Contamination Profile of the Mini C-Arm Fluoroscopy Unit in Orthopedic Surgery

Abstract

Category: Other; Ankle Introduction/Purpose: Fluoroscopy is critical for orthopaedic surgery. The mini C-arm is popular among foot and ankle surgeons owing ease of easy, maneuverability, and cost effectiveness. However, there are concerns that the mini C-arm may represent a potential source of contamination and increasing the risk of postoperative infection. Evaluation of large c-arm drapes have shown high rates of contamination. However, the mini C-arm may be even more concerning due to how it is handled. The mini c-arm is continuously manipulated by the surgical team who then return to the surgical field carrying with them any potential cross-contamination.Objective: We hypothesize that there is significant contamination of the drape, and that specific locations of the drape are at higher risk. Methods: 50 foot and ankle surgery cases which required the use of mini C-arm fluoroscopy were included. Eight locations on the mini C-arm drape were chosen for sampling. Locations were defined based on commonly touched areas on the drape by the surgical team, and their proximity to the non-sterile field. Negative controls were obtained by separately sampling an additional 20 mini C-arm drapes after draping c-arm and waiting for average surgery time. Positive controls were obtained by sampling non- sterile surfaces within the OR.Culture Q-swabs were used for sampling defined locations, using an established semiquantitative technique. Plates were incubated at 37 °C for 48 hours. Based on the number of quadrants on plate where colony growth was observed, bacterial growth was graded on a scale of 0, 1+, 2+, 3+, or 4+. Contamination threshold was defined as any growth pattern of 1+ or higher. Results: Figure 1 shows the contamination rates of the sampled areas of the c-arm drape. Contamination was noted in 70% of the cases for at least one area, and in two or more areas in 38% of cases.Contamination rates were significantly higher on defined locations in comparison with their relative negative control, except for locations 4 and 5. (P<0.05)The most frequently contaminated location was location #2 (30%) followed by Location 1 (26%), and then location 8 (22%). (P<0.05) Conclusion: Bacterial contamination of the drape was found to be common (70% of cases) after foot and ankle surgery. Contamination was more common on the superior and inferior aspects of the mini c-arm. This correlates to the area that is most commonly manipulated by the surgical team to position the arms of the c-arm. This information can be utilized by surgeons to identify and avoid high risk areas and, in high risk cases, they may consider changing gloves or re-draping the mini c-arm part way through the case.