Short parenteral antibiotic treatment for adult septic arthritis after successful drainage

Arthroscopic Treatment of the Septic Ankle

Ankle joint sepsis is a relatively rare but potentially devastating pathologic process of the lower extremity that requires expeditious identification and management. Establishing the diagnosis of ankle joint sepsis is often challenging as it may present with concomitant pathologies and often lacks consistency in regard to classic clinical characteristics. Once a diagnosis has been established, prompt management is imperative to minimize the potential for long-term sequelae. The purpose of this chapter is to address the diagnosis and management of the septic ankle with a focus on arthroscopic treatment.

Redefining Staphylococcus aureus bacteremia: A structured approach guiding diagnostic and therapeutic management

The current duration of therapy in patients with Staphylococcus aureus bacteremia (SAB) is based on differentiating complicated from uncomplicated disease. While this approach allows clinicians and investigators to group SAB patients into broadly similar clinical categories, it fails to account for the intrinsic heterogeneity of SAB. This is due in part to the fact that risk factors for metastatic infection and confirmed metastatic infection are considered as equivalent in most scoring systems. In this viewpoint, we propose a two-step system of categorizing patients with SAB. Initially, patients with SAB would be categorized as 'high risk' or 'low risk' for metastatic infection based upon an initial set of diagnostic procedures. In the second step, patients identified as 'high-risk' would undergo additional diagnostic evaluation. The results of this stepwise diagnostic evaluation would define a 'final clinical diagnosis' to inform an individualized final treatment plan.

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.

Retrospective evaluation of 103 cases of septic arthritis in dogs

OBJECTIVE

This study examines inciting causes, diagnosis, treatment and risk factors for the recurrence and outcome of septic arthritis (SA) in dogs.

STUDY DESIGN

Medical records spanning 17 years from five referral hospitals were surveyed for presumptive and confirmed cases of SA.

RESULTS

SA was identified in 103 cases. Spontaneous septic SA was the most common inciting cause. The most commonly affected joints were the stifle (40%) and elbow (24%). Pre-existing osteoarthritis (OA) was present in 63% of septic joints and was associated with recurrence (p = 0.03). Treatment with antibiotics prior to presentation was associated with a negative synovial fluid culture (p = 0.014). A successful outcome was associated with early treatment (p = 0.001) and SA due to direct penetration (p = 0.04) or spontaneous cause (p = 0.003). Recurrence was more likely in dogs with unsuccessful outcomes (p = 0.004) and bodyweights >30 kg (p = 0.009).

CLINICAL SIGNIFICANCE

SA should be considered as a differential diagnosis in large breed dogs with pre-existing OA presenting with either an acute or chronic monoarthropathy. In the majority of cases, a successful outcome was achieved regardless of treatment type. Recurrence rates were low, but associated with pre-existing OA and higher bodyweight. Although treatment should be implemented as soon as possible to maximise outcome success, synovial fluid samples should ideally be obtained before empiric antibiotic administration.

Osteoarticular infections: a specific program for older patients?

BACKGROUND

With the increasing number of elderly patients, arthroplasties, fractures and diabetic foot infections, the worldwide number of osteoarticular infections (OAI) among the elderly is concomitantly expected to rise.

AIMS

We explore existing scientific knowledge about OAI in the frail elderly population.

METHODS

We performed a literature search linking OAIs to geriatric patients and comparing elderly patients (> 65 years) with average adults (range 18-65 years).

RESULTS

In this literature, financial aspects, comparison of diverse therapies on quality of life, reimbursement policies, or specific guidelines or nursing recommendations are missing. Age itself was not an independent factor related to particular pathogens, prevention of OAI, nursing care, and outcomes of OAI. However, geriatric patients were significantly more exposed to adverse events of therapy. They had more co-morbidities and more conservative surgery for OAI.

CONCLUSION

Available literature regarding OAI management among elderly patients is sparse. In recent evaluations, age itself does not seem an independent factor related to particular epidemiology, pathogens, prevention, nursing care, rehabilitation and therapeutic outcomes of OAI. Future clinical research will concern more conservative surgical indications, but certainly reduce inappropriate antibiotic use.

Limited improvement and high rate of complication in patients undergoing reverse total shoulder arthroplasty for previous native shoulder infection

BACKGROUND

The outcomes of reverse total shoulder arthroplasty (RTSA) surgery for the sequelae of former septic native joint shoulder arthritis are unknown but might be inferior to patients without prior bacterial arthritis.

METHODS

We performed a single-center case-control study embedded in our prospective RTSA cohort. We matched all patients with prior infections in a 1:1 ratio with patients who underwent RTSA for other indications. The matching variables were indication for surgery, age, sex, dominant/nondominant shoulder, and body mass index. We evaluated outcomes by Constant score and active function.

RESULTS

Among 1249 patients in the RTSA cohort, 14 were operated for sequelae of previous native shoulder joint infections. Although both groups significantly improved from preoperative to postoperative values, the outcome of postinfectious patients was clearly inferior in comparison with the control group (absolute [38 ± 17 vs. 75 ± 8, P < .01], relative Constant score [47 ± 19 vs. 88 ± 9, P < .01], Constant pain score [11.0 ± 3.1 vs. 14.3 ± 1.3, P < .01], subjective shoulder value [43 ± 26 vs. 85 ± 10, P < .01], abduction [70 ± 43 vs. 148 ± 29°, P = .001], and elevation [82 ± 49° to 131 ± 16°, P = .02]). Moreover, in the postinfectious group, overall surgical complications occurred in 36%, with the need for revision in 21%. There was, however, no recurrence of infection in any of the patients' shoulders.

CONCLUSION

RTSA for end-stage postinfectious joint disease is associated with a high number of complications and reoperations. Clinical outcomes are inferior to those without past infection.

Medical versus surgical treatment in native hip and knee septic arthritis

OBJECTIVE

Antibiotic treatment and arthroscopic or open drainage is the gold standard for septic arthritis. Full recovery takes time after surgery and hospital stay is longer than for arthrocentesis at the bedside. We aimed to evaluate the effectiveness of arthrocentesis (medical approach) versus a surgical approach.

METHOD

We retrospectively included 97 cases of native joint arthritis (hip and knee) between 2010 and 2017. The primary outcome was treatment failure of medical and surgical approaches (defined as surgical intervention within 7 days following diagnosis). Risk factors of failure were identified by univariable and multivariable logistic regression.

RESULTS

We included 72 cases of knee arthritis, of which 43 and 29 were treated medically and surgically, respectively; 25 cases of hip arthritis, of which 8 and 17 were treated medically and surgically, respectively. Failure was observed in 39.2% of cases in the medical group and in 30.4% in the surgical group (P=0.2) (37.5% vs. 52.9% and 39.5% vs. 17.2% for hip and knee, respectively). The univariate analysis identified age and male sex as risk factors for failure (P=0.048 and P=0.02, respectively), but only age was independently associated with failure (P=0.04). Hospital length of stay was 12 days shorter in the medical group (21 vs. 33 days, P=0.02), sequelae were less frequent and less important in the medical group (31.7% vs. 60%).

CONCLUSION

The medical treatment seems to be as effective as the surgical treatment for native joint septic arthritis with a shorter hospital stay and better functional outcome. Further prospective studies are warranted.

Surgical Options and Approaches for Septic Arthritis of the Native Hip and Knee Joint

Septic arthritis (SA) of the adult knee and hip is a constantly evolving and urgent surgical issue. The epidemiology has shifted over the last few decades as have the most popular antibiotics and surgical treatments. SA of all types is increasing in the United States. There remains a high variability in the conservative and surgical management options available. This review will outline the most current understanding of the etiology and epidemiology of SA and will also discuss the distribution of causative organisms and appropriate treatments for each. A summary of evidence for different debridement and reconstructive techniques will also be presented in addition to novel areas of research to decrease the morbidity of this constantly growing problem.

Short postsurgical antibiotic therapy for spinal infections: protocol of prospective, randomized, unblinded, noninferiority trials (SASI trials)

BACKGROUND

There are several open scientific questions regarding the optimal antibiotic treatment of spinal infections (SIs) with or without an implant. The duration of postsurgical antibiotic therapy is debated.

METHODS

We will perform two unblinded randomized controlled trials (RCTs). We hypothesize that shorter durations of systemic antibiotic therapy after surgery for SI are noninferior (10% margin, 80% power, α = 5%) to existing (long) treatment durations. The RCTs allocate the participants to two arms of 2 × 59 episodes each: 3 vs. 6 weeks of targeted postsurgical systemic antibiotic therapy for implant-free SIs or 6 vs. 12 weeks for implant-related SIs. This equals a total of 236 adult SI episodes (randomization scheme 1:1) with a minimal follow-up of 12 months. All participants receive concomitant multidisciplinary surgical, re-educational, internist, and infectious disease care. We will perform three interim analyses that are evaluated, in a blinded analysis, by an independent study data monitoring committee. Besides the primary outcome of remission, we will also assess adverse events of antibiotic therapy, changes of the patient's nutritional status, the influence of immune suppression, total costs, functional scores, and the timely evolution of the (surgical) wounds. We define infection as the presence of local signs of inflammation (pus, wound discharge, calor, and rubor) together with microbiological evidence of the same pathogen(s) in at least two intraoperative samples, and we define remission as the absence of clinical, laboratory, and/or radiological evidence of (former or new) infection.

DISCUSSION

Provided that there is adequate surgical debridement, both RCTs will potentially enable prescription of less antibiotics during the therapy of SI, with potentially less adverse events and reduced overall costs.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04048304. Registered on 5 August 2019.

PROTOCOL VERSION

2, 5 July 2019.

Optimization of the antibiotic management of diabetic foot infections: protocol for two randomized controlled trials

BACKGROUND

Few studies have addressed the appropriate duration of antibiotic therapy for diabetic foot infections (DFI) with or without amputation. We will perform two randomized clinical trials (RCTs) to reduce the antibiotic use and associated adverse events in DFI.

METHODS

We hypothesize that shorter durations of postdebridement systemic antibiotic therapy are noninferior (10% margin, 80% power, alpha 5%) to existing (long) durations and we will perform two unblinded RCTs with a total of 400 DFI episodes (randomization 1:1) from 2019 to 2022. The primary outcome for both RCTs is remission of infection after a minimal follow-up of 2 months. The secondary outcomes for both RCTs are the incidence of adverse events and the overall treatment costs. The first RCT will allocate the total therapeutic amputations in two arms of 50 patients each: 1 versus 3 weeks of antibiotic therapy for residual osteomyelitis (positive microbiological samples of the residual bone stump); or 1 versus 4 days for remaining soft tissue infection. The second RCT will randomize the conservative approach (only surgical debridement without in toto amputation) in two arms with 50 patients each: 10 versus 20 days of antibiotic therapy for soft tissue infections; and 3 versus 6 weeks for osteomyelitis. All participants will have professional wound debridement, adequate off-loading, angiology evaluation, and a concomitant surgical, re-educational, podiatric, internist and infectiology care. During the surgeries, we will collect tissues for BioBanking and future laboratory studies.

DISCUSSION

Both parallel RCTs will respond to frequent questions regarding the duration of antibiotic use in the both major subsets of DFIs, to ensure the quality of care, and to avoid unnecessary excesses in terms of surgery and antibiotic use.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04081792. Registered on 4 September 2019.

Bone and joint infections of the hand

BACKGROUND

Little guidance is currently available for standardized diagnostic protocols and therapeutic recommendations for bone and joint infections (BJIs) of the hand.

OBJECTIVES

To summarize the available data in the scientific English-language literature on the diagnosis and treatment of native BJIs of the hand. To illustrate these concepts from a narrative point of view in areas where there is lack of evidence.

SOURCES

We performed a systematic PubMed and Internet search of studies that investigated hand BJIs in adult patients.

CONTENT

Few studies have systematically investigated and validated diagnostic concepts, classifications or surgical treatment protocols. Most concepts derive from traditional intra-institutional experience, expert opinions and extrapolations from infections in large joints and long bones. Similarly, there is no uniformly accepted infection definition of BJIs of the hand. The best-documented literature is available for microbiological findings and antibiotic treatment duration in uncomplicated native joint arthritis of the fingers. Retrospective studies and one prospective randomized trial suggest that post-surgical targeted antibiotic therapy of 2 weeks results in a microbiological cure rate of ≥88%.

IMPLICATIONS

Studies on diagnostic workup and infection definition and classification are urgently needed to compare inter-institutional outcome results and generate guidelines for the best patient care. For uncomplicated pyogenic arthritis of native joints, current evidence suggests that a 2-week course of antibiotic therapy following surgery cures the infection.

Inhibitor discovery for the E. coli meningitis virulence factor IbeA from homology modeling and virtual screening

Escherichia coli (E. coli) K1 is the most common Gram-negative bacteria cause of neonatal meningitis. The penetration of E. coli through the blood-brain barrier is a key step of the meningitis pathogenesis. A host receptor protein, Caspr1, interacts with the E. coli virulence factor IbeA and thus facilitates bacterial penetration through the blood-brain barrier. Based on this result, we have now predicted the binding pattern between Caspr1 and IbeA by an integrated computational protocol. Based on the predicted model, we have identified a putative molecular binding pocket in IbeA, that directly bind with Caspr1. This evidence indicates that the IbeA (229-343aa) region might play a key role in mediating the bacteria invasion. Virtual screening with the molecular model was conducted to search for potential inhibitors from 213,279 commercially available chemical compounds. From the top 50 identified compounds, 9 demonstrated a direct binding ability to the residues within the Caspr1 binding site on IbeA. By using human brain microvascular endothelial cells (hBMEC) with E. coli strain RS218, four molecules were characterized that significantly attenuated the bacteria invasions at concentrations devoid of cell toxicity. Our study provides useful structural information for understanding the pathogenesis of neonatal meningitis, and have identified drug-like compounds that could be used to develop effective anti-meningitis agents.

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.

Remission in diabetic foot infections: Duration of antibiotic therapy and other possible associated factors

AIM

To determine the most appropriate duration of antibiotic therapy for diabetic foot infections (DFIs).

METHODS

Using a clinical pathway for adult patients with DFIs (retrospective cohort analysis), we created a cluster-controlled Cox regression model to assess factors related to remission of infection, emphasizing antibiotic-related variables. We excluded total amputations as a result of DFI and DFI episodes with a follow-up time of <2 months.

RESULTS

Among 1018 DFI episodes in 482 patients, we identified 392 episodes of osteomyelitis, 626 soft tissue infections, 246 large abscesses, 322 episodes of cellulitis and 335 episodes of necrosis; 313 cases involved revascularization. Patients underwent surgical debridement for 824 episodes (81%), of which 596 (59%) required amputation. The median total duration of antibiotic therapy was 20 days. After a median follow-up of 3 years, 251 of the episodes (24.7%) were followed by ≥1 additional episode(s). Comparing patients with and without additional episodes, risk of recurrence was lower in those who underwent amputation, had type 1 diabetes, or underwent revascularization. On multivariate analysis including the entire study population, risk of remission was inversely associated with type 1 diabetes (hazard ratio [HR] 0.3, 95% confidence interval [CI] 0.2-0.6). Neither duration of antibiotic therapy nor parenteral treatment affected risk of recurrence (HR 1.0, 95% CI 0.99-1.01 for both). Similarly, neither >3 weeks versus <3 weeks of therapy, nor >1 week versus <1 week of intravenous treatment affected recurrence. In stratified analyses for both soft tissue DFIs or osteomyelitis separately, we did not observe associations of antibiotic duration with microbiological or clinical recurrences of DFI. The HRs were 1.0 (95% CI 0.6-1.8) for an antibiotic duration >3 weeks overall and 0.6 (95% CI 0.2-1.3) for osteomyelitis cases only. Plotting of duration of antibiotic therapy failed to identify any optimal threshold for preventing recurrences.

CONCLUSIONS

Our analysis found no threshold for the optimal duration or route of administration of antibiotic therapy to prevent recurrences of DFI. These limited data might support possibly shorter treatment duration for patients with DFI.

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.

Enterococci in orthopaedic infections: Who is at risk getting infected?

Some orthopaedic patients might be at risk for enterococcal infections and might benefit from adapted perioperative prophylaxis.

METHODS

We performed a single-center cohort of adult patients with orthopaedic infections.

RESULTS

Among 2740 infection episodes, 665 surgeries (24%) involved osteosynthesis material, including total joint arthroplasties. The recommended perioperative prophylaxis was cefuroxime (or vancomycin in case of documented MRSA body carriage). Patients had received antibiotic therapy before surgery in 1167 episodes (43%); among them with potential anti-enterococcal activity (penicillins, glycopeptides, imipenem, linezolid, daptomycin, aminoglycosids, tetracyclins) in 725 (62%) cases. Overall, enterococci were identified in intraoperative samples of 100 different infections (3.6%) (Enterococcus faecalis, 95; Enterococcus faecium, 2; and other enterococci, 3). However, only 15/100 (15%) enterococcal infections were monomicrobial and 19 were nosocomial (19/2740; 0.7%), of which 15 had previous cephalosporin perioperative prophylaxis without other antibiotic exposure. This association to prior cephalosporin use was significant (Pearson-χ²-test; 148/2640 vs. 15/100, p < 0.01). By multivariate analysis, the presence of diabetic foot infection (odds ratio 1.9, 95% confidence interval 1.2-2.9), and polymicrobial infection (OR 6.0, 95%CI 3.9-9.4) were the main predictors of enterococcal infection, while sex, age, and type of material were not.

CONCLUSIONS

Community-acquired or nosocomial enterococcal infections in orthopaedic surgery are mostly polymicrobial, rare and very seldom attributed to a nosocomial origin. Thus, even if they are formally associated with prior cephalosporin use, we do not see a rational for changing our antibiotic prophylaxis.

Proposal for shorter antibiotic therapies

OBJECTIVES

Reducing antibiotic consumption has now become a major public health priority. Reducing treatment duration is one of the means to achieve this objective. Guidelines on the therapeutic management of the most frequent infections recommend ranges of treatment duration in the ratio of one to two. The Recommendation Group of the French Infectious Diseases Society (SPILF) was asked to collect literature data to then recommend the shortest treatment durations possible for various infections.

METHODS

Analysis of the literature focused on guidelines published in French and English, supported by a systematic search on PubMed. Articles dating from one year before the guidelines publication to August 31, 2015 were searched on the website.

RESULTS

The shortest treatment durations based on the relevant clinical data were suggested for upper and lower respiratory tract infections, central venous catheter-related and uncomplicated primary bacteremia, infective endocarditis, bacterial meningitis, intra-abdominal, urinary tract, upper reproductive tract, bone and joint, skin and soft tissue infections, and febrile neutropenia. Details of analyzed articles were shown in tables.

CONCLUSION

This work stresses the need for new well-conducted studies evaluating treatment durations for some common infections. Following the above-mentioned work focusing on existing literature data, the Recommendation Group of the SPILF suggests specific study proposals.

Variables associated with remission in spinal surgical site infections

BACKGROUND

There is few medical literature regarding factors associated with remission after surgical and medical treatment of postoperative spine infections.

METHODS

Single-centre case-control study 2007-2014. Cluster-controlled Cox regression model with emphasis on surgical and antibiotic-related parameters.

RESULTS

Overall, we found 66 episodes in 48 patients (49 episodes with metalwork) who had a median follow-up of 2.6 years (range, 0.5 to 6.8 years). The patients had a median of two surgical debridements. The median duration of antibiotic therapy was 8 weeks, of which 2 weeks parenteral. Clinical recurrence after treatment was noted in 13 episodes (20%), after a median interval of 2 months. In 53 cases (80%), the episodes were considered as in remission. By multivariate analyses, no variable was associated with remission. Especially, the following factors were not significantly related to remission: number of surgical interventions [hazard ratio (HR) 0.9; 95% confidence interval (CI), 0.8-1.1]; infection due to Staphylococcus aureus (HR 0.9; 0.8-1.1), local antibiotic therapy (HR 1.2; 0.6-2.4), and, duration of total (HR 1.0; 0.99-1.01) (or just parenteral) (HR 1.0; 0.99-1.01) antibiotic use.

CONCLUSIONS

In patients with post-operative spine infections, remission is achieved in 80%. The number of surgical debridement or duration of antibiotic therapy shows no association with recurrence, suggesting that individual risk factors might be more important than the duration of antibiotic administration.

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.].

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.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.