Patent ID: 6280443
Filing Date: 2001-08-28
Classification: A61B

Abstract:
A spinal fixation system for fixing at least one injured or decompressed vertebrae to a spine comprising:a plurality of pedicle screws, each pedicle screw having a stem protruding from a top portion thereof, the stem having threads on its outer surface, a spherical head formed below the stem, and a threaded shaft which is insertable to a pedicle of the vertebrae;a pair of rods for being located in a lateral aspect of the spine and connected to the pedicle screws, the rods extending are capable of on both sides of a plurality of spinal processes of the spine along the length of the spine for preventing a movement of the vertebrae;a number of correctors for coupling each of the pedicle screws to the rods with lateral adjustment, each connector having a rod passage formed to receive the rod therethrough, a set member bore formed in an upper portion of the connector to intersect perpendicular to the rod passage, and a support portion of a hemispherical shell which provides rotational freedom in coupling the pedicle screw and the connector, the support portion having an opening formed through a middle part of the support portion for holding the stem of the pedicle screw and a recessed hemispherical wall therein;a number of set members, each set member being inserted into the set member bore of the connector for fastening the rod inserted in the rod passage of the connector; anda number of fixing caps, each fixing cap having a stem bore formed to adapt the stem of the pedicle screw therethrough and a recessed hemispherical bottom surface,wherein the rod passage is made to have an outer boundary of two circles of slightly different diameters located at slightly eccentric center positions, and wherein at least a three point contact occurs between the rod and the rod passage by tightening the fixing cap regardless a degree to which the rod is bent.