In Vitro Effects of Alcohol-Based Surgical Skin Markers on Common Organisms in Orthopedic Infections

Surgical marking pens are commonly used for marking operative sites, anatomical landmarks, and demarcating wounds with cellulitis. Reuse of these pens by surgeons and registrars poses a risk of transmitting multiresistant bacteria. We aim to investigate this risk, hypothesizing that the alcohol-based ink may have inherent antimicrobial properties.

Five study groups were included: one control and four bacterial groups. Multiple pens were used in the bacterial groups for repeatability. Pens were inoculated with common organisms from prosthetic infections and swabbed at various time points. In total, 65 swabs were taken for bacterial culture.

All pens were sterile before inoculation, and the control group remained negative, confirming initial sterility. At 2 min, all 12 inoculated pens showed heavy bacterial growth. From 15 to 120 min, bacterial load decreased on all pens. Reinoculation of pens to account for the debridement effect of the swab demonstrated bacterial growth in at least 1 pen in all bacterial groups at T120.

The study confirms that the alcohol-based pens are sterile out of the box and exhibit bactericidal properties over a 120-min period. However, sterility cannot be guaranteed with reuse.