SBIR Phase II: Development of Osteogenic Pedicle Screws for Posterolateral Spinal Fusion

The broader impact/commercial potential of this project relates to the development of non-pharmacological interventions capable of improving clinical outcomes following spinal fusion surgery. Between 1998 and 2008, the annual number of spinal fusion surgeries increased 137% from 174,223 to 413,171 and the national bill for spinal fusion increased 7.9-fold. The greatest risk in spinal fusion procedures is failure to fuse, which can be particularly troublesome in high risk patients. Failure to fuse leads to poor surgical outcomes for patients and may result in chronic pain, secondary surgical procedures, reduced productivity, and/or permanent disability. In addition, failure to fuse results in greater clinical burden for physicians and increased cost per patient for payers. Lumbar fusions, in particular, have a cumulative reoperation rate of 19% over the 11 years following the initial procedure (BCC Research, 2010). The present project could result in the identification of new surgical devices and techniques capable of improving surgical outcomes, reducing complications, and eliminating costs associated with unsuccessful surgery. Osteogenic surgical device and techniques developed in the present project may also be used to accelerate bone healing and improve clinical outcomes following fractures of the skull, face, and long bones. This Small Business Innovation Research (SBIR) Phase 2 project is to demonstrate in an animal model that osteogenic spinal instrumentation accelerates new bone formation and improves the rate of posterolateral fusion compared to clinically-accepted best practices in spinal fusion surgery. Innovative osteogenic spinal instrumentation (pedicle screws, rods, etc.) facilitates both mechanical stabilization of the spine and focused delivery of fusion-stimulating direct electric current (DC) at the fusion site. Application of therapeutic stimuli via selectively anodized pedicle screws accelerates the rate at which new bone is formed in critical regions of the spine such as the zygapophyseal joint and lateral gutter. The propensity of newly formed bone to create a robust, biomechanically sound fusion of adjacent vertebrae is also increased under osteogenic stimulation. Phase I results demonstrate that selectively-anodized electroactive pedicle screws effectively deliver focused osteogenic stimuli to key regions of the lumbar spine critical to spinal fusion. Results provide computational evidence for the technological and clinical success of novel osteogenic instrumentation in spinal fusion surgery. Phase II will confirm that the system of electroactive spinal instrumentation has the potential to accelerate bone growth and improve post-surgical fusion outcomes compared to gold-standard interventions utilizing a clinically relevant large animal model.