Method for attaching articulated, pedicle screws joined to a longitudinal member for spinal osteosynthesis

Abstract

A pedicle screw is pre-connected to a longitudinal member by an articulation joint. The articulation range is through an angle extending at least from a 90° angle between the longitudinal axis of the pedicle screw and the longitudinal axis of the longitudinal member to an angle sufficiently near a coaxial orientation between those longitudinal axes to permit the first pedicle screw to be screwed into a pedicle of a first vertebra with the longitudinal member attached to the first pedicle screw. A lock fixes the longitudinal member to the first pedicle screw in a selected orientation. A second pedicle screw has an anchor joint with a lock for receiving and being fixed to the longitudinal member after the longitudinal member is rotated into engagement with the anchor joint. The pre-connection with sufficient articulation eliminates the need to connect the longitudinal member to one of the pedicle screws through an incision and assures proper alignment of any bend placed in the longitudinal member.

1 . An improved method for surgically attaching a spinal implant to provide internal spinal fixation, the implant including at least two pedicle screws and a longitudinal member for rigid attachment to the pedicle screws to retain vertebrae in a selected, relative orientation, wherein the improvement comprises:
 (a) pre-connecting a first one of the pedicle screws in articulated attachment to a longitudinal member before installing the first pedicle screw in the pedicle of a vertebra;   (b) installing the first pedicle screw in a first vertebral pedicle while the longitudinal member is in articulated attachment to the first pedicle screw;   (c) installing the second pedicle screw in a second vertebral pedicle; and   (d) articulating the longitudinal member into engagement with the second pedicle screw.   
   
   
       2 . The method of  claim 1  wherein the longitudinal member is oriented substantially coaxially with the first pedicle screw while the first pedicle screw is being installed in the first pedicle. 
   
   
       3 . The method of  claim 2  and further comprising bending the longitudinal member while the longitudinal member is pre-connected to a first one of the pedicle screws and before installing that first one of the pedicle screws in a pedicle. 
   
   
       4 . The method of  claim 1  and further comprising locking the longitudinal member to the pedicle screws after the longitudinal member is articulated into engagement with the second pedicle screw. 
   
   
       5 . The method of  claim 4  and further comprising securing the longitudinal member in a selected orientation relative to the pedicle screws and preventing articulation away from that orientation. 
   
   
       6 . The method of  claim 5  wherein the longitudinal member is oriented substantially coaxially with the first pedicle screw while the first pedicle screw is being installed in the first pedicle. 
   
   
       7 . The method of  claim 6  and further comprising bending the longitudinal member while the longitudinal member is pre-connected to a first one of the pedicle screws and before installing that first one of the pedicle screws in a pedicle.