Can the radiopaque marker in surgical swabs scratch orthopaedic implant surfaces?

Aims To determine whether the radiopaque marker strip, which is woven in surgical swabs, causes measureable wear on metal implants at pressures typically used to wipe off fluid from their surface. Materials and methods Finger pressure used to wipe a surface was measured and used as a reference pressure for further testing. A tribological wear rig was then used to analyse the wear caused on polished titanium plates by a cobalt chromium pin (the control test), the pin covered by a surgical swab and the pin covered by a radiopaque marker strip. Results It was found that the cotton part or the radiopaque marker of surgical swabs on polished medical grade titanium plates caused no significant wear. In contrast severe scratching was observed from the cobalt chromium pin on its own. Conclusion To our knowledge, this is the first study in the literature analysing the wear caused by the surgical swabs and radiopaque strip on metal implants. The results suggest that surgical swabs are safe to use on metallic implants at pressures typical of a wiping motion.