Spinal disc herniation and the resulting symptoms of intractable pain, weakness, sensory loss, incontinence and progressive arthritis are among the most common debilitating conditions back problems. When conservative treatment fails, and diagnostic imaging evidence of nerve root or spinal cord compression is apparent, a discectomy, followed by fusion of the segment is performed. However this often results in progressive degeneration of discs at adjacent levels in the longer term. Hence disc replacements, which restore motion are a promising alternative to fusion. Current disc replacements use metal/PE bearings, which have historically shown a high incidence of failures. We seek to develop and demonstrate a novel motion preserving total disc replacement implant, designed from a patent pending ultra-low wear bearing material. The bearing material, which has shown impressive mechanical and tribological properties under an on-going NIH- Phase 2 grant for hip articulations, promises to leapfrog the current generation of total disc replacements presently in clinical trials. The implant will have no PE wear debris, permit full range of lateral bending and flexion-extension while limiting rotation, and will present no imaging problems, allowing the clinician full diagnostic """"""""access"""""""" to the disc space. In Phase I, we propose to fabricate and evaluate the full range of bio-mechanical properties and characterize the range of motion of the proposed total disc implant using human cadaver spines. In Phase 2 we plan to demonstrate the bio-mechanical functionality in-vivo: rapid bone in-growth characteristics, effective integration with host vertebral bodies and imaging compatibility of the implant in a sheep intervertebral model.
