Abstract: A tibial anchoring assembly comprising a tibial tray and an anchor. The tibial tray comprises an upper surface for engagement with a femoral component and a lower surface for engagement with a tibia bone. The lower surface defines at least one retaining aperture. The anchor is adapted to compressively couple the tibial tray to the tibia bone. The anchor comprises a longitudinally extending base, a top section coupled to the base and having a shape to be received into the retaining aperture of the tibial tray, and a flexible blade member protruding from the base. The flexible blade member is adapted to be flexed in tension while being inserted into the tibia bone, thereby exerting a compressive force between the tibial tray and the tibia bone. A deforming fixture may be used to shape the flexible blade member. Methods of affixing an implant to a bone structure are also provided.

Abstract: A tibial anchoring assembly comprising a tibial tray and an anchor. The tibial tray comprises an upper surface for engagement with a femoral component and a lower surface for engagement with a tibia bone. The lower surface defines at least one retaining aperture. The anchor is adapted to compressively couple the tibial tray to the tibia bone. The anchor comprises a longitudinally extending base, a top section coupled to the base and having a shape to be received into the retaining aperture of the tibial tray, and a flexible blade member protruding from the base. The flexible blade member is adapted to be flexed in tension while being inserted into the tibia bone, thereby exerting a compressive force between the tibial tray and the tibia bone. A deforming fixture may be used to shape the flexible blade member. Methods of affixing an implant to a bone structure are also provided.

Abstract: An elongated plastic slide bearing (10) comprises a top (30), sidewalls (32, 34) depending from the top (30), and connecting to walls (36, 44, 48 and 38, 46, 50) that form laterally inwardly extending recesses (40, 42). Lock ribs (62, 64) extend upwardly and inwardly from the inner walls (44, 46) of the recesses (40, 42) to upper edges (66, 68). The upper edges (66, 68) are spaced below the bearing top (30). The bearing (10) is adapted to be set down onto a support beam (14) that includes laterally outwardly projecting lock flanges (22, 24) at its top. The lock ribs (62, 64) contact the lock flanges (22, 24). When the bearing (10) is pushed downwardly, the lock ribs (62, 64) bend outwardly and allow the lock ribs (62, 64) to move into a position below the lock flanges (22, 24). When that happens, the lock ribs (62, 64) assume substantially unstressed positions in which their upper edges (66, 68) are below the lock flanges (22, 24).

Abstract: Solid-state deformation processing of crosslinked high molecular weight polymers such as UHMWPE, for example by extrusion below the melt transition, produces materials with a desirable combination of physical and chemical properties. Crosslinked bulk materials are heated to a compression deformable temperature, and pressure is applied to change a transverse dimension of the material. After cooling and stress relieving, a treated bulk material is obtained that has enhanced tensile strength in the axial direction orthogonal to the dimension change. In preferred embodiments, medical implant bearing materials are machined from the treated bulk material with the in vivo load bearing axis substantially parallel or coincident with the axial direction of the treated bulk material.

Abstract: Solid-state deformation processing of crosslinked high molecular weight polymers such as UHMWPE, for example by extrusion below the melt transition, produces materials with a combination of high tensile strength and high oxidative stability. The materials are especially suitable for use as bearing components in artificial hip and other implants. Treated bulk materials are anisotropic, with enhanced strength oriented along the axial direction. The material is oxidatively stable even after four weeks of accelerated aging in a pressure vessel containing five atmospheres of oxygen (ASTM F2003). Because of its oxidative stability, the deformation processed material is a suitable candidate for air-permeable packaging and gas sterilization, which has thus far been reserved for remelted crosslinked UHMWPE.

Abstract: A radiation crosslinked (50 kGy), pressure-treated UHMWPE material has been developed by applying compressive force on a crosslinked polymer in a direction orthogonal to an axial direction. The deformed material is then cooled while held in a deformed state. The resulting material is anisotropic, with enhanced strength oriented along the axial direction. The directionally engineered material is oxidatively stable even after four weeks of accelerated aging in a pressure vessel containing five atmospheres of oxygen (ASTM F2003). Because of its oxidative stability, the deformation processed material is a suitable candidate for air-permeable packaging and gas sterilization, which has thus far been reserved for remelted highly crosslinked UHMWPEs.