Device for connecting a longitudinal bar to a pedicle screw

Abstract

A device for connecting a longitudinal bar to a pedicle screw for fixation of the spine includes a body having an axis, an upper end, a lower end, a hole coaxial with the axis, and a through hole positioned perpendicular to the axis. The device also includes a collet chuck slidably disposed within the hole. The collet chuck includes a through hole substantially aligned with the through hole of the body for receiving the longitudinal bar. The collet chuck also includes a chamber defined by elastic tongues for receiving the head of the pedicle screw.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This is a division of U.S. patent application Ser. No. 10 / 122,405, filed Apr. 16, 2002, now U.S. Pat. No. ______, which is a continuation of U.S. patent application Ser. No. 09 / 341,963, now U.S. Pat. No. 6,371,957, which is a national stage of PCT International Application No. PCT / CH97 / 00019, filed Jan. 22, 1997, all of which are hereby incorporated by reference in their entireties.FIELD OF THE INVENTION [0002] The invention concerns a device for connecting a longitudinal bar to a pedicle screw. BACKGROUND OF THE INVENTION [0003] From the related art, a large number of pedicle screws for fixation of the spinal column are already known; these known pedicle screws have the advantage that the individual pedicle screw can be attached to or removed from the longitudinal bar at any time without having to dismantle the entire fixation system. Such a pedicle screw is known from European Patent No. 330,881 B, for example. [0004] The disadvantage...

AI Technical Summary

Benefits of technology

The invention provides a device for connecting a longitudinal bar to a pedicle screw that is easy to handle and allows for bending of the screw within a certain range. The device includes a body with a through hole for receiving the longitudinal bar and an opening in the bottom surface leading to the interior of the body. A collet chuck is slidably received in the interior of the body and has a through hole alignable with the body's through hole for insertion of the longitudinal bar. The collet chuck also has resilient tongues that flex outward for receiving the fastener head and flex back inward for retaining the fastener head in the chamber. The connector also includes a locking element for securing the longitudinal bar and collet chuck through holes. The device allows for a primary connection between the longitudinal bar and the pedicle screw and can be easily snapped onto the already implanted screw. The device offers the advantage of allowing the pedicle screws to be secured perpendicular to the longitudinal bar and also allows for an angle bend of up to ±25°. The refinement includes a spherical head with structuring to improve fixation.

Problems solved by technology

The disadvantage of this and similar pedicle screws is the relatively complicated locking mechanisms for securing the longitudinal bar inserted into the open pedicle screw head.

Furthermore, in most cases the head of the screw can be aligned with the position of the longitudinal bar only to a limited extent, necessitating complicated bending of the longitudinal bar to correct the angle.

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