Radiation and melt treated ultra high molecular weight polyethylene prosthetic devices
AssigneesThe General Hospital Corporation, Massachusetts Institute of Technology
InventorsEdward W. Merrill, William H. Harris, Murali Jasty, Orhun K. Muratoglu, Charles R. Bragdon, Daniel O. O'Connor, Premnath Venugopalan
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Abstract
A medical prosthesis for use within the body which is formed of radiation treated ultra high molecular weight polyethylene having substantially no detectable free radicals, is described. Preferred prostheses exhibit reduced production of particles from the prosthesis during wear of the prosthesis, and are substantially oxidation resistant. Methods of manufacture of such devices and material used therein are also provided.
Claims22
A method for making a cross-linked ultra high molecular weight polyethylene (UHMWPE) article having substantially no detectable free radicals, comprising the steps of:
- a) providing UHMWPE having polymeric chains;
- b) heating the UHMWPE at a temperature that is below the melting point of the UHMWPE;
- c) irradiating the UHMWPE at a dose rate to provide a total absorbed dose to
- (i) cross-link the polymeric chains of the UHMWPE, and
- (ii) generate irradiation-induced heat,
- wherein the irradiation partially melts the UHMWPE, wherein the irradiation is performed in a manner to reduce the loss of heat;
- and
- d) cooling the heated UHMWPE.
A method for making cross-linked ultra high molecular weight polyethylene (UHMWPE) article having substantially no detectable free radicals, comprising the steps of:
- a) providing UHMWPE having polymeric chains;
- b) heating the UHMWPE to a temperature of no more than 90° C.;
- c) irradiating the UHMWPE at a dose rate to provide a total absorbed dose to
- (i) cross-link the polymeric chains of the UHMWPE, and
- (ii) generate irradiation-induced heat,
- wherein the irradiation partially melts the UHMWPE, wherein the irradiation is performed in a manner to reduce the loss of heat;
- and
- d) cooling the UHMWPE.
A method for making cross-linked ultra high molecular weight polyethylene (UHMWPE) article having substantially no detectable free radicals, comprising the steps of:
- a) providing UHMWPE having polymeric chains;
- b) heating the UHMWPE to a temperature ranging from about 90° C. to below the melting point of the UHMWPE;
- c) irradiating the UHMWPE at a dose rate to provide a total absorbed dose to
- (i) cross-link the polymeric chains of the UHMWPE, and
- (ii) generate irradiation-induced heat,
- wherein the irradiation partially melts the UHMWPE, wherein the irradiation is performed in a manner to reduce the loss of heat;
- and
- d) cooling the irradiated and heated UHMWPE.
A method for making a cross-linked ultra high molecular weight polyethylene (UHMWPE) article having substantially no detectable free radicals, comprising the steps of:
- a) providing UHMWPE having polymeric chains that is at room temperature or below room temperature;
- b) irradiating the UHMWPE at a dose rate to provide a total absorbed dose to
- (i) cross-link the polymeric chains of the UHMWPE, and
- (ii) generate irradiation-induced heat,
- wherein the irradiation partially melts the UHMWPE, wherein the irradiation is performed in a manner to reduce the loss of heat;
- and
- c) cooling the UHMWPE.
Dependencies are inferred from the claim text.