The technology was developed via a collaboration between Germany's Fraunhofer Institute for Manufacturing Technology and Advanced Materials, and the Charité-Universtitätsmedizin Berlin. It's part of the larger AntiSelectInfekt project.
The first step involves utilizing a laser to finely structure the surface of an existing titanium hip. Doing so leaves the surface of the metal full of microscopic pores, each one similar in shape to a tiny amphora – this means they're wider at the bottom than they are at the top.
Next, a technique known as physical vapor deposition is used to apply a thin layer of silver to the metal. The silver, which has antimicrobial properties, coats the inside walls of each pore without actually filling it up.
Finally, right before implantation, the titanium hip is dipped in an antibiotic solution. That liquid is drawn into the pores.
Once the hip has been implanted, the antibiotic (which is tailored to the specific needs of each patient) starts flowing from the pores into the surrounding tissue. This helps keep any infections from developing immediately after surgery. The silver, however, releases bacteria-killing ions for the next several weeks, providing protection against infections throughout the healing phase.