OBJECTIVE: The purpose of this report was to describe the longer-term (>12 months) envelope effects on infection reduction and complications.
METHODS: All trial patients who underwent CIED replacement, upgrade, revision, or initial cardiac resynchronization therapy - defibrillator implantation received standard-of-care infection prophylaxis and were randomized in a 1:1 ratio to receive the envelope or not. CIED infection incidence and procedure and system-related complications were characterized through all follow-up (36 months) by using Cox proportional hazards regression modeling.
RESULTS: In total, 6800 patients received their intended randomized treatment (3371 envelope; 3429 control; mean follow-up period 21.0 ± 8.3 months). Major CIED-related infections occurred in 32 envelope patients and 51 control patients (Kaplan-Meier [KM] estimate 1.3% vs 1.9%; hazard ratio [HR] 0.64; 95% confidence interval [CI] 0.41-0.99; P = .046). Any CIED-related infection occurred in 57 envelope patients and 84 control patients (KM estimate 2.1% vs 2.8%; HR 0.69; 95% CI 0.49-0.97; P = .030). System- or procedure-related complications occurred in 235 envelope patients and 252 control patients (KM estimate 8.0% vs 8.2%; HR 0.95; 95% CI 0.79-1.13; P < .001 for noninferiority); the most common were lead dislodgment (1.1%), device lead damage (0.5%), and implant site hematoma (0.4%). Implant site pain occurred less frequently in the envelope group (0.1% vs 0.4%; P = .067). There were no (0.0%) reports of allergic reactions to the components of the envelope (mesh, polymer, or antibiotics).
CONCLUSION: The effects of the TYRX envelope on the reduction of the risk of CIED infection are sustained beyond the first year postprocedure, without an increased risk of complications.
METHODS: PMMA pellets were prepared with three separate concentrations of each of the two antibiotics tested. They were tested to determine the effect of increasing concentration of antibiotics on the biomechanical properties of PMMA and antibiotic activity by measuring the zone of inhibition and broth elution assay.
RESULTS: Ceftaroline PMMA at 3 wt%, three-point bending was 37.17 ± 0.51 N ( p < 0.001) and axial loading was 41.95 N ± 0.51 ( p < 0.001). At 5-wt% vancomycin-PMMA, three-point bending was 41.65 ± 0.79 N ( p = 0.02) and axial loading was 49.49 ± 2.21 N ( p = 0.01). Stiffness of ceftroline-loaded PMMA in low and medium concentration was significantly higher than the vancomycin. The zone of inhibition for ceftaroline was higher than vancomycin. Ceftaroline at 3 wt% eluted up to 6 weeks (0.3 ± 0.1 μg/ml) above the minimum inhibitory concentration (MIC) and vancomycin at 2.5 wt% eluted up to 3 weeks, same as MIC, that is, 0.5 ± 0.0 μg/ml.
CONCLUSIONS: Ceftaroline, loaded at similar concentrations as vancomycin into PMMA, is a more potent alternative based on its more favourable bioactivity and elution properties, while having a lesser effect on the mechanical properties of the cement. The use of 3-wt% ceftaroline as antibiotic laden PMMA against MRSA is recommended. It should be noted that this was an in vitro study and to determine the clinical efficacy would need prospective, controlled and randomized studies.
METHOD: We created an iontophoresis cell; 3% CF was inserted within medullary segment of goat bone and sealed from external saline solution. The cell operated at the following voltages 30, 60 and 90 V and at the following durations 5, 10, 15, 20, 25 and 30 min. Information regarding optimal conditions for its application was then obtained. After which, correlation between voltages and time with CF concentration in the bone was analysed. A bioavailability test was also conducted to observe the optimal rate of CF elution from the graft.
RESULT: The optimal condition for the impregnation process is 3% CF at 90 V for 10 min. Bone graft impregnated with CF at optimal conditions can elute above minimum inhibitory concentration of the CF against MRSA for 21 days.
CONCLUSION: CF iontophoresis was found feasible for allograft impregnation. The technique is simple, inexpensive and reproducible clinically. Iontophoresis offers a novel solution to reduce the rate of perioperative infection in reconstructive surgery involving use of bone graft.
Material and Methods: Retrospective review was done to the patients who received two-stage revisions with an antibiotic loaded cement-spacer for PJI of the hip between January 2010 to May 2015. We found 65 patients (65 hips) with positive culture findings. Eight patients were lost to follow-up and excluded from the study. Among the rest of the 57 patients, methicillin-resistant infection (MR Group) was found in 28 cases. We also evaluate the 29 other cases that caused by the other pathogen as control group. We compared all of the relevant medical records and the treatment outcomes between the two groups.
Results: The mean of follow-up period was 33.7 months in the methicillin-resistant group and 28.4 months in the control group (p = 0.27). The causal pathogens in the methicillin-resistant group were: Methicillin-resistant Staphylococcus aureus (MRSA) in 10 cases, Methicillin-resistant Staphylococcus epidermidis (MRSE) in 16 cases and Methicillin-resistant coagulase-negative Staphylococcus (MRCNS) in two cases. The reimplantation rate was 92.8% and 89.6% in the methicillin-resistant and control group, respectively (p= 0.66). The rates of recurrent infection after reimplantation were 23.1% (6/26) in the methicillin-resistant group and 7.6% (2/26) in the control group (p= 0.12). The overall infection control rate was 71.4% (20/28) and 89.6% (26/29) in the methicillin-resistant and control group, respectively (p = 0.08). Both groups showed comparable baseline data on mean age, BMI, gender distribution, preoperative ESR/CRP/WBC and comorbidities.
Conclusions: Two-stage revision procedure resulted in low infection control rate and high infection recurrency rate for the treatment of methicillin-resistant periprosthetic joint infection (PJI) of the hip. Development of the treatment strategy is needed to improve the outcome of methicillin-resistant periprosthetic joint infection (PJI) of the hip.