Importance

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Abstract

A minimally invasive orthopedic bone attachment system comprising a pedicle screw and guide support sleeve for insertion of the screw. The pedicle screw is a self-boring, self-tapping integral screw having a distal sharply pointed end for guiding the insertion of the screw as well as forming a borehole for the self-tapping threads of the screw. The proximal end of the screw provides a cylindrical extension which can include a recess for receiving a rotational drive tool or wrench. The length of the threads and the type of threads provided in the screw are designed for the type of orthopedic surgery that is intended. A relatively thin hollow support sleeve including an internal threaded section in the distal end is provided to match the threads and the length of the threaded portion of the pedicle screw. The proximal end of the sleeve includes a central passageway having an internal diameter that can receive the extension portion of the screw and also guide and receive a drive device for the screw. A retainer clip associated with circumferential slots spacedly indexed along the longitudinal surface of the drive device can be used to limit the depth of the screw upon insertion as well as to lock the drive device as an assembly with the screw and sleeve to form the attachment system. A small diameter passageway can be provided along the longitudinal axis of the assembly extending from the proximal end of the drive device through the screw to exit through the pointed distal end of the screw. A thin rigid rod having a point at the distal end is slidably positioned within the narrow passageway. The proximal end of the road includes a cap. A flange surface on the under portion of the cap limits the travel of the rod through the assembly. The length of the rod is determined so that it equals the length of the assembly plus an additional dimension corresponding to the anticipated installed depth of the screw. Prior to insertion of the screw, the rod is driven into the bone through the assembly. The location of the rod is ascertained by an image guidance system to determine the correct final projected location of the screw upon installation.

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First Claim