PEEK Titanium Composite (PTC) for Spinal Implants

Since the development of the posterior lumbar interbody fusion (PLIF) and anterior approach for anterior cervical discectomy and fusion (ACDF) many different fusion substrates such as grafts and devices, have been explored. This includes autografts, allografts, and interbody spacers made from polyether-ether-ketone (PEEK), porous tantalum and titanium.In an attempt to combine only the advantages from both the PEEK and titanium interbody devices, a novel type of PEEK titanium composite (PTC) interbody fusion device has been developed. This device combines a PEEK core with titanium alloy endplates made from a novel 3-dimensional (3D) titanium mesh (Ti6Al4V) to potentially enable a better bone apposition and ingrowth while enabling imaging of the fusion site.This chapter covers how the novel PTC interbody devices are manufactured, which applications the PTC technology have currently been applied to, and how the mechanical properties of the interbody devices that employ the PTC technology compare to that of standard PEEK devices. In addition, the surface topography of the Ti6Al4V endplates will be discussed alongside a presentation of several in vitro and in vivo studies that have been completed for the PTC technology. Specifically, two in vitro studies will be presented showing the effect of each of the structural components (PEEK, Ti6Al4V) on the proliferation and differentiation of immature and mature osteoblasts. Furthermore, two in vivo studies will illustrate the effect of the structural components (PEEK, Ti6Al4V) on bone ingrowth/ongrowth and biocompatibility in a rabbit model, and the effect of a clinical PTC device in an ovine lumbar fusion model. Lastly, a discussion will summarize the presented studies and make the case for the PTC technology as a new standard for interbody devices in spine fusion.