|Load Bearing Implants Using Laser Engineered Net Shaping (LENS) |
|Amit Bandyopadhyay, Washington State University|
12:10 PM, CCR 201
Musculoskeletal disorders are recognized as among the most significant human health problems that exist today with over 800,000 bone-grafting procedures each year and afflicting one out of seven Americans. In spite of enormous magnitude of this problem, there is still a lack of bone replacement material that is appropriate for restoring lost structure and function, particularly for load bearing applications. A typical example is total hip replacements (THR) in which a dense metal is used with significantly higher density, stiffness and strength than natural bone, which is a porous material. Typical lifetime of a THR is between seven to twelve years and this lifetime has remained almost constant over the past fifty years, even though significant research and development has gone towards understanding the problem. First major problem concerning metallic implants is the mismatch of Young's modulus between bone (10-30 GPa) and metallic materials (1l0 GPa for Ti and 210 GPa for Co-Cr-Mo). The second problem lies in the interfacial bond between the tissue and the implant due to bio-inert nature of metals. Use of porous materials in implants can reduce the stiffness mismatches due to porosity and achieve stable long-term biological fixation due to bone-tissue in-growth into interconnected porosity from the surface to the inside, which can enhance ill vivo lifetime. Laser engineered net shaping (LENSTM), an advanced rapid prototyping based manufacturing technology, is used to fabricate porous implants using Ti, CoCrMo and nitinol alloys to understand the influence of porosity on mechanical and biological properties. The presentation will discuss application of LENSTM towards load bearing implants as well as other advanced ceramics and metal ceramics composites.
Hosts: Ahmad Safari, Stephen Danforth