Patent ID: 8715322
Filing Date: 2014-05-06
Classification: A61B

Abstract:
1. A spine fixation device containing a set screw having a double spiral form comprising: a pedicle fixation screw which has a head portion having a receiving groove with a certain depth formed therein and a plurality of female screws formed in one region of the inner circumference of the receiving groove, and a screw portion which is extended lengthwise from one side of the head portion to be embedded into a pedicle and is fixed to a damaged pedicle; a spinal rod which is received in the receiving groove to connect pedicle fixation screws, thereby realigning the angle and interval of the pedicle; and a set screw in which a plurality of male screws having the same screw inner diameter, the same screw thread direction and different pitches are formed, and which is screw-coupled to the plurality of female screws of the pedicle fixation screw to prevent movement of the rod received in the receiving groove; wherein the set screw includes: wherein the first male screw portion is connected to the second male screw portion, and the number of male screws of the second male screw portion is n and the second pitch has a size 1/n times the first pitch, wherein n is a natural number of 2 or more.