterial arthritis using a glucometer

Bacterial arthritis is a medical emergency. However, prompt diagnosis and differentiation from non-infectious diseases are challenging. As bacterial metabolism leads to glucose reduction, measurement of synovial fluid glucose seems to be a promising diagnostic approach. The purpose of this study was to determine whether synovial fluid glucose levels could be accurately measured by using a glucometer and to evaluate its diagnostic accuracy in diagnosing bacterial arthritis compared to currently available markers. In a prospective diagnostic study, 102 consecutive patients with atraumatic joint effusion were included. Synovial fluid glucose concentrations were determined using both glucometer and automated analyzer respectively. Synovial fluid culture, crystal analysis, and synovial cell analysis were performed. Blood samples were taken for blood cultures, analyses of serum infection markers, and serum glucose. There was a high correlation between synovial fluid glucose measured by the glucometer and the automated analyzer (r ² = 0.92). According to the receiver operating characteristic curve, a threshold of 1.4 mmol/l had a sensitivity of 100 % (95 % CI 78.2-100 %), a specificity of 92.0 % (95 % CI 84.1-96.7 %), a positive predictive value of 68.2 % (95 % CI 45.1-86.1 %), and a negative predictive value of 100 % (95 % CI 95.5-100 %). These results suggest that synovial fluid glucose concentrations could be reliably measured using a glucometer. Due to its simplicity, this test has the potential to be an adjunct in the diagnostic cascade of bacterial arthritis.

Retrospective evaluation of the efficacy of isolating bacteria from synovial fluid in dogs with suspected septic arthritis

OBJECTIVE

To evaluate the efficacy of synovial fluid culture in obtaining the causative organism from dogs with suspected septic arthritis.

METHODS

In this retrospective evaluation, synovial fluid cytology and microbiology submissions from dogs with suspected septic arthritis from March 2007 to August 2011 were reviewed. Synovial fluid cytology consistent with joint sepsis was identified. Cultures of synovial fluid from dogs with clinical histories and abnormalities consistent with septic arthritis were used to evaluate the efficacy of bacterial isolation.

RESULTS

In total, 36 dogs met the inclusion criteria. Initial aerobic cultures of joint fluid yielded bacterial growth in 44% of these dogs. All anaerobic cultures were negative. In 19% of the dogs with positive cultures, antibiotics had been administered prior to arthrocentesis compared with 10% of dogs with negative cultures. There was no association between culture efficacy and the administration of antimicrobial treatment prior to synovial fluid culture or recent surgery involving the affected joint (P=0.637 and P=0.106, respectively).

CONCLUSION

Culture of synovial fluid from dogs with suspected septic arthritis has a low yield, necessitating a more effective means of identifying bacteria from suspected septic joints in dogs.

Comparison of synovial fluid culture and 16S rRNA PCR in dogs with suspected septic arthritis

OBJECTIVE

To prospectively compare the sensitivity and specificity of 16S rRNA PCR with culture for identifying the causative organism in synovial fluid obtained from dogs with suspected septic arthritis.

METHODS

Synovial fluid cytology, PCR analysis and aerobic, anaerobic and Mycoplasma culture of samples from the affected joints of 18 dogs presenting with suspected septic arthritis were performed. Synovial fluid samples from the corresponding contralateral joints of 7 dogs were also analysed as negative controls.

RESULTS

There was no significant difference between the sensitivity of bacterial detection via culture (63.2%) versus PCR (73.7%) of synovial fluid (P=0.728) or between culture and combined PCR and culture (89.5%) of synovial fluid (P=0.124). The specificity of PCR (42.9%) was significantly lower than culture specificity (100%) (P=0.07).

CONCLUSION

Although 16S PCR may hold potential as an ancillary diagnostic test for identifying the causative organism in dogs with septic arthritis, our study failed to demonstrate improved accuracy compared with traditional synovial fluid culture.

Septic arthritis due to Clostridium ramosum

OBJECTIVES

Clostridium species are anaerobic bacilli that are rarely reported as etiologic agents of infectious arthritis. Previous cases of arthritis caused by Clostridium ramosum have not been reported. We describe the first 2 cases of C. ramosum arthritis.

METHODS

We reviewed the etiology of arthritis in our hospital during the previous 15 years.

RESULTS

Both patients had underlying immunocompromising conditions and their infections involved a joint with preexisting disease: patient 1 had rheumatic arthritis and a prosthetic joint; patient 2, chronic renal failure on dialysis and hip osteoarthritis. The infection was hematogenously acquired and the course was indolent but destructive in both the cases. Management included open arthrotomy and resection arthroplasty. The infection had a persisting and relapsing course, and prolonged antibiotic treatment was required. In the literature review, we found 55 previous cases of arthritis caused by Clostridium species between 1966 and 2014; Clostridium perfringens was the most common infecting species; the infection was traumatically acquired in most of the cases. A total of 15 patients have been described with infections caused by C. ramosum; none had septic arthritis. The majority were elderly or immunocompromised adults. Proper collection, transportation and processing of clinical specimens is essential for diagnosing clostridial infections. More information about the best management of clostridial arthritis are needed.

CONCLUSIONS

We describe the first 2 cases of septic arthritis caused by C. ramosum. They shared several pathogenic and clinical features. The possibility of anaerobic arthritis should always be considered when collecting diagnostic specimens. An increasing number of clostridial arthritis cases are likely to be diagnosed in future years.

Clinical findings of bacteremic septic arthritis according to the site of acquisition: The overlap between health care-related and community- and nosocomial-acquired cases

BACKGROUND

The site of acquisition of infection may have a major impact on outcome. The health care-related (HCR) environment has recently come under scrutiny. In a group of patients with bacteremic septic arthritis (SA), we compared their characteristics, type of SA, microbiology and prognosis according to the site of acquisition: community-acquired (CA), nosocomial-acquired (NA), and HCR.

METHODS

We studied all patients with bacteremic SA seen at our institution between 1985 and 2013. Data were obtained from a protocol of prospectively recorded bacteremia cases.

RESULTS

There were 273 cases of bacteremic SA (CA: 51%; NA: 31%; and HCR: 18%). NA and HCR sites were more frequent in older and fragile patients. SA of peripheral joints was the most common presentation; infections of the axial skeleton predominated in CA and HCR (24%), and prosthetic joint infection in NA (44%). MRSA and Pseudomonas aeruginosa were mainly found in NA (21% and 6% respectively) and HCR (14% and 8% respectively), whereas Streptococcus spp. was more frequent in CA (30%) and HCR (28%). The 30-day mortality rates were: CA 7%, HCR 18%, and NA 26%.

CONCLUSION

The characteristics of HCR-SA overlapped with those of the CA or NA-SA cases. The HCR and NA cases presented more advanced age, greater fragility, and the predominance of difficult-to-treat microorganisms, while the HCR and CA cases presented an involvement of the axial skeleton, streptococcal etiology, and a lower number of prosthetic joint infections. Our data show that the site of acquisition should be considered when planning diagnostic and therapeutic management for SA.