Toxicological safety of silver

A previous attempt to incorporate silver as a bactericide onto the surface of an orthopaedic implant utilised electroplating techniques to deposit silver metal onto the surface of pins used on external fixation devices. This practice was abandoned in the early nineties because body fluids penetrating through the silver layer and causing preferential corrosion of the metal substrate. This in turn led to delamination of the silver layer and the release of relatively large amounts of metallic silver into the surrounding tissues.

The concentration of silver added to the implant surface by the Agluna™ process however has been controlled to a level more than sufficient to provide bactericidal activity. but also well below concentrations that would cause any potential toxicological side effects to patients.^7,8

Analysis has shown that the concentration of silver in treated implants is typically in the range of 5-10 μg/cm2 of the implant surface. Even in a typically large  mega-prosthesis⁹ this would result in a total inventory of  silver of in the order of 6 mg. For an average size patient this would represent a silver concentration approximately  300 times lower than the 'No Observable Adverse Effects Level' for humans of 32 mg/kg reported in the literature.