Patent ID: 9011545
Filing Date: 2015-04-21
Classification: A61F,A61L

Abstract:
1. A method for replacing a nucleus pulposus in an intervertebral disk, which method comprises: providing a spinal intervertebral disk replacement molded-dry-product for nucleus pulposus which has a hollow region disappeared comprising a polyvinylalcohol gel that is irradiated with γ ray at an intensity of 50 to 100 kGy; and inserting the spinal intervertebral disk replacement molded-dry-product for nucleus pulposus into a prosthetic space inside an anulus fibrosus through an incision opening of the anulus fibrosus, wherein the molded-dry-product changes its shape into an almost cylindrical or almost elliptically cylindrical shape so that a hollow region comes into existence at a shape deformation rate of 200 vol % or more and at a volume swelling ratio of 135 vol % or less by water absorption, wherein the percentage of saturated water content of said polyvinylalcohol gel before irradiation is 18 to 25 wt %.