The highly popular 3D printing process is being used to build complete orthopedic implants, including the roughened surface, in one single process. The process is fast, ideal for low runs, and can create nearly production-ready implants. 3D printing utilizes a CAD program to build an implant, one layer at time. Layer thickness can be controlled down to a few microns. Using the CAD software, engineers determine the desired coating specifications and build the entire implant in a single run, with minimum post processing. 3D printing machines use either a laser or an electron beam to fuse the materials and build the parts.

EOS (laser) and Arcam (electron beam) are at the forefront in this market. Both companies have validated processes that orthopedic companies have used to build implants that have received 510(k) approval from the FDA. Ultimately 3D printing saves time and money by completing parts in a matter of hours instead of days, eliminating secondary steps, reducing material waste, and speeding time to market.

Thin HA Coatings

Plasma sprayed HA coatings have seen a great amount of success in the orthopedic industry since the time they were introduced into the market. However, plasma spraying is a high-temperature process that only coats the visible area of the implant. A thin HA coating will not only overcome these drawbacks, but also improve the functionality of the implant. Less than five microns in thickness, the coating covers the entire surface of the implant, including the insides of the pores, which helps osteointegration. As the bone grows into the pores, the HA coating inside the pores continues to promote growth. Applying the thin coatings is a low-temperature process that is relatively fast process, which shortens processing time delivering an improved product.

Thin HA coatings improve functionality compared to traditional coatings because the thin HA coats the inside of the porous surface. This is especially true for geometrically complex implants and devices. Because there are no thin HA coatings yet on the market, one of the greatest challenges in developing thin coatings is regulatory. The FDA has guidelines for plasma HA coating, but not for thin HA coatings. Companies are now conducting animal studies to test biocompatibility and to see if these coatings are beneficial for osteointegration. Coating characterization data will also be prepared and submitted.

Future Developments

Research and development is being conducted for all these technology advancements. The next step is receiving FDA clearance, which has established guidelines for porous metallic and HA coatings. It can take about 6 to 10 months to create a master file with the FDA for each of these coatings.

As these technologies become commercialized and enter the marketplace, OEMs can expect increased functionality and performance from their products. The payback comes in faster time to market, longer life cycle, improved end-user satisfaction, and better patient outcomes. Technology and material discoveries in the orthopedic market will likely have applications in other advanced manufacturing industries as well, such as biotechnology and aerospace.

This article was written by Parimal Bapat, Research Engineer, Orchid Orthopedic Solutions, Holt, MI. For more information, Click Here .