The Far Side Opposite the Surgeon is Most Prone to Contamination From the C-Arm

Fluoroscopy is used in many orthopaedic procedures. The C-Arm drape is known to be easily contaminated during orthogonal imaging. However, it is unknown if one area of the operative field is more prone to contamination than another. The purpose of this study was to determine if secondary transfer of contaminate from the undraped portion of the C-Arm occurs.

A C-Arm was utilized with standardized draping in a simulated operating room. We used a simulated contaminant: a fluorescent powder that phosphoresces under ultraviolet light. The powder was placed over nonsterile portions. A darkened room with a black light, and a camera was used. C-Arm movements were simulated by cycling through lateral to Anteroposterior imaging. Images were taken before (control) and after cycles of orthogonal imaging. The change in light intensity was quantified at each time point over each area as a percentage of change.

Contamination of the surgical field was observed in all areas after 15 cycles, with the area adjacent to the C-Arm being most pronounced. A linear increase in intensity with increased cycles was observed (R = 0.297; P = 0.036), with the mean increase in intensity of 5% after 15 cycles (95% confidence interval, 1.97-7.86). The remaining areas (closest to surgeon and middle) showed an increase as well but were not significant (P > 0.05).

Secondary contamination of the surgical field from the C-Arm occurs. The area most prone to contamination is the area immediately adjacent to the fluoroscopy unit, usually opposite the surgeon.