New Trends in Orthopedic Implant Coatings

Most orthopedic implant manufacturers still rely heavily on traditional coatings for their implants, such as sintered bead and plasma-sprayed metallic and hydroxyapatite (HA) coatings. These technologies are well-established, very familiar to both surgeons and the FDA, and have accumulated large bodies of supporting clinical and patient data for validation. However, there are some challenges to traditional coatings—for example, sintered bead coatings do not work on substrates of a different composition, such as a titanium coating adhering to a cobalt-chrome surface. Plasma spray coatings require surface preparation before coating, which can reduce fatigue strength of the implant, especially in titanium implants. Both sintered bead and plasma sprayed coatings are high-temperature processes that require more time and greater control, respectively.