Rates and Predictors of Treatment Failure in Staphylococcus aureus Prosthetic Joint Infections According to Different Management Strategies: A Multinational Cohort Study-The ARTHR-IS Study Group.

INTRODUCTION: Guidelines have improved the management of prosthetic joint infections (PJI). However, it is necessary to reassess the incidence and risk factors for treatment failure (TF) of Staphylococcus aureus PJI (SA-PJI) including functional loss, which has so far been neglected as an outcome. METHODS: A retrospective cohort study of SA-PJI was performed in 19 European hospitals between 2014 and 2016. The outcome variable was TF, including related mortality, clinical failure and functional loss both after the initial surgical procedure and after all procedures at 18 months. Predictors of TF were identified by logistic regression. Landmark analysis was used to avoid immortal time bias with rifampicin when debridement, antibiotics and implant retention (DAIR) was performed. RESULTS: One hundred twenty cases of SA-PJI were included. TF rates after the first and all surgical procedures performed were 32.8% and 24.2%, respectively. After all procedures, functional loss was 6.0% for DAIR and 17.2% for prosthesis removal. Variables independently associated with TF for the first procedure were Charlson ≥ 2, haemoglobin < 10 g/dL, bacteraemia, polymicrobial infection and additional debridement(s). For DAIR, TF was also associated with a body mass index (BMI) > 30 kg/m2 and delay of DAIR, while rifampicin use was protective. For all procedures, the variables associated with TF were haemoglobin < 10 g/dL, hip fracture and additional joint surgery not related to persistent infection. CONCLUSIONS: TF remains common in SA-PJI. Functional loss accounted for a substantial proportion of treatment failures, particularly after prosthesis removal. Use of rifampicin after DAIR was associated with a protective effect. Among the risk factors identified, anaemia and obesity have not frequently been reported in previous studies. TRIAL REGISTRATION: This study is registered at clinicaltrials.gov, registration no. NCT03826108.

Staphylococcus aureus is one of the most virulent bacteria and frequently causes prosthetic joint infections.Knowledge of the treatment of this type of infection has advanced in recent years, and treatment guidelines have led to improved management. Typically, the successful treatment of these infections has been determined by clinical cure, that is, the symptoms of infection have disappeared, but has not taken into account loss of function (such as significant difficulties walking), which is critical for the patient's quality of life. Our aim in this study was to evaluate the success of current management strategies for S. aureus prosthetic joint infection, including recovery of functionality, and the factors that predict why some of these infections are not cured, to identify areas for improvement.In a multinational cohort of 128 patients with S. aureus prosthetic joint infection, rates of treatment failure were found to be high, with significant rates of loss of function, especially when the prosthesis needed to be removed. Loss of function was less frequent when the infection was initially treated with surgical cleaning without removal of the prosthesis, even when this procedure failed at first. We found that anaemia and obesity were associated with lower treatment success, and that the probability of treatment success increased when surgical cleaning without prosthesis removal was performed early, and when the antibiotic rifampicin was used in combination with another antibiotic.

Preoperative and perioperative risk factors, and risk score development for prosthetic joint infection due to Staphylococcus aureus: a multinational matched case-control study.

OBJECTIVES: We aim to identify the preoperative and perioperative risk factors associated with post-surgical Staphylococcus aureus prosthetic joint infections (PJI) and to develop and validate risk-scoring systems, to allow a better identification of high-risk patients for more efficient targeted interventions. METHODS: We performed a multicenter matched case-control study of patients who underwent a primary hip and knee arthroplasty from 2014 to 2016. Two multivariable models by logistic regression were performed, one for the preoperative and one for perioperative variables; predictive scores also were developed and validated in an external cohort. RESULTS: In total, 130 cases and 386 controls were included. The variables independently associated with S. aureus-PJI in the preoperative period were (adjusted OR; 95% CI): body mass index >30 kg/m2 (3.0; 1.9 to 4.8), resident in a long-term care facility (2.8; 1.05 to 7.5), fracture as reason for arthroplasty (2.7; 1.4 to 5.03), skin disorders (2.5; 0.9 to 7.04), previous surgery in the index joint (2.4; 1.3 to 4.4), male sex (1.9; 1.2 to 2.9) and American Society of Anesthesiologists index score 3 to 4 (1.8; 1.2 to 2.9). The area under the receiver operating characteristic curve was 0.73 (95% CI 0.68 to 0.78). In perioperative model, the risk factors were the previous ones plus surgical antibiotic prophylaxis administered out of the first 60 minutes before incision (5.9; 2.1 to 16.2), wound drainage for >72 hours after arthroplasty (4.5; 1.9 to 19.4) and use of metal bearing material versus ceramic (1.9; 1.1 to 3.3). The area under the receiver operating characteristic curve was 0.78 (95% CI 0.72 to 0.83). The predictive scores developed were validated in the external cohort. DISCUSSION: Predictive scores for S. aureus-PJI were developed and validated; this information would be useful for implementation of specific preventive measures.

Adjunctive dexamethasone in bacterial meningitis: a meta-analysis of individual patient data.

BACKGROUND: Dexamethasone improves outcome for some patients with bacterial meningitis, but not others. We aimed to identify which patients are most likely to benefit from dexamethasone treatment. METHODS: We did a meta-analysis of individual patient data from the randomised, double-blind, placebo-controlled trials of dexamethasone for bacterial meningitis in patients of all ages for which raw data were available. The pre-determined outcome measures were death at the time of first follow-up, death or severe neurological sequelae at 1 month follow-up, death or any neurological sequelae at first follow-up, and death or severe bilateral hearing loss at first follow-up. Combined odds ratios (ORs) and tests for heterogeneity were calculated using conventional Mantel-Haenszel statistics. We also did exploratory analysis of hearing loss among survivors and other exploratory subgroup analyses by use of logistic regression. FINDINGS: Data from 2029 patients from five trials were included in the analysis (833 [41.0%] aged <15 years). HIV infection was confirmed or likely in 580 (28.6%) patients and bacterial meningitis was confirmed in 1639 (80.8%). Dexamethasone was not associated with a significant reduction in death (270 of 1019 [26.5%] on dexamethasone vs 275 of 1010 [27.2%] on placebo; OR 0.97, 95% CI 0.79-1.19), death or severe neurological sequelae or bilateral severe deafness (42.3%vs 44.3%; 0.92, 0.76-1.11), death or any neurological sequelae or any hearing loss (54.2%vs 57.4%; 0.89, 0.74-1.07), or death or severe bilateral hearing loss (36.4%vs 38.9%; 0.89, 0.73-1.69). However, dexamethasone seemed to reduce hearing loss among survivors (24.1%vs 29.5%; 0.77, 0.60-0.99, p=0.04). Dexamethasone had no effect in any of the prespecified subgroups, including specific causative organisms, pre-dexamethasone antibiotic treatment, HIV status, or age. Pooling of the mortality data with those of all other published trials did not significantly change the results. INTERPRETATION: Adjunctive dexamethasone in the treatment of acute bacterial meningitis does not seem to significantly reduce death or neurological disability. There were no significant treatment effects in any of the prespecified subgroups. The benefit of adjunctive dexamethasone for all or any subgroup of patients with bacterial meningitis thus remains unproven. FUNDING: Wellcome Trust UK.