Background: Many orthopedic surgeries utilize intraoperative fluoroscopy. The mini C-arm is an advantageous device as it can be easily used without the need for a dedicated radiology technician. However, there are concerns that the mini C-arm may represent a potential source of contamination and subsequent postoperative infection. Previous investigations of standard C-arm drapes have shown high rates of contamination. Similar contamination rates would be even more concerning for the mini C-arm as it requires physically maneuvering the machine. This study aimed to determine the rate of mini C-arm drape contamination and identify high-risk areas.
Methods: Fifty foot and ankle surgeries requiring the use of mini C-arm fluoroscopy were included. Eight locations on the mini C-arm drape were sampled at the conclusion of each procedure. Culture Q-swabs were used for sampling defined locations. Swab samples were then assessed for bacterial growth on a 5% blood agar plate using a semiquantitative technique.
Results: In 70% of surgical cases, contamination was observed in at least 1 location. Six of the 8 evaluated locations were found to have significantly higher contamination in comparison with their corresponding negative controls (Mann-Whitney U test, P < .05). The "outer portion of the upper arm" (location 1) exhibited bacteria growth in 26% (P < .0001) of cases. The "superior portion of the x-ray source" (location 2) exhibited growth in 30% (P < .0001) of cases. These were the highest-risk areas for contamination and were both significantly more likely to be involved than the "inferior portion of the x-ray source" and "superior portion of the beam receiver," locations 4 and 5, respectively. Fourteen percent (7/50) C-arm cases and 1.72% (1/58) Achilles tendon surgery control cases developed surgical site infection (P = .0234; OR, 9.27).
Conclusion: Bacterial contamination of the mini C-arm drape was found to be common after foot and ankle procedures. Contamination was more prevalent on the outer ring areas of the C-arm, both at the emitter and receiver.
Level of evidence: Level III, prospective cohort study.
Keywords: contamination; draping; fluoroscopy; foot and ankle; infection; mini C-arm; sterility.