Hundreds of thousands of orthopedic implantations are performed each year in the U.S., yet failure rates of these replacements remain significant. Second generation cementless prostheses, the hopeful alternative to poly-methylmethacrylate fixation, have not fulfilled their promise of long term stability. The cause remains essentially the same: differential stress at the bone-implant interface which impairs osteointegration and results in the formation of particulate debris and the reactive formation of poorly defined and mechanically unstable fibrous tissue. Lynntech, Inc., proposes to develop a bioelectronic coating for porous prostheses which combines the osteoconductive properties of a biological matrix with a piezoelectric polymer (polyvinylidene difluoride) that has proven osteoinductive capability. It is anticipated that this combination will not only lead to improved initial osteointegration of implants, but that PVDF, being bioinert, will remain associated with newly formed tissue at the bone-implant interface. Being permanently piezoelectric, it may then provide the basis for response to changes in stress at this interface by electrically stimulating further bone remodeling. The result would be a prosthetic surface capable of active response to a dynamic environment, thus decreasing failure rates.
