Does an Antimicrobial Incision Drape Prevent Intraoperative Contamination? A Randomized Controlled Trial of 1187 Patients

Abstract

Background The risk of periprosthetic joint infection (PJI), a serious complication after arthroplasty, has not changed for years. Interventions such as eradication of Staphylococcus aureus and antibiotic bone cement are used to diminish infection risk but despite these efforts, the percentage of infection in TKA remains constant. Antimicrobial drapes have a dual action, acting both as a physical and antimicrobial barrier to counter bacterial contamination of the surgical wound. To study the effect of antimicrobial drapes, we used intraoperative contamination as a proxy for infection in our investigation. Questions/purposes (1) Do antimicrobial surgical drapes reduce the risk of intraoperative microbial contamination in patients undergoing primary knee arthroplasty? (2) Are other factors such as sex, season, age, type of arthroplasty and duration of surgery associated with an increased risk of contamination in patients undergoing primary knee arthroplasty? (3) Does loosening of the antimicrobial drape increase contamination risk? Methods An investigator-initiated, two-arm, non-blinded, multicenter, randomized, controlled trial was performed at five different hospitals in the capital and central regions of Denmark. Twenty-four surgeons participated in the study. Participants were patients older than 18 years undergoing primary knee arthroplasty. We excluded patients with an iodine allergy, previous open knee surgery, previous septic arthritis, any antibiotics taken 4 weeks before surgery, and if they were unable to understand the implications of study participation. Patients were randomly assigned to operation with an antimicrobial drape (intervention group) or operation without (control group). We screened 1769 patients, of which 100 were ineligible and 10 declined to participate. In all, 94% (1659 of 1769) of patients consented and were randomized to the intervention group (51%, 838 of 1659) and control group (49%, 821 of 1659), respectively. In all, 36% (603 of 1659) of patients in the intervention group and 35% (584 of 1659) patients in the control group were available for final analysis. No crossover was performed, and analysis was done per-protocol. Patients were excluded due to logistic failures like lack of utensils, samples disappearing en route to the laboratory mainly caused by implementation of a new electronic patient chart (EPIC, Verona, WI, USA), and forgetful surgeons. Intraoperatively, we swabbed for bacteria at the surgical site and in a rinse from the surgeons’ gloves. All samples were sent for cultivation, and colony forming units (CFUs) counts ≥ 1 were deemed contaminated. The primary outcome measure was the difference in the proportion of contaminated patients between the two randomized groups. Secondary outcome measures were the affiliation of sex, season, age, type of implant used, and duration of surgery on contamination risk. To investigate whether other factors were affiliated with contamination risk, we did a logistic regression to control for confounding variables, including sex, age, season, type of implant and duration of surgery. Results Use of iodinated drapes reduced contamination, with contamination detected in 10% (60 of 603) procedures where iodinated drapes were used compared with 15% (90 of 584) when they were not (odds ratio 0.61 [95% CI 0.43 to 0.87]; p = 0.005), with a relative risk reduction of 35% (95% CI 12.3 to 52.5) and a number needed to treat of 18 patients. After controlling for confounding variables such as sex, age, type of implant, and duration of surgery, we found that not using an antimicrobial drape increased contamination risk by a factor of 1.6 (95% CI 1.08 to 2.35; p = 0.02). Female sex and undergoing surgery in the central region were associated with lower odds of contamination (OR 0.55 [95% CI 0.39 to 0.8]; p = 0.002 and OR 0.45 [95% CI 0.25 to 0.8]; p = 0.006, respectively). Patients with more than a 10-mm separation of the drape from the skin had higher odds of contamination (OR 3.54 [95% CI 1.64 to 11.05]; p = 0.0013). Conclusions The use of an antimicrobial drape resulted in lower contamination risk than operating without an antimicrobial drape. Our findings suggest that antimicrobial drapes are useful in infection prevention, but further studies are needed to investigate the effect of antimicrobial drapes on infection. Level of Evidence Level I, therapeutic study.

Does intraoperative contamination during primary knee arthroplasty affect patient-reported outcomes for patients who are uninfected 1 year after surgery? A prospective cohort study of 714 patients

“…The contamination rate of 12% is within the range found in similar studies (Byrne et al 2007 , Font-Vizcarra et al 2011 , Frank et al 2011 , Lindeque et al 2014 ) and in between the 10% (use of antimicrobial drape) and 15% (no use of antimicrobial drape) found in the study by Hesselvig et al ( 2020 ) (for 363 of the 714 included patients antimicrobial drapes were used). Average age and sex distribution of included patients were comparable to those reported in the Danish Knee Arthroplasty Register (DKR), which has a completion rate of 95%.…”

“…The study design was according to STROBE guidelines. This prospective cohort study combines data from 2 prospective multicenter studies, ICON (Hesselvig et al 2020 ) and SPARK (Mørup-Petersen et al, personal communication). These 2 studies enrolled patients from multiple hospitals over a 2-year period (2016–2018) with a partially shared patient cohort.…”

“…The analyses included adjustment of the parameter estimates for differences in the distributions of sex, age, type of prosthesis, and duration of surgery. These variables are known to influence either contamination (Byrne et al 2007 , Hesselvig et al 2020 ) or PRO improvements (Weber et al 2018 , Tolk et al 2019 ), and based on clinical experience they may reasonably be suspected of being confounders. None of the variables can induce bias when adjusting for these, as neither exposure nor outcome can affect the variables (i.e., they cannot be either a mediator or collider) (Shrier and Platt 2008 ).…”

“…Intraoperative bacterial contamination occurs in up to one-fourth of joint replacement procedures (Byrne et al 2007 , Font-Vizcarra et al 2011 , Frank et al 2011 , Lindeque et al 2014 , Hesselvig et al 2020 ). Periprosthetic joint infections (PJIs) causing clinical signs occur in approximately 1% of patients and it is suspected that most contaminations are of no clinical importance.…”

The Utility of Perioperative Products for the Prevention of Surgical Site Infections in Total Knee Arthroplasty and Lower Extremity Arthroplasty: A Systematic Review

“…Of the nine included studies that compared the use of iodine-impregnated surgical incise drapes to other practices, five reported decreased rates of SSIs with their use compared with groups of patients in which surgical incise drapes were not used. 19,35,[118][119][120] In one study, it was found that clear plastic adhesive incise drapes increased the risk of SSIs while iodine-impregnated alternatives did not have this effect. 121 Two studies found equivalent SSI rates between patients who received no incise drapes, 122,123 and one study reported similar rates between iodine-impregnated and clear plastic adhesive drapes (see ►Table 4).…”