Spinal fixation system and method

摘要

A spinal fixation system is provided that, in one form, comprises a pedicle screw assembly having a coupling device with an elongate member for guiding a fixation element, such as a spinal rod, into the coupling device and a lock device for fixing the spinal rod to the coupling device. The pedicle screw assembly may be passed through a small incision and connected to a vertebral bone. By connecting a second pedicle screw assembly to a second vertebral bone, the elongate members of the pedicle screw assemblies provide guideposts for directing the spinal rod subcutaneously between the pedicle screw assemblies and into the coupling devices thereof.

主权项

1. A spinal fixation system for securing a spinal rod relative to a spinal bone, the system comprising:
a bone anchor having a spherical head and a shank depending from the head, the shank extending along a longitudinal axis; a coupling device for being connected to the bone anchor; an elongate guide member of the coupling device having a proximal end portion and a distal end portion and a longitudinal axis extending therebetween, the distal end portion including a flexible socket sized for fitting about the spherical head of the bone anchor for forming a ball and socket joint therewith; an outer surface of the elongate guide member for engaging and guiding the spinal rod; a body of the coupling device having a through opening sized to receive the proximal end portion of the elongate guide member extending therethrough to permit the body to be advanced along the elongate guide member toward the distal end portion thereof; an upwardly open seat of the body laterally offset from the shank longitudinal axis and the elongate guide member outer surface to permit the spinal rod to be slid downward along the outer surface and received on the upwardly open seat laterally offset from the shank longitudinal axis; a cup portion of the body configured to engage and constrict the flexible socket of the elongate guide member about the spherical bone anchor head for fixing the elongate guide member relative to the bone anchor with shifting of the body cup portion distally over the elongate guide member flexible socket; a locking device having a through opening sized to receive the elongate guide member therethrough and permit the locking device to be guidingly advanced downward along the elongate guide member; a capture member of the locking device for securing the spinal rod on the body seat; and mating surfaces of the elongate guide member and the locking device capture member which have a non-rotatable mating fit therebetween with the elongate guide member extending through the locking device through opening.