This project presents a novel strategy and technology platform to achieve durable spinal stabilization despite non-fusion/pseudoarthrosis. The team proposes to develop novel nanotube enhanced micron porous interbody fusion devices (IFDs) and nanotube enhanced pedicle screws as fixation devices for spinal reconstruction. The technology is expected to speed up and maximize new bone formation and bone-to-implant fixation strength to durably stabilize spine segments in the absence of bridging bone - potentially reducing the significant human and societal costs of pseudoarthrosis-related complications in aging patients. In this study, the team first proposes to assess safety issues such as long term wear generation and risk of delamination of the material, then evaluate in vitro the affinity of materials to bone cells, and finally assess in vivo implant (IFDs and pedicle screws, respectively) to bone fixation strength in sheep models. The team also proposes to assess the feasibility of a new pseudoarthrosis animal model which would be used to assess the durability of stabilization over a longer term and the reduction in the severe and costly complications of pseudoarthrosis. Importantly there are no formally FDA reviewed and cleared nano technology labeled implants in the orthopedic market today and there is a lack of commercially oriented translational research focusing on long term wear debris analysis and reductions in complications of pseudoarthrosis. This project will provide regulators important translational data before implant nanotechnology can move forward and be used in products that benefit society.
There were an estimated 614,000 instrumented spinal fusion procedures between 2011 and 2012 in the United States alone. Spinal pseudoarthrosis leads to a significant chance of reoperation and a poor long term outcome including severe complications such as recurring debilitating pain, segmental instability, hardware loosening, hardware failure, and infection. Spinal fusion yields pseudoarthrosis rates up to 60% which are highly patient-related. Notably, higher risk patients include those aged, with multiple fusion levels, osteopenia, diabetes, cancer, and previously failed fusions. The toll in human suffering of the complications of pseudoarthrosis is considerable and the economic cost is quantifiable with an estimated $28,069 in Medicare patients. If one assumes 10% of all patients require re-operation for pseudoarthrosis, the estimated annual cost is $1.7 billion annually in the United States alone. To address the above serious clinical and societal issues created by the complications ofpseudoarthrosis, the team proposes to evaluate and commercialize an innovative technology platform. The high risk/high reward nature of this proposal is that the platform will be capable of stabilizing a spine segment without fusion. Specifically, the team proposes to combine our nanotube surface technology with our 3D micron porous titanium scaffold-PEEK implant technology to create a rapid stabilization platform of interbody fusion devices and pedicle screws. The platform is expected to provide faster and stronger biologic fixation that create in effect, a 'fast fusion' despite pseudoarthrosis while preserving PEEK's desirable modulus and imaging for IFDs.
