Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1999-08-16
2002-11-12
Medley, Margaret (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C523S115000, C523S116000, C523S122000, C424S426000, C623S016110, C623S923000
Reexamination Certificate
active
06479565
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to compositions and methods for enhanced fixation of implants to bone.
BACKGROUND OF THE INVENTION
Although acrylic bone cement (self-curing poly-methyl-methacrylate) (PMMA) has been the mainstay of total hip and knee fixation for over three decades, it is inert and does not form a bone bond. Rather, it induces the formation of a fibrous membrane, which separates the implant cement mantle from the approximating host bone. Accordingly, it has been recognized that PMMA merely forms a mechanical fixation, as opposed to a biological bond of tissue.
Despite many efforts to improve acrylic cement, the desired end result of increasing the longevity of implant fixation and decreasing aseptic loosening has, to date, not greatly changed the long-term prognosis of implant recipients treated with such cements.
In recent years, investigators have sought to move from “cement fixation” to “bioactive fixation” with bioactive materials such as hydroxyapatite, bioactive glasses or ceramics. Bioactive glass is a bioactive silica-structured glass that undergoes a corrosive chemical reaction of dissolution, leaching and precipitation when contacted with tissue (body) fluids, simulated body fluids (SBFs) or aqueous solutions which permit interaction of the bioactive glass with approximating cells and tissues. These chemical reactions promote the formation of a carbonate hydroxyapatite (HCA) layer upon the bioactive ceramic or glass core, which acts as an osseoconductive (bone forming stimulus) agent, and new bone formation bridges the gap between the implant and the adjacent host bone (osseointegration), thus forming a true biological bond. However, the disadvantage of
known bioactive glass or other bioactive ceramic systems, even when mixed with appropriate resins, is that it takes months to produce enough new bone to achieve weight-bearing capacity. This is in contrast to the quick-fix-set of PMMA cement which at least provides in immediate weight-bearing capacity, even though as noted above, tending to fail in the long term.
SUMMARY OF THE INVENTION
The present invention provides a solution to the problems with known cements by providing a composition comprising (a) microscopic anhydrous pellets or particles containing the most important components of biological fluids or synthetic biological fluids (SBFs), (b) bioactive glass or other bioactive ceramic particles and (c) an appropriate resin such as, but not limited to, bisphenol-alpha-glycidyl methacrylate (BIS-GMA), to form a bone-forming cement which enhances (accelerates) bone production and bone bonding.
As a recipient's body or tissue fluids contact the components of the composition of this invention, a corrosive chemical reaction begins in which the anhydrous pellets or particles containing the components of biological fluids or SBF pellets are dissolved, thereby enhancing the corrosive chemical reaction at the surface of the bioactive glass or ceramic, and thereby accelerating a more uniform and significant amount of bone formation, not only on the surface of the cement mantle, but penetrating to a deeper level throughout the entire thickness of the mantle until the stem surface is reached. This process occurs in a continuous fashion over a period of time shorter than that typically required for bone infiltration when using bioactive glass or ceramic alone. The presence of anhydrous particles of biological fluids or SBFs, upon dissolution, produces voids into which bone cells easily migrate, until all the voids created by the dissolution of the pellets and the spaces between the resin particles are filled in with bone. This process is significantly different and superior to the quick initial cure and fixation set that occurs with PMMA cements, or the unacceptably long period of time required with bioactive glass or bioactive ceramic alone.
Accordingly, it is one object of this invention to provide a composition for rapidly and securely fixing an implant to a recipient's bone, while at the same time promoting autogenous bone infiltration into the cementous mantle about the implant.
A further object of this invention is to provide a method for rapidly and securely fixing an implant to a recipient's bone, while at the same time promoting autogenous bone infiltration into the cementous layer about the implant.
A further object of this invention is to provide a method for making and using a composition for rapidly and securely fixing an implant to a recipient's bone, while at the same time promoting autogenous bone infiltration into the cementous layer about the implant.
REFERENCES:
patent: 3971754 (1976-07-01), Jurecic
patent: 4224023 (1980-09-01), Cheung
patent: 4718910 (1988-01-01), Draenert
patent: 4725234 (1988-02-01), Ethridge
patent: 4758612 (1988-07-01), Wilson et al.
patent: 4772203 (1988-09-01), Scheunemann
patent: 4775646 (1988-10-01), Hench et al.
patent: RE33100 (1989-10-01), Ibsen et al.
patent: 4904264 (1990-02-01), Scheunemann
patent: 5079277 (1992-01-01), Wilson et al.
patent: 5218035 (1993-06-01), Liu
patent: 5453456 (1995-09-01), Mitra et al.
patent: 5874101 (1999-02-01), Zhong et al.
patent: 5914356 (1999-06-01), Erbe
patent: 6010713 (2000-01-01), Zhong et al.
patent: 6171986 (2001-01-01), Zhong et al.
patent: 2094326 (1982-09-01), None
patent: WO 91/17777 (1991-11-01), None
Andersson, O. H., and Kangasniemi, L. (1991). Calcium phosphate formation at the surface of bioactive glass in vitro. J. Biomed. Mater. Res., 25, 1019-1030.
Andersson, O. H., Rosenqvist, J., and Karlsson, K. H. (1993). Dissolution, leaching, and Al2O3enrichment at the surface of bioactive glasses studied by solution analysis. J. Biomed. Mater. Res., 27, 941-948.
Chang, R. W. (1996). A Cost-effectiveness Analysis of Total Hip Arthroplasty for Osteoarthritis of the Hip. JAMA. vol. 275, No. 11.
Clark, A. E., Pameijer, C. H., and Stanley, H. R. (1996). “Bioglass ® as a pulpcapping agent”. J. Dent. Res. 75 Special Issue. Abstract #2104, p. 280.
Filgueriras, R. M., La Torre, G., and Hench, L. L. (1993). Solution effects on the surface reactions of a bioactive glass. J. Biomed. Mater. Res., 27, 445-453.
Filgueriras, R. M. (1993) Solution Effects on the Surface Reaction of Three Bioactive Glass Compositions. J. Biomed. Mater. Res., vol. 27, 1485-1493.
Frigstad, J. R., Kang, Y. H., and Park, J. B. (1997). “Reinforcement of PMMA bone cement with a continuous wire coil: a canine implantation study”. Transactions of Society for Biomaterials, New Orleans, La., Apr. 30-May 4, p. 239.
Fritsch, E. W. (1996). “Static and fatigue properties of two new low-viscosity PMMA bone cements improved by vacuum mixing”. J. Biomed. Mater. Res. 31: 451-456.
Gainey, G. M., Landesberg, R. L., and Katz, R. W. “Binding of osteoblast cell lines to extra cellular matrix proteins”. J. Dent Res. (1998) 77 Special Issue A, Abstract #861, p. 213.
Gross, K. A., Berndt, C. C, Goldschlag, D. D., and Iacono, V. J. (1997). “In vitro changes of hydroxyapatite coatings”. Int. J. Oral Maxillofac. Implants 12: 589-597.
Hench, L. L. (1991). Bioceramics: From concept to clinic. J. Am. Ceram. Soc. 74, 1487-1510.
Hench, L.L. (1997). Bioceramics: Centennial Feature. J. Am. Ceram. Soc., vol. 81 No. 7, pp. 1705-1727.
Hench, L. L. (1998). “Bioactive materials, The potential for tissue regeneration”. J. Biomed. Mater. Res. 41: 511-518.
Hench, L. L., and Ethridge, E. C. (1982). Biomaterials: An Interfacial Approach. Academic Press, New York, Chaps. 5, 7, 14.
James, R. (1984). Tissue response to dental implant devices. In Clinical Dentistry, vol. 5 (J. W. Clark, ed.). Harper & Row, Philadelphia, Chap. 48, pp. 8-9.
Jonck, L. M., Grobbelaar, C. J. and Strating, H. (1989). “The biocompatibility of a glass-ionomer cement in joint replacement: bulk testing”. Clinical Mater. 4: 85-107.
Jonck, L. M., Grobbelaar, C. J. and Strating, H. (1989). “Biological evaluation of glass-ionomer cement (Ketac-O) as an interface material in total joint replacement. A screening test”. Clin. Mater. 4: 201-224.
Kangasniemi, I. M. O., Vedel, E., de Blick-Hogerw
Fischer Joseph
Medley Margaret
Van Dyke Timothy H.
Van Dyke & Associates, P.A.
LandOfFree
Bioactive ceramic cement does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bioactive ceramic cement, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bioactive ceramic cement will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2946232