Potential for contamination of orthopaedic implants using individually wrapped screws

There has been an anecdotal shift away from screw banks in orthopaedic surgery in preference for individually wrapped screws. Our hypothesis is that opening individually wrapped items introduces a possible source of contamination of the surgical set-up and repeated opening compounds this potential. Theoretically, this could pose a greater infection risk to the patient than the alternative of a screw bank.

One hundred screws were double wrapped in an identical fashion to the standard practice at our hospital. We used Glitterbug (Glitterbug cream is a commercially available product available from Brevis Corporation, Salt Lake City, Utah, USA) cream, which is designed to be near invisible to the naked eye but visible under ultraviolet light. After bathing their hands in the cream, 5 theatre nurses opened 20 screws as if being carried out during an operation. Ultraviolet light was used to evaluate transfer of the cream. Samples were considered positive if there was any evidence of fluorescence under ultraviolet light. Five screw banks were also opened and inspected using the same methods for comparison.

We identified contamination in one of the 100 screws. No contamination of the inner packaging of the screw banks was observed. At no stage did any participants believe that contamination had occurred.

This study has shown that the opening of individually wrapped items increases the risk for potential contamination of an operative field, suggesting that the move towards using individually wrapped components for surgery warrants further investigation. We believe that orthopaedic operating theatres should consider the use of screw banks to minimize the risk of contamination.