Gram and acridine orange staining for diagnosis of septic arthritis in different patient populations

The accuracy and diagnostic value of gram staining joint aspirates in suspected joint infections

BACKGROUND

Septic arthritis is a debilitating condition with prolonged treatment and adverse outcomes. A gram stain is often performed from the joint aspirate sample, followed by a definitive culture. In our study, we assessed the accuracy of gram staining for suspected septic arthritis and explored factors associated with positive culture growth and false negatives in the gram stain.

METHODS

We retrospectively reviewed joint aspirates performed from 2015-2021 at a major trauma centre. Aspirates not cultured for septic arthritis were excluded. Data collected included aspirate site, gram stain and culture result delay, patient demographics, orthopaedic/rheumatological history, and comorbidities. Outcomes measured were gram stain sensitivity and specificity. Factors influencing positive cultures and false negative gram stain results were analysed using logistic regression.

RESULTS

Of 408 joint aspirates meeting the criteria, 37 did not undergo initial gram staining. Gram stain sensitivity was 30.4%, specificity was 97.6%. The delay from aspirate to definitive gram stain and culture results was 1.1 and 5.4 days, respectively Logistic regression identified that prosthetic joint(p = 0.007), past joint infections(p = 0.006), arthritis(p < 0.001), hypertension(p = 0.007), diabetes(p = 0.019) were positively associated with positive cultures. Past joint infections(p = 0.004) were positively associated with false negative gram stain results. Patients on antibiotics during the aspirate had a higher risk of false negative gram stain results (OR = 5.538, 95%CI, 2.802-10.948; p < 0.001).

CONCLUSIONS

In conclusion, the initial gram stain has limited sensitivity and caution should be exercised when interpreting negative results. Vigilance is crucial when the highlighted comorbidities or antibiotic use are present, to assess patients with potential joint infections.

Initial antibiotic therapy for postoperative moderate or severe diabetic foot infections: Broad versus narrow spectrum, empirical versus targeted

AIM

To retrospectively evaluate clinical and microbiological outcomes after combined surgical and medical therapy for diabetic foot infections (DFIs), stratifying between the empirical versus the targeted nature, and between an empirical broad versus a narrow-spectrum, antibiotic therapy.

METHODS

We retrospectively assessed the rate of ultimate therapeutic failures for each of three types of initial postoperative antibiotic therapy: adequate empirical therapy; culture-guided therapy; and empirical inadequate therapy with a switch to targeted treatment based on available microbiological results.

RESULTS

We included data from 332 patients who underwent 716 DFI episodes of surgical debridement, including partial amputations. Clinical failure occurred in 40 of 194 (20.6%) episodes where adequate empirical therapy was given, in 77 of 291 (26.5%) episodes using culture-guided (and correct) therapy from the start, and in 73 of 231 (31.6%) episodes with switching from empirical inadequate therapy to culture-targeted therapy. Equally, a broad-spectrum antibiotic choice could not alter this failure risk. Group comparisons, Kaplan-Meier curves and Cox regression analyses failed to show either statistical superiority or inferiority of any of the initial antibiotic strategies.

CONCLUSIONS

In this study, the microbiological adequacy of the initial antibiotic regimen after (surgical) debridement for DFI did not alter therapeutic outcomes. We recommend that clinicians follow the stewardship approach of avoiding antibiotic de-escalation and start with a narrow-spectrum regimen based on the local epidemiology.

Assessment and diagnosis of the acute hot joint: a systematic review and meta-analysis

OBJECTIVES

Prompt diagnosis of septic arthritis (SA) in acute native hot joints is essential for avoiding unnecessary antibiotics and hospital admissions. We evaluated the utility of synovial fluid (SF) and serum tests in differentiating causes of acute hot joints.

METHODS

We performed a systematic literature review of diagnostic testing for acute hot joints. Articles were included if studying ≥1 serum or SF test(s) for an acute hot joint, compared with clinical assessment and SF microscopy and culture. English-language articles only were included, without date restriction. The following were recorded for each test, threshold and diagnosis: sensitivity, specificity, positive/negative predictive values and likelihood ratios. For directly comparable tests (i.e. identical fluid, test and threshold), bivariate random-effects meta-analysis was used to pool sensitivity, specificity, and areas under the curves.

RESULTS

A total of 8443 articles were identified, and 49 were ultimately included. Information on 28 distinct markers in SF and serum, differentiating septic from non-septic joints, was extracted. Most had been tested at multiple diagnostic thresholds, yielding a total of 27 serum markers and 156 SF markers. Due to heterogeneity of study design, outcomes and thresholds, meta-analysis was possible for only eight SF tests, all differentiating septic from non-septic joints. Of these, leucocyte esterase had the highest pooled sensitivity [0.94 (0.70, 0.99)] with good pooled specificity [0.74 (0.67, 0.81)].

CONCLUSION

Our review demonstrates many single tests, individually with diagnostic utility but suboptimal accuracy for exclusion of native joint infection. A combination of several tests with or without a stratification score is required for optimizing rapid assessment of the hot joint.

Diagnostic Utility of Synovial Fluid Cell Counts and CRP in Pediatric Knee Arthritis: A 10-Year Monocentric, Retrospective Study

Background: Orthopedic surgeons often use the intra-articular white blood counts (WBCs) and the percentage of polymorphonuclear cells (PMN) in the diagnosis of an acute swollen and painful knee joint in children. Today, there is no established threshold for the synovial WBC, and their differentiation, as indicative of native joint knee bacterial arthritis. We determine the sensitivity and specificity of synovial WBCs and PMN percentages in the prediction of a community-acquired, acute bacterial native joint septic arthritis (SA) in the pediatric population. Methods: A retrospective study on healthy children 0–16 years of age who underwent knee joint aspiration for a community-acquired, acute irritable knee effusion in our tertiary-care children’s hospital between May 2009 and April 2019 was conducted. We divided the study population into two groups according to the detection of bacterial arthritis in the synovial fluid (bacterial arthritis versus its absence) and compared the intra-articular leukocyte and C-reactive protein (CRP) levels. Results: Overall, we found a statistically significant difference regarding the total CRP (p = 0.017), leukocyte or PMN counts (p ≤ 0.001 in favor of a bacterial arthritis). In contrast, the percentage of the neutrophils was not determinant for the later confirmation of bacterial pathogens, and we were unable to establish diagnostically determining minimal thresholds of the intra-articular CRP and leukocyte levels. Conclusions: This pilot study suggests that either the leukocyte or PMN counts may be associated with a bacterial origin of knee arthritis in children. We plan a larger prospective interventional study in the future to confirm these findings including the investigation of other joint aspirate biomarkers.

Histological Stains in the Past, Present, and Future

Certain contemporary histology stains and methods are not the same as those used in the past. This progression has delved into the requirement for more precise, less complex, and efficient staining procedures. The objective of this study is to assess historical and contemporary stains and procedures, as well as the challenges surrounding their improvement. Carmine, hematoxylin, silver nitrate, Giemsa, trichome stain, Gram stain, and mauveine were among the first histological stains discovered in nature. Aside from their utility in the study of tissues at the time, they also laid the groundwork for the development of commercial dyes that are still in use today. Hematoxylin and eosin, Ziehl-Nielsen (ZN) stain, periodic acid-Schiff stain, and Grocott-Gomori methenamine silver stain are some of the most recently developed histological stains. The future of histological stains and processes appears to be influenced by technological advancements and the demand for cost-effective diagnostic approaches in the healthcare system. Thus, currently used histological stains appear to be economical, quick, and reliable tools for interpreting, archiving, and delivering essential diagnoses that could not be achieved by any other means.

Gram stain microscopy in septic arthritis

Septic arthritis is a serious condition that can lead to rapid destruction of joint if it is not rapidly diagnosed and treated appropriately. The reported annual incidence is 10 in 100 000 although this increases to 70 in 100 000 in those with risk factors for developing septic arthritis mainly rheumatoid arthritis and immune-compromised patients. The aim of this study is to examine the sensitivity and specificity, and thus the clinical usefulness, of gram stain results. This was a single centre, retrospective case series. All joint aspirates over a three year period from May 2015 to April 2018 were reviewed. The gram stain and final culture results noted. 830 samples were included from both native and replaced joints. Native joints accounted for a total of 701 cases (84%) of the aspirates, whilst those obtained from prosthetic joints 129 (16%). In 74 (9%) cases there was a discrepancy between the gram stain and culture results. The sensitivity of the gram stain in this case series is 22% and the specificity of the test is 99.6%. The clinician should have a low threshold for overlooking a negative gram stain result and place greater emphases on the clinical findings in conjunction with biochemical markers.

Leukocyte Esterase and Glucose Reagent Test Can Rule in and Rule out Septic Arthritis

BACKGROUND/AIM

Septic arthritis (SA) requires rapid diagnosis and therapy to avoid joint damage. This study evaluated the diagnostic accuracy of leukocyte esterase (LE) and glucose (GLC) strip tests for diagnosing SA.

PATIENTS AND METHODS

Synovial fluids from 455 patients with atraumatic joint effusions were assessed prospectively over a 5-year period with LE and glucose strip tests. Results were compared to modified Newman criteria for diagnosing joint infections. Synovial fluid cultures, crystal, blood and synovial cell analyses were also performed.

RESULTS

Forty-one patients had SA and 252 non-SA. A positive LE reading combined with negative glucose reading could detect SA with 100% specificity, 85% sensitivity, 100% positive predictive value (PPV) and 98% negative predictive value (NPV). Positive synovial LE reading alone detected SA with 82% specificity, 95% sensitivity, 47% PPV, and 99% NPV.

CONCLUSION

Combined LE and glucose strip tests represent a low-cost tool for rapidly diagnosing or ruling out SA.

Performances of automated digital imaging of Gram-stained slides with on-screen reading against manual microscopy

The objective of this study was to evaluate the performances of the automated digital imaging of Gram-stained slides against manual microscopy. Four hundred forty-three identified Gram-stained slides were included in this study. When both methods agreed, we considered the results as correct, and no further examination was carried out. Whenever the methods gave discrepant results, we reviewed the digital images and the glass slides by manual microscopy to avoid incorrectly read smears. The final result was a consensus of multiple independent reader interpretations. Among the 443 slides analyzed in this study, 101 (22.8%) showed discrepant results between the compared methods. The rates of discrepant results according to the specimen types were 5.7% (9/157) for positive blood cultures, 42% (60/142) for respiratory tract specimens, and 22% (32/144) for sterile site specimens. After a subsequent review of the discrepant slides, the final rate of discrepancies dropped to 7.0% (31/443). The overall agreement between the compared methods and the culture results reached 78% (345/443) and 79% (349/443) for manual microscopy and automated digital imaging, respectively. According to culture results, the specificity for automated digital imaging and manual microscopy were 90.8% and 87.7% respectively. In contrast, sensitivity was 84.1% for the two compared methods. The discrepant results were mostly encountered with microorganism morphologies of rare occurrence. The results reported in this study emphasize that on-screen reading is challenging, since the recognition of morphologies on-screen can appear different as compared to routine manual microscopy. Monitoring of Gram stain errors, which is facilitated by automated digital imaging, remains crucial for the quality control of reported Gram stain results.

Diagnostic Accuracy of Synovial Lactate, Polymerase Chain Reaction, or Clinical Examination for Suspected Adult Septic Arthritis

BACKGROUND

Adult septic arthritis can be challenging to differentiate from other causes of acute joint pain. The diagnostic accuracy of synovial lactate and polymerase chain reaction (PCR) remains uncertain.

OBJECTIVE

Our aim was to quantify the diagnostic accuracy of synovial lactate, PCR, and clinical evaluation for adults with possible septic arthritis in the emergency department (ED).

METHODS

We report a prospective sampling of ED patients aged ≥ 18 years with knee symptoms concerning for septic arthritis. Clinicians and research assistants independently performed history and physical examination. Serum and synovial laboratory testing was ordered at the discretion of the clinician. We analyzed frozen synovial fluid specimens for l- and d-lactate and PCR. The criterion standard for septic arthritis was bacterial growth on synovial culture and treated by consultants with operative drainage, prolonged antibiotics, or both. Diagnostic accuracy measures included sensitivity, specificity, likelihood ratios, interval likelihood ratios, and receiver operating characteristic area under the curve.

RESULTS

Seventy-one patients were included with septic arthritis prevalence of 7%. No finding on history or physical examination accurately ruled in or ruled out septic arthritis. Synovial l- and d-lactate and PCR were inaccurate for the diagnosis of septic arthritis. Synovial white blood cell count and synovial Gram stain most accurately rule in and rule out septic arthritis.

CONCLUSIONS

Septic arthritis prevalence in ED adults is lower than reported previously. History and physical examination, synovial lactate, and PCR are inadequate for the diagnosis of septic arthritis. Synovial white blood cell count and Gram stain are the most accurate tests available for septic arthritis.

The accuracy of joint aspiration for the diagnosis of shoulder infections

BACKGROUND

Shoulder joint aspirations are frequently performed to rule out infection. In case of unsuccessful aspiration, physicians often augment the aspiration liquid by injecting saline solution.

METHODS

We performed shoulder joint aspirations by fluoroscopic assistance and analyzed the value of an additional saline solution irrigation in patients undergoing revision shoulder surgery. Native joints and post-fracture repair, post-arthroscopy, and post-arthroplasty shoulders were included. A minimum of 3 deep intraoperative tissue samples served as the microbiological gold standard.

RESULTS

We performed 106 aspirations occurring between 0 and 179 days before revision surgery. Among them, we could sample intra-articular liquid directly in 60 cases and after saline solution injection in 43 cases, whereas 3 cases remained unsuccessful. According to intraoperative samples, 24 shoulders were infected but only 10 of 24 (42%) yielded pathogens in the aspirate. Moreover, of the 43 saline solution-enforced irrigations, none revealed bacteria but 8 (17%) confirmed infection in intraoperative samples. Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of presurgical aspirations were 33%, 98%, 80%, and 83%, respectively.

CONCLUSION

When surgical revision is planned, presurgical shoulder joint aspiration is not reliable to sufficiently exclude shoulder joint infection. Nevertheless, a positive aspiration finding can guide clinical decision making, so we propose to perform aspiration only if there is a clinically high index of suspicion for an infection. Irrigation after unsuccessful primary aspiration is futile.

Comparison of acridine orange fluorescent microscopy and gram stain light microscopy for the rapid detection of bacteria in cerebrospinal fluid

OBJECTIVE

Bacterial meningitis is a life threatening condition that requires prompt recognition and treatment. Currently, Gram stain is widely used for the microscopic detection of bacterial pathogens in cerebrospinal fluid (CSF). In Nepal, fluorescent microscopes have been installed in laboratories as a part of the National tuberculosis control program. However, information on the utility of the acridine orange (AO) stain for the direct detection of bacteria in CSF samples in Nepal is not available. Therefore, this study aims to compare Gram stain and AO stain for the rapid detection of bacterial pathogens in CSF of clinically suspected meningitis cases in Kathmandu, Nepal.

RESULTS

Bacterial pathogens were detected in 9.30% (36/387) by either of the three tests, 9.04% (35/387) by AO stain, 8.27% (32/387) by culture and 6.46% (25/387) by Gram's stain. Considering culture as a gold standard, the sensitivity of AO stain was higher than Gram stain. The specificity of AO stain was 98.87%. Detection and differentiation of the bacteria was much clear in AO staining than Gram staining. AO is a better alternative to Gram stain in the rapid detection of bacterial pathogens in CSF in the setting where fluorescent microscope is available.

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

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

Two weeks versus four weeks of antibiotic therapy after surgical drainage for native joint bacterial arthritis: a prospective, randomised, non-inferiority trial

Objective

The optimal duration of postsurgical antibiotic therapy for adult native joint bacterial arthritis remains unknown.

Methods

We conducted a prospective, unblinded, randomised, non-inferiority study comparing either 2 or 4 weeks of antibiotic therapy after surgical drainage of native joint bacterial arthritis in adults. Excluded were implant-related infections, episodes without surgical lavage and episodes with a follow-up of less than 2 months.

Results

We enrolled 154 cases: 77 in the 4-week arm and 77 in the 2-week arm. Median length of intravenous antibiotic treatment was 1 and 2 days, respectively. The median number of surgical lavages was 1 in both arms. Recurrence of infection was noted in three patients (2%): 1 in the 2-week arm (99% cure rate) and 2 in the 4-week arm (97% cure rate). There was no difference in the number of adverse events or sequelae between the study arms. Of the overall 154 arthritis cases, 99 concerned the hand and wrist, for which an additional subgroup analysis was performed. In this per-protocol subanalysis, we noted three recurrences: one in the 2-week arm (97 % cure); two in the 4-week arm (96 % cure) and witnessed sequelae in 50% in the 2-week arm versus 55% in the 4-week arm, of which five (13%) and six (13%) needed further interventions.

Conclusions

After initial surgical lavage for septic arthritis, 2 weeks of targeted antibiotic therapy is not inferior to 4 weeks regarding cure rate, adverse events or sequelae and leads to a significantly shorter hospital stay, at least for hand and wrist arthritis.

Trial registration number

NCT03615781.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

[Synovial fluid cytodiagnosis]

Synovial fluid samples represent only a very small percentage of routine work in a cytology laboratory. However, its microscopic examination allows us to observe different types of cells, particles and structures that, due to their morphological characteristics, may provide relevant data for cytodiagnosis. We present certain aspects related to arthrocentesis, the relationship between the gross appearance of synovial fluid and certain pathological processes, as well as the different techniques for processing and staining the smears. Furthermore, we describe the main cytological findings in various pathological conditions of the synovial joints, such as infections (bacterial and fungal), non-infectious inflammatory type (osteoarthrosis, rheumatoid arthritis, connective tissue diseases) and tumoral, distinguishing between primary and metastatic, both solid and haematological neoplasms.

Gram Stain is Not Clinically Relevant in Treatment of Pediatric Septic Arthritis

BACKGROUND

The diagnosis of pediatric septic arthritis (SA) can be challenging due to wide variability in the presentation of musculoskeletal infection. Synovial fluid Gram stain is routinely obtained and often used as an initial indicator of the presence or absence of pediatric SA. The purpose of this study was to examine the clinical utility of the Gram stain results from a joint aspiration in the diagnosis and management of pediatric SA.

METHODS

All patients with suspected SA who underwent arthrocentesis and subsequent surgical irrigation and debridement at an urban tertiary care children's hospital between January 2007 and October 2016 were identified. Results of the synovial fluid Gram stain, as well as synovial cell count/differential and serum markers, were evaluated.

RESULTS

A total of 302 patients that underwent incision and drainage for suspected SA were identified. In total, 102 patients (34%) had positive synovial fluid cultures and 47 patients (16%) had a microorganism detected on Gram stain. Gram stain sensitivity and specificity for the detection of SA were 0.40 and 0.97, respectively. This yielded a number needed to misdiagnose of 4.5 (ie, every fifth patient was misdiagnosed by Gram stain). For gram-negative organisms, the sensitivity dropped further to 0.13, with only 2/16 gram-negative organisms identified on Gram stain. Stepwise regression showed that age, serum white blood cell, and absolute neutrophil count were significant independent predictors for having a true positive Gram stain result. Elevated synovial white blood cell count was a significant predictor of having an accurate (culture matching the Gram stain) result.

CONCLUSIONS

The Gram stain result is a poor screening tool for the detection of SA and is particularly ineffective for the detection of gram-negative organisms. The clinical relevance of the Gram stain and cost-effectiveness of this test performed on every joint aspiration sent for culture requires additional evaluation. Patients with gram-negative SA may be at high risk for inadequate coverage with empiric antibiotics due to poor detection of gram-negative organisms on initial Gram stain.

LEVEL OF EVIDENCE

Level III-case-control study.

Native septic arthritis is not an immediate surgical emergency

Acute native joint septic arthritis is generally considered a surgical emergency, requiring drainage within hours, including during night, weekend or holiday shifts. However, there are few data supporting the need for the disruption caused by this degree of urgency.

METHODS

We performed a retrospective review of all adult patients seen in our medical center from 1997-2015 with culture-proven septic arthritis and noted the epidemiology of sequelae, and their possible association with a delay in surgical drainage.

RESULTS

Of 204 septic arthritis episodes, 46 (23%) involved interdigital hand and foot joints. Large joints involved included the knee (n = 67), shoulder (48), hip (22), ankle (8), acromio-clavicular (5), elbow (4), wrist (3), and sterno-clavicular (1) regions. All patients underwent surgical drainage of the joint and received targeted systemic antibiotic therapy. Sequelae of varying severity occurred in 83 patients (41%): recurrences (n = 15); secondary arthrosis (30); persistent pain (9); Girdlestone procedure (9); arthrodesis (9); amputation (8); stiffness (8); and Chronic Regional Pain Syndrome (2). By multivariate Cox regression analysis factors did not predict sequelae included: age; treatment with systemic corticosteroids; pre-existing clinical or radiological arthropathy; total duration of antibiotic therapy; type of joint; and, number of surgical interventions. Similarly, there was no association of sequelae with the number of days of pre-hospitalization joint symptoms (hazard ratio 1.0, 95% confidence interval 0.99-1.01) or hours spent in the emergency department (HR 1.0, 0.9-1.2). Notably, patients who had joint lavage within 6 h of presentation had similar functional outcomes as those with lavage done at 6-12 h, 12-24 h, or > 24 h after presentation.

CONCLUSIONS

Our data suggest that for native septic arthritis, in the absence of clinical sepsis immediate joint drainage does not appear to reduce the risk of sequelae compared with delayed drainage.

Administration of antibiotic agents before intraoperative sampling in orthopedic infections alters culture results

Many physicians and surgeons think that prescribing antibiotics before intraoperative sampling does not alter the microbiological results.

METHODS

Case-control study of adult patients hospitalized with orthopedic infections.

RESULTS

Among 2740 episodes of orthopedic infections, 1167 (43%) had received antibiotic therapy before surgical sampling. Among these, 220 (19%) grew no pathogens while the proportion of culture-negative results in the 2573 who had no preoperative antibiotic therapy was only 6%. By multivariate analyses, pre-operative antibiotic exposure was associated with significantly more culture-negative results (odds ratio 2.8, 95% confidence interval 2.1-3.7), more non-fermenting rods and skin commensals (odds ratio 2.8 and 3.0, respectively). Even a single pre-operative dose of antibiotic was significantly associated with subsequent culture-negative results (19/93 vs. 297/2350; χ²-test, p = 0.01) and skin commensals (17/74 vs. 274/2350; p = 0.01) compared to episodes without preceding prophylaxis.

CONCLUSIONS

Prior antibiotic use, including single-dose prophylactic administrations, is three-fold associated with culture-negative results, non-fermenting rods and resistant skin commensals.

Septic arthritis in immunocompetent and immunosuppressed hosts

Septic arthritis has long been considered an orthopedic emergency. Historically, Neisseria gonorrhoeae and Staphylococcus aureus have been the most common causes of septic arthritis worldwide but in the modern era of biological therapy and extensive use of prosthetic joint replacements, the spectrum of microbiological causes of septic arthritis has widened considerably. There are also new approaches to diagnosis but therapy remains a challenge, with a need for careful consideration of a combined medical and surgical approach in most cases.