Prosthetic polyethylene bearing having enhanced wear properties
AssigneeHowmedica Interntional Inc.
InventorChristina Doyle
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Abstract
A prosthetic bearing element having a bearing surface is made from an ultra-high molecular weight polyethylene with a molecular weight greater than 1,000,000 with a multi-axially molecular orientation. From tests which have been applied to such material, it has been found that the wear rate is lowered and preferably the direction of one of said axial molecular orientations extends parallel with or along the length of the bearing surface.
Claims11
A prosthetic bearing element having a bearing surface, said bearing surface made from a polyethylene material taken from close to the internal diameter of a drawn polyethylene tube, said tube made from polyethylene having a molecular weight greater than 1,000,000, said tube subjected to a single solid phase deformation in two directions to cause an orientation of the polymeric chains parallel to a bearing surface of said bearing element in only two perpendicular directions in the same area of the bearing surface, said deformation in two directions, having a deformation ratio of 1.3 to 1.9.
Dependencies are inferred from the claim text.