| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a replacement material for nucleus pulposuses of intervertebral discs which shows relatively high load supporting properties, reduces damage to fibrous rings for the insertion at the surgery, is retained in the fibrous ring stably after the surgery, and prevents the damage caused by the sliding movements against vertebral body cartilage endplates or the fibrous ring around a place where a prosthesis is placed, and its manufacturing method. <P>SOLUTION: The replacement material 4 for nucleus pulposuses of interval discs comprises a PVA (polyvinyl alcohol) gel dried body with a saturated moisture content of 18-50 percent by weight and varies shapes at a rate of shape deformation equal to or more than 150 volume percent when being hydrated. The method of manufacturing the replacement material 4 includes a process of making the PVA with the saturated moisture content of 20-53 percent by weight, of making the PVA into a PVA hydrogel in the hydrated state and forming it into a shape with a hollow part 4a, of irradiating the PVA hydrogel with γ rays of 20-100 kGy, and of drying while the PVA hydrogel is deformed to make the hollow part 4a disappear. <P>COPYRIGHT: (C)2007,JPO&INPIT |
