Does a New Antibiotic Scheme Improve the Outcome of Staphylococcus aureus-Caused Acute Prosthetic Joint Infections (PJI) Treated with Debridement, Antibiotics and Implant Retention (DAIR)?

One of the most commonly used treatments for acute prosthetic joint infection (PJI) is DAIR (debridement, antibiotics and implant retention), which comprises the debridement and the retention of the implant, followed by antibiotic treatment. The efficacy of DAIR remains unclear, as the literature has demonstrated variable success rates, ranging from 26% to 92%. The Staphylococcus aureus is one of the most closely related causative microorganisms, especially with acute and late-acute PJI; it has been identified as one of the most significant predictors of DAIR failure. The current guidelines consider the use of vancomycin as the therapy of choice, but it requires the close control of possible side effects. The aim of this study is to determine if a new combination of antibiotics (a highly bactericidal initial combination followed by an antibiofilm scheme) decreases the failure of DAIR-treated acute prosthetic joint infection (PJI) caused by Staphylococcus aureus. A retrospective analysis of cases of orthopedic infections during a nine-year period (2011-2019) was performed. A total of 45 acute PJI cases caused by S. aureus were diagnosed. The results of two antibiotic schemes were compared: a novel scheme comprising 5 days of daptomycin (10 mg/kg/24 h) + cloxacillin (2 g/6 h) followed by levofloxacin (500 mg/24 h) + rifampicin (600 mg/24 h), versus a traditional, less bactericidal scheme of vancomycin (1000 mg/12 h) plus rifampicin (600 mg/24 h) or levofloxacin (500 mg/24 h) plus rifampicin (600 mg/24 h). Twenty-two out of the twenty-four patients treated with the new scheme (91.6%) were free of infection after 24.8 months of mean follow-up, whereas fourteen out of twenty-one patients (66.6%) were free of infection after 46.6 months of follow-up. This difference was statistically significant (p = 0.036). Demographic comparisons demonstrated homogeneous features, except the Charlson score, which was higher in the novel scheme group (p = 0.047). The combination of high-dose daptomycin and cloxacillin, followed by levofloxacin plus rifampicin, together with surgical treatment, shows better results when compared with other antibiotic schemes for treating acute PJI caused by S. aureus in which DAIR was performed.

Comparative In Vitro Study of Biofilm Formation and Antimicrobial Susceptibility in Gram-Negative Bacilli Isolated from Prosthetic Joint Infections.

Prosthetic joint infections (PJIs) are typically caused by microorganisms that grow in biofilms. Traditional antimicrobial susceptibility tests are based on the study of planktonic bacteria that might lead to missing the biofilm behavior and to a treatment failure. This study was designed to analyze the antimicrobial susceptibility of clinical Gram-negative bacilli (GNB) isolates from PJIs in planktonic and sessile states and the possible relationship between antimicrobial resistance and biofilm formation. A total of 46 clinical isolates from patients with PJIs (mainly hip and knee prostheses) plus three GNB ATCC isolates were studied. The Minimal Inhibitory Concentration (MIC), minimal bactericidal concentration (MBC), minimal biofilm inhibitory concentration (MBIC), and minimal biofilm eradication concentration (MBEC) were assessed using a previously published methodology. Almost all of the GNB clinical isolates tested were biofilm forming. Pseudomonas aeruginosa was the largest biofilm-forming species. A comparison of MBIC90 versus MIC90 shows an increase higher than 1- to -2-fold dilutions in most antimicrobials studied, and MBEC90 was significantly higher than MIC90, becoming resistant to all the antimicrobial drugs tested. Higher biofilm production values were obtained in antibiotic-susceptible Escherichia coli in comparison to their resistant counterparts. However, regarding the relationships between antimicrobial resistance and biofilm formation, our analysis showed that each strain differed. A high antimicrobial resistance rate was found among the GNB studied. Moreover, almost all bacterial isolates were in vitro biofilm formers. Although there was no significant association between biofilm and antibiotic resistance, multidrug-resistant isolates were found to be greater biofilm formers than non-multidrug-resistant isolates. IMPORTANCE This study is the first one to analyze a high number of isolates of Gram-negative bacilli that are the cause of prosthetic joint infection. The analysis includes biofilm development and antimicrobial susceptibility testing of both planktonic and sessile bacteria. The obtained results support the clinical knowledge about the treatment of these bacteria when biofilms are involved.

Evaluation of the use of sonication of retrieved implants for the diagnosis of prosthetic joint infection in a routine setting.

In order to evaluate the usefulness of sonication of retrieved implants for the diagnosis of prosthetic joint infection (PJI) in a large group of patients in a routine setting, we designed a 3-year retrospective study. Patients were classified into two groups: those meeting the clinical criteria of PJI and those that did not (control group). Two hundred patients and 276 samples were included. The types of infection were early (n = 44), delayed (n = 53), positive intraoperative cultures (n = 13) and late-acute (n = 8). The culture sensitivities of sonicate fluid, periprosthetic tissue, synovial fluid and combination of periprosthetic tissue and/or synovial fluid were 69.5, 52.8, 54.8 and 60.2%, respectively. The specificities were 97.6, 90.3, 93.0 and 89.9%, respectively. Sonicate fluid culture of implants was more sensitive than peri-implant tissue, synovial fluid and combination of periprosthetic tissue and/or synovial fluid for all infection types, though it was especially useful in delayed infection: 91.3% vs. 60.0% (p = 0.0015), 63.2% (p = 0.0005) and 66.7% (p = 0.0001), respectively. When sonicate fluid culture of implants was performed in addition to conventional cultures, the sensitivity increased significantly in total (from 60.2 to 77.1%) and delayed PJI (from 45.1 to 71.7%). On the other hand, for early PJI, sonicate fluid culture of prosthesis was not superior to conventional diagnostic methods.

Inmovilización frente a tratamiento funcional en esguinces de tobillo grado III / Inmobilisation vs functional treatment for grade III ankle sprain treatment

Objetivo: Comparar los resultados obtenidos en eltratamiento de los esguinces de tobillo grado III usandoalternativamente tratamiento inmovilizador con férulaposterior y vendaje elástico funcional con movilizaciónprecoz y carga progresiva.Material y métodos: Estudio prospectivo, cuasi-aleatorizado, con valoración prospectiva por observadores independientes ciegos al tratamiento utilizado, de 111 pacientes con esguince de tobillo grado III según la clasificación sistemática de West Point. Fueron tratados alternativamente según orden de llegada con inmovilización con férula posterior sin permitircarga o mediante tratamiento funcional con carga parcial.Fueron revisados al mes y a los 3 meses mediante un examenfísico protocolizado, cuestionario de "De Bie" y escala desatisfacción del paciente. Resultados: Cincuenta y ocho pacientes (52,2%) recibieron tratamiento funcional frente a 53 (47,7%) tratados con inmovilización. El resultado al mes de revisión fue 71,6 en la escala de "Bie" en el grupo tratado funcionalmente frente al 55,8 en los tratados con inmovilización (p=0,002). A los tresmeses el resultado fue 88,8 en el grupo funcional frente a70,1 en la inmovilización (p=0,00l). Se encontrarondiferencias estadísticamente significativas (p<0,05) al mes y a los tres meses. Los pacientes tratados funcionalmente estuvieron más satisfechos al mes y a los tres meses de evolución. Conclusiones: El tratamiento funcional parece ser una estrategia favorable para el tratamiento de esguinces de tobillo grado III comparándolo con la inmovilización. Los pacientes tratados funcionalmente se encuentran más satisfechos con su tratamiento

Objetive: To study the early outcomes of patients with grade III acute lateral ankle ligament injuries treated either with immobilisation orwith functional treatment. Material and Methods: Prospective oren trial with external blinded assessor of 111 consecutive patients treated at the A&E department of our Hospital with acute grade III (West Point c1assification) lateral ankle 1igament injuries. The patients weret reated alternatively with immobilisation in a posterior plaster cast for three weeks with no weight bearing permitted or with functional treatment with early mobilization and assisted weight bearing. Patients were reviewed one and three months after the injury. We use a standardised follow-up examination and the De Bie ankle assessment questionnaire for evaluation. A patient satisfaction questionnaire was also performed. Results: Fifty eight patients (52,2%) received functional treatment and 53 (47,8%) were treated with immobilisation. At one month follow-up we found an average De Bie score of 71.6 in the group treated functionally and 55.8 in the group treated by immobilisation (p=0.002). At three months follow-up we found an average De Bie score of 88.8 in the group treated functionally and 70.1 in fue group treated by immobilisation (p=0.001). Statistically significant differences (p<0.05) were found at one and three months follow-up. Patients treated functionally were more satisfied with their treatment. Conclusions: Functional treatment appears to be a favourable strategy for treating acute grade III ankle sprains when compared with immobilisation. Patients treated functionally were more satisfied with their treatment