In typical orthopedic implant fixation situations, such as spinal fusion or trauma repair, the role of the implant is to provide primary stabilization to the affected area until complete arthrodesis occurs, which can take several months. These implants are typically constructed from titanium or stainless as these are two of the most biocompatible materials available. Unfortunately, the modulus of these materials does not adequately match that of natural bone, leading to multiple failure modes. Even with new 3D-printed titanium and stainless-steel implants in which the modulus can be somewhat matched, emerging evidence is showing after initial integration, bone will pull away from the implant. 3D-printed polyetheretherketone (PEEK) has recently emerged as a material for fixation implants due to the radiolucency, biocompatibility and bone matching modulus. Although PEEK has several advantageous properties, the inert nature of the polymer restricts close contact between bone and implant surface, which can result in failure due to fibroblast encapsulation. Creating a sub-micron layer of nano-textured CP titanium on PEEK has shown in vivo to not have these issues. Full attachment of bone is achieved while keeping the modulus matching characteristics of bare PEEK, creating a much more robust implant, less susceptible to failure.
- Understand the interaction of an implant with the body, from both bulk material properties and surface characteristics
- Design the next generation of orthopedic implants
- Understand that 3D printing sometimes needs help to be successful