| 摘要 |
<p>1390445 Surgical implants VITEK Inc 18 May 1972 [20 May 1971] 23427/72 Heading A5R [Also in Divisions C1 and C3] A composite article suitable for in vivo implantation e.g. an artificial tooth or denture, a prosthetic joint, tendon or soft tissue, comprises biocompatible fibres bonded with a biocompatible polymer, the article having a porous fibrous structure, and the biocompatible fibres comprise a substantial portion of the internal and external surface of said article so that the critical surface tension over at least these portions of the surface is from 35 to 80 dynes/cm. The porosity is due to both spheroidal and dendritic spaces. The preferred fibres include carbon, including graphite fibres. The biocompatible polymer may be a perfluorinated polymer, polyethylene or a polyester. It may for example be PTFE at least part of which is in a fibrous form. The voids of article may constitute at least 60% of the total volume. The article may also incorporate a wear material bonded to a surface of the structrue. Said wear material comprising carbon fibres and PTFE sintered with the fibres so as to bind them together. The composite article may also contain a bonding resin attached to one surface of the body and adapted to bond the structure to other resins and to metal. The porous body of the invention may be made from a composition comprising biocompatible fibres, biocompatible polymer and a leachable substance such that when the composition is subjected to leaching, said substance is removed from the composition and the required porous structure is obtained. It is preferred that the leachable substance is water soluble for example sodium chloride of a particle size of 10 to 600 microns. A bonding material may be attached to the surface of the composition containing the leachable substance provided the leachable substance has been removed from that surface. The bonding material is preferably a fluorinated ethylene propylene polymer. An appliance for implantation may comprise such an article or composition bonded to a metal prosthesis preferably it is bonded to that part of the. prosthesis by means of which the prosthesis is implanted in and attached to the healthy bone or tissue of the patient. A tendon may comprise a high strength fabric e.g. of glass fibre or fluorinated ethylene propylene polymer with a porous article as defined above attached to each end. The composition containing the leached material may be prepared by forming a slurry comprising carbon fibres, PTFE fibres and a leachable substance in an isoparafinnic organic solvent in which the leachable material is insoluble, filtering to form a filter cake, compressing to further reduce the solvent content, rolling, oven heating and sintering at 610‹F to 680‹F for at least three minutes. A plurality of oven heated filter cakes may be stacked together before sintering to produce a material of desired thickness.</p> |
