Total joint arthroplasty is the recommended treatment for patients with end-stage osteoarthritis, as it reduces disability and pain and restores joint function. However, prosthetic joint infection is ...a serious complication of this procedure, with the two-stage exchange being the most common treatment method. While there is consensus on diagnosing prosthetic joint infection, there is a lack of agreement on the parameters that can guide the surgeon in performing definitive reimplantation in a two-stage procedure. One approach that has been suggested to improve the accuracy of microbiologic investigations before definitive reimplantation is to observe a holiday period from antibiotic therapy to improve the accuracy of cultures from periprosthetic tissues, but these cultures report some degree of aspecificity. Therefore, several pieces of evidence highlight that performing reimplantation using continuous antibiotic therapy should be considered a safe and effective approach, leading to higher cure rates and a shorter period of disability. Dosage of C-reactive protein (CRP), erythrocyte sedimentation rate (ERS) and D-dimer are helpful in diagnosing prosthetic joint infection, but only D-dimer has shown sufficient accuracy in predicting the risk of infection recurrence after a two-stage procedure. Synovial fluid analysis before reimplantation has been shown to be the most accurate in predicting recurrence, and new cutoff values for leukocyte count and neutrophil percentage have shown a useful predictive rule to identify patients at risk of unfavourable outcome. A new scoring system based on a numerical score calculated from the beta coefficient derived through multivariate analysis of D-dimer levels, synovial fluid leukocytes and relative neutrophils percentage has demonstrated high accuracy when it comes to guiding the second step of two-stage procedure. In conclusion, reimplantation may be a suitable option for patients who are on continuous therapy without local symptoms, and with CRP and ERS within the normal range, with low synovial fluid leukocytes (< 952/mL) and a low relative neutrophil percentage (< 52%) and D-dimer below 1100 µg/mL. A numerical score derived from analysing these three parameters can serve as a valuable tool in determining the feasibility of reimplantation in these patients.
Background
Stroke has relevant morbidity and mortality despite appropriate treatments and early diagnosis. Beside common risk factors such as diabetes and atrial fibrillation, infections can be ...involved in stroke pathogenesis, probably causing a systemic release of cytokines and other inflammatory mediators, triggering a latent pro-thrombotic state or damaging the vascular endothelium. In other cases, infections can occur as stroke-like syndromes, requiring a high grade of suspicion to avoid a delay in establishing a correct diagnosis.
Results
Treatment of stroke or stroke-like syndromes of infectious origin can be difficult. When a previous infective event triggers stroke, Alteplase administration can be associated with a higher incidence of bleeding and the extension of the ischaemic area can be major than expected. On the other hand, when stroke is part of some infectious diseases’ presentation as in endocarditis, bacterial or tuberculous meningitis and meningo-vascular syphilis, a correct diagnosis can be difficult. The management of these stroke-like syndromes is not standardised because common treatments proven to be effective for patients with stroke of vascular origin can worsen the prognosis, as it can be demonstrated after to be incorrect Alteplase administration to patients with endocarditis with septic embolism to the brain is associated with an increase of the risk of haemorrhage.
Conclusions
Stroke or stroke-like syndrome of infectious origin can be observed in an important proportion of case presenting with sensory-motor deficit of unknown origin; their accurate diagnosis has a considerable impact in terms of treatment choices and outcome.
Knee arthrodesis with intramedullary (IM) nail or external fixator (EF) is the most reliable therapeutic option to achieve definitive infection control in patients with septic failure of total knee ...arthroplasty (TKA). The first aim of this study was to compare re-infection rates following knee arthrodesis for periprosthetic joint infection (PJI) with IM nail or EF. The second aim was to compare rates of radiographic union, complication, and re-operation as well as clinical outcomes.
A systematic search was performed in electronic databases for longitudinal studies of PJIs (minimum ten patients; minimum follow-up = 1 year) treated by knee arthrodesis with IM nail or EF. Studies were also required to report the rate of re-infection as an outcome measure. Eligible studies were meta-analyzed using random-effect models.
The rate (95% confidence intervals) of re-infection was 10.6% (95% CI 7.3 to 14.0) in IM nail arthrodesis studies. The corresponding re-infection rate for EF was 5.4% (95% CI 1.7 to 9.1). This difference was significant (p = 0.009). The use of IM nail resulted in more advantages than EF for frequency of major complications and limb shortening. Other postoperative clinical and radiographic outcomes were similar for both surgical strategies.
The available evidence from the aggregate published data suggests that knee arthrodesis with EF in the specific context of PJI has a reduced risk of re-infection in comparison with the IM nail strategy. The use of IM nail is more effective for the complication rate and shortening of the affected limb.
Although synovial fluid can be used to diagnose periprosthetic joint infections (PJI) effectively, only the cutoff values adopted at the time of PJI diagnosis have been standardized, and few data are ...currently available about effectiveness of synovial fluid examination before definitive reimplantation.
We asked: (1) What are the most appropriate thresholds for synovial fluid leukocyte counts (WBC) and neutrophil percentage (PMN percentage) in a patient group undergoing definitive reimplantation after an uninterrupted course of antibiotic therapy for chronic PJI? (2) What is the predictive value of our synovial WBC and PMN percentage threshold compared with previously proposed thresholds?
In all, 101 patients with PJI were evaluated for inclusion from January 2016 to December 2018. Nineteen percent (19 of 101) of patients were excluded because of the presence of a chronic inflammatory disease, acute/late hematogenous infection, low amount of synovial fluid for laboratory investigations or infection persistence after spacer placement, and adequate antibiotic therapy. Finally, 81% (82 of 101) of patients with a median (range) age of 74 years (48 to 92) undergoing two-stage revision for chronic TKA infection, who were followed up at our institution for a period 96 weeks or more, were included in this study. The patients did not discontinue antibiotic treatment before reimplantation and were treated for 15 days after reimplantation if intraoperative cultures were negative. No patient remained on suppressive treatment after reimplantation. Synovial fluid was aspirated aseptically with a knee spacer in place to evaluate the cell counts before reimplantation. Thirteen percent (11 of 82) of patients had persistent or recurrent infection, defined as continually elevated erythrocyte sedimentation rate or C-reactive protein levels coupled with local signs and symptoms or positive cultures. The synovial fluid WBC counts and PMN percentage from the 11 patients with persistent or recurrent PJI were compared with the 71 patients who were believed to be free of PJI. Receiver operating characteristic (ROC) curve analyses assessed the predictive value of the parameters, and the areas under the curves (AUCs) were evaluated. The sensitivities, specificities, and positive and negative predictive values were determined for the WBC count and PMN percentage. Patients with persistent or recurrent infection had higher median WBC counts (471 cells/µL versus 1344 cells/µL; p < 0.001) and PMN percentage (36% versus 61%; p < 0.001) than did patients believed to be free of PJI.
ROC curve analysis identified the best threshold values to be a WBC count of 934 cells/µL or more (sensitivity 0.82 95% CI 0.71 to 0.89, specificity 0.82 95% CI 0.71 to 0.89) as well as a PMN percentage of at least 52% (sensitivity 0.82 95% CI 0.71 to 0.89 and specificity 0.78 95% CI 0.67 to 0.86. We found no difference between the AUCs for the WBC count and the PMN percentage (0.87 95% CI 0.79 to 0.96 versus 0.84 95% CI 0.73 to 0.95. Comparing the sensitivities and specificities of the synovial fluid WBC count and PMN percentage proposed by other authors, we find that a PMN percentage more than 52% showed better predictive value than previously reported.
Based on our findings, we believe that patients with WBC counts of at least 934 and PMN percentage of 52% or more should not undergo reimplantation but rather a repeat debridement, as their risk of persistent or recurrent PJI appears prohibitively high. The accuracy of the proposed cutoffs is better than previously reported.
Level III, diagnostic study.
Abstract
Background
The septic arthritis of the hip is a complex condition characterized by a variety of clinical presentations, a challenging diagnosis and different surgical treatment options, ...including arthroscopy, resection arthroplasty and one and two-stage total hip replacement. Each technique reports variable results in terms of infection eradication rate. The aim of this systematic review is to compare the most relevant studies available in current literature and to assess if a better treatment outcome can be predicted based on the microbiology, history, and type of infection (active vs quiescent) of each case.
Methods
A systematic review of the literature was performed in accordance with the PRISMA guidelines, including the studies dealing with the treatment of hip septic arthritis in adult patients. Electronic databases, namely the MEDLINE, Scopus, and Web of Science, were reviewed using a combination of following keywords “septic arthritis” AND “hip joint” OR “hip” AND “adult”.
Results
The total number of patients included in this review was 1236 (45% of which females), for 1238 hips. The most common pathogen isolated was
Staphylococcus aureus
in its Methicillin-sensitive variant ranging from 2 to 37% of cases. Negative cultures were the second most common finding. It was also differentiated the type of infection of the hip, 809 and 417 patients with active and quiescent hip infection, respectively, were analyzed. Eradication rates for two-stage revision arthroplasty ranged between 85 and 100%, for one-stage approach between 94 and 100%, while for arthroscopic debridement/lavage between 89 and 100%.
Conclusion
Staphylococcus aureus
is the most common microorganism isolated followed by culture negative infections. Arthroscopic, one and two stage procedures can be effective in the treatment of hip septic arthritis when the indication is consistent with the type of infection retrieved.
Level of evidence
IV, therapeutic study.
Introduction
Two methods are currently available for the assay of α-defensin: the enzyme-linked immunosorbent assay (ELISA) and the lateral flow test. We aimed to assess the diagnostic accuracy of ...synovial fluid α-defensin and to compare the accuracy of the laboratory-based test and the qualitative assessment for the diagnosis of hip and knee prosthetic infection.
Materials and methods
We searched (from inception to May 2018) MEDLINE, Scopus, EMBASE, Web of Science, and Cochrane for studies on α-defensin in the diagnosis of periprosthetic joint infection (PJI). Sensitivity, specificity, positive and negative likelihood ratio (LR), and diagnostic odds ratio were analyzed using the bivariate diagnostic random-effects model. The receiver-operating curve for each method was calculated.
Results
We included 13 articles in our meta-analysis, including 1170 patients who underwent total hip and knee arthroplasties revision; 368 (31%) had a joint infection according to MSIS and MSIS-modified criteria. Considering the false-positive result rate of 8% and false-negative result rate of 3%, pooled sensitivity and specificity were 0.90 (95% CI 0.83–0.94) and 0.95 (0.92–0.96), respectively. The area under the curve (AUC) was 0.94 (0.92–0.94). No statistical differences in terms of sensitivity and specificity were found between the laboratory-based and qualitative test. The pooled sensitivity and specificity of the two alpha-defensin assessment methods were: laboratory-based test 0.97 (95% CI 0.93–0.99) and 0.96 (95% CI 0.94–0.98), respectively; qualitative test 0.83 (95% CI 0.73–0.91) and 0.94 (95% CI 0.89–0.97), respectively.
The diagnostic odds ratio of the α-defensin laboratory based was superior to that of the qualitative test (1126.085, 95% CI 352.172–3600.702 versus 100.9, 95% CI 30.1–338.41;
p
< 0.001). The AUC for immunoassay and qualitative tests was 0.97 (0.95–0.99) and 0.91 (0.88–0.99), respectively.
Conclusion
Detection of α-defensin is an accurate test for diagnosis of hip and knee prosthetic infections. The diagnostic accuracy of the two alpha-defensin assessment methods is comparable. The lateral flow assay is a valid, rapid, and more available diagnostic tool, particularly to rule out PJI.
Arthroscopic partial meniscectomy is a common procedure in orthopedic practice. Infections are uncommon complications of this procedure with an incidence rate of 0,01% - 3,4%. Staphylococcus spp are ...the predominant causative agents in such cases. We present a case of knee septic arthritis caused by α-hemolytic Streptococcus.
A 22-year-old woman diagnosed with obesity (body mass index BMI 35 kg/m
) but with no other major comorbidities underwent an arthroscopic selective meniscectomy with administration of intravenous cefazolin for antibiotic prophylaxis. After an uneventful period of 2 months, the patient returned with pain, fever and a discharging sinus at the site of anterolateral arthroscopic portal. Blood tests and magnetic resonance imaging revealed osteomyelitis involving the tibial plate. Cultures of synovial fluid obtained from the knee and a pharyngeal swab yielded α-hemolytic Streptococcus. Five days later, the patient underwent arthroscopic debridement with partial synovectomy. Intraoperative specimens yielded α-hemolytic Streptococcus. The patient received intravenous piperacillin/tazobactam, followed by an associative regimen of amoxicillin and clindamycin with clinical, laboratory and instrumental evidence of symptom resolution.
The incidence of knee septic arthritis after arthroscopic partial meniscectomy is 0.01-3.4%. This infection is usually caused by Staphylococcus spp. and in rare cases by commensal bacteria, such as α-hemolytic streptococci, secondary to transient bacteremia. Screening of the colonized area is important to prevent possible transient bacteremia. Diagnosis is based on isolation of the causative organisms from synovial fluid cultures, and treatment comprises arthroscopic debridement with individualized systemic antibiotic therapy based on the results of an antibiogram.
The current literature on the diagnosis of periprosthetic joint infection provides controversial evidence on the diagnostic accuracy of MLR, NLR, PVR, and PLR. Therefore, this critical literature ...search and meta-analysis was aimed to summarize the diagnostic accuracy of these biomarkers for the diagnosis of hip and knee prosthetic infection. According to the PRISMA flowchart, we searched MEDLINE, Scopus, and Web of Science, for studies on these ratios for diagnosing PJI. Sensitivity, specificity, positive and negative likelihood ratio, diagnostic odds ratio, and AUC were analyzed. We included 11 articles in our meta-analysis, including 7537 patients who underwent total hip and knee arthroplasties; among these, 1974 (26%) patients reported a joint infection. The pooled sensitivity and specificity were 0.72 and 0.74, respectively, for NLR, 0.72 and 0.77 for PVR, and 0.77 and 0.75 for PLR. The sensitivity of MLR ranges from 0.54 to 0.81, while the specificity ranges from 0.78 to 0.81. Regarding the evaluation of AUCs, the best diagnostic performance was achieved by MLR (AUC = 0.77) followed by PLR (AUC = 0.75), NLR (AUC = 0.73), and PVR (AUC = 0.70). This meta-analysis demonstrates a fair diagnostic accuracy of these ratios, thus not being useful as a screening tool.
Background: Highly Active Antiretroviral Therapy (HAART) for HIV infection and Direct-Acting Antivirals (DAA) for HCV infection currently represent the main treatment options for HIV/HCV co-infected ...patients. However, HAART has been associated with increased lipids. This study aimed to evaluate lipid profile changes after the DAA cycle in HIV/HCV co-infected patients undergoing HAART/DAA therapy. Methods: A prospective, longitudinal, observational study among HIV/HCV co-infected patients undergoing HAART/DAA treatment was conducted at the Infectious Diseases Unit of the University Hospital of Salerno. Inclusion criteria were age > 18 years, written informed consent, completion of the DAA cycle, and virologic suppression on HAART. Changes in the lipid profile were analyzed from baseline during and after DAA therapy at 12, 24, and 48 weeks after the sustained virologic response (SVR). A t-test was used to compare continuous variables. An analysis of variance was performed for each antiretroviral drug and genotype. Results: Fifty-four HIV/HCV patients (men/women n. 34/20 68/32%, median age 56 years), all naïve to HCV therapy, were enrolled. HCV infection was caused by genotype 1 in 55% of cases and by genotype 3 in 29%. An increase in total cholesterol was recorded after the DAA treatment (from 165.03 ± 46.5 to 184.7 ± 44.9 mg/dL, p < 0.0001), after 12, 24, and 48 weeks, and in LDL-C at 24 weeks follow-up (at baseline 86.7 ± 34 mg/dL to 103.4 ± 41.38 mg/dL, p < 0.0001). Conclusions: Changes in the lipid profile after combined DAA/HAART treatment represent an important prognostic index. Further evaluation of cardiovascular-associated risk is necessary to implement appropriate prevention strategies.
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