Allergy protection of TiNbN-, TiN- coated implants

In the following we would like to inform about the PVD coating method and its impact for the treatment of metal allergic patients. The growing number of metal allergic patients represents a increasing problem of planning and success of  he prosthetic treatments in orthopedic and traumatologic surgeries The first endeavor for the surgeon is to investigates the constituents of the used alloys to prevent an allergic reaction. Although it is not scientifically proven if the contact between the metal components (i.e. with Nickel or Chrom contents) and the human bone lead to a subcutaneous allergic reaction the surgeon would like to reduce the remaining risk. Particularly the articulating surfaces of endoprosthetic components are made from CoCrMo metal alloy due to the better wear resistance in the combination with polyethylene parts. These alloys have a content of Nickel and Chromium which are critical for allergic reactions. The use of titanium alloys for articulating surfaces represents a weak compromise because of the higher wear.

Known from the early 50, implantcast GmbH and their partners offering the ceramic PVD coating of implant components since more than 10 years. The used PVD coating method lead to a ceramic surface. When a TiN ceramic film is applied to titanium or other metal alloys, the film to substrate interface is not susceptible to corrosion, and thus to corrosion delamination. In fact, a titanium coating is applied to steel parts to be coated with TiN for applications requiring corrosion resistance. The use of TiN coatings is now also becoming widespread to protect the cutting edges of hardened steel surgical instruments. A plasma vacuum chamber is used for the plasma vacuum deposition process (PVD Coating) (figure 1). The melted particles of the titanium source provide a TiNbN- bzw. TiN- layers on the implant surface of a thickness between  3 and 4µm.